How to get directions in deep space?How to determine one's position in space?How close to interstellar space travel could humans get in the near future?Runaway Starship RampsHow to get into space from northern latitudes?Alternative to cryogenic sleep / deep hibernation?Explaining Stealthy Space WarfareDeep Space Communication InfrastructureIs depicting scenes of sub-FTL deep space travel with burning engines accurate?What happens when a moving vehicle loses all its kinetic energy at onceFeasability of plasma based garbage recycling into pure constituent elementsThe Colonist - Part II: Landing

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How to get directions in deep space?


How to determine one's position in space?How close to interstellar space travel could humans get in the near future?Runaway Starship RampsHow to get into space from northern latitudes?Alternative to cryogenic sleep / deep hibernation?Explaining Stealthy Space WarfareDeep Space Communication InfrastructureIs depicting scenes of sub-FTL deep space travel with burning engines accurate?What happens when a moving vehicle loses all its kinetic energy at onceFeasability of plasma based garbage recycling into pure constituent elementsThe Colonist - Part II: Landing













6












$begingroup$


A spaceship crew, during their interstellar travel loses control of the spaceship for a few hours due to external factors (exact factor not important). This causes the spaceship to deviate from its original course. The deviation is sudden and large (imagine the spaceship spinning(?) in space during deviation).



The question is, once the crew stopped the spaceship from spinning, how are they going to re-orient it along its original direction? What reference points can one use in space?



I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. So, is there anyway for my space travellers to save themselves or are they doomed??










share|improve this question









New contributor




Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    Welcome to the site Arkadipta Sarkar. You asked a good question, you should take the tour and read up about our culture in our help center . Something you should know, we traditionally wait 24 hours after asking a question before awarding accepted answer status as you did to Renan, as otherwise it may tend to deter other usefull answers from being given.
    $endgroup$
    – Agrajag
    6 hours ago







  • 1




    $begingroup$
    Definitely related, possible duplicate: How to determine one's position in space? Full disclosure: The accepted answer is my own.
    $endgroup$
    – a CVn
    5 hours ago










  • $begingroup$
    As for the "imagine the spaceship spinning in space during deviation", unless the engines are on, the impact of that on the spacecraft's trajectory is going to be, for all intents and purposes, zero. There might be a very small undesired course change as the ship moves through interstellar matter in an unexpected attitude, but really, that stuff is so sparse that you are unlikely to even notice; microsecond-level burn timing uncertainties are likely to have a bigger effect on the final position.
    $endgroup$
    – a CVn
    5 hours ago






  • 1




    $begingroup$
    It seems quite likely that a spacecraft whose engines would have the option to get back on an interstellar course after a deviation like this would have a navigation system that does not rely solely on earth-centered coordinates, and would be able to figure out exactly where the spacecraft was when switched on. What type of range does this spacecraft have, and how far were they thrown out of it?
    $endgroup$
    – notovny
    4 hours ago










  • $begingroup$
    But aren't we already all on a spaceship in deep space called "Earth" ? The techniques we use to get directions in space from here (mainly distant stars), should apply for any craft.
    $endgroup$
    – pilko
    3 hours ago
















6












$begingroup$


A spaceship crew, during their interstellar travel loses control of the spaceship for a few hours due to external factors (exact factor not important). This causes the spaceship to deviate from its original course. The deviation is sudden and large (imagine the spaceship spinning(?) in space during deviation).



The question is, once the crew stopped the spaceship from spinning, how are they going to re-orient it along its original direction? What reference points can one use in space?



I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. So, is there anyway for my space travellers to save themselves or are they doomed??










share|improve this question









New contributor




Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    Welcome to the site Arkadipta Sarkar. You asked a good question, you should take the tour and read up about our culture in our help center . Something you should know, we traditionally wait 24 hours after asking a question before awarding accepted answer status as you did to Renan, as otherwise it may tend to deter other usefull answers from being given.
    $endgroup$
    – Agrajag
    6 hours ago







  • 1




    $begingroup$
    Definitely related, possible duplicate: How to determine one's position in space? Full disclosure: The accepted answer is my own.
    $endgroup$
    – a CVn
    5 hours ago










  • $begingroup$
    As for the "imagine the spaceship spinning in space during deviation", unless the engines are on, the impact of that on the spacecraft's trajectory is going to be, for all intents and purposes, zero. There might be a very small undesired course change as the ship moves through interstellar matter in an unexpected attitude, but really, that stuff is so sparse that you are unlikely to even notice; microsecond-level burn timing uncertainties are likely to have a bigger effect on the final position.
    $endgroup$
    – a CVn
    5 hours ago






  • 1




    $begingroup$
    It seems quite likely that a spacecraft whose engines would have the option to get back on an interstellar course after a deviation like this would have a navigation system that does not rely solely on earth-centered coordinates, and would be able to figure out exactly where the spacecraft was when switched on. What type of range does this spacecraft have, and how far were they thrown out of it?
    $endgroup$
    – notovny
    4 hours ago










  • $begingroup$
    But aren't we already all on a spaceship in deep space called "Earth" ? The techniques we use to get directions in space from here (mainly distant stars), should apply for any craft.
    $endgroup$
    – pilko
    3 hours ago














6












6








6


1



$begingroup$


A spaceship crew, during their interstellar travel loses control of the spaceship for a few hours due to external factors (exact factor not important). This causes the spaceship to deviate from its original course. The deviation is sudden and large (imagine the spaceship spinning(?) in space during deviation).



The question is, once the crew stopped the spaceship from spinning, how are they going to re-orient it along its original direction? What reference points can one use in space?



I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. So, is there anyway for my space travellers to save themselves or are they doomed??










share|improve this question









New contributor




Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




A spaceship crew, during their interstellar travel loses control of the spaceship for a few hours due to external factors (exact factor not important). This causes the spaceship to deviate from its original course. The deviation is sudden and large (imagine the spaceship spinning(?) in space during deviation).



The question is, once the crew stopped the spaceship from spinning, how are they going to re-orient it along its original direction? What reference points can one use in space?



I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. So, is there anyway for my space travellers to save themselves or are they doomed??







science-based space-travel






share|improve this question









New contributor




Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 1 hour ago









Brythan

20.6k74285




20.6k74285






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asked 7 hours ago









Arkadipta SarkarArkadipta Sarkar

332




332




New contributor




Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Arkadipta Sarkar is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







  • 1




    $begingroup$
    Welcome to the site Arkadipta Sarkar. You asked a good question, you should take the tour and read up about our culture in our help center . Something you should know, we traditionally wait 24 hours after asking a question before awarding accepted answer status as you did to Renan, as otherwise it may tend to deter other usefull answers from being given.
    $endgroup$
    – Agrajag
    6 hours ago







  • 1




    $begingroup$
    Definitely related, possible duplicate: How to determine one's position in space? Full disclosure: The accepted answer is my own.
    $endgroup$
    – a CVn
    5 hours ago










  • $begingroup$
    As for the "imagine the spaceship spinning in space during deviation", unless the engines are on, the impact of that on the spacecraft's trajectory is going to be, for all intents and purposes, zero. There might be a very small undesired course change as the ship moves through interstellar matter in an unexpected attitude, but really, that stuff is so sparse that you are unlikely to even notice; microsecond-level burn timing uncertainties are likely to have a bigger effect on the final position.
    $endgroup$
    – a CVn
    5 hours ago






  • 1




    $begingroup$
    It seems quite likely that a spacecraft whose engines would have the option to get back on an interstellar course after a deviation like this would have a navigation system that does not rely solely on earth-centered coordinates, and would be able to figure out exactly where the spacecraft was when switched on. What type of range does this spacecraft have, and how far were they thrown out of it?
    $endgroup$
    – notovny
    4 hours ago










  • $begingroup$
    But aren't we already all on a spaceship in deep space called "Earth" ? The techniques we use to get directions in space from here (mainly distant stars), should apply for any craft.
    $endgroup$
    – pilko
    3 hours ago













  • 1




    $begingroup$
    Welcome to the site Arkadipta Sarkar. You asked a good question, you should take the tour and read up about our culture in our help center . Something you should know, we traditionally wait 24 hours after asking a question before awarding accepted answer status as you did to Renan, as otherwise it may tend to deter other usefull answers from being given.
    $endgroup$
    – Agrajag
    6 hours ago







  • 1




    $begingroup$
    Definitely related, possible duplicate: How to determine one's position in space? Full disclosure: The accepted answer is my own.
    $endgroup$
    – a CVn
    5 hours ago










  • $begingroup$
    As for the "imagine the spaceship spinning in space during deviation", unless the engines are on, the impact of that on the spacecraft's trajectory is going to be, for all intents and purposes, zero. There might be a very small undesired course change as the ship moves through interstellar matter in an unexpected attitude, but really, that stuff is so sparse that you are unlikely to even notice; microsecond-level burn timing uncertainties are likely to have a bigger effect on the final position.
    $endgroup$
    – a CVn
    5 hours ago






  • 1




    $begingroup$
    It seems quite likely that a spacecraft whose engines would have the option to get back on an interstellar course after a deviation like this would have a navigation system that does not rely solely on earth-centered coordinates, and would be able to figure out exactly where the spacecraft was when switched on. What type of range does this spacecraft have, and how far were they thrown out of it?
    $endgroup$
    – notovny
    4 hours ago










  • $begingroup$
    But aren't we already all on a spaceship in deep space called "Earth" ? The techniques we use to get directions in space from here (mainly distant stars), should apply for any craft.
    $endgroup$
    – pilko
    3 hours ago








1




1




$begingroup$
Welcome to the site Arkadipta Sarkar. You asked a good question, you should take the tour and read up about our culture in our help center . Something you should know, we traditionally wait 24 hours after asking a question before awarding accepted answer status as you did to Renan, as otherwise it may tend to deter other usefull answers from being given.
$endgroup$
– Agrajag
6 hours ago





$begingroup$
Welcome to the site Arkadipta Sarkar. You asked a good question, you should take the tour and read up about our culture in our help center . Something you should know, we traditionally wait 24 hours after asking a question before awarding accepted answer status as you did to Renan, as otherwise it may tend to deter other usefull answers from being given.
$endgroup$
– Agrajag
6 hours ago





1




1




$begingroup$
Definitely related, possible duplicate: How to determine one's position in space? Full disclosure: The accepted answer is my own.
$endgroup$
– a CVn
5 hours ago




$begingroup$
Definitely related, possible duplicate: How to determine one's position in space? Full disclosure: The accepted answer is my own.
$endgroup$
– a CVn
5 hours ago












$begingroup$
As for the "imagine the spaceship spinning in space during deviation", unless the engines are on, the impact of that on the spacecraft's trajectory is going to be, for all intents and purposes, zero. There might be a very small undesired course change as the ship moves through interstellar matter in an unexpected attitude, but really, that stuff is so sparse that you are unlikely to even notice; microsecond-level burn timing uncertainties are likely to have a bigger effect on the final position.
$endgroup$
– a CVn
5 hours ago




$begingroup$
As for the "imagine the spaceship spinning in space during deviation", unless the engines are on, the impact of that on the spacecraft's trajectory is going to be, for all intents and purposes, zero. There might be a very small undesired course change as the ship moves through interstellar matter in an unexpected attitude, but really, that stuff is so sparse that you are unlikely to even notice; microsecond-level burn timing uncertainties are likely to have a bigger effect on the final position.
$endgroup$
– a CVn
5 hours ago




1




1




$begingroup$
It seems quite likely that a spacecraft whose engines would have the option to get back on an interstellar course after a deviation like this would have a navigation system that does not rely solely on earth-centered coordinates, and would be able to figure out exactly where the spacecraft was when switched on. What type of range does this spacecraft have, and how far were they thrown out of it?
$endgroup$
– notovny
4 hours ago




$begingroup$
It seems quite likely that a spacecraft whose engines would have the option to get back on an interstellar course after a deviation like this would have a navigation system that does not rely solely on earth-centered coordinates, and would be able to figure out exactly where the spacecraft was when switched on. What type of range does this spacecraft have, and how far were they thrown out of it?
$endgroup$
– notovny
4 hours ago












$begingroup$
But aren't we already all on a spaceship in deep space called "Earth" ? The techniques we use to get directions in space from here (mainly distant stars), should apply for any craft.
$endgroup$
– pilko
3 hours ago





$begingroup$
But aren't we already all on a spaceship in deep space called "Earth" ? The techniques we use to get directions in space from here (mainly distant stars), should apply for any craft.
$endgroup$
– pilko
3 hours ago











5 Answers
5






active

oldest

votes


















17












$begingroup$


I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




We are smarter than that.



The Pioneer golden plaques, besides having porn, also had this:



Pioneer Plaque



With this you can locate the sun, by figuring out where the signals of 14 pulsars meet in a specific way.



If you can track objects of interest, you can find yourself. Before GPS was invented, US military jets of the 60's to the 90's sometimes used the position of stars to locate themselves:




In flight, the ANS, which sat behind the reconnaissance systems officer's (RSO's), position, tracked stars through a circular quartz glass window on the upper fuselage. Its "blue light" source star tracker, which could see stars during both day and night, would continuously track a variety of stars as the aircraft's changing position brought them into view. The system's digital computer ephemeris contained data on a list of stars used for celestial navigation: the list first included 56 stars, and was later expanded to 61. The ANS could supply altitude and position to flight controls and other systems, including the mission data recorder, automatic navigation to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fixed points loaded into the ANS before takeoff. According to Richard Graham, a former SR-71 pilot, the navigation system was good enough to limit drift to 1,000 ft (300 m) off the direction of travel at Mach 3.





Also remember that in space you are always orbiting something. If you can figure your altitude from the barycenter and your orbital speed, you can calculate the shape of your orbit. Find any other two objects also orbiting that barycenter and, given database entries of those objects' orbits you may not only know where you are, but also when you are.



If you've got a math geek with a knack for astronomy onboard, they may be able to calculate that with pen and paper just like old man Kepler and his pals used to. They will use the same equations that Kerbal Space Program uses to position your spacecrafts whenever you load a saved game.






share|improve this answer











$endgroup$












  • $begingroup$
    Thank you. This helps a lot.
    $endgroup$
    – Arkadipta Sarkar
    7 hours ago






  • 1




    $begingroup$
    While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
    $endgroup$
    – Ville Niemi
    6 hours ago


















7












$begingroup$


I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




Wrong.



We also know geometry, and if know the geocentric coordinates and the present coordinates, we can determine the displacement vector between the two, which give us the desired information: where are we in space.



One or more wide field images can help in finding known stars, and from there determine the rotation with respect the last known position. Mind that, knowing the trajectory up until before the incident, the maps are quite updated.






share|improve this answer











$endgroup$












  • $begingroup$
    Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
    $endgroup$
    – Arkadipta Sarkar
    7 hours ago






  • 2




    $begingroup$
    @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
    $endgroup$
    – Arkenstein XII
    6 hours ago


















3












$begingroup$

A lot of time in science fiction, and in real life space craft use pulsars to navigate.




X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to triangulate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. Experimental demonstrations have been reported in 2018.







share|improve this answer











$endgroup$












  • $begingroup$
    While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
    $endgroup$
    – Frostfyre
    6 hours ago


















1












$begingroup$

If you're relying on near-future (i.e slower-than-light) tech, getting lost in deep space would take a long, long time. The crew is on a journey of light-years, and in the worst case scenario you'll only be off course by a matter of light-hours.



For example, suppose you're travelling from Earth to Alpha Centauri. The propulsion systems that we currently have and expect to have in the near future are most efficient when they provide a little bit of thrust over a long period of time. As such, it's likely that the ship would start out at Earth and start accelerating toward Alpha Centauri until it reaches the halfway point, where it would turn itself around and begin decelerating so that it is travelling at a reasonably slow speed by the time it reaches its destination.



The best case scenario for your voyagers is that the deviation is caused by their ship spinning and the engine pushing in the wrong directions due to that spin. If that is the case the overall effect of the push will be a net zero, meaning their velocity will be the same as before they began to spin. They just need to see which way they are going, and then resume accelerating or decelerating.



Slightly worse than this is if somehow the ship got spun around, then stopped spinning and accelerated in a single unknown direction for a while before the crew managed to fix the ship controls. Their velocity now is not the same as it was before the deviation, but remember that they've been accelerating for a long time at this point (or they're close enough to the sun that they can use it as an obvious reference point). If they're close to halfway, then they've been accelerating for years - the deviation caused by even a full day of accelerating in the wrong direction would be less than 1% of their overall velocity. They can still just figure out which direction they're going, and make the small adjustment necessary to correct their velocity.



The worst case scenario is something like alien shenanigans causing them to suddenly accelerate to ludicrous speed (say, 0.99c) in an unknown direction. In this case they're probably doomed simply because the energy requirement for decelerating from that speed is absolutely ridiculous (on the scale of converting 9 tenths of the mass of their ship into pure energy for use in slowing themselves down, and doing so with 100% efficiency). However knowing where they are still isn't a huge issue - even travelling at that speed, they'd be off course by a matter of light-hours. So they'll be less than 1% off course - they would be able to take a picture of their surrounds and quickly orient themselves.



If you're relying on faster-than-light tech, you actually could be so far away from your intended path that the star field would be significantly different. In this case, you'd want to use the pulsar method that other answers have mentioned.






share|improve this answer









$endgroup$




















    0












    $begingroup$

    Since the question provides little context, a simple answer is to assume that the spacecraft will still be in contact with Earth or wherever it took off from, and/or possibly other places already colonized by humans if this scenario is assumed to be playing out in the near future (the moon, Mars, Mars' moons, maybe even a few of the most-likely-habitable moons of the giant gas planets, https://en.wikipedia.org/wiki/Habitability_of_natural_satellites).
    Thus, the spacecraft would never have been lost as their position with respect to their launching point would be constantly tracked through whatever communication means the ship has with human bases on earth and/or throughout the solar system.



    Albeit realistic, my first answer might seem a it trivial (and therefore not as interesting). Let's spice things up a bit and assume that there's no contact with any other humans outside of the ship. Also, since there's no specification of the speed at which the ship travels, lets assume it's only a fraction of the speed of light (as another answer assumed as well). Since control was lost for only a few hours and interstellar distances are so enormous, the position of the spacecraft would be relatively close to where they were when they lost control and not too far to the curve that traces their intended route.
    They ship would VERY LIKELY be equipped with good (geocentric) maps of all the observable/known universe before they set out. Given such comprehensive 3D map models, they could easily predict what the sky should look like from any other point on the map. Thus, they could quickly run a computational search to find a match with what they are seeing. That is, they could take snapshots of what they see in different directions from their spacecraft, and then correlate their observations with predictions of how the sky would look like from different points on the map. The search for "simulated" views on the map would be quite small -they only have to generate simulated views from a narrow radius accounting for the distance travelled since they lost control. They could even figure out what new direction they're traveling in (assuming they got completely off course through propulsion/acceleration in the wrong direction when they lost control) if they took snapshots at two different time points, long enough for differences to be perceptible in at least one of the many directions they could collect snapshots from. Then, with knowledge of their new trajectory, they could easily correct course to intersect their prior trajectory at the final destination. If following the EXACT original trajectory were important, they could do that too: calculate the shortest distance from their current trajectory to the original one, and get back on track along the original route with careful manipulation of their propulsion/acceleration systems. Of course, the supercomputer on the spacecraft would do most or all of this automatically (individual pilots would not need to know trigonometry, geometry or physics themselves).





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      5 Answers
      5






      active

      oldest

      votes








      5 Answers
      5






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes









      17












      $begingroup$


      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      We are smarter than that.



      The Pioneer golden plaques, besides having porn, also had this:



      Pioneer Plaque



      With this you can locate the sun, by figuring out where the signals of 14 pulsars meet in a specific way.



      If you can track objects of interest, you can find yourself. Before GPS was invented, US military jets of the 60's to the 90's sometimes used the position of stars to locate themselves:




      In flight, the ANS, which sat behind the reconnaissance systems officer's (RSO's), position, tracked stars through a circular quartz glass window on the upper fuselage. Its "blue light" source star tracker, which could see stars during both day and night, would continuously track a variety of stars as the aircraft's changing position brought them into view. The system's digital computer ephemeris contained data on a list of stars used for celestial navigation: the list first included 56 stars, and was later expanded to 61. The ANS could supply altitude and position to flight controls and other systems, including the mission data recorder, automatic navigation to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fixed points loaded into the ANS before takeoff. According to Richard Graham, a former SR-71 pilot, the navigation system was good enough to limit drift to 1,000 ft (300 m) off the direction of travel at Mach 3.





      Also remember that in space you are always orbiting something. If you can figure your altitude from the barycenter and your orbital speed, you can calculate the shape of your orbit. Find any other two objects also orbiting that barycenter and, given database entries of those objects' orbits you may not only know where you are, but also when you are.



      If you've got a math geek with a knack for astronomy onboard, they may be able to calculate that with pen and paper just like old man Kepler and his pals used to. They will use the same equations that Kerbal Space Program uses to position your spacecrafts whenever you load a saved game.






      share|improve this answer











      $endgroup$












      • $begingroup$
        Thank you. This helps a lot.
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 1




        $begingroup$
        While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
        $endgroup$
        – Ville Niemi
        6 hours ago















      17












      $begingroup$


      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      We are smarter than that.



      The Pioneer golden plaques, besides having porn, also had this:



      Pioneer Plaque



      With this you can locate the sun, by figuring out where the signals of 14 pulsars meet in a specific way.



      If you can track objects of interest, you can find yourself. Before GPS was invented, US military jets of the 60's to the 90's sometimes used the position of stars to locate themselves:




      In flight, the ANS, which sat behind the reconnaissance systems officer's (RSO's), position, tracked stars through a circular quartz glass window on the upper fuselage. Its "blue light" source star tracker, which could see stars during both day and night, would continuously track a variety of stars as the aircraft's changing position brought them into view. The system's digital computer ephemeris contained data on a list of stars used for celestial navigation: the list first included 56 stars, and was later expanded to 61. The ANS could supply altitude and position to flight controls and other systems, including the mission data recorder, automatic navigation to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fixed points loaded into the ANS before takeoff. According to Richard Graham, a former SR-71 pilot, the navigation system was good enough to limit drift to 1,000 ft (300 m) off the direction of travel at Mach 3.





      Also remember that in space you are always orbiting something. If you can figure your altitude from the barycenter and your orbital speed, you can calculate the shape of your orbit. Find any other two objects also orbiting that barycenter and, given database entries of those objects' orbits you may not only know where you are, but also when you are.



      If you've got a math geek with a knack for astronomy onboard, they may be able to calculate that with pen and paper just like old man Kepler and his pals used to. They will use the same equations that Kerbal Space Program uses to position your spacecrafts whenever you load a saved game.






      share|improve this answer











      $endgroup$












      • $begingroup$
        Thank you. This helps a lot.
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 1




        $begingroup$
        While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
        $endgroup$
        – Ville Niemi
        6 hours ago













      17












      17








      17





      $begingroup$


      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      We are smarter than that.



      The Pioneer golden plaques, besides having porn, also had this:



      Pioneer Plaque



      With this you can locate the sun, by figuring out where the signals of 14 pulsars meet in a specific way.



      If you can track objects of interest, you can find yourself. Before GPS was invented, US military jets of the 60's to the 90's sometimes used the position of stars to locate themselves:




      In flight, the ANS, which sat behind the reconnaissance systems officer's (RSO's), position, tracked stars through a circular quartz glass window on the upper fuselage. Its "blue light" source star tracker, which could see stars during both day and night, would continuously track a variety of stars as the aircraft's changing position brought them into view. The system's digital computer ephemeris contained data on a list of stars used for celestial navigation: the list first included 56 stars, and was later expanded to 61. The ANS could supply altitude and position to flight controls and other systems, including the mission data recorder, automatic navigation to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fixed points loaded into the ANS before takeoff. According to Richard Graham, a former SR-71 pilot, the navigation system was good enough to limit drift to 1,000 ft (300 m) off the direction of travel at Mach 3.





      Also remember that in space you are always orbiting something. If you can figure your altitude from the barycenter and your orbital speed, you can calculate the shape of your orbit. Find any other two objects also orbiting that barycenter and, given database entries of those objects' orbits you may not only know where you are, but also when you are.



      If you've got a math geek with a knack for astronomy onboard, they may be able to calculate that with pen and paper just like old man Kepler and his pals used to. They will use the same equations that Kerbal Space Program uses to position your spacecrafts whenever you load a saved game.






      share|improve this answer











      $endgroup$




      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      We are smarter than that.



      The Pioneer golden plaques, besides having porn, also had this:



      Pioneer Plaque



      With this you can locate the sun, by figuring out where the signals of 14 pulsars meet in a specific way.



      If you can track objects of interest, you can find yourself. Before GPS was invented, US military jets of the 60's to the 90's sometimes used the position of stars to locate themselves:




      In flight, the ANS, which sat behind the reconnaissance systems officer's (RSO's), position, tracked stars through a circular quartz glass window on the upper fuselage. Its "blue light" source star tracker, which could see stars during both day and night, would continuously track a variety of stars as the aircraft's changing position brought them into view. The system's digital computer ephemeris contained data on a list of stars used for celestial navigation: the list first included 56 stars, and was later expanded to 61. The ANS could supply altitude and position to flight controls and other systems, including the mission data recorder, automatic navigation to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fixed points loaded into the ANS before takeoff. According to Richard Graham, a former SR-71 pilot, the navigation system was good enough to limit drift to 1,000 ft (300 m) off the direction of travel at Mach 3.





      Also remember that in space you are always orbiting something. If you can figure your altitude from the barycenter and your orbital speed, you can calculate the shape of your orbit. Find any other two objects also orbiting that barycenter and, given database entries of those objects' orbits you may not only know where you are, but also when you are.



      If you've got a math geek with a knack for astronomy onboard, they may be able to calculate that with pen and paper just like old man Kepler and his pals used to. They will use the same equations that Kerbal Space Program uses to position your spacecrafts whenever you load a saved game.







      share|improve this answer














      share|improve this answer



      share|improve this answer








      edited 1 hour ago

























      answered 7 hours ago









      RenanRenan

      49.8k13115251




      49.8k13115251











      • $begingroup$
        Thank you. This helps a lot.
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 1




        $begingroup$
        While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
        $endgroup$
        – Ville Niemi
        6 hours ago
















      • $begingroup$
        Thank you. This helps a lot.
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 1




        $begingroup$
        While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
        $endgroup$
        – Ville Niemi
        6 hours ago















      $begingroup$
      Thank you. This helps a lot.
      $endgroup$
      – Arkadipta Sarkar
      7 hours ago




      $begingroup$
      Thank you. This helps a lot.
      $endgroup$
      – Arkadipta Sarkar
      7 hours ago




      1




      1




      $begingroup$
      While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
      $endgroup$
      – Ville Niemi
      6 hours ago




      $begingroup$
      While star trackers were used by aircraft and missiles before GPS and inertial navigation were practical, nowadays they apparently are mostly used by spacecraft (<- kind of relevant?) and satellites. Maybe sometimes as backups on missiles and aircraft?
      $endgroup$
      – Ville Niemi
      6 hours ago











      7












      $begingroup$


      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      Wrong.



      We also know geometry, and if know the geocentric coordinates and the present coordinates, we can determine the displacement vector between the two, which give us the desired information: where are we in space.



      One or more wide field images can help in finding known stars, and from there determine the rotation with respect the last known position. Mind that, knowing the trajectory up until before the incident, the maps are quite updated.






      share|improve this answer











      $endgroup$












      • $begingroup$
        Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 2




        $begingroup$
        @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
        $endgroup$
        – Arkenstein XII
        6 hours ago















      7












      $begingroup$


      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      Wrong.



      We also know geometry, and if know the geocentric coordinates and the present coordinates, we can determine the displacement vector between the two, which give us the desired information: where are we in space.



      One or more wide field images can help in finding known stars, and from there determine the rotation with respect the last known position. Mind that, knowing the trajectory up until before the incident, the maps are quite updated.






      share|improve this answer











      $endgroup$












      • $begingroup$
        Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 2




        $begingroup$
        @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
        $endgroup$
        – Arkenstein XII
        6 hours ago













      7












      7








      7





      $begingroup$


      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      Wrong.



      We also know geometry, and if know the geocentric coordinates and the present coordinates, we can determine the displacement vector between the two, which give us the desired information: where are we in space.



      One or more wide field images can help in finding known stars, and from there determine the rotation with respect the last known position. Mind that, knowing the trajectory up until before the incident, the maps are quite updated.






      share|improve this answer











      $endgroup$




      I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates.




      Wrong.



      We also know geometry, and if know the geocentric coordinates and the present coordinates, we can determine the displacement vector between the two, which give us the desired information: where are we in space.



      One or more wide field images can help in finding known stars, and from there determine the rotation with respect the last known position. Mind that, knowing the trajectory up until before the incident, the maps are quite updated.







      share|improve this answer














      share|improve this answer



      share|improve this answer








      edited 7 hours ago

























      answered 7 hours ago









      L.DutchL.Dutch

      88.1k29205429




      88.1k29205429











      • $begingroup$
        Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 2




        $begingroup$
        @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
        $endgroup$
        – Arkenstein XII
        6 hours ago
















      • $begingroup$
        Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
        $endgroup$
        – Arkadipta Sarkar
        7 hours ago






      • 2




        $begingroup$
        @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
        $endgroup$
        – Arkenstein XII
        6 hours ago















      $begingroup$
      Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
      $endgroup$
      – Arkadipta Sarkar
      7 hours ago




      $begingroup$
      Thank you for your answer but can you elaborate it a bit? Whereas I agree that the displacement vector can be easily calculated, won't it be difficult to find the star we are aiming for in the first place? Since there is no up/down/left/right on space?
      $endgroup$
      – Arkadipta Sarkar
      7 hours ago




      2




      2




      $begingroup$
      @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
      $endgroup$
      – Arkenstein XII
      6 hours ago




      $begingroup$
      @ArkadiptaSarkar One can identify a star by spectrum, luminosity, and variability.
      $endgroup$
      – Arkenstein XII
      6 hours ago











      3












      $begingroup$

      A lot of time in science fiction, and in real life space craft use pulsars to navigate.




      X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to triangulate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. Experimental demonstrations have been reported in 2018.







      share|improve this answer











      $endgroup$












      • $begingroup$
        While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
        $endgroup$
        – Frostfyre
        6 hours ago















      3












      $begingroup$

      A lot of time in science fiction, and in real life space craft use pulsars to navigate.




      X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to triangulate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. Experimental demonstrations have been reported in 2018.







      share|improve this answer











      $endgroup$












      • $begingroup$
        While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
        $endgroup$
        – Frostfyre
        6 hours ago













      3












      3








      3





      $begingroup$

      A lot of time in science fiction, and in real life space craft use pulsars to navigate.




      X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to triangulate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. Experimental demonstrations have been reported in 2018.







      share|improve this answer











      $endgroup$



      A lot of time in science fiction, and in real life space craft use pulsars to navigate.




      X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to triangulate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. Experimental demonstrations have been reported in 2018.








      share|improve this answer














      share|improve this answer



      share|improve this answer








      edited 6 hours ago

























      answered 7 hours ago









      SciFiGuySciFiGuy

      1,43811




      1,43811











      • $begingroup$
        While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
        $endgroup$
        – Frostfyre
        6 hours ago
















      • $begingroup$
        While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
        $endgroup$
        – Frostfyre
        6 hours ago















      $begingroup$
      While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
      $endgroup$
      – Frostfyre
      6 hours ago




      $begingroup$
      While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review
      $endgroup$
      – Frostfyre
      6 hours ago











      1












      $begingroup$

      If you're relying on near-future (i.e slower-than-light) tech, getting lost in deep space would take a long, long time. The crew is on a journey of light-years, and in the worst case scenario you'll only be off course by a matter of light-hours.



      For example, suppose you're travelling from Earth to Alpha Centauri. The propulsion systems that we currently have and expect to have in the near future are most efficient when they provide a little bit of thrust over a long period of time. As such, it's likely that the ship would start out at Earth and start accelerating toward Alpha Centauri until it reaches the halfway point, where it would turn itself around and begin decelerating so that it is travelling at a reasonably slow speed by the time it reaches its destination.



      The best case scenario for your voyagers is that the deviation is caused by their ship spinning and the engine pushing in the wrong directions due to that spin. If that is the case the overall effect of the push will be a net zero, meaning their velocity will be the same as before they began to spin. They just need to see which way they are going, and then resume accelerating or decelerating.



      Slightly worse than this is if somehow the ship got spun around, then stopped spinning and accelerated in a single unknown direction for a while before the crew managed to fix the ship controls. Their velocity now is not the same as it was before the deviation, but remember that they've been accelerating for a long time at this point (or they're close enough to the sun that they can use it as an obvious reference point). If they're close to halfway, then they've been accelerating for years - the deviation caused by even a full day of accelerating in the wrong direction would be less than 1% of their overall velocity. They can still just figure out which direction they're going, and make the small adjustment necessary to correct their velocity.



      The worst case scenario is something like alien shenanigans causing them to suddenly accelerate to ludicrous speed (say, 0.99c) in an unknown direction. In this case they're probably doomed simply because the energy requirement for decelerating from that speed is absolutely ridiculous (on the scale of converting 9 tenths of the mass of their ship into pure energy for use in slowing themselves down, and doing so with 100% efficiency). However knowing where they are still isn't a huge issue - even travelling at that speed, they'd be off course by a matter of light-hours. So they'll be less than 1% off course - they would be able to take a picture of their surrounds and quickly orient themselves.



      If you're relying on faster-than-light tech, you actually could be so far away from your intended path that the star field would be significantly different. In this case, you'd want to use the pulsar method that other answers have mentioned.






      share|improve this answer









      $endgroup$

















        1












        $begingroup$

        If you're relying on near-future (i.e slower-than-light) tech, getting lost in deep space would take a long, long time. The crew is on a journey of light-years, and in the worst case scenario you'll only be off course by a matter of light-hours.



        For example, suppose you're travelling from Earth to Alpha Centauri. The propulsion systems that we currently have and expect to have in the near future are most efficient when they provide a little bit of thrust over a long period of time. As such, it's likely that the ship would start out at Earth and start accelerating toward Alpha Centauri until it reaches the halfway point, where it would turn itself around and begin decelerating so that it is travelling at a reasonably slow speed by the time it reaches its destination.



        The best case scenario for your voyagers is that the deviation is caused by their ship spinning and the engine pushing in the wrong directions due to that spin. If that is the case the overall effect of the push will be a net zero, meaning their velocity will be the same as before they began to spin. They just need to see which way they are going, and then resume accelerating or decelerating.



        Slightly worse than this is if somehow the ship got spun around, then stopped spinning and accelerated in a single unknown direction for a while before the crew managed to fix the ship controls. Their velocity now is not the same as it was before the deviation, but remember that they've been accelerating for a long time at this point (or they're close enough to the sun that they can use it as an obvious reference point). If they're close to halfway, then they've been accelerating for years - the deviation caused by even a full day of accelerating in the wrong direction would be less than 1% of their overall velocity. They can still just figure out which direction they're going, and make the small adjustment necessary to correct their velocity.



        The worst case scenario is something like alien shenanigans causing them to suddenly accelerate to ludicrous speed (say, 0.99c) in an unknown direction. In this case they're probably doomed simply because the energy requirement for decelerating from that speed is absolutely ridiculous (on the scale of converting 9 tenths of the mass of their ship into pure energy for use in slowing themselves down, and doing so with 100% efficiency). However knowing where they are still isn't a huge issue - even travelling at that speed, they'd be off course by a matter of light-hours. So they'll be less than 1% off course - they would be able to take a picture of their surrounds and quickly orient themselves.



        If you're relying on faster-than-light tech, you actually could be so far away from your intended path that the star field would be significantly different. In this case, you'd want to use the pulsar method that other answers have mentioned.






        share|improve this answer









        $endgroup$















          1












          1








          1





          $begingroup$

          If you're relying on near-future (i.e slower-than-light) tech, getting lost in deep space would take a long, long time. The crew is on a journey of light-years, and in the worst case scenario you'll only be off course by a matter of light-hours.



          For example, suppose you're travelling from Earth to Alpha Centauri. The propulsion systems that we currently have and expect to have in the near future are most efficient when they provide a little bit of thrust over a long period of time. As such, it's likely that the ship would start out at Earth and start accelerating toward Alpha Centauri until it reaches the halfway point, where it would turn itself around and begin decelerating so that it is travelling at a reasonably slow speed by the time it reaches its destination.



          The best case scenario for your voyagers is that the deviation is caused by their ship spinning and the engine pushing in the wrong directions due to that spin. If that is the case the overall effect of the push will be a net zero, meaning their velocity will be the same as before they began to spin. They just need to see which way they are going, and then resume accelerating or decelerating.



          Slightly worse than this is if somehow the ship got spun around, then stopped spinning and accelerated in a single unknown direction for a while before the crew managed to fix the ship controls. Their velocity now is not the same as it was before the deviation, but remember that they've been accelerating for a long time at this point (or they're close enough to the sun that they can use it as an obvious reference point). If they're close to halfway, then they've been accelerating for years - the deviation caused by even a full day of accelerating in the wrong direction would be less than 1% of their overall velocity. They can still just figure out which direction they're going, and make the small adjustment necessary to correct their velocity.



          The worst case scenario is something like alien shenanigans causing them to suddenly accelerate to ludicrous speed (say, 0.99c) in an unknown direction. In this case they're probably doomed simply because the energy requirement for decelerating from that speed is absolutely ridiculous (on the scale of converting 9 tenths of the mass of their ship into pure energy for use in slowing themselves down, and doing so with 100% efficiency). However knowing where they are still isn't a huge issue - even travelling at that speed, they'd be off course by a matter of light-hours. So they'll be less than 1% off course - they would be able to take a picture of their surrounds and quickly orient themselves.



          If you're relying on faster-than-light tech, you actually could be so far away from your intended path that the star field would be significantly different. In this case, you'd want to use the pulsar method that other answers have mentioned.






          share|improve this answer









          $endgroup$



          If you're relying on near-future (i.e slower-than-light) tech, getting lost in deep space would take a long, long time. The crew is on a journey of light-years, and in the worst case scenario you'll only be off course by a matter of light-hours.



          For example, suppose you're travelling from Earth to Alpha Centauri. The propulsion systems that we currently have and expect to have in the near future are most efficient when they provide a little bit of thrust over a long period of time. As such, it's likely that the ship would start out at Earth and start accelerating toward Alpha Centauri until it reaches the halfway point, where it would turn itself around and begin decelerating so that it is travelling at a reasonably slow speed by the time it reaches its destination.



          The best case scenario for your voyagers is that the deviation is caused by their ship spinning and the engine pushing in the wrong directions due to that spin. If that is the case the overall effect of the push will be a net zero, meaning their velocity will be the same as before they began to spin. They just need to see which way they are going, and then resume accelerating or decelerating.



          Slightly worse than this is if somehow the ship got spun around, then stopped spinning and accelerated in a single unknown direction for a while before the crew managed to fix the ship controls. Their velocity now is not the same as it was before the deviation, but remember that they've been accelerating for a long time at this point (or they're close enough to the sun that they can use it as an obvious reference point). If they're close to halfway, then they've been accelerating for years - the deviation caused by even a full day of accelerating in the wrong direction would be less than 1% of their overall velocity. They can still just figure out which direction they're going, and make the small adjustment necessary to correct their velocity.



          The worst case scenario is something like alien shenanigans causing them to suddenly accelerate to ludicrous speed (say, 0.99c) in an unknown direction. In this case they're probably doomed simply because the energy requirement for decelerating from that speed is absolutely ridiculous (on the scale of converting 9 tenths of the mass of their ship into pure energy for use in slowing themselves down, and doing so with 100% efficiency). However knowing where they are still isn't a huge issue - even travelling at that speed, they'd be off course by a matter of light-hours. So they'll be less than 1% off course - they would be able to take a picture of their surrounds and quickly orient themselves.



          If you're relying on faster-than-light tech, you actually could be so far away from your intended path that the star field would be significantly different. In this case, you'd want to use the pulsar method that other answers have mentioned.







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          answered 5 hours ago









          Rob WattsRob Watts

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              0












              $begingroup$

              Since the question provides little context, a simple answer is to assume that the spacecraft will still be in contact with Earth or wherever it took off from, and/or possibly other places already colonized by humans if this scenario is assumed to be playing out in the near future (the moon, Mars, Mars' moons, maybe even a few of the most-likely-habitable moons of the giant gas planets, https://en.wikipedia.org/wiki/Habitability_of_natural_satellites).
              Thus, the spacecraft would never have been lost as their position with respect to their launching point would be constantly tracked through whatever communication means the ship has with human bases on earth and/or throughout the solar system.



              Albeit realistic, my first answer might seem a it trivial (and therefore not as interesting). Let's spice things up a bit and assume that there's no contact with any other humans outside of the ship. Also, since there's no specification of the speed at which the ship travels, lets assume it's only a fraction of the speed of light (as another answer assumed as well). Since control was lost for only a few hours and interstellar distances are so enormous, the position of the spacecraft would be relatively close to where they were when they lost control and not too far to the curve that traces their intended route.
              They ship would VERY LIKELY be equipped with good (geocentric) maps of all the observable/known universe before they set out. Given such comprehensive 3D map models, they could easily predict what the sky should look like from any other point on the map. Thus, they could quickly run a computational search to find a match with what they are seeing. That is, they could take snapshots of what they see in different directions from their spacecraft, and then correlate their observations with predictions of how the sky would look like from different points on the map. The search for "simulated" views on the map would be quite small -they only have to generate simulated views from a narrow radius accounting for the distance travelled since they lost control. They could even figure out what new direction they're traveling in (assuming they got completely off course through propulsion/acceleration in the wrong direction when they lost control) if they took snapshots at two different time points, long enough for differences to be perceptible in at least one of the many directions they could collect snapshots from. Then, with knowledge of their new trajectory, they could easily correct course to intersect their prior trajectory at the final destination. If following the EXACT original trajectory were important, they could do that too: calculate the shortest distance from their current trajectory to the original one, and get back on track along the original route with careful manipulation of their propulsion/acceleration systems. Of course, the supercomputer on the spacecraft would do most or all of this automatically (individual pilots would not need to know trigonometry, geometry or physics themselves).





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                0












                $begingroup$

                Since the question provides little context, a simple answer is to assume that the spacecraft will still be in contact with Earth or wherever it took off from, and/or possibly other places already colonized by humans if this scenario is assumed to be playing out in the near future (the moon, Mars, Mars' moons, maybe even a few of the most-likely-habitable moons of the giant gas planets, https://en.wikipedia.org/wiki/Habitability_of_natural_satellites).
                Thus, the spacecraft would never have been lost as their position with respect to their launching point would be constantly tracked through whatever communication means the ship has with human bases on earth and/or throughout the solar system.



                Albeit realistic, my first answer might seem a it trivial (and therefore not as interesting). Let's spice things up a bit and assume that there's no contact with any other humans outside of the ship. Also, since there's no specification of the speed at which the ship travels, lets assume it's only a fraction of the speed of light (as another answer assumed as well). Since control was lost for only a few hours and interstellar distances are so enormous, the position of the spacecraft would be relatively close to where they were when they lost control and not too far to the curve that traces their intended route.
                They ship would VERY LIKELY be equipped with good (geocentric) maps of all the observable/known universe before they set out. Given such comprehensive 3D map models, they could easily predict what the sky should look like from any other point on the map. Thus, they could quickly run a computational search to find a match with what they are seeing. That is, they could take snapshots of what they see in different directions from their spacecraft, and then correlate their observations with predictions of how the sky would look like from different points on the map. The search for "simulated" views on the map would be quite small -they only have to generate simulated views from a narrow radius accounting for the distance travelled since they lost control. They could even figure out what new direction they're traveling in (assuming they got completely off course through propulsion/acceleration in the wrong direction when they lost control) if they took snapshots at two different time points, long enough for differences to be perceptible in at least one of the many directions they could collect snapshots from. Then, with knowledge of their new trajectory, they could easily correct course to intersect their prior trajectory at the final destination. If following the EXACT original trajectory were important, they could do that too: calculate the shortest distance from their current trajectory to the original one, and get back on track along the original route with careful manipulation of their propulsion/acceleration systems. Of course, the supercomputer on the spacecraft would do most or all of this automatically (individual pilots would not need to know trigonometry, geometry or physics themselves).





                share








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                user1222838 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                Check out our Code of Conduct.






                $endgroup$















                  0












                  0








                  0





                  $begingroup$

                  Since the question provides little context, a simple answer is to assume that the spacecraft will still be in contact with Earth or wherever it took off from, and/or possibly other places already colonized by humans if this scenario is assumed to be playing out in the near future (the moon, Mars, Mars' moons, maybe even a few of the most-likely-habitable moons of the giant gas planets, https://en.wikipedia.org/wiki/Habitability_of_natural_satellites).
                  Thus, the spacecraft would never have been lost as their position with respect to their launching point would be constantly tracked through whatever communication means the ship has with human bases on earth and/or throughout the solar system.



                  Albeit realistic, my first answer might seem a it trivial (and therefore not as interesting). Let's spice things up a bit and assume that there's no contact with any other humans outside of the ship. Also, since there's no specification of the speed at which the ship travels, lets assume it's only a fraction of the speed of light (as another answer assumed as well). Since control was lost for only a few hours and interstellar distances are so enormous, the position of the spacecraft would be relatively close to where they were when they lost control and not too far to the curve that traces their intended route.
                  They ship would VERY LIKELY be equipped with good (geocentric) maps of all the observable/known universe before they set out. Given such comprehensive 3D map models, they could easily predict what the sky should look like from any other point on the map. Thus, they could quickly run a computational search to find a match with what they are seeing. That is, they could take snapshots of what they see in different directions from their spacecraft, and then correlate their observations with predictions of how the sky would look like from different points on the map. The search for "simulated" views on the map would be quite small -they only have to generate simulated views from a narrow radius accounting for the distance travelled since they lost control. They could even figure out what new direction they're traveling in (assuming they got completely off course through propulsion/acceleration in the wrong direction when they lost control) if they took snapshots at two different time points, long enough for differences to be perceptible in at least one of the many directions they could collect snapshots from. Then, with knowledge of their new trajectory, they could easily correct course to intersect their prior trajectory at the final destination. If following the EXACT original trajectory were important, they could do that too: calculate the shortest distance from their current trajectory to the original one, and get back on track along the original route with careful manipulation of their propulsion/acceleration systems. Of course, the supercomputer on the spacecraft would do most or all of this automatically (individual pilots would not need to know trigonometry, geometry or physics themselves).





                  share








                  New contributor




                  user1222838 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                  Check out our Code of Conduct.






                  $endgroup$



                  Since the question provides little context, a simple answer is to assume that the spacecraft will still be in contact with Earth or wherever it took off from, and/or possibly other places already colonized by humans if this scenario is assumed to be playing out in the near future (the moon, Mars, Mars' moons, maybe even a few of the most-likely-habitable moons of the giant gas planets, https://en.wikipedia.org/wiki/Habitability_of_natural_satellites).
                  Thus, the spacecraft would never have been lost as their position with respect to their launching point would be constantly tracked through whatever communication means the ship has with human bases on earth and/or throughout the solar system.



                  Albeit realistic, my first answer might seem a it trivial (and therefore not as interesting). Let's spice things up a bit and assume that there's no contact with any other humans outside of the ship. Also, since there's no specification of the speed at which the ship travels, lets assume it's only a fraction of the speed of light (as another answer assumed as well). Since control was lost for only a few hours and interstellar distances are so enormous, the position of the spacecraft would be relatively close to where they were when they lost control and not too far to the curve that traces their intended route.
                  They ship would VERY LIKELY be equipped with good (geocentric) maps of all the observable/known universe before they set out. Given such comprehensive 3D map models, they could easily predict what the sky should look like from any other point on the map. Thus, they could quickly run a computational search to find a match with what they are seeing. That is, they could take snapshots of what they see in different directions from their spacecraft, and then correlate their observations with predictions of how the sky would look like from different points on the map. The search for "simulated" views on the map would be quite small -they only have to generate simulated views from a narrow radius accounting for the distance travelled since they lost control. They could even figure out what new direction they're traveling in (assuming they got completely off course through propulsion/acceleration in the wrong direction when they lost control) if they took snapshots at two different time points, long enough for differences to be perceptible in at least one of the many directions they could collect snapshots from. Then, with knowledge of their new trajectory, they could easily correct course to intersect their prior trajectory at the final destination. If following the EXACT original trajectory were important, they could do that too: calculate the shortest distance from their current trajectory to the original one, and get back on track along the original route with careful manipulation of their propulsion/acceleration systems. Of course, the supercomputer on the spacecraft would do most or all of this automatically (individual pilots would not need to know trigonometry, geometry or physics themselves).






                  share








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                  answered 7 mins ago









                  user1222838user1222838

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                  1




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