5 ms·

Could the ISS be retrofit with boosters and sent to mars? Honest question... I don't know the physics behind this. Would the structure hold enough fuel to be

Could the ISS be retrofit with boosters and sent to mars? Honest question... I don't know the physics behind this. Would the structure hold enough fuel to be able to slow down? We have shown people can live there for a year at a time.

gramstrong 10y ago
I think a more feasible idea would be to build a mars shuttle in parallel orbit to the ISS.
- nradov 10y ago
  ISS is in the wrong orbit for a spacecraft to launch for Mars. The inclination is too high.
  - prodigal_erik 10y ago
    At any inclination, isn't it still moving parallel to the orbital plane halfway between the ascending and descending nodes?
    - nradov 10y ago
      No the ISS never moves parallel to Mars' orbital plane.
roywiggins 10y ago
Years at a time, yes, but with regular resupplies from the surface... I'd be more worried about how much force the structure can actually take - is it stiff enough to hold together if you strap a big rocket to the back and turn it on?
- benmorris 10y ago
  It can handle some degree since they do reboosting burns occasionally. But it does remind me of this incident quite a while ago. http://www.space.com/4432-nasa-weighs-excessive-vibrations-space-station.html http://www.space.com/4432-nasa-weighs-excessive-vibrations-s...
  - aschampion 10y ago
    The reboosts are at hundredths of a g.
zardo 10y ago
It would make about as much sense as turning a fishing boat into an airplane. You're better off starting from scratch.
aschampion 10y ago
AFAIK the ISS isn't very rigid and isn't designed to withstand high-g accelerations, hence the robotic arm docking, etc.
- dogma1138 10y ago
  Spacecraft dock with the ISS without the robotic arm, the arm is used only with the current version of Dragon spacecraft because it's not certified for unilateral docking. The next version of the Dragon will dock with the station by it self just like the Soyuz does.
vanattab 10y ago
I have asked this same question before and the consensus response was that it would be more expensive to try and retro fit the station then to build a new interplanetary vehicle. For example the joints between the compartments are probably not designed to have a rocket strapped to one compartment and fired up.
- phire 10y ago
  They already have a rocket strapped to one of the compartments, which they use several times a year to reboost the ISS to higher altitudes. Getting to Mars just requires boosting for longer.
  - deleted 10y ago
    [deleted]
hoorayimhelping 10y ago
Reboosting is a capability that ISS supports. If it can handle the G force of acceleration through a reboost, it could presumably handle the same acceleration and deceleration for the longer burn time it takes to get to Mars. But in reality it's probably just more economical to send a new ship to Mars. https://en.wikipedia.org/wiki/Reboost https://en.wikipedia.org/wiki/Reboost
- dalke 10y ago
  ISS reboost is about 0.0185 m/s/s, says https://youtu.be/ZkdfkRC4DbA?t=121 https://youtu.be/ZkdfkRC4DbA?t=121 . Delta-V Earth/Mars is 5,748 m/s, says http://www.projectrho.com/public_html/rocket/appmissiontable.php http://www.projectrho.com/public_html/rocket/appmissiontable... . That's 3.5 days of boost. The ISS mass is 419,455 kg. The minimum energy needed is 1/2 m v^2 or 7E12 J. A Saturn V is about 1E11J, says http://www.ocean.washington.edu/courses/envir215/energynumbers.pdf http://www.ocean.washington.edu/courses/envir215/energynumbe... . So if you attach a few score Saturn Vs to ISS, you might be able to pull it off.
  - krallja 10y ago
    The ISS engines might be more efficient than the F-1 was, so the mass could be less than 70 Saturn Vs. Still a ridiculously enormous amount of energy. Makes you wonder how we're ever supposed to build anything significant on or around Mars.
    - Dylan16807 10y ago
      It seems to use UDMH and N2O4 or similar, a hypergolic mix that's convenient for maneuvering thrusters but is not particularly efficient.
      - krallja 10y ago
        That is the only option which makes sense. LOX isn't good for things which wait. Solids have low efficiency. Hypergolics are a good choice for something that has to sit idle for a very long time, and the chemistry has been understood for decades. I guess I was hoping the Russians had figured out ion thrusters in the 70s or something.
jdhawk 10y ago
Lets land it on the moon, and use it for spare parts when we build a Lunar Base!
krschultz 10y ago
I believe the biggest issue is that ISS is not built to withstand the higher radiation you are exposed to in higher orbits / between planets. Also the thermal loads are different when you are in sun 24/7/365 rather than orbiting the earth and spending a significant portion of time in a shadow - though I don't know if that is better or worse.

gramstrong 10y ago

I think a more feasible idea would be to build a mars shuttle in parallel orbit to the ISS.

nradov 10y ago
ISS is in the wrong orbit for a spacecraft to launch for Mars. The inclination is too high.
- prodigal_erik 10y ago
  At any inclination, isn't it still moving parallel to the orbital plane halfway between the ascending and descending nodes?
  - nradov 10y ago
    No the ISS never moves parallel to Mars' orbital plane.

roywiggins 10y ago

Years at a time, yes, but with regular resupplies from the surface... I'd be more worried about how much force the structure can actually take - is it stiff enough to hold together if you strap a big rocket to the back and turn it on?

benmorris 10y ago
It can handle some degree since they do reboosting burns occasionally. But it does remind me of this incident quite a while ago. http://www.space.com/4432-nasa-weighs-excessive-vibrations-space-station.html http://www.space.com/4432-nasa-weighs-excessive-vibrations-s...
- aschampion 10y ago
  The reboosts are at hundredths of a g.

zardo 10y ago

It would make about as much sense as turning a fishing boat into an airplane. You're better off starting from scratch.

aschampion 10y ago

AFAIK the ISS isn't very rigid and isn't designed to withstand high-g accelerations, hence the robotic arm docking, etc.

dogma1138 10y ago
Spacecraft dock with the ISS without the robotic arm, the arm is used only with the current version of Dragon spacecraft because it's not certified for unilateral docking. The next version of the Dragon will dock with the station by it self just like the Soyuz does.

vanattab 10y ago

I have asked this same question before and the consensus response was that it would be more expensive to try and retro fit the station then to build a new interplanetary vehicle. For example the joints between the compartments are probably not designed to have a rocket strapped to one compartment and fired up.

phire 10y ago
They already have a rocket strapped to one of the compartments, which they use several times a year to reboost the ISS to higher altitudes. Getting to Mars just requires boosting for longer.
- deleted 10y ago
  [deleted]

hoorayimhelping 10y ago

Reboosting is a capability that ISS supports. If it can handle the G force of acceleration through a reboost, it could presumably handle the same acceleration and deceleration for the longer burn time it takes to get to Mars. But in reality it's probably just more economical to send a new ship to Mars. https://en.wikipedia.org/wiki/Reboost https://en.wikipedia.org/wiki/Reboost

dalke 10y ago
ISS reboost is about 0.0185 m/s/s, says https://youtu.be/ZkdfkRC4DbA?t=121 https://youtu.be/ZkdfkRC4DbA?t=121 . Delta-V Earth/Mars is 5,748 m/s, says http://www.projectrho.com/public_html/rocket/appmissiontable.php http://www.projectrho.com/public_html/rocket/appmissiontable... . That's 3.5 days of boost. The ISS mass is 419,455 kg. The minimum energy needed is 1/2 m v^2 or 7E12 J. A Saturn V is about 1E11J, says http://www.ocean.washington.edu/courses/envir215/energynumbers.pdf http://www.ocean.washington.edu/courses/envir215/energynumbe... . So if you attach a few score Saturn Vs to ISS, you might be able to pull it off.
- krallja 10y ago
  The ISS engines might be more efficient than the F-1 was, so the mass could be less than 70 Saturn Vs. Still a ridiculously enormous amount of energy. Makes you wonder how we're ever supposed to build anything significant on or around Mars.
  - Dylan16807 10y ago
    It seems to use UDMH and N2O4 or similar, a hypergolic mix that's convenient for maneuvering thrusters but is not particularly efficient.
    - krallja 10y ago
      That is the only option which makes sense. LOX isn't good for things which wait. Solids have low efficiency. Hypergolics are a good choice for something that has to sit idle for a very long time, and the chemistry has been understood for decades. I guess I was hoping the Russians had figured out ion thrusters in the 70s or something.

jdhawk 10y ago

Lets land it on the moon, and use it for spare parts when we build a Lunar Base!

krschultz 10y ago

I believe the biggest issue is that ISS is not built to withstand the higher radiation you are exposed to in higher orbits / between planets. Also the thermal loads are different when you are in sun 24/7/365 rather than orbiting the earth and spending a significant portion of time in a shadow - though I don't know if that is better or worse.