Air and Space Photos from Alternate Worlds.

nixonshead

Pipcard said:
H-10-K Enterprises Gateway Station (by Capt_hensley on Orbiter-Forum)

Constructed from 2017-2021
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Wow, that would take some serious re-boosting! :eek:

Back in Part III post #17 of Eyes Turned Skywards there was a discussion of the joint US-Russian Fobos Together mission, which included an innovative concept for a low-gravity spring powered asteroid rover, Sojourner. In Part III post #23 we found out that this rover design was also under consideration for other asteroid and comet exploration missions.

sojourner.jpg
 

e of pi

22iron thunder said:
Amazing once again Nixonshead.:cool: Love the "rover". I dont quite understand how it moves and stuff............
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Basically, it's designed for bodies like Phobos and asteroids where the surface gravity is very low--Phobos is only about 6/10,000ths of Earth gravity! Since wheels or legs depend on forces between the rover and the surface to generate sideways motion, it's very hard to design one that doesn't push off a bit too hard and goes flying off on a very long hop. This rover is designed to turn that on its head--instead of trying to stick to the surface, it uses those long, spring-loaded legs to push off from the surface and jump!

In Phobos' low gravity (and that of other "minor bodies") a mere couple of m/s is enough to fly a long way up (getting good, low aerial views for onboard cameras) and progress around the surface of the moon by hundreds of meters, or even kilometers at a time. Mid-leap, it can use the mounted thrusters to slightly adjust its trajectory, and then it uses the legs again as shock absorbers when it touches down. On Earth or even our Moon, it'd be impossible, but on such small planetoids, it's actually a pretty fuel-efficient way of getting around.

Just Leo said:
Same mobility system.
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If the moons of Mars came with stagehands and hooks hung from the ceiling, that'd be darn handy, wouldn't it? :p
 

22iron thunder

e of pi said:
Basically, it's designed for bodies like Phobos and asteroids where the surface gravity is very low--Phobos is only about 6/10,000ths of Earth gravity! Since wheels or legs depend on forces between the rover and the surface to generate sideways motion, it's very hard to design one that doesn't push off a bit too hard and goes flying off on a very long hop. This rover is designed to turn that on its head--instead of trying to stick to the surface, it uses those long, spring-loaded legs to push off from the surface and jump!

In Phobos' low gravity (and that of other "minor bodies") a mere couple of m/s is enough to fly a long way up (getting good, low aerial views for onboard cameras) and progress around the surface of the moon by hundreds of meters, or even kilometers at a time. Mid-leap, it can use the mounted thrusters to slightly adjust its trajectory, and then it uses the legs again as shock absorbers when it touches down. On Earth or even our Moon, it'd be impossible, but on such small planetoids, it's actually a pretty fuel-efficient way of getting around.
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Wow, ingenious. Love to buy an album of those pictures. But how long is it designed to survive (and operate) on that little moon?
 

nixonshead

22iron thunder said:
Wow, ingenious. Love to buy an album of those pictures. But how long is it designed to survive (and operate) on that little moon?
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Regarding Sojourner's lifetime, according to Part III post #17 which covered the mission:

Sojourner was the first to cease functioning, running out of vital hydrazine in early 2003, after just over six months of operation. With no way to trim its trajectory, it would have been unable to make a precision return to Fobos-Grunt for updated commands or to relay any recorded detail. Emergency instructions for just such a case had been included in the rover’s memory, however, and it is assumed that it performed a nominal shutdown in line with the operations plan uploaded a few weeks earlier. If so, the rover’s hardware is likely, given the vacuum and quiet of the moon’s surface, relatively intact; the electronics systems may have been damaged by bombardment by cosmic rays and solar radiation, but the mechanical systems should still be operational if a future mission travels to the moon.
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