Lithobraking

[Acemcbean]

If you dont know already, Lithobraking is a way of rapidly decreasing one's velocity via collision with a physical body, or hitting the ground very hard to slow down. Yeah, its INCREDIBLY impractical, but is there any logic to the idea? I mean, Rule of Cool and all, but could it actually be done and what are the benefits?

[ZooNamedGames]

If you dont know already, Lithobraking is a way of rapidly decreasing one's velocity via collision with a physical body, or hitting the ground very hard to slow down. Yeah, its INCREDIBLY impractical, but is there any logic to the idea? I mean, Rule of Cool and all, but could it actually be done and what are the benefits?

Its VERY practical- You could waste fuel and time BURNING to slow your orbit or use several passes through the dense and high atmosphere of whatever body your near to preform a free aerocapture. Also- for slamming- The Russian Luna missions collided I believe.

[Dkmdlb]

Spirit and Opportunity used lithobraking.

Edited January 5, 2015 by Dkmdlb

[Bill Phil]

Yeah. The first objects to the moon lithobraked. Luna 1 and the first few.

[pincushionman]

Its VERY practical- You could waste fuel and time BURNING to slow your orbit or use several passes through the dense and high atmosphere of whatever body your near to preform a free aerocapture. Also- for slamming- The Russian Luna missions collided I believe.

not AERObraking, ZNG. LITHObraking. I believe the term originated as a tongue-in-cheek admission of "we messed up and crashed" before somebody started taking the concept seriously, as in "how can we design a lander so we don't care so much how hard it hits the ground" or "in what missions do we not care at all how hard it hits?" The Spirit/Opportunity landers were a result of the former question; any "impactor" probes and the Rods From God concept are a result of the latter.

[ZooNamedGames]

not AERObraking, ZNG. LITHObraking. I believe the term originated as a tongue-in-cheek admission of "we messed up and crashed" before somebody started taking the concept seriously, as in "how can we design a lander so we don't care so much how hard it hits the ground" or "in what missions do we not care at all how hard it hits?" The Spirit/Opportunity landers were a result of the former question; any "impactor" probes and the Rods From God concept are a result of the latter.

Collisions-ah well simple response is it's still practical- As long as you can absorb the impact or use it to your advantage... For example the challenge (was it Google who did it?) to make a lander that lands on the moon and travels 500m (or 100m?) could be muuuch simpler if you bounced at least 250m to the goal- which on the moon getting this distance should be easier (if used properly).

[Nuke]

philae used lithobreaking.

[Camacha]

The Russian Luna missions collided I believe.

As did early American ones in the form of the Ranger probes. They had trouble enough targeting the moon, so hitting it was considered a huge win. Speed was not relevant.

[toric5]

you could say that all spacecraft use lithobreaking to bleed of the last few m/s, but i don't think thats what your asking.