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Comment by dist-epoch | Hacker News Reader

Dumb question, but why can't it have a few simple telescopic sticks which extend to flip it over if it lands upside down.

Seems it's the second time they fail in this mode.

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Definitely not a dumb question. The first lander to land on the Moon (after many failures) is pretty amusing. [1] The Soviets a designed a lander that'd be launched right into the Moon but, just before impact would jettison the lander which itself was a highly reinforced ball that was then designed to simply pound into the Moon at 54kph, but survive the crash. The egg then unfurled and finally humanity had achieved a 'soft' landing on the Moon. Somehow it kind of makes one think of a really elaborate egg drop contest paired with a 'what happens if you jump right before the elevator crashes.'

Like another comment mentioned, complexity and size are big issues. Some more are power/mechanics (fluids, such as for hydraulics, and -280F aren't gonna play well together) and then there's the fact that there's not even a guarantee it'd work. Your legs could get damaged, you might end up in an orientation where none of the legs are appropriate, and so on. So you may be adding a whole bunch of complexity for stuff that might not even save you in the situation it was designed for!

[1] - https://en.wikipedia.org/wiki/Luna_9

Just give the RCS thrusters enough power to lift it sideways. Works every time in KSP.

Moe parts, more complexity, more weight.

Mass. Each kilogram costs what, millions? Hundreds of millions?

There's a small chance that navigation or landing fails in a way that would make those legs useful, and an even smaller chance that they'll save the mission.

Given tight budgets, this is almost certainly not a gamble worth taking

NASA paid $65M for the launch. It's about 2,000 kilos.

$32k/kilo or so.

battlebots did it first!

Because: 1. It cannot fail in this mode. 2. Testing is done by the user, test results are sent by telemetry and the fix will be done, when the bug can be reproduced on developer's computers.

How about a parachute to keep it the right way up?

Not enough of an atmosphere.

How about a balloon then?

Absent an atmosphere, a balloon is just a heavier parachute.

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