[X] My Assistant

[cIclops]

In his recent long piece on spacedaily.com Bruce Moomaw reports:

... JPL's Pete Theisinger and Mike Meyer (chief engineer and scientist of the 2009 Mars Surface Lab) confirmed that the current plan is to have MSL land using a strange, Rube Goldbergian system called "Skycrane".

Skycrane is a very innovative landing system and now that MSL appears to be planning to use this approach there are lots of open questions, such as: How exactly does it work? What advantages does it have over legs, airbags or pallets? What the heck is it anyway?

Some background info:

JPL note

Space.com article

[dvandorn]

Most landers haven't worked but much was learned from those failures. For example MPL, Deep Space 2 as well as several Surveyor and Ranger lander probes. And I won't mention the numerous Russian lander failures ...

Since you don't want to get into Soviet/Russian lander failures, looking at just American attempts, there have been three loss-of-vehicle failures in thirteen attempts at lunar/planetary soft landings(*). 10-3 is a pretty decent track record.

Now, if you add in American attempts at hard landers, at which we're zip out of five(**), you're still talking seven failures out of seventeen attempts. 10-8 is still a winning record.

Finally, if you include American manned soft-lander attempts into the total -- one failure (in which the landing itself wasn't even attempted) out of seven tries(***) -- you achieve a whopping sixteen successes versus only nine failures. Winning nearly twice as often as you lose will get you thrown out of any casino in Vegas. And if you look just at American soft-landers, both manned and unmanned, the record is a phenomenal 16-4.

So, I'm thinking maybe NASA is a little better at landing probes on other planets than you suggest... *smile*... At the very least, "most landers haven't worked" is an inaccurate assessment of American lunar/planetary landing attempts.

All of that said, I agree with your main point. We learn from our failures just as much as we learn from our successes. In fact, we learn the things we want to learn from our successes, but we more often learn the things we need to learn from our failures...

* - American soft-lander failures: Surveyors II and IV, Mars Polar Lander. Successful soft-landers: Surveyors I, III, V-VII; Vikings 1 and 2; Mars Pathfinder; MERs A & B (Spirit and Opportunity).

** - American hard-lander failures: Rangers 3-5; Deep Space 2 (two hard landers). No successful hard-landers.

*** - American manned soft-lander failure: Apollo 13. Successful manned soft-landers: Apollos 11-12, 14-17.

-the other Doug