Solander Point, Sol 3387 - 3511 (August 4, 2013 - December 12, 2013) |
Solander Point, Sol 3387 - 3511 (August 4, 2013 - December 12, 2013) |
Aug 4 2013, 08:39 PM
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Senior Member Group: Moderator Posts: 3431 Joined: 11-August 04 From: USA Member No.: 98 |
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Sep 11 2013, 02:49 AM
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
I think it's wise to remember here that the Viking landing sites were selected in part based on Earth-based radar interpretations of surface smoothness in the 1970s, which frankly were kinda off the mark.
The VOs didn't have nearly the cam resolution that even MGS had, and all that came before them were the Mariners. We're kinda spoiled nowadays...not that I'm complaining. Pains me to say it, but we were REALLY lucky that both of the VLs made it down safely. (To be fair, though, the history of science itself is replete with luck; serendipity is definitely a part of of the process of discovery.) As a result, we sent more spacecraft & learned enough about the planet so that we are now able to set down rovers in both terrain-accessible & geologically interesting locales. Moving on now. Always. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Sep 11 2013, 09:19 PM
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Senior Member Group: Members Posts: 1089 Joined: 19-February 05 From: Close to Meudon Observatory in France Member No.: 172 |
... we were REALLY lucky that both of the VLs made it down safely. Well... And to complement Phil's good statement, the radar gave good echoes for the actual VL1 site (then named "Alpha") that predicted with good accuracy small to medium-sized rocks (i.e. no larger than 30 cm). Regarding the landing itself, it has nothing to do with luck. Hundred of major tests (plus thousands of minor tests) were designed by the engineers at JPL and at Lockheed-Martin PLUS an important margin for the deceleration with the parachute PLUS an important margin on deceleration possibilities with the retrorockets for the last phase of the descent PLUS a landing radar "à la Lunar Module" to trigger the final slowdown and for a last-second avoiding of big boulders. In fact, they were quite confident for mission success and even should the orbiter failed entering orbit, the engineers designed a "salvage" mission in which they were only rotating the orbiter to aim at the planet with a proper angle and then released the lander. In such a desperate case, Jim Martin and Tom Young, were still giving more than 50% probability for mission success... "...and that's better than no mission at all !" they said. |
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Sep 11 2013, 09:54 PM
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
PLUS a landing radar "à la Lunar Module" to trigger the final slowdown and for a last-second avoiding of big boulders... Viking had no ability to avoid big boulders or any other landing hazard; its terminal descent radar only measured velocity vectors. See www.cs.odu.edu/~mln/ltrs-pdfs/NASA-76-cr159388.pdf -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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