Gut feeling... Options

[SFJCody]

Something I have not posted online before...
Back in 2003, as four spacecraft approached Mars, I wrote down on a piece of paper my guess (based on nothing more than public information & gut feeling) at what each craft's chance of success (either at landing or orbital insertion) might be.
My guesses were:

Nozomi: 15%
Beagle 2: 20%
MER A: 60%
MER B: 60%
Mars Express: 85%

In 2005 I guessed that MRO had a 90% chance of success

Now, in 2008, I'm going to put a figure on Phoenix. That figure is:

55%


What do you think? Too low? Too high?

[djellison]

I've been trying to figure this out for myself. I decided that Phoenix has a better chance than Lewis Hamilton has of not winning the Monaco Grand Prix.

67% is the figure I've come up with. 2/3rds - which, by chance, is the ratio of powered decent landings on Mars.

Doug

[tedstryk]

With all the MPL discussion and the fact that we haven't found it, I am left wondering about something. MARDI on Phoenix was turned off because of fear that it would interfere with the EDL sequence and cause the mission to crash. I wonder if that is what did MPL in? If the generally accepted failure mode is wrong, this would be a favorite of mine (in terms of preference, not necessarily likelihood), because Phoenix has already worked around it.

[mcaplinger]

With all the MPL discussion and the fact that we haven't found it, I am left wondering about something. MARDI on Phoenix was turned off because of fear that it would interfere with the EDL sequence and cause the mission to crash. I wonder if that is what did MPL in?

The probability that the software bug with the leg deployment on MPL caused its failure is something greater than 50%. The probability that the MARDI/PACI issue caused it is a very small number (1:100000 would be my off-the-cuff guess). So I'm going with the software bug (which has also already been addressed for PHX.)