Why does the Mars Spirit Rover have an expected lifetime of 90 days?

[RickJay]

@Cervaise

The astronauts who went to the moon took quite a few rads in the process. I read somewhere, though I don’t remember where so I can’t dig up a cite quickly, that the lunar explorers have shown a somewhat elevated rate of cancer. However, since there’s fewer than twenty of them, it’s not really an epidemiologically reliable sample.

There were 24 Apollo astronauts who actually flew all the way to the Moon:

Jim Lovell
William Anders
Frank Borman
Thomas Stafford
John Young
Gene Cernan
Neil Armstrong
Buzz Aldrin
Michael Collins
Charles Conrad
Richard Gordon
Alan Bean
John Swigert, whose Bacon number is 0
Fred Haise
Alan Shepard
Stuart Roosa
Edgar Mitchell
David Scott
Alfred Worden
James Irwin
Tom Mattingly
Charlie Duke
Ronald Evans
Harry Schmitt

Lovell, Young, and Cernan went twice.

Of those, two are dead of cancer. Not unusual given that most of these men are pretty old now, although Swigert died young.

[Sam_Stone]

Clayton_e: No prob. Here’s your link: Mars Science Laboratory Mission

The landing technique is interesting for this one, and quite ingenious. A series of parachutes slows it down just like the Spirit rover, but instead of being dropped in an airbag, the descent engine hovers over the ground and lowers the rover on a cable. When the rover touches down, it cuts the cable, and the descent stage flies away and then crashes some distance from the rover.