On 20 Jun 2011 10:57:00 +0200, wrote:


The PU-238 RTG has problems. The roover was bound for a launch in 2008:

http://nasawatch.com/archives/2011/0....html#comments
From the report: Department of Energy officials stated that the power
degradation issue is unlikely to cause a catastrophic failure. However,
as a cautionary measure, MSL Project managers have reduced the missionÆs
performance capabilities to processing 28 rather than 74 soil and rock
samples and to traversing 4.5 kilometers rather than 20 kilometers.

For some reason, this seriously reduced capability was not highlighted
elsewhere in the report.

Remember that this is the baseline (contract required) capability.
Like Spirit and Opportunity, Curiosity will probably greatly exceed
these requirements.

The OIG report said "unexpected degradation". PU-238 half-life is 88 years.
So I expect a new type of RTG thermocouples degraded and they have no
replacement. It is in prototype phase, has 110 We (2 kW thermal) nominal
by 4 kg Pu. Btw, the RTG is 100% DoE and build by Boeing, no fault at NASA.
They hide the percentage power loss from public but the 4.5 km to 20 km
gives a hint. Probably the power for data transmission is now restricted
too. That means considerable less images to expect. Still worth launch?
Maybe.

Curiosity will be transmitting most of its data back to Earth through
MRO and Odyssey, so that's not a problem.

Brian