Just ran across an interesting recent paper on Martian surface sulfates, which appears to be based largely on GRS data from Odyssey:

http://www.eurekalert.org/pub_releases/201...u-ddi072516.php


Doug M.

ODY's 15th anniversary of entering Mars orbit passed unnoticed last month. Next milestone: in February 2017, the 15th anniversary of the beginning of its science mission.


Doug M.

17 years since arrival at Mars.

What space probes are still active that are older than MODY? The two Voyagers, of course. In Earth orbit, or at an Earth Lagrange point, we have Hubble (1990), Geotail (1992), Wind (1994), SOHO (1995), ACE (1997), Chandra (1999), Landsat 7 (1999), Terra (1999), XMM-Newton (1999) and Cluster II (2000). However, I'm pretty sure that MODY is now the third oldest active human spacecraft outside Earth orbit.


Doug M.

There have been so many missions who depended on ODY for their relay! We often give it for granted but the way this mission has been managed even in spite of the ever decreasing budget is quite remarkable.

Paolo

Are you talking ODY's budget, cause I thought the over all NASA's budget had increased this year.

http://www.planetary.org/blogs/casey-dreie...18-omnibus.html

Yes, I meant ODY budget.

Paolo

This week marks the 18th anniversary of MODY's insertion into Mars orbit.

MODY is the third longest-lived active spacecraft beyond Earth orbit, after the two Voyagers. It's lost an instrument and a flywheel, but is still functional and still doing science.


Doug M.

i saw this atrophied thread finally get an update and clicked in expecting the worst... but instead its yet another seemingly unbeatable milestone (unbeatable? just wait!)

It's 20 years, two months and two days since MODY arrived in Mars orbit. The 20th anniversary of science operations will come in February of 2022.

MODY had a near death experience last year, when the Trump Administration's proposed budget for NASA eliminated it, leaving only a token sum for decommissioning. But the mission survived, and looks good to continue into its third decade. In addition to the ongoing science mission, MODY is also serving as a relay for both of NASA's Mars rovers.

It's incredibly impressive how robust this mission has been.


Doug M.

The recent NASA Planetary Science Advisory Committee had an update on the rovers (see attached screenshots). All are doing well and the most of the fleet has the resources to remain functional through at least this decade.

ODY has about 10 years fuel remaining. MRO 19 years (likely something else will fail before that?). No firm data for MAVEN, but I believe that the bus is largely a copy of MRO, so I presume it carried substantial fuel reserves to Mars. Slide says fuel usage planned to allow operations through 2030.

Mars Express, though, has extremely low fuel reserves.

Low propellant level is not the largest immediate danger for Mars Express, it's a bureaucratic one, Mars Express is still slated for termination at the end of 2022, the decision for an extension into 2023-2025 - awaited early next year - "is NOT granted".

[Edit] Regarding the propellant issue: "The fuel is still a (literal) unknown quantity since, in the worst case, it should have run out in 2016. But Mars Express keeps on ticking, and Godfrey, using Venus Express as a model, reckoned that there was a chance that what is left (possibly 5.6kg) might last until 2035." (The Register, 2 Jun 2021)

Five (!) years later...

Geotail -- gone. It was decommissioned in November 2022, after its data recorder stopped working.
Wind is still going strong and should be good for years to come.
SOHO is still going.
ACE is still going though it may be running out of propellant soon.
Chandra, still going.
Landsat 7 -- gone. It was decommissioned in 2021.
Terra ate a budget cut but is still going. Decommission is expected no later than 2026.
XMM-Newton, still going and fully funded through the end of FY 2026.
Cluster II, still going and funded through the end of FY 2024.

Along with the two Voyagers, these seven spacecraft are the Elders, the active survivors of the previous century. Are there any others from 2000 or before still operational?

Some may think Soujouner’s circling Carl Sagan’ mother ship