[X] My Assistant

[SFJCody]

Is a Discovery class Titan lander/aerobot remotely conceivable?

It would be nice to see Cassini's relay capability get a second workout...

[edstrick]

Regarding Argon and soviet mars probes, as I recall it...

Mars 3 was warming up instrumentation during descent for taking a panorama immediately after landing. Warming up may have been literally true: vaccuum tubes in some circuitry.

Mars 6 was prepping a mass spectrometer during descent for atmosphere composition analysis immediately upon landing. One of the very limited telemetry parameters transmitted during descent was a voltage or current on the mass spec's "ion pump" or something like that, that functions to maintain the vaccum in the analysis chamber. The pump current (i think) was abnormally high and way above expected levels. Since the vehicle was never heard from again after retrofire (followed within a fraction of a second of first impact, like the MER rovers), all they had was this anomalous engineering data to interpret. It could be reproduced by having a very significant amount of Argon in the atmosphere, which would be hard for the ion pump to trap or remove, compared with C02 or N2, and they suggested the atmosphere could be 30% or some largish fraction Argon, in addition to the CO2.

This was of major interest to the Viking GCMS team as their instrument was potentially damagable by ion pump overloading in a high argon atmosphere. As it turned out, both argon and nitrogen are in the few percent range. 1.5 % and 2.5% or so for one and/or the other. <can't remember which is which>