Cryosat Mission Feared Lost Options

[general]

http://news.bbc.co.uk/1/hi/sci/tech/4319596.stm

Mission control at ESA is growing increasingly concerned about the fate of Europe's ice monitoring spacecraft, Cryosat.

The Cryosat spacecraft was launched at 1902 local time today, Oct 8, from the Plesetsk Cosmodrome in northern Russia, but mission controllers have failed to receive a signal from the spacecraft.

[Guest_BruceMoomaw_*]

The report (V.G. Perminov, "The Difficult Road to Mars", 1999) doesn't mention helium -- but it does say: "Suddenly, during testing of the power system, the onboard blocks started to fail. Analysis showed thqat in all cases the power system malfunctioned because of a failure of the 2T312 transistor, which was fabricated at the Voronezhskiy plant. An interministry commission carefully analyzed this problem and came to the conclusion that the reason for the transistors' failure was intercrystalline corrosion in the area of the transistor lead.

"To save gold resources, some 'smart person' suggested that the gold leads be replaced by aluminum ones. The necessary tests were not made. And so 2 yeasrs later, this suggestion caused major trouble. The only way to remedy the situation was to replace the flawed transistors with ones fabricated according to the old technology."

Since this would have taken at least 6 months, and studies showed a 50-50 chance that any craft carrying the transistors would make it to Mars before they started to fail, the Kremlin decided to gamble on flying the four 1973 Mars craft in the hope that they could pull off a Mars landing before the Vikings got there. But three of the four craft malfunctioned en route -- Mars 4 faiiled to fire its retrorocket (although it did snatch some photos), Mars 7's lander failed to fire its trajectory-change rocket after ejection, and Mars 6 totally lost its radio transmission system only 2 months out. It neverthless carried out the remainder of its mission automatically, but it's still not known why the lander lost contact virtually at the moment of landing.

By the way, Perminov also reveals that the crash of the Mars 2 lander -- the first man-made object ever to hit the planet -- occurred not because of any onboard failure, but because the Mars ephemeris data programmed into Mars 2's autonomous navigation system for the final midcourse maneuver was slightly inaccurate, so that the lander entered at too steep a trajectory. He's still a little bitter at the US not providing the USSR with the better ephemerides they already had (which occurred only a year later, in exchange for the Soviets releasing more of their data from the Veneras). He also thinks that the post-landing Mars 3 failure may have been due to a static discharge from the massive ongoing dust storm.

[ljk4-1]

Since this would have taken at least 6 months, and studies showed a 50-50 chance that any craft carrying the transistors would make it to Mars before they started to fail, the Kremlin decided to gamble on flying the four 1973 Mars craft in the hope that they could pull off a Mars landing before the Vikings got there.  But three of the four craft malfunctioned en route -- Mars 4 faiiled to fire its retrorocket (although it did snatch some photos), Mars 7's lander failed to fire its trajectory-change rocket after ejection, and Mars 6 totally lost its radio transmission system only 2 months out.  It neverthless carried out the remainder of its mission automatically, but it's still not known why the lander lost contact virtually at the moment of landing.

Jonathan McDowell told me that Mars 6 came down at too fast a speed on very rough terrain, which could certainly explain the sudden lost of contact.

http://www.planet4589.org/space/space.html

The estimated impact speed was 61 meters per second.

http://en.wikipedia.org/wiki/Mars_2

So, if the Soviets had not screwed up on this technical point, perhaps the first transmissions from the Martian surface would not have been the Vikings.

I still hope some day the Mars 2, 3, and 6 landing/crash sites are found and investigated.