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_*]

Unfortunately, that Wikipedia article still leaves wide open whether the Mars 6 failure was due to the retrorockets exploding, or to their failing to fire at all, or simply to the lander touching down by bad luck in rough terrain: "Contact with the descent module was lost at 09:11:05 UT in " 'direct proximity to the surface', probably either when the retrorockets fired or when it hit the surface at an estimated 61 m/s." (The latter presumably would have happened if the retrorockets had not fired at all.) Nor can I find anything more in McDowell's very brief description. Aviation Week said at the time that contact was lost 2 seconds before the planned landing, although I've never seen this anywhere else.

However, the Wikipedia article does contain two interesting notes that are new to me. First: "The [Mars 6] descent module transmitted 224 seconds of data before transmissions ceased, the first data returned from the atmosphere of Mars. Unfortunately [this is new to me], much of the data were unreadable due to a flaw in a computer chip which led to degradation of the system during its journey to Mars." (That transistor error really loused up the Soviets disastrously -- it seems likely that it may also have caused the retros to fail to fire, and even if the lander had touched down it might have transmitted only gibberish.)

Second: " Due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) the [Mars 7] landing probe separated prematurely (4 hours before encounter) and missed the planet by 1300 km. The early separation was probably due to a computer chip error which resulted in degradation of the systems during the trip to Mars. The intended landing site was 50° S, 28° W." I'm a bit skeptical of part of this -- 4 hours before closest approach actually sounds about right for such a lander's separation, and it may be that the only failure was the failure of its course-diversion rocket to fire. But in any case I had no idea that its intended landing site had ever been announced.

By the way, Perminov's account provides no new information at all on the possible cause of the Mars 6 failure -- he just says he doesn't know. (We will likely never know, even if some future traveller in that antique land stumbles across its remains.) But he does provide, as I say, a lot of interesting new stuff -- including confirmation, after three decades, of my suspicion that while the 1970s Soviet Mars landers carried no biological experiments, they DID carry an X-ray spectrometer to analyze the elemental composition of Mars soil (presumably like the one on the Lunokhods). He also says that the addition of that new radio transmission channel to send data during the descent itself was virtually the only difference between the 1971 and 1973 landers -- and that he had to fight like hell to get it added.

[ljk4-1]

However, the Wikipedia article does contain two interesting notes that are new to me.  First: "The [Mars 6] descent module transmitted 224 seconds of data before transmissions ceased, the first data returned from the atmosphere of Mars. Unfortunately [this is new to me], much of the data were unreadable due to a flaw in a computer chip which led to degradation of the system during its journey to Mars."  (That transistor error really loused up the Soviets disastrously -- it seems likely that it may also have caused the retros to fail to fire, and even if the lander had touched down it might have transmitted only gibberish.) 

Second: " Due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) the [Mars 7] landing probe separated prematurely (4 hours before encounter) and missed the planet by 1300 km. The early separation was probably due to a computer chip error which resulted in degradation of the systems during the trip to Mars. The intended landing site was 50° S, 28° W."  I'm a bit skeptical of part of this -- 4 hours before closest approach actually sounds about right for such a lander's separation, and it may be that the only failure was the failure of its course-diversion rocket to fire.  But in any case I had no idea that its intended landing site had ever been announced.

Mars 7 was supposed to land on Mars at 50 degrees south/28 degrees west, which I believe came from Kenneth Gatland's 1971 book Robot Explorers.

The Mars 6 atmosphere data, which said there was a larger amount of argon in the Red Planet's atmosphere than expected, caused the Viking team to actually attune the Viking lander sensors for this gas. It later turned out to be faulty data.

In a letter by Bart Hendrixx in the BIS Spaceflight magazine around 1991, he wrote that they had planned to put life detection equipment on the first Mars landers in the 1960s. They tested them out on the Kazahk steppes. The detectors failed to find life and the devices were not included, as the scientists assumed that if they could not find life on Earth, they certainly wouldn't find any on Mars.