НАСА докопалось: Mars Global Surveyor проработал в четыре раза дольше ресурса, а подох от паталогически дырявого софта. Вообще-то это явление уже как песня а-ля П.П.Шариков с балалайкой, приплясом и бинтами на голове. Раньше АМС дохли от естесственных причин — износа техники, непредсказуемых условий, ошибок операторов, а сейчас вот от неискоренимо дырявого софта для бортовых компов. Почитайте, очень внушаить.
Ironically, a software fix sent up to NASA's Mars Global Surveyor spacecraft in June 2006 ultimately led to its failure five months later, a new report
The main culprit appears to be commands mistakenly sent up to the wrong memory address on the onboard computer in June 2006. "This resulted in the corruption of two independent parameters and had dire consequences for the spacecraft," the report states.
One of the two corrupted 'parameters' caused a solar array on the spacecraft to try to move beyond its limits when ground controllers commanded the arrays to swivel away from the Sun on 2 November.
Because the solar array was "driven against its hard stop", the spacecraft entered a special error mode, reorienting itself in space. In its new orientation, one of its batteries was directly exposed to the Sun, causing it to become overheated.
Ground controllers were unaware of the actual trouble throughout this critical time span, however, because of the second 'parameter' caused by the incorrect June 2006 software upload.
That parameter caused the spacecraft's high-gain antenna, which is used to communicate with Earth, to point away from the Earth. "Communication from the spacecraft to the ground was therefore impossible, and the unsafe thermal and power situation could not be identified by the MGS's ground controllers," says the report.
The incorrect June 2006 software upload was, in turn, meant to fix a problem created in September 2005.
That is when two different engineers updated – in slightly different ways – two redundant control systems for the pointing of the high-gain antenna in 'error' mode. This led to a discrepancy in the computer's two memories, which the June 2006 upload was meant to fix.