死因來了...軟體工程師要GG了嗎?
Computing glitch may have doomed Mars lander
系統錯誤可能毀了火星登陸器
Preliminary analysis suggests that the lander began the manoeuvre flawlessly,
braking against the planet’s atmosphere and deploying its parachute. But at
4 minutes and 41 seconds into an almost 6-minute fall, something went wrong.
The lander’s heat shield and parachute ejected ahead of time, says Vago.
Then thrusters, designed to decelerate the craft for 30 seconds until it was
metres off the ground, engaged for only around 3 seconds before they were
commanded to switch off, because the lander's computer thought it was on the
ground.
初步分析顯示登陸器一開始完美作動，也張開降落傘氣動煞車。
但是4分41秒後出錯了，進入6分鐘的自由落體。
隔熱罩跟降落傘被過早拋棄。
而原本應該燃燒30秒的逆向噴射只作用了3秒就被關閉
因為登陸器認為她已經著陸了。
The lander even switched on its suite of instruments, ready to record Mars’s
weather and electrical field, although they did not collect data. “My guess
is that at that point we were still too high. And the most likely scenario is
that, from then, we just dropped to the surface,” says Vago.
登陸器甚至開啟了上面的儀器準備紀錄火星的氣象跟電場，雖然沒搜集到任何資訊。
沒收集到的原因可能是高度過高，之後就摔到地上了。
The craft probably fell from a height of between 2 and 4 kilometres before
slamming into the ground at more than 300 kilometres per hour, according to
estimates based on images of the probe’s likely crash site, taken by NASA’s
Mars Reconnaissance Orbiter on 20 October.
從NASA 10月20號拍攝的撞擊坑影像來判斷
登陸器可能從高度2~4公里掉落並以超過時速300公里速度撞擊火星地表。
The most likely culprit is a flaw in the craft’s software or a problem in
merging the data coming from different sensors, which may have led the craft
to believe it was lower in altitude than it really was, says Andrea Accomazzo
最有可能的原因是登陸器自身軟體瑕疵或各偵測器資訊整合出錯
造成登陸器認為自身高度比實際高度還低。
上次日本JAXA的瞳也是軟體(定位程式)有瑕疵，最後瘋狂旋轉到解體。
JAXA的94億台幣跟NASA的22.7億台幣都變成地球軌道上的太空垃圾