At about 2232 PDT, NASA’s latest robotic explorer landed safely on the surface of Mars. This might not seem like such a big deal: the Russians achieved the first Martian soft landing in 1971 with the Mars 3 probe, and the Americans followed suit with the Vikings in 1976. Since then, several landers and rovers have successfully poked, prodded, and probed the Red Planet. The big deal with this landing was, the landing method was batshit crazy.
I’d thought the airbag landing of the Pathfinder was outside the box thinking, but the Curiosity landing method was a whole new level of innovation. Have a look at this graphic:
The inset on the graphic details the ‘skycrane’ part of the landing sequence, and the part that I’m sure caused many a sleepless night for NASA engineers. The idea was to suspend a one ton rover from the descent stage with rockets blasting away, and then cut the cables after landing and have the descent stage fly off. What could go wrong?
Everything. You miss the very narrow entry window, and you burn up in the atmosphere. Parachute (and there’s only one) fails, or the retros fail, or the separation sequences don’t come off, and Mars has a $2.5 billion crater. Cables don’t separate, or the descent stage doesn’t get the memo about crashing somewhere else, and Mars has the solar system’s most expensive junkyard.
None of that happened. Everything worked. Perfectly. Considering that the success rate for Mars landers is on par with a really good baseball player’s hitting average, and the fact that this was untried technology, Curiosity’s landing comes near the minor miracle category.
As I watched the live coverage of the landing, I was acutely aware, as was everyone in Mission Control, that when the signal for orbiter separation was received, the landing was a done deal. Either it was successful, or it wasn’t. There was no middle ground. So while the events of the landing were fascinating, there was the knowledge that, in a sense, it was academic. This made watching the landing a bit surreal, because the outcome was already determined. Light may seem to move instantaneously in our everyday experience, but even over the relatively short distances between planets, it moves at a leisurely pace.
Because the landing was AI controlled, and the humans on the home planet had no control over events, Curiosity’s landing sequence has been referred to as the ‘Seven Minutes of Terror’. But because the people who conceived, designed, and screwed the thing together would accept nothing less than the best, it became Seven Minutes of Excellence.
Notes on the Coverage
NASA has a problem. Since the Shuttle, we don’t have cool views from spaceships with people in the mix. So when a big mission comes off, what we get are shots of a room full of engineers sitting at consoles. This is not interesting TV. You can hear the conversations:
“Honey, what are you watching?”
“The Mars landing.”
“What are they showing?”
“A bunch of people sitting in front of computers”
“Let’s watch some Olympics”
NASA did show some neat computer simulations of the entry, and when the lander broke through the atmosphere, they switched to a dashboard with gauges showing parameters as measured by the probe in real (-20 minutes) time.
Alongside the video NASA had a scrolling window with their Twitter feed. There were anthropomorphic Twits from the spacecraft amongst the official Twitter entries. These were entertaining, but one of the Twits from the ‘lander’ was a bit odd: “Gale Crater, I am inside you!” OK, I”ll leave that one alone.