This Sunday night around 10:31 PST, the Mars Science Laboratory Sky Crane will deliver the rover Curiosity to the surface of Mars. It will land inside the geologically interesting Gale Crater, to be exact. Even among planetary landings it’s an exciting one, and for an historian it has some pretty interesting heritage. I’ve covered a few aspects of the mission’s history before, so here’s a small selection of articles to get you up to date on teh mission and excited about the most daring landing attempted to date on Mars.
Previous Mars missions have used relatively simple landing technology. Landers like the Viking and Phoenix used a parachute then retrorockets to land softly on the surface. Rovers like Spirit and Opportunity used airbags to bounce and roll to a stop on Mars.
Curiosity is too big and heavy for these types of landing systems, so JPL engineers invented the Sky Crane. It’s the most complicated landing system ever sent to the red planet. It uses a supersonic parachute, a heat shield, a retrorocket-powered descent module, guidance from a landing radar, and finally a tether. If all the small pieces work, Curiosity will land on its wheels ready to explore Mars. My article on Scientific American’s Guest Blog has the details on all of the Sky Crane’s moving parts and where this unique vehicle fits in with the history of Mars landers.
The first part of Curiosity’s descent hardware – it’s parachute – has an interesting history in itself. Unfurling and inflating on Mars where the atmosphere is one percent as thick at Earth’s and the gravity is on third as strong is roughly equivalent to a parachute inflating in our upper atmosphere. But NASA didn’t run any high altitude supersonic parachute tests leading up to Curiosity’s mission; it didn’t have the money. Instead, it relied on tests done in 1968 – back when NASA did have money for these types of tests.
It takes data 15 minutes to make the journey from Mars to Earth and it will take only seven minutes for Curiosity to make the journey from upper atmosphere to surface. That means when the first EDL telemetry starts trickling in to mission control, the rover will already be on Mars, dead or alive. It’s sure to be a tense evening, and I’m very excited to be making the trip to Pasadena to be on site at JPL when it all happens!