One of the biggest unknowns for the Mars Science Lab — a.k.a Curiosity — is the landing system, called the Sky Crane, which has never been used before for a spacecraft landing on another planet. It is similar to a sky crane heavy-lift helicopter, and it works like this: after a parachute slows the rover’s descent toward Mars, a rocket-powered backpack will lower the rover on a tether during the final moments before landing. This method allows landing a very large, heavy rover on Mars (instead of the airbag landing systems of previous Mars rovers).
The MSL team conducted a drop test of the Sky Crane, and you can see how it worked in the video, above.
Curiosity will also use a new high-precision entry, descent, and landing (EDL) system that will place it in a 20 kilometer (12 mile) landing ellipse, as opposed to the 150 kilometer by 20 kilometer (about 93 miles by 12 miles) landing ellipse of the landing systems used by the Mars Exploration Rovers.
Curiosity will be over five times as heavy as and carry over ten times the weight of scientific instruments as the Spirit and Opportunity rovers. Curiosity is scheduled for launch in November 2011 and then will land on Mars in August 2012.
And don’t forget, you can watch live as engineers build the MSL, on the “Curiosity Cam”
Jeez – she looked a bit violent when the wheel frames deployed! Rang the damn thing like a bell…
The system may work fine as long as the crane is fixed to the ceiling of the test hall. But fixed to a moving descent stage that has its descent jets running, deploing the rover by a tether is nothing but easy. While being deplyed, the rover may accidently come into the flows of hot gases that are ejected by the nozzles, and this may cause the tethered rover to sway, making the whole assembly unstable. Therfore, the descent stage must be able to stabilize the assembly automatically such that it balances such swaying. Further, as the rover is on the ground, it must disconnect from the tether reliably and the descent stage be lifted and move up and away to avoid the rover to get entangled in the tether or the descent stage landing on top of the rover and bury it alive. There is a lot more to be tested.
It is great.
I, too, noticed how “violent” the release from the rocket-powered backpack seemed to be. But it happened under Earth gravity so I wonder if it will really be so violent under Martian gravity?
As for getting into the flow of hot gasses from the rocket-powered backpack I imagine that will be well accounted for. Perhaps the tether will be long enough to avoid that possibility, but surely that has already been taken into account, while the Rover was still in its design stage!