Slashdot Mirror
Getting the Latest Rover To Mars
derGoldstein writes "New Scientist has a great video up detailing every step of how the latest Mars rover will reach its target and get deployed. It's drastically different than the bouncing air-bag delivery system previously used (YouTube video)."
The rover is too big/heavy for the bounce trick they used for the previous ones.
Heat shield/parachute entry is not complicated. Apollo era technology.
The retro rockets are like what the moon landers used. Also Apollo era technology.
The only new thing here is the tether. I suspect it uses explosive bolts to release and that is Apollo era tech.
While it looks complicated, I think we should have mastered those things pretty well by now.
Not showing the scale of the rover is inexcusable! Thank you for mentioning it.
Here are some people next to it: http://en.wikipedia.org/wiki/File:Mars_Science_Laboratory_wheels.jpg
When I saw the last stage I almost fell out of my chair!. What the hell happened to keeping it simple!
It's no worse than the various lunar landers. The real question is whether they can get the budget to send that much mass to Mars.
Landing anything big on Mars turns out to be quite hard. There's not enough atmosphere for a soft parachute landing. But there's enough atmosphere to require a heat shield while plowing through it. Then there's not enough atmosphere to brake from Mach 5 to Mach 1 before running out of altitude. There's too much gravity for a full rocket-powered descent. A rocket facing into the atmosphere won't work until the craft has slowed below supersonic speeds.
That's what leads to what looks like an overly complex system.
http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Power_source
The Curiosity rover will be powered by radioisotope thermoelectric generators (RTGs), as used by the successful Mars landers Viking 1 and Viking 2 in 1976.[29][30] Radioisotope power systems are generators that produce electricity from the natural decay of plutonium-238, which is a non-fissile isotope of plutonium used in power systems for NASA spacecraft. Heat given off by the natural decay of this isotope is converted into electricity, providing constant power during all seasons and through the day and night, and waste heat can be used via pipes to warm systems, freeing electrical power for the operation of the vehicle and instruments.[29][30]
The Curiosity power source will use the latest RTG generation built by Boeing, called the "Multi-Mission Radioisotope Thermoelectric Generator" or MMRTG.[31] Based on classical RTG technology, it represents a more flexible and compact development step,[31] and is designed to produce 125 watts of electrical power at the start of the mission and 100 watts after its minimum lifetime of 14 years.[32][33] The MSL will generate 2.5 kilowatt hours per day compared to the Mars Exploration Rovers which can generate about 0.6 kilowatt hours per day.[13]
"Running out of altitude" is the most awesome synonym for hitting the ground I've yet heard.