Getting the Latest Rover To Mars 191
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 difference is size (Score:5, Informative)
This rover is FAR larger the current ones, those tires? Not cute cart wheels, they are roughly the same size as a car tire. The entire vehicle is easily the size of a large SUV although far more open. (Hey nasa, if you want to make things understandable how about instead of adding sounds in space, maybe project a human next to thing so we get a sense of scale)
A bouncing ball for this vehicle wouldn't need to be far to large. It is the old story of how spider won't even notice a 4 meter fall, a human would shatter bones and an elephant would go splat.
There are a lot of risks with this method, so many parts that can fail, but if you want something big to land safely...
Not that this is new. There are airdrop uses on this planet that involve just wrapping what you want to drop in something bouncy and throwing it out of an aircraft, works for small supplies in remote areas where a parachute might drift to far and the russians have used rocket decelerated chute systems for dropping tanks out of aircraft. Because finding enough bubble wrap for a tank is a hard.
Did I complain yet about the sound in space? Yes? Well, it is a pretty big fucking issue. Everything you need to know about the US can be summarized as a NASA science video having sound in space... why not go the whole way and include cute green aliens on mars to show the life you might have found if Mars wasn't the hell hole it is?
Re:Stop me if I'm wrong but... (Score:5, Informative)
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.
Re:The difference is size (Score:5, Informative)
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 [wikipedia.org]
Re:Stop me if I'm wrong but... (Score:5, Informative)
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. [universetoday.com] 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.
Re:Power? (Score:5, Informative)
http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Power_source [wikipedia.org]
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]
Re:Stop me if I'm wrong but... (Score:5, Informative)
Lithobraking [wikipedia.org]
Re:Stop me if I'm wrong but... (Score:5, Informative)
And that's exactly why NASA is testing the bejesus out of it. Including delaying for exactly that reason
Bouncy rover is good and simple, but the Sojourney rover is the size of a toy car, Curiosity is about the size of a Mini Cooper.
http://science.howstuffworks.com/mars-rover3.htm [howstuffworks.com]
They got burned with rockets (no pun intended) on Mars Polar Lander, but guess what, Viking landed with rockets. And Mars Phoenix, and several other craft.
I'm skeptic about the whole crane thing, but they want that for a 'precision landing'.