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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)."
Won't all that extra propellant for the various deceleration stages add up to a lot more than the bouncing airbag thingie in the end?
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?
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
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]
I am in absolute awe after watching the video about the new rover. As people bicker over whether NASA's miniscule budget is worth it, because "space isn't important", it's nice that NASA can still bring out that child-like wonder in me. How can you not be amazed that we can send a robot like this to another planet, land it safely with precision, and study the composition of the planet from millions of miles away? Isn't that awe worth a few billion dollars a year, even if "it doesn't benefit me"?
(Also, it has a laser tricorder. I mean, come on.)
"Single point of failure" is an engineering term. A system can have any number of them.
Science is all about firing a drunk pig out of a cannon just to see what happens.
It could, but that would mean landing in the same area. Mars is quite large, and it would be a shame to send a probe to the same location unless that location happens to be of extremely notable interest (such as either a potential human landing site, or something truly unique in almost science fiction proportions).
Who is going to build that colony? Not hundreds of humans in bulky suits who need to be supplied with oxygen, nutrients and shelter, who can work less than twelve out of twenty-four hours, and are easily injured or bored. Most of the large-scale construction (before a pressurized habitable area can even exist) must be done robotically because it's too dangerous and taxing.
Figuring out how to engineer remotely guided robots and how to keep them from failing is at least as much part of these rover missions as exploring Mars.
I thought there was no sound in the vacuum of space.
But then maybe all that manmade global warming New Scientist likes to report is causing air molecules in our atmosphere to heat up and expand into the other reaches of space, causing all that whooshing noise as the mars lander speeds by the camera.
Or maybe they consulted with George Lucas before making the video...
Here's the only physical test I found: http://www.youtube.com/watch?v=YasCQRAWRwU
Earth's atmosphere is entirely different. If you tried using the same scale, the same thrusters, and the same weight, the entire thing would crash. I'm sure there were separate tests of the individual steps, using dummy loads, but I can't find any videos of them.
Entomologically speaking, the spider is not a bug, it's a feature.
No need for a calculator. This type of problem (1 in n chance of an event occurring, what are the odds of it occurring in m trials, when n=m?) converges to 1 - 1/e. The total number of failures adds up to 100% (it has to be to maintain the original odds), but some of those outcomes are multiple failures (i.e. 2+ parts failing on your million part machine). If you have 100 letters which you randomly put into 100 mailboxes, some of those mailboxes will get 2+ letters, meaning obviously that some mailboxes will not get any letters. As it turns out, it's 1/e mailboxes which get no letters, and 1 - 1/e mailboxes which get at least 1 letter.
I counted 8 systems where any problem at all would kill the mission:
Heatshield that has to protect, then deploy (or fall off in non-techno speak)
... and pay out slowly enough
... and detach when the lander is down safely
Guidance rockets that have to work just right
A parachute that mustn't rip or tangle
A hovering system that must balance,irrespective of any storms it may encounter
A winch that must not jam (after 40+ weeks in cold and vacuum)
and finally the hovering platform that must not run out of fuel and drop onto the lander, or think it's detached and fly off with the lander in tow (If they got that on video, I'd laugh for a week)
In short there are far too many ways it can fail, and far too many things that have to work perfectly. I think there's a bad case of hubris from having 2 landers out of 2 that not only survived the trip, but exceeded expectations. Sadly, I think this thing will even up the score.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
The only permanent, extra-terrestrial life-supporting, man-made object is the ISS. That needed 14 years of construction (predicted to last only about 14 more once it's finished), needed the Americans, Soviets, Europeans and Japanese to all abandon their individual projects and concentrate on only that, costs about 100bn Euros, and is 200 miles away.
The Moon is 200,000 miles away. Mars is 150,000,000 miles away.
There will be no short-term supply trips to give people several years worth of food (i.e. the time until we can send a "real" supply) - hell, food would constitute the vast majority of their payload because you won't be growing anything self-sustainable on the Moon/Mars for at least a year even under ideal "Earth-like" conditions simulated inside some kind of greenhouse (it's called farming - plant stuff, wait a year, eat it).
There's a hell of a lot less heat and you're going to be constantly pumping heat into a cold void in order to keep things at room temperature (considering we can just about rustle-up a handful of watts for the Mars rovers, or a couple of hundred for the new ones using radioactive materials, your heating bill is going to be... well... astronomical). We just about managed it for a handful of days in the past, for just spacesuits. The Apollo astronauts barely stayed a day.
There will be a bit more than the ISS's 10 major incidents in that time (not counting the VASTLY increased chances of problems with the travel outside the Earth's influence, landing and living on another rock that we can barely keep a rover running on) and no backup to send spare parts within weeks like we've done with the ISS.
Just think about the first few days - if you don't manage to ship enough stuff and people to build a air-tight shelter against the dust storms, warm enough to keep a human happy, pumped full of oxygen, large enough to hold decent amount of food, people and living space, in one of the most hostile environments that humans would ever have set foot upon, you're dead before you even start. That's assuming those humans even make it there - most of the stuff we've sent to orbit Mars hasn't made it at all or lasted anywhere near it's planned lifetime - the exceptions don't bring up the averages much.
Humans are literally two-three days away from death at any time. Rovers can live for decades and we can send 100 of them for the cost of one man (just in a single mission, if we so wanted). It was estimated recently that Apollo cost $170bn (adjusted for today) for a handful of people to walk on the moon for a day. The Mars rovers cost US$820 million originally, nearly $1bn with all the extensions. Curiosity costs about $3bn. That entire program cost less than 1-2% of the cost of putting a couple of men on the Moon for only a day.
Humans aren't built for travel. Wherever we go we have to take Earth with us. And that, quite literally, costs the Earth each time.