NASA Wants Spacecraft For Mars Return Trip 193
coondoggie writes "If we ever do get to Mars, getting home might prove to be as difficult. NASA today selected three companies — Alliant Techsystems, Lockheed Martin and Northrop Grumman — to being the task of defining the spacecraft that will leave Mars, presumably at first loaded with red planet rock samples, then later possibly humans — for a safe trip back to Earth. The engineering challenges those three companies face are immense."
One Way (Score:4, Interesting)
Pale red dot (Score:4, Interesting)
"There does not seem to be sufficient short-term profit to motivate private industry. If we humans ever go to these worlds, then, it will be because a nation or a consortium of them believes it to be to its advantage" -Sagan
Please see the Case for Mars... (Score:2, Interesting)
...Robert Zubrin 1996 http://en.wikipedia.org/wiki/The_Case_for_Mars for a decent affordable, credible, realistic and possible plan.
Then, if anyone reading this knows Elon Musk, please send him a copy.
Re:WTF (Score:4, Interesting)
Huh?
We have ways to get to Mars just fine. An Atlas V 541 is enough to get the massive MSL Curiosity Rover there, and a measly Atlas V 401 is plenty for the Maven orbiter coming after that.
The hard part is getting back. I imagine grabbing resources from the surface and air to create rocket fuel while performing its mission will be the right way to go.
A Mars Sample Return is where the Mars program is headed, and we have a roadmap to get there. And it will force the development of In-Situ Resource Development (ISRU), while will be of huge benefit to all future manned and unmanned programs.
Getting ahead of themselves (Score:5, Interesting)
Before they start working on how to get OFF of Mars they need to figure out how to get ON Mars. A couple of years ago I found this article (sorry, lost the original link).
Getting Large Payloads to the Surface of Mars
by Nancy Atkinson
July 17th, 2007
Some proponents of human missions to Mars say we have the technology today to send people to the Red Planet. But do we? Rob Manning of the Jet Propulsion Laboratory discusses the intricacies of entry, descent and landing and what needs to be done to make humans on Mars a reality.
There’s no comfort in the statistics for missions to Mars. To date over 60% of the missions have failed. Even among those who have devoted their careers to the task, mention sending a human mission to land on the Red Planet, with payloads several factors larger than an unmanned spacecraft, and the trepidation grows even larger.
Why? Nobody knows how to do it.
Surprised? Most people are, says Rob Manning the Chief Engineer for the Mars Exploration Directorate and presently the only person who has led teams to land three robotic spacecraft successfully on the surface of Mars. "It turns out that most people aren’t aware of this problem and very few have worried about the details of how you get something very heavy safely to the surface of Mars," said Manning.
He believes many people immediately come to the conclusion that landing humans on Mars should be easy. After all, humans have landed successfully on the Moon and we can land our human-carrying vehicles from space to Earth. And since Mars falls between the Earth and the Moon in size and atmosphere, it should be easy. "There’s the mindset that we should just be able to connect the dots in between," said Manning.
The real problem is the combination of Mars’ atmosphere and the size of spacecraft needed for human missions. While the Apollo lunar lander weighed approximately 10 metric tons, a human mission to Mars will require three to six times that mass, given the restraints of staying on the planet for a year. Landing a payload that heavy on Mars is currently impossible, using our existing capabilities. "It’s this ugly, grey zone", said Manning, "There’s too much atmosphere on Mars to land heavy vehicles like we do on the moon, using propulsive technology and there’s too little atmosphere to land like we do on Earth. Until we come up with a whole new system, landing humans on Mars will be an ugly and scary proposition."
In 2004 NASA organized a Road Mapping session to discuss the current capabilities and future problems of landing humans on Mars. Manning co-chaired this event and the major conclusion that came from the session was that no one has yet figured out how to safely get large masses from speeds of entry and orbit down to the surface of Mars.
"We call it the Supersonic Transition Problem," said Manning. With our current capabilities, a large, heavy vehicle, streaking through Mars’ thin atmosphere only has about ninety seconds to slow from Mach 5 to under Mach 1, re-orient itself from a being a spacecraft to a lander, deploy parachutes to slow down further, then use thrusters to translate to the landing site and finally, gently touch down.
When this problem is first presented to people, the most offered solution, Manning says, is to use airbags, since they have been so successful for the missions that he has been involved with; the Pathfinder rover, Sojourner and the two Mars Exploration Rovers (MER), Spirit and Opportunity.
But engineers feel they have reached the capacity of airbags with MER. "It's not just the mass or the volume of the airbags, or the size of the airbags themselves, but it's the mass of the beast inside the airbags," Manning said. "This is about as big as we can take that particular design."
In addition, an airbag landing subjects the payload to forces between 10-20 G’s. While robots can withstand such force, humans can’t. This doesn’t mean airbags will never be