View Full Version : A Cheap Solution for Getting to Mars?

2009-Jan-08, 05:00 PM
The space shuttles are slated to be retired in September of 2010. NASA put out a call recently to ask what should be done with the shuttles post-retirement, and many think they should be put in museums or on display in rocket parks. But futurist and entrepreneur Eric Knight, (founder of UP Aerospace [...]

More... (http://www.universetoday.com/2009/01/08/a-cheap-solution-for-getting-to-mars/)

2009-Jan-08, 05:26 PM
Cool. Scrap the descent to the surface and send the guys into an orbital mission, a la Apollo 10. It would be useful for many kinds of experiments.

2009-Jan-08, 05:29 PM
A one-way journey with mostly existing hardware... It's so crazy it just might work.
(I'm not volunteering).

2009-Jan-08, 06:08 PM
What about designing a lander and stowing the lander in one of the shuttle cargo bays?

Ivan Viehoff
2009-Jan-09, 12:31 PM
Just not big enough, Swift.

While landing a large object on Mars is a huge headache, part of the reason it is such a huge headache is that you need something rather large to get back off the Martian surface. That is what makes any realistic human return trip to Mars much, much bigger than this. Getting back from Mars is much trickier than getting back from the Moon, because Mars has a lot more gravity. So getting back off the Martian surface just can't be done with the little thing that got the astronauts back up off the moon. So you have to get rather a large payload onto the Martian surface, without breaking it, or exploding the fuel, in order to be able to get back off it again.

Getting back from Martian orbit to earth obviously requires quite large quantities of fuel and food/water supplies for the astronauts, so it makes sense to have a pre-supplied return vehicle in place in orbit around Mars, which the astronauts and return cargo from the surface transfer into. That greatly reduces the payload you must get up off the surface, and hence what you have to land on it. Probably you send this return vehicle to Mars separately in advance. This has the benefit of reducing the payload needed on the outbound transport ship. Though maybe you can reuse it if you have a system for refuelling and resupplying the transport ship in Martian orbit. You will also have to be clever enough to achieve the necessary rendezvous between the Martian lift-off vehicle and the return vehicle.

This is why any feasible human return visit to the Martian surface is going to require a much larger fleet of spacecraft and payload than a couple of space shuttles. But he does at least agree with one common conclusion of anyone who studies this problem. Getting all this payload up off the earth in one go in the first place is a problem. It is not going to be practically done in just one launch. He does it with 2 separate space shuttles, but in reality many more launches are likely to be required.

Wernher von Braun tried sizing all this back in 1952. He reckoned we need to put about 1000 space-shuttle-sized loads into orbit around the earth. Techinical progress means we could probably do it rather more economically these days. Though as an order of magnitude assessment, it is probably still fairly valid.