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User: athyr

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  1. Beal's Rockets Not For Mars Missions on Bigger Rockets For 'Heavy' Lifting · · Score: 2

    Everyone has been commenting about the importance of these rockets for possible Mars missions. As an astronomy major, I can say Beal's new rockets mean very little.

    Beal's BA-2 rockets use iquid hyrodgen as fuel. However, there are diminishing returns for the amount of fuel you pack into a rocket. The more fuel you have, the more thrust you need to lift it off the ground. Now this isn't too much of a problem for lifting sattelites into orbit. But for a Mars mission - you have to pack along a hefty amount of fuel for the return trip. Chemical reactions are not efficient enough to make this a reality.

    NASA's got lots of issues with the Mars mission. Check out these numbers:
    * The Mars trip would take 259 days - ONE WAY. There's no getting around this. It's called a Hohmann Transfer Orbit, and it's just not worth getting there any different way.
    * Being a science major, I work in metric units. So for all you nerds out there - it would take 2.11x10^11 Joules of energy to get a 1000kg shuttle to Mars. Now, I'm not sure how long the Beal rocket can sustain it's 810,000lbs thrust (stoopid Standard units), but that's A LOT of energy. That's not to Mars & back, just to Mars. And let's face it, they're going to have to carry a lot more than 1000kg (about 1 ton) of fuel for the return trip.

    My guess is that alternative fuels will be used to travel to and from other planets. Ion drive technology may actually become a reality for large-scale projects in the future. Who knows. But I think it's safe to say that Beal will be using their rockets as advertised - for commercial sattelites, not for Mars.