Solar super-sail could reach Mars in a month

http://www.newscientist.com/channel/mec ... 524846.500

Sounds interesting, and if this is correct it could make things a lot easier for us!.

Just a month trip to mars.. not bad

I guess this will only be one way At least, the part about the month-duration.

Dr. Gregory Benford, in addition to being a respected scientist, is a well-known, award winning science fiction writer (including at least two Nebulas). I've had the pleasure of being on a panel with him years ago. He's a great guy and I am pleased to see someone with such incredible vision engaging in what has the potential to become a practical means of space travel.

Still a long way to go, however. Both figuratively and literally.

--Ralph

Ok, assuming they can build all the hardware required (microwave beamer included) then it should be great. But when it gets to mars, going like really really fast, wont it need to be slowed down before it ... y'know ... dives in?

If so, how can they do that bit?

DKH

I imagine they could slow down by turning the sail 180 degrees and firing the microwave beam again. If the special paint is only on one side of the sail, and it evaporates only due to heat, maybe it could be heated from the back. I don’t know enough about microwaves to know if this would really work though.

Damn that's a nice idea. Hey are you old enough to smoke? Somebody get this kid a cigar!

DKH

I am old enough to still have a slide rule. And I may even remember how to use it! But I don’t smoke.

But I am worried about how much the microwave beam would spread out at the distance of Mars. To focus microwaves tightly enough at that distance would require a transmitting antenna many kilometers wide I think. But it could be done with a phased array I would imagine. They could maybe even fit high power transmitters to the VLA.

Slide rule? SRA accuracy? Heh, heh... I remember that from my engineering student days back in the 60s. I still have my Post VersaLog. Never needs batteries!

--Ralph

Good for you, but if your age is so advanced that you still have a slide rule then perhaps smoking can't really do you any harm now. You should think about taking it up, it really annoys people most satisfactorily.

Do you think that it might make more sense in putting a beamer on the surface of mars ... or perhaps in orbit around mars might be easier to keep maintained. The difficulty of having a beam maintain coherency (?) over the large distances between earth and mars might be greater than establishing a beamer at the other end.

Heck, you wouldn't even have to turn the bugger (the sail) around then, just have your paint on both sides.

DKH

If they are going to make this work before I die, it will have to be with Earth based power. I can’t see such a large installation being placed on or near Mars any time soon, given how hard we find it just to get a few small automated space craft safely to Mars.

And I have been thinking a bit about their numbers. They say the space craft could accelerate to 60 km/s in only one hour. That would imply an acceleration on the order of 1 gee. I wonder how large a sail would have to be and how many kilograms of paint it would have to evaporate to get 1 gee of acceleration.

(EDIT) OH! It says a 100 meter sail right in the article. It does not say how large a payload though.

campbelp2002,

Slide rule? Huh? How old are you?

Old enough to have watched the Apollo (and even Mercury) missions live on TV. I once wondered if I would live long enough to see the almost magical year of 2001. Well, here I am. No manned interplanetary capability, no moon base, no orbiting hotels, no high speed monorails connecting cities, no robot maids, no flying cars. I believed that the future would be SO amazing. But it isn’t.

Gimme a couple years, I'm workin' on it! At least let me get outta college.

Oh. I'm sorry about that. I'm 20 and in college, so at least there's more hope for me.

OK.

I'm counting on you.

Don't let me down!