Mission to Mars Muscle Problem

The least-energy 'Hohmann' transfer orbit is okay for robotic spacecraft but it's ridiculous to expect humans to spend 10 months free floating in space (subject to various dangers including micro-meteors and solar flares), then spend a year exploring Mars and then spend another 10 months free floating in space -- in all nearly 3 years away from Earth -- just for some rock samples.

Conversely, a trip to Mars in a spacecraft having a constant 0.1 g acceleration (half the trip accelerating at 0.1 g; the other half decelerating at 0.1 g) can make the trip to Mars in only 21 days. The stay on Mars could be a more realistic period of, say, one month. Then another 21 day trip back to Earth. The entire trip would last less than 3 months. This type of trip does not expose the astronauts to the medical hazards of long-term weightlessness, and it dramatically reduces the exposure to the dangers of deep space -- solar flares, etc.

The key problem is, of course, fuel to maintain the constant 0.1 g acceleration. Recent rocket engine research has been finding new propulsion technologies. One of these technologies, coupled with robotic refueling supply ships stationed along the projected 'orbit', may provide the solution. My guess, too, is that the total cost for the additional refueling ships would be far less than the cost of a ship (or ships) and supplies to maintain a crew for 3 years.

The solution is a Solar Sail. constant acceleration, no fuel required. and the Japanese have proven it is possible. works great in the inner solar system where the solar flux is strong. can even provide solar power in the process.

There was a Kremer prize for Human Powered flight (Gossamer Condor)

There is the Sikorsky price for human powered Helicopter flight

and many other human powered technologies.

so this is a great opportunity for someone to design a human powered spacecraft... and that will provide exercise too.

Chris

I've done it sir! Me sir me sir!
Get 'em to pedal a big Wimshurst machine, the charged particles they strip off can be fired out the back of the space ship to provide propulsion. When the space ship becomes too heavilly charged in the opposte sense you switch to shooting out partcles of the opposite polarity.
And the electric field required to shoot out the particles?
Powered by their pedalling!
I demand a Nobel prize... No? How about a tin of Tuna?...
Ok well it's gotta be worth a GA ?
Del

ok, you get your GA. Actually that isn't a bad idea for powering attitude quads, put all of that juice into a supercapacitor bank and use the juice to power ion thrusters for stationkeeping and course correction (with a back-up power supply of some sort for when the guys are too busy puking their guts up due to a massive CME radiation dose.). But relying on it for propulsion might be asking a bit too much. The thrust would be unpredictable which would make astrogation a nightmare. Any excess power could go to operate the ship's systems. That additional power source might just come in handy for emergency situations as well so it could serve three interconnected functions, which is one of the requirements of aerospace design.

What about connecting them up to a TENS unit when they are sleeping? put em in a vest tied off to bulkheads with bungee cords and have them do electro-calisthenics while they are sleeping. Or put them each in a tube of say heavy water (for rad shielding of course!) or maybe something even denser and more viscous with a face mask (and a water intrusion alarm!) and let them work out in water while they sleep. It'll keep them clean and non-stinky too!

Maybe Barium Sulfate mixed with heavy water for the sleep tank... that should afford them some rad shielding as well as make the fluid viscous enough to give the muscles some resistance.

Don't forget -- conservation of angular momentum would mean that their pedaling would spin the spacecraft, providing pseudo gravity in the form of centrifugal force.

Maybe you should 'peddle' your idea to NASA.

a Wimshurst machine has two counter rotating disks so it SHOULD counter the reaction torque for the most part. AND it works best in dry atmospheres (to keep the charges from bleeding off) so I'd bet it would work even better in the vacuum of space. the disks could be mounted outside the cabin and the power could be transmitted through a mag coupling on either side of the cabin wall.

hee hee

you know when I wrote that I was thinking that even urinating off the back deck of the spaceship would provide thrust! lol I've never even heard of a wimshurst machine.. so thanks for the free education..

Chris

Just remember Chris, you get what you pay for. A free education is often worth no more than what you paid for it.

No........we'll give you the Nobel prize you'll be amongst your peers......I can see it now.

Captain: Every thing is working perfectly......We're making very good time...........Mars is coming into veiw............. time to start braking............

Scotty: Brakes? oh $hi#

Usbports suggestion of just reducing the travel time sounds like the best solution to me.

I seem to remember reading an article in new scientist about going to mars - the conclusion was that it would take so long to get there (I can't remember what their estimate was), that each of the crew would have a 50% chance of dying on the way from radiation poisoning.

I don't like the sound of those odds!

Unless we had made huge advances in radiation sheilding, why are we talking about sending anyone anywhere in space? Even the international space station gets some radiation sheilding from earth.

Thanks. Here's a link to an article about one of the new technology rocket (ion) engines:

http://www.newscientist.com/article/dn17476-ion-engine-could-one-day-power-39day-trips-to-mars.html?full=true

I also like the solar sail idea mentioned by Rorschach, but I haven't read enough about the concept to know what the expected trip time to Mars would be. Could a solar sail generate anything close to 0.1 g; also, could the sail be oriented to 'tack' into the solar wind for the return trip to Earth? I need to read more...

The Japanese Ikaros sail can only generate about a millionth of a G, but it does it continuously with no power input. But that is not to say that you couldn't put the vessel in a remote operated solar slingshot maneuver and then have a manned capsule catch up to it as it passes back by earth after it has picked up some speed.

Yes the sail can tack, and it can even be designed to hover. (Dr. Robert L. Forward came up with some innovative solar sail ideas before he died. He was Hughes Aircraft's resident "mad scientist" and was tasked with coming up with off the wall ideas)

Thanks for the links.

By the way, this might answer your question: Paul Johansson is John Galt

I just hope they do the book justice and not screw it up and make it look like BS.

Several possibilities come to mind.

It would be a fairly simple matter to build a spacecraft with a rotating crew section, thus using centripetal acceleration to simulate gravity. Of course the spacecraft would then be considerably larger, more massive and more expensive. None the less, it would solve the problem of muscular atrophy on long duration space flights. This type of craft has been imagined in countless science fiction novels and is fairly well understood.

A nuclear powered VASIMIR engine is a very nice idea. Even fairly low level continuous acceleration would drastically reduce transit times. While the limits of the technology remain to be seen, it is at least possible that such engines could be engineered on a scale which could produce significant accelerations, even for very large and massive spacecraft. This could perhaps be used with the type of vehicle mentioned above.

One technology which has been largely ignored for decades is the Orion nuclear pulse engine, in which small nuclear explosives detonated behind a heavy pusher-plate and shock absorber system could be used to provide acceleration. Such a technology could lift huge craft directly from Earth surface to orbit, and in open space could accelerate a spacecraft to upwards of .1c. And while I know that environmentalists will scream bloody murder at the very idea, our knowledge of nuclear explosives has progressed to the point where they are relatively clean and EMP can be minimized. Such a craft would be able to make the jump from Earth to Mars in a matter of days, rather than weeks or months with lesser propulsion systems. http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

As for shielding, there are several fairly simple solutions. One would be to cover the crew quarters with thick layers of shielding materials, such as industrial slag. This would of course add considerable mass and expense to the project. Another technology which has shown considerable promise of late is magnetic shielding. www.islandone.org/Settlements/MagShield.html

Obviously, a Hohmann transfer orbit with a minimalistic craft is the worst possible solution.

Spindle repair for NASA, trips to mars and beyond. We repair spindles used to create all of this awesome stuff. Really like the images (especially the teddy bear in a space suit).