New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

rpshadow · 2004-02-07 11:08:28

I apologize if this has already been posted here. I am new to this board. Of course I am no scientist and I am sure that you have already considered this, but I feel it is my duty to bring it up anyway.

The President is interested in creating some "Crew Vehicle" to go to the Moon and/or Mars, etc. Since funding is being cut on the space station, my question is this:

Why not use the space station as your spaceship? You already have HAB modules and other pieces that could make the station even more useful in this endeavor. For instance, why couldn't NASA prepare some of the following modules to assist them in this endeavor?

Propulsion: One or more modules connected to the station which would propel it to its destination. The propulsion would have to be gentle and be able to run for extended periods. Obviously, the ION engines we already employ would be the first to come to mind.

Habitat: You already have designs for this.

Longevity: Add storage for supplies and necessities. The Italian-named modules do this already.

Command and control: This module would be new. It might be located at the front of the station and would essentially be used as the "Cockpit" including enhanced telecommunications, an excellent view, and complete control over the craft's navigation and movement.

Descent Module: This would also be new and would probably be duplicated a few times so as to offer multiple descents. I would envision a Lander with some cargo capability attached to the station for planet or moon landings.

So, to summarize. You add some of the logistic modules, a propulsion module, a cockpit module, a couple of Lander craft and a habitat module (already designed) and voila'! You have your spaceship. It just seems silly to put all of this money into a whole new breed of craft (Especially considering funding for ISS science missions is decreasing) when you can simply add the appropriate modules to an already good design!

Although I'm positive there are some very good reasons why this cannot be done, my hope is that I can do whatever I can to help NASA's endeavors. Even in my very tiny way.

Thanks for your consideration.

Ryan Mcmillen
ryan@mcmillenonline.com

John Creighton · 2004-02-07 12:46:18

The space station should have been built this way. However, I don?t think it is designed to withstand the stresses.

rpshadow · 2004-02-07 14:46:03

But wouldn't the stress of something as subtle as an that of an ION engine be barely noticeable?

Rxke · 2004-02-07 17:39:24

sure, but the travel time would become very long... Look at ESA's ion driven moon probe, it will take months to reach the moon. That's ok for unmanned stuff, but not for manned vehicules...

rpshadow · 2004-02-07 17:54:20

OK, that begs two questions

1) since the progress modules are already used to raise the ISS to higher orbits, then I assume the station can handle certain stresses. Why not use a derivitive of the progress to propel the station out of orbit and to such a speed that the IONs can take over once the Progress is depleted?

2) I read that the ION is not a good choice for short hops (the moon) for the very reasons you mentioned. However, the same article noted that longer planetary missions would benefit due to the extreme distances. The ION gets up to a speed greater than conventional methods after a certain time. Let me research this.

rpshadow · 2004-02-07 18:15:39

From Space.com

The ions travel out into space at 68,000 miles (109,430 kilometers) per hour. But Deep Space 1 doesn?t move that fast in the other direction because it is much heavier than the ions. Its cruising speed is closer to 33,000 miles (53,100 kilometers) per hour.
The thrust itself is amazingly light -- about the force felt by a sheet of paper on the palm of your hand.
"If you want a mission in which you want to reach your destination in a hurry or accelerate quickly, ion propulsion's not for you," Rayman said. "It takes four days to go from zero to 60 (miles per hour). I like to say it's acceleration with patience."
But once ion propulsion gets going, nothing compares to its acceleration. Over the long haul, it can deliver 10 times as much thrust-per-pound of fuel as more traditional rockets. Each day the thrust adds 15 to 20 miles (25 to 32 kilometers) per hour to the spacecraft's speed. By the end of Deep Space 1's mission, the ion engine will have changed its speed by 6,800 miles (11,000 kilometers) per hour.

That means the ship could gain 500MPH every month. If a ship started out at 10,000mph we could be up to 16,00MPH within 1 year. 24,000mph in two, etc. That's cruisin!

Rxke · 2004-02-08 02:37:43

Again yes and no...

When they boost ISS, either with a Progress or the Shuttle, to alleviate stress on the station, they have to 'unlock' the solarpanels, they essentially get switched off and are rotated in a direction that minimises stress. That's ok for short 'hops' but ISS needs those panels for power, and it would be very inconvenient to keep them unorientated to the sun for longer periods. Also, once in leo, there is simply not enough propellant left in the Progress (may payload is some metric tonnes, but not all of that is propellant)
The rather big mass of ISS would require quite a bit of propellant to get it out of LEO, and there's no simple/cheap way to get it all to the station in one go... And multiple launches would not be possible, for there is not enough free docks to attach numerous Progresses.

(Too bad, i sometimes play with the idea, too...)

Aetius · 2004-02-08 07:32:33

The Russian 'Mars 1989'-class solar electric spacecraft is one of my favorite designs for a piloted interplanetary vehicle. It has a radial symmetry like the Mir space station had, and uses large farms of solar panels to provide power. It also relies on xenon-fueled ion thrusters for primary propulsion.

This ship is very much an extension of your "Space Station With A Rocket Attached" concept. In fact, if you look closely, you can clearly see similarities to Mir.

I understand the logic behind Mars Direct, but as a thing of sheer beauty, I'd rather be flying this girl around the inner solar system :

[http://www.astronautix.com/craft/mars1989.htm]http://www.astronautix.com/craft/mars1989.htm

I'd love to see an updated version of this vehicle. It could utilize inflatable components wherever feasible. I'd also like to use abundant, less-expensive, argon or krypton fuel instead of the 165 tons of vanishingly scarce xenon originally called for.

I don't like the short-duration surface mission the Russians call for, however. Seven days on the surface of Mars does not produce enough science to justify the expense of building this kind of vehicle.

I still think it's a beautiful ship, though. Just not in a streamlined, 1950's-esque, Hollywood kind of way.

'Marspost' is a new Russian design which, as we Americans say, "super-sizes" the original 'Mars 1989' idea. I don't think that the "Battlestar Galactica" scale of 'Marspost' is desirable or necessary, however.

With regard to the ISS, though, I personally don't think that the huge redesign and retrofit efforts would be worth the expense. Honestly, it really would be cheaper (and safer) to design and launch a new Mars ship from scratch.

Hazer · 2004-02-08 21:44:08

Well, as I have heard from a fellow at NASA-the ISS 1) Doesn't have the necessary radiation shielding 2) Couldn't withstand enough acceleration to leave LEO

rpshadow · 2004-02-08 22:05:46

Well, I guess that's good enough for me. Thanks for answering (in my mind at least) my question.

John Creighton · 2004-02-18 10:39:04

So, at first glance, it doesn't look fesiable. Still, I'd like to here some further exploration. What needs to be done to make the ISS flight worthy. Is the trus strong enough? What might be done to strengthin it? Is there enough radiation shielding? How might we impove the sheilding? Can we counteract the effects of zero g on the space station? Do the solar panels generate enough power to drive an ION engine and still run all the other systems? How might we better suport the solar panels to deal with accelerations? At over 100 billion could you realy build a ship of the same size form scratch, cheaper then the cost of modifying the ISS?

sethmckiness · 2004-02-20 02:05:10

I think the ISS serves it's purpose, if it is ever finished and fully staffed. There is plenty of long term zero-G Micro-G research that could be done. Plus getting people to pay for research to be done etc.. Finish it, get it done. Leave it there.

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#1 2004-02-07 11:08:28

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#2 2004-02-07 12:46:18

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#3 2004-02-07 14:46:03

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#4 2004-02-07 17:39:24

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#5 2004-02-07 17:54:20

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#6 2004-02-07 18:15:39

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#7 2004-02-08 02:37:43

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#8 2004-02-08 07:32:33

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#9 2004-02-08 21:44:08

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#10 2004-02-08 22:05:46

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#11 2004-02-18 10:39:04

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

#12 2004-02-20 02:05:10

Re: New Vehicle? We already have one. - Why not use the ISS for Moon/Mars?

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