ISS to Mars

[nesp]

Sorry if this has been discussed, but I recently read the following article, where Michael Benson argues for the ISS to be used as an interplanetary vehicle.
http://www.washingtonpost.com/wp-dyn/co ... 02394.html
Here is a blog on the idea
http://www.dailygalaxy.com/my_weblog/20 ... -an-i.html

When I first heard this I dismissed it due to the fuel needs, the resupply, the inbalanced flight configuration. But the more I considered it, the idea seems infinitely better than a $156B deorbit in 2016, 2026, or ever.

How about keeping it in orbit until we ready some ion thrusters to slowly but surely move it to low Mars orbit, where it can serve as a docking station for Mars landers? The ISS could be resupplied by a series of unmanned cargo vehicles that remain in low Mars orbit until the manned ships arrive to ferry supplies to the station.

May not be feasible for a long time, but if the ISS were to be boosted until we could move it to Mars orbit, it could be placed in a long lasting Mars orbit, which should not be too difficult given the low atmospheric drag.

So, is this a crazy idea, or might it be a good long term use for the ISS?

 

[kk434]

This is basicly good idea. But the ISS is too large and needs too much fuel to get to mars. However a smaller station would only need a smaller add on motor that would accelarate it to earth escape velocity. The whole concept is great, you dont need a HLV, only a couple of ISS size habitable modules that are connected in space plus a dedicated propolsion stage. I even think that the russians tried to go to mars this way.

 

[DarkenedOne]

This is basicly good idea. But the ISS is too large and needs too much fuel to get to mars. However a smaller station would only need a smaller add on motor that would accelarate it to earth escape velocity. The whole concept is great, you dont need a HLV, only a couple of ISS size habitable modules that are connected in space plus a dedicated propolsion stage. I even think that the russians tried to go to mars this way.

Exactly. That is what I do not get. If we can build space stations piece by piece with large commercial sized payloads than why can't we do the same thing with a interstellar spaceship. Ultimately spaceships and space stations have very much in common, in fact a spaceship can be considered a space station that is designed to move around.

 

[raptorborealis]

"This is basically a good idea'

No it isn't. It's ridiculous and shows a complete misunderstanding of what the ISS is.

 

[Floridian]

This is basicly good idea. But the ISS is too large and needs too much fuel to get to mars. However a smaller station would only need a smaller add on motor that would accelarate it to earth escape velocity. The whole concept is great, you dont need a HLV, only a couple of ISS size habitable modules that are connected in space plus a dedicated propolsion stage. I even think that the russians tried to go to mars this way.

"This is basicly good idea. But the ISS is too large and needs too much fuel to get to mars. "

Not true, though retrofitting it (not very retro as this was possible during the 1960s) with a nuclear pulse set-up would be hard, throwing a few nuclear reactors up there and using ion thrusters would be quite easy, but NASA refuses to use nuclear.

I have the found the idea of de-orbitting the ISS completely absurd and a huge waste. NASA is basically a waste of funds in my book and should be completely shut-down for their utter refusal to use nuclear and advanced technology, they have wasted decades of time and money.

Why not fill it with supplies and break orbit, at the very least floating is space is a much better alternative than de-orbitting all those years of launching materials and assembly. Its got solar cells too. It could be some operational. And with a nuclear reactor, we could just slowly move it until it can reach a Mars Orbit. Better than waiting 50 years for a rocket-fueled manned mission to Mars where we plant a flag and leave.

What would be cool is filling it with supplies, so when it finally reached Mars, it would be a refill station for astronauts and docking station.

This would lighten the load for when we send a manned mission later.

 

[nesp]

"This is basically a good idea'

No it isn't. It's ridiculous and shows a complete misunderstanding of what the ISS is.

That was my initial reaction. And there is little doubt that this is a ridiculous idea as long as the ISS is performing its intended mission. But we're not talking about what the ISS is today, but what it will be in 2016+ when it reaches its end of life. At that point, its only mission would be to become a flaming shower of debris as it burns up through the atmosphere.

The question then becomes, is there a better end for the ISS, an end that may be a new beginning for a different mission? We should at least consider raising it to a more stable orbit to buy time while we debate its end. 2016 is only 6 years away, hardly enough time to design compatible thrusters, but enough time to figure out how to keep it from decaying.

 

[raptorborealis]

It is a RIDICULOUS idea now and an equally non-starter in 2016 or in 2026.

It isn't going to happen because engineers at Nasa are not that stupid. ...and not because of a silly article in which the author claims it won't happen because the engineers lack imagination.

Good grief...this is the level of understanding of space technology in 2010? ....so sad.

 

[nesp]

It is a RIDICULOUS idea now and an equally non-starter in 2016 or in 2026.

It isn't going to happen because engineers at Nasa are not that stupid. ...and not because of a silly article in which the author claims it won't happen because the engineers lack imagination.

Good grief...this is the level of understanding of space technology in 2010? ....so sad.

Ok, so you think this is a crazy idea, which is the direct answer to the question I posed. Can you elaborate on the technical reason for this? So far your reasoning has been along the lines of the ISS mission and the intelligence or NASA engineers vs rest of us. And maybe you are right, so could you educate us?

 

[crazyeddie]

I think trying to save it by boosting it into a higher orbit is a good idea......but only because it would be a shame to waste all that hardware. But it was never meant to be an interplanetary spacecraft. It must be serviced and resupplied on a regular basis. And even if an ion engine could somehow be attached to it, it would take a huge amount of fuel and a very, very long time to gently boost it to an escape trajectory. Once it was in interplanetary space, it would lose the shielding the Earth's magnetic field provides. See, the thing about Mars is you need to get there fast, in order to minimize your exposure to solar and cosmic radiation. The ISS structure is just not suitable for this kind of mission.

 

[nesp]

I think trying to save it by boosting it into a higher orbit is a good idea......but only because it would be a shame to waste all that hardware. But it was never meant to be an interplanetary spacecraft. It must be serviced and resupplied on a regular basis. And even if an ion engine could somehow be attached to it, it would take a huge amount of fuel and a very, very long time to gently boost it to an escape trajectory. Once it was in interplanetary space, it would lose the shielding the Earth's magnetic field provides. See, the thing about Mars is you need to get there fast, in order to minimize your exposure to solar and cosmic radiation. The ISS structure is just not suitable for this kind of mission.

Thanks for the explanation. Some comments/questions. I realize the ISS was never meant to be an interplanetary spacecraft, we're talking about a salvage operation that might better than a flaming death. You say it must be serviced and resupplied on a regular basis. But you realize, we're talking about sending it unmanned to Mars? Would it need to be serviced and resupplied on such a mission? Assuming it has adequate fuel for maneuvers, is there a need for any other resupply? Same with the loss of earth shielding. If it was unmanned, would shielding still be necessary?

As far as the boost engine requirements, doing some rough back of the envelope estimates, the delta v required for a Hohmann transfer orbit to Mars would only be around 4000 m/s, which could be reasonably achieved even with today's chemical engines of ISPs in the 500s and fuel loads of 15-20,000kgs. The boost engine would have to line up with the center of gravity of the ISS, but we have to do this anyway for orbit boosts. This is back of the envelope, so maybe I'm off in a decimal place, but t doesn't seem a technical impossibility. Oh, double the fuel need for braking into a Mars orbit.

With Plan B being a fiery death, I don't unerstand the thinking that this is just a ridiculous idea.

 

[sxjenks]

Another point worth noting is that you could jetison a whole heap of unnecessary equipment, science gear and maybe even entire modules... A soyuz lifeboat for one won't be of much use... Turning ISS into a mars ship doesn't mean you have to take the whole thing with you!

Keep the frame, trusses, requied solar panels, 3-4 hab modules and ditch the rest!

 

[planetling]

Another point worth noting is that you could jetison a whole heap of unnecessary equipment, science gear and maybe even entire modules... A soyuz lifeboat for one won't be of much use... Turning ISS into a mars ship doesn't mean you have to take the whole thing with you!

Keep the frame, trusses, requied solar panels, 3-4 hab modules and ditch the rest!

Yes. And there is no reason that in the future more advanced hab modules couldn't be attached that would provide for shielding. And no matter how long it would take to build, at the current rate that NASA has been going, it would CERTAINLY be faster than waiting another 30, 40, 50 or so years.

The question becomes, how can we, the owners (tax-payers) of the ISS, persuade NASA to seriously consider this idea? Or is the space.com forum just a wishful thinking group without a voice? I don't mean to sound negative, I just don't know what impact this forum has, if even a small voice? Does it have a voice?

 

[Polishguy]

It simply can't be done. The ISS isn't built to handle the thrust of interplanetary injections. It's built to sit around in LEO, with an occasional low-thrust boost. And even if you reduced the weight by removing excess modules and Soyuz capsules, you'd have to add that weight back in solar panels, because at the distance of Mars, you need twice as much solar panel area to generate the same amount of power.

Besides, the weight of the propellant is mind-boggling. With chemical engines, you'd need about 1,700 tonnes of fuel and tankage to get the ISS to Mars. With Nuclear Thermal, you'd need about 1,300 tonnes of fuel, tankage, and reactor. With VASIMR, assuming half of what Chang Diaz said is true, you'd need about the same amount as Nuclear Thermal, but you'd get there two months faster. In any event, you'd need to launch 800 to 1,300 tonnes of propellant and tanks to Low Earth Orbit, the equivalent of either 5 Ares V launches, 7 Direct or Saturn V flights, 8 Energias, or about 30 launches of the Falcon 9 Heavy. Probably a bit more due to LH2 boiloff in vacuum. Total cost: $3 Billion, most optimistic estimate from SpaceX. And that's all assuming that the damn thing would survive the flight, and there's no guarantee of that. Since it spent its life in LEO, under the earth's magnetosphere, you'd need to add radiation shielding due to cosmic rays and solar flares, most likely increasing weight by 10%. Plus the aforementioned issue that it won't hold together. And for that same cost of launches, you could send either 3 chemical or NTR Mars Direct-style landings on Mars, or 5 VASIMR-powered flights. And all it would do is a manned version of the Mars Recon Orbiter, for more cost and less achievement. And the idea of using it as some sort of "docking station" for landers is just nonsense. What point is it to dock at a space station? Why not just take your transfer vessel (assuming there is one, because a Mars-Direct style mission would use the lander as a transfer vehicle on the way in) and dock with the Lander the easy way, i.e. track it down (as you must anyway) and fly to it without the stop at a space station. This is not impossible. Back in Gemini and Apollo, this is how they docked with the Agena target and the Lunar Module.

Now, there are uses for the structure. NASA is looking into using Node 3 for its asteroid mission. The Russians are thinking of taking their half and using it for a new space station. But using the ISS as a Mars station is just absurd.

 

[nesp]

Now, there are uses for the structure. NASA is looking into using Node 3 for its asteroid mission. The Russians are thinking of taking their half and using it for a new space station. But using the ISS as a Mars station is just absurd.

Well, I was just going to argue the other side, the difficulty of the idea, but you've done it much better than me. My initial motivation was not so much about using the ISS as an interplanetary vehicle, that thought came from the articles I posted. My motivation was against using the ISS as a $150B fireworks show. Reusing the structure for uses such as you mentioned seem like a very good idea. But you would still need to refurbish and maybe stengthen some parts, such as seals, shielding, etc. Thanks for putting numbers to the fuel needs, I was only looking at the delta-v required. I'm surprised that much is needed.

Bottom line, it can be done but would be costly and its utility in Mars orbit is questionable. But let's not let it burn up.

 

[Polishguy]

Well, I was just going to argue the other side, the difficulty of the idea, but you've done it much better than me. My initial motivation was not so much about using the ISS as an interplanetary vehicle, that thought came from the articles I posted. My motivation was against using the ISS as a $150B fireworks show. Reusing the structure for uses such as you mentioned seem like a very good idea. But you would still need to refurbish and maybe stengthen some parts, such as seals, shielding, etc. Thanks for putting numbers to the fuel needs, I was only looking at the delta-v required. I'm surprised that much is needed.

Bottom line, it can be done but would be costly and its utility in Mars orbit is questionable. But let's not let it burn up.

Well, my equation for mass estimates is a modified form of the Tsiolkovsky one. For total LEO mass, you take [mass of dry payload] x [2.72^[(delta-v)/[specific impulse multiplied by .0098 (accleration of earth's gravity in km/s)]]]. Then add a bit based on estimates for fuel tank weight, maybe 1/6 of the total fuel mass. My estimates were about 100 tonnes too high, but putting an additional 1,200 tonnes in LEO is still not practical.

BTW, you can also calculate the payload of a rocket to a point in space by dividing its LEO payload by the right half of that equation.

Now, let's brainstorm some other ideas of what to do with ISS modules. I'd think Bigelow could find a use for a Node, rather than building one himself. Zarya would fit best, but a combination of Node 1, a truss segment with solar panels, and a reboost stage, like the old ISS propulsion module suggestions in NASA, would fit nicely. If anyone's in the market to buy them, Kibo and Columbus can also find new life as private research modules.

 

[orionrider]

I think the problem is not so much of getting it there, but to get it to STOP there. It has not be designed to areobrake and the cost of an orbital injection burn would be prohibitive. VASIMR engines would not work since the giant solar panels don't provide enough power. The whole station is designed for science in low Earth orbit, not space travel.

 

[dryson]

Exactly. That is what I do not get. If we can build space stations piece by piece with large commercial sized payloads than why can't we do the same thing with a interstellar spaceship. Ultimately spaceships and space stations have very much in common, in fact a spaceship can be considered a space station that is designed to move around.

Actually I have been working on a design that uses the modules of the I.S.S. The design would work because it is based off of the I.S.S. modules. How the design would work is each habitat or science module would be connected linearly together with a specially designed airlock similar to the joint quest airlock. The airlock would not have the EVA extension just the portion that connects to the ports on the module. The inter-connection airlock would allow the design to be a straightline design instead crooked if the PMA is used.

Here is the link to the inter-connecting airlock and the Pilyhas-1 design concept.

Pilyhas-1

Inter-Connecting Airlock

 

[kk434]

The now canceled JIMO was to be nuclear electric powered and assambled in space. The ISS astronauts can assamble a couple of modules (near the ISS) and then there is a posibility to launch a huge interplanetary craft whithout a HLV.