What about this earth based ISRU?

One ISRU thought is to break up lunar water by electrolyses and then to use the O2 at least as propellant. But as far as I understand it the other compenent to be used is the H2.

Both elements are used by some launchers at Earth too.

At least one XPRIZE team had the concept to launch out of the ocean (Interorbital System)

Would it be possible to place a launcher in theocean, let it electrolyse water it is surrounded by and extracted and launch it then - but using water only up to an altitude from where it will come down to the ocean again as rain?

Is that possible in principle?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

yes, it is possible, but no its far from practicle. First you need to electrolyse the 'h2o' into O2 and H(2). Then you would need to liquify the H2 by cooling it to 21 Kelvin and then you can rocket it to where you want it to go. And then i'm not even talking about the salt and other waste products you get from the salty seawater.

Btw, check this:
http://www.lr.tudelft.nl/DARE/Galleries ... s-test.htm
liquid methane and oxygen

The thought behind the idea merely was that the reaction products of the burn during flight would be available as water for following flights instead of going lost into space.

Another thought was that the vehicle of Interorbital systems wouldn't be a danger fro the environment anymore - it's using Wight Fuming Nitric Acid currently.

The third thought is that the propellent would have to be delivered to the launch site.

The sat wouldn't be a problem - it would be a useful by-product which can be sold at the markets and this way resulting in revenues which would contribute to covering the costs.

So the major "problem" would be the cooling and liquifying of the hydrogen. Currently this is done on land - are the equipments that heavy that they can't be used within the oceans? What about installing them at the ground or let them dive as deep as they do simply because of Physics?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

First of all, i don't have a clue how big they are, but i imagine that they could fill a big truck. You could do it, but in the end, it's no better then how they do it now. It takes a long time to electrolyse a lot of hydrogen and then liquify it. Before you could launch a rocket, such a system would probably spent a week electrolysing all the hydrogen and then you have to liquify it. Not to mention you need a huge ass tank

It's a nice thought, but simply impractical. There is no advantage to use such a system on the water, you would also need a cleaning installatino first.

Alright - there is a fourth idea connected with it. If ISRU should be used at Mars really it needs to be tested. This could be done this way although it tends to be looking extrem etc.

As far as I know at Mars - and at the moon too - water is going to be brought up really and the got hydrogen and oxygen ar going to be used as propellant then. May be that I am wrong concerning Mars and the idea is to create methane by involving the martian CO2.

You mentioned methane as the better solution - do methane + LOX result in water too?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

The process on Mars works by reacting carbon extracted from its atmosphere or frozen CO2 deposits with hydrogen made from the Mars water ice to make the methane. This will result in Oxygen as a by product.

Another thing to consider with having a O2/H2 plant at sea on your rocket launch platform is the obvious risk that arise. By putting everything together you not only loose your rocket if there is an accident you use your whole facility as well.

I'm not sure if the term better would be fit, but as i understand it, current rocket fuel is total garbage for the envornmint, methane is not. I honestly don't know what the result would be, but i guess CH4 + O2 will make water with a bit of carbon or carbondioxide.

About the water on Mars. I hope it's primary use is not fuel, but more for use on the surface

Certainly. In fact--that was Bob Truax's idea behind Sea Dragon.

His idea was to make very large, but very simple launch vehicles that were pressure-feds.

Sea Dragon was to put 550 tons in Low-Earth Orbit (ISS in one shot). It was to be towed out to sea with only RP in the first stage, with LOX for both stages and hydrogen for the payload and upper stage taken from sea-water. Now he was going to use an aircraft carrier to split the water into LH2/Lox--but that seems unlikely.

I always thought that Sea Dragon would be better for the Russians to pursue, for the following reasons:

1.) Russian shipyards are hurting--and space money now going to Baikonur's Kazakhs would go to Russian ship builders instead--so every dollar spent on space also helps re-build their maritime industry. Now the Russians are trying to build new carriers--a stupid waste of money.

2.) The Russians are disposing large submarines, whose hulls would be perfect Sea Dragon Components with some mods. Ship-breaking costs a lot of money--this is why a 30 mile stretch of beach in Alang India--with workers being paid $350 US PER YEAR have become so attractive. Perhaps they could build Sea Dragon.

3.) The Russians have powerful nuclear powered icebreakers like the ARKTIKA with dual reactors good for cracking water. The Sea Launch tow vehicle used to tow the Zenit oil/launch platform should also be able to pull Sea Dragon. The Russians have no fear of size when undertaking new projects.

As you can see, gigantism is taking hold of the 'oceaneering' industry. We are using large oil derricks for X-Band radars. Such derricks might also be useful for Space Elevator platforms.

To truly revolutionize space--we must apply these lessons learned to the space industry.
A Russian/Chinese Sea Dragon would bring new life to shipworkers, give us $250 per pound cargoes, have free hydrolox propellants from the sea cracked by ARKTIKA and towed by the Sea Launch tow-and-tracking ship. Space Elevator cables would be launched by Sea Dragon, to link with oil derricks below.

So the Sea-Space connection all works together.

For large scale Space Solar Powersats, this way is best. Also--when it comes to interstellar craft, Sea Dragon also works. Project Orion needed a mega booster to get it above most of the atmosphere--and a launch site in mid-ocean reduces envio concerns. Plus, the heavy submarine-like construction lessons of Orion would first be learned for Sea Dragon--allowing General Atomics a back-door way to re-awaken that program .

Large Nuclear Salt Water Rockets (NSWR) would get their water from the ocean as well, with only the uranium salt in the payload and kero in the first stage placed aboard Sea Dragon. The water for the salt mix and the LH2/LOX for lower stages could be had for free. What is more--the NSWR has both high thrust and high specific impulse, and unlike Orion, is much simpler and yields a steady 1g thrust. So with a little uranium salt, a little kero--and a whole lot of free sea water--you could have a true starship, whose technology is no more advanced than the fuel injection in your car.

So we could learn a lot from the shipbuilding industry. We need more of a naval model for space. The Soviets used the Medaris type Army method--where OSP EELV was the Air Force model.

People have asked me what the biggest difference between Soviet and American space forces. I could go into launch vehicle design, about how the R-7 was brilliant in that it is wise to build rockets bigger than you need them as opposed to playing catch up, etc.

But I usually go back to one point--the difference between US and USSR programs was this. The Reds were smart enough to keep their Air Force the heck away from space, where our blue-suits ran it right into the ground. It is time for a naval model.

It is time we built spaceships.

Hrmph. I'll have to think that one over. The AF logically has the most experience with things that go fast, but the Navy knows how to operate individual vessels thousands of miles away from the nearest availiable port... The Army's out of the running, since their specialty is blowing stuff up (a very bad idea if you're in a space vehicle): the only use they have for missiles is for long-range artillery.

Trouble is, anything that flies must be light weight. The old "Voyage to the Bottom of the Sea" flying submarine is impossible because it can't be both heavy enough to sink and light enough to fly.

Sea Dragon would actually pop like a cork out of the water--same as that submarine that all but breached like a whale under the Japanese fishing vessel. The sub survived--but the ship didn't.

Here is more on Sea Dragon and family:

http://www.astronautix.com/lvs/searagon.htm
http://www.up-ship.com/apr/extras/seadr ... dragon.htm
http://www.up-ship.com/ptm/market.htm Model wish list!!

What really killed SD:

The design was reviewed with Todd Shipyards, who concluded that it was well within their capabilities, and not too unlike making a submarine hull. 8 mm thick maraging steel was used, similar to the Aerojet 260 inch solid motor of the time. NASA Marshall gave the Aerojet designs to TRW for evaluation. TRW fully confirmed Aerojet's costs and engineering, a great surprise to both TRW and NASA. Aerojet was considering purchasing Sudden Ranch as a launch site for Sea Dragon. This property included several kilometres of coastline between Santa Barbara and Vandenberg AFB. This was the only site on the continental United States that could launch directly into a polar orbit without overflying populated areas (and was later incorporated into Vandenberg).

But this came just as Apollo was being cut back and the Viet Nam war was eating an ever greater amount of the US budget. NASA dissolved their Future Projects Branch (dropping almost all the manned Mars landing work). Prospects for Sea Dragon essentially disappeared, and Aerojet could no longer fund it on IR&D.

http://www.globalsecurity.org/space/systems/sealar.htm


And here is more on Medaris.
http://www.astronautix.com/astros/medaris.htm

All missiles are forms of artillery in the truest since--and should have remained under the Army. Medaris wanted Phil Bono type troop rockets. The Air Force wanted runt space fighters. Medaris book Countdown For Decision is a good book about how the Air Force muscled in. The Soviet launch facilities were run by artillery-men up until very recently. Their model was closest to the Medaris model.

And that is clearly a winner:

http://www.moonminer.com/CATS.html
http://www.russianspaceweb.com/soyuz_lv.html
http://www.zarya.info/index.htm