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Using Fuel Depots Instead of Giant Rockets
EccentricAnomaly writes "The New York Times has a story about a leaked NASA study that showed it would cost $80 BIllion less and get astronauts to an asteroid sooner if NASA used fuel depots instead of developing a new rocket. According to the article, NASA's response to the leaked study is to start developing fuel depots in addition to continuing its new rocket program. Because, after all, who doesn't need more cool stuff."
There won't be an astronaut on an asteroid. Forget it, get over it. We no longer have the raw energy capacity to spare for these kinds of grandiose stunts. Besides, we already know what's out there, we have pictures. Technology keeps getting better and better, there's no reason to send a person when you can send thousands of probes instead.
I doubt that any current rocket could make use of an on orbit depot, because 90% of all current rockets are discarded before orbit is achieved, not to mention that none of them are designed to be refueled after use (most rockets are ignited externally for example). It might just be that a new rocket is needed as well...
We could easily have both. Easily. Let me show you how:
NASA's budget: $18.724 billion (Fiscal Year 2011) (source: http://en.wikipedia.org/wiki/Budget_of_NASA)
Department of Defense's budget: $663.8
Which does NOT including Iraq and Afghanistan, which together are approximately $900 billion, and does NOT including the care for the approximately 33,000 wounded veterans those wars have produced... which is probably a few billion, but I couldn't find an easy source so let's just go with nothing. But remember it's there.
Adding those into DoD's budget gives: $1,563.8 billion. (source: http://en.wikipedia.org/wiki/Military_budget_of_the_United_States)
That means that DOD gets 83 times as much as NASA gets. They could reduce their budget by 1/83rd and double Nasa's budget.
A country needs defense. I get it. But seriously -- NASA is one of those organizations that, if your pour money into it, does AMAZING things. Things that give so much back to the scientific community -- things like computers, insulation, search and rescue, navigation, everything. So, so, so, so, so, so, so, so many technologies can be traced back to the space program... and while DoD are great inventors too, especially in medical treatment, materials, transportation... NASA gives so much back too and no brown people have to die.
Can't we just have a couple less B2 Stealth Bombers (B-52's bomb brown people just fine) and a couple less F-22's (F-15 Eagles still have never been defeated in combat) and GET THE FUCK TO MARS?
Check out my sci-fi book "Lacuna" at http://goo.gl/MVxX8
This is an old idea that should have been implemented long ago. Fuel tanks can survive much higher g-forces and can be built and launched relatively cheaply compared to satellites and personnel.
In fact, fuel is just about the perfect candidate for a mass driver where energy can be stored up and then released in a burst into a linear induction motor or similar technology. This means that much less expensive and less polluting energy sources can be used in the launch as opposed to most rocket fuels. It's also inherently safer since you don't have a 5000 degree F flame that you need to feed and control.
Once the fuel tanks are exhausted they can be converted into modules for space stations or spacecraft, probably much more efficient than building them to survive a re-entry to get re-used. Why waste all the energy it took to get them up there and the energy it would take to send up a pre-built module when you can design the tanks for re-use?
Yeah, there's a lot of complexity that I'm doing some hand-waving around but it's still a great concept that should be developed further.
Sapere aude!
You'll need to use less complex rockets and systems to haul fuel to depots, and since it's carrying only compact cargo costs by weight decrease also.
Big rocket systems are expensive and require lots of safeguards to handle human beings, or everyone would be killed or injured by the intense g-forces or by strong vibrations. Plus, space crafts that transport astronauts usually have lower density, so the cost by weight lifted increases.
The downside is, that there isn't that much experience in operating logistical infrastructure in space. Everything is a throwaway product, and the current space station is a joke as a science platform. And there is the nagging question of why maintaining such infrastructure just for human space flight if we don't have any other use for it?...
I don't get it. If you don't have a rocket to get astronauts to the fuel depot, what good is the depot? Can someone explain this to me?
The Daddy casts sleep on the Baby. The Baby resists!
Moderate Parent: +what
We are back to the discussion about if we should invest in a moon base or a satellite that sits between earth and the moon. IMHO a satellite would be a better investment.
Having to work for a living is the root of all evil.
Picture one of these coming down to Earth, crashing onto a playground at the largest kindergarten in the world, deep frying ten thousand little tykes in a hellacious ball of fire. Sure, it will never happen -- cause it will never be built. Actually, it WILL be built, right after the government fixes the economy.
Say did Arthur C Clarke patent the idea of using Europa as a fuel depot?
(I don't really think we have to worry about large black monoliths telling us not to go there
CONgress, namely Shelby(R), Wolfe(R), Hatch(R), Hutchinson(R), Coffman(R), Nelson(D), and many others, are pushing this nightmare. The only reason is not because they believe that it is needed for the space program, but these slimes have turned NASA into a jobs bill.
The good news is that by 2014, SLS will be dead. The fact is, that once SpaceX launches FH, no president will support. It does not matter whom is in office. The project will be dead. Hopefully, we will then hold a COTS for 2 SHLV. At the same time, HOPEFULLY, these above slimes or whomever replaces them, will continue funding for NASA to support nuclear engines (not for launch on earth, but interplanetary travel and perhaps launch on the moon and mars), private space, ISS partners exploration of the moon, and NASA continuing their push for BEO.
I prefer the "u" in honour as it seems to be missing these days.
Your panth are ugly because you keep thitting in them, you thithead! Thath why it smelth bad there.
It costh too much to send Americanth into space becauthe they are too fat and PIG DITHGUTHTING. Do you want a pitha? A hamburder?!
Yes, Bash.org was hacked. Apparently they shouldn't use IIS.
According to the article, NASA's response to the leaked study is to start developing fuel depots in addition to continuing its new rocket program. Because, after all, who doesn't need more cool stuff.
Undoubtedly NASA reacted this way because the US Congress has legislatively mandated development of a new heavy-lift rocket to preserve jobs in states with influential (Republican) senators, as a substitute for the cancelled Constellation program. It no longer matters what NASA itself thinks is the most efficient and technologically feasible solution. Even if the fuel depot plan would save twice as much, in practice it is ultimately subject to Congressional veto.
We need chemicals for a short time. BUT, for moving around in space, Chemicals do not provide much promise long term. Instead, moving to using solar to move cargo around LEO makes good sense. For humans, we will use chemicals to move humans, but far safer, faster and cheaper to use nukes in the moderate haul on. And as to launch, today, we use rockets, but that is going to change. Scaled Composites launch of cargo will happen in about 3 years or less. It will be a fraction of the costs of SpaceX. Likewise, it is certain that Skylon will work. Once it does, all companies will quickly change. Why? ECONOMICS. Space is no longer about access, but economics (which is why SLS will be dead sooner, not later).
I prefer the "u" in honour as it seems to be missing these days.
Space is no longer about access. It is about economics. The SLS is based on a design that was the best that we could nearly 50 years ago. Now, we can do much better.
I prefer the "u" in honour as it seems to be missing these days.
US has to have a huge military budget. Otherwise Canadians will invade Washington! (Not to mention the Mexicans.)
Pants are ugly because an ugly person pours him/herself into them every morning. (Well, on the mornings that he/she hasn't just slept in those panst!) If you were to lose about 180 pounds, you might find that you can get some nice looking pants, and you won't have to pay Omar in excess of $200 and a goat for each pair!
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
The fuel cost savings involved with inflight refueling are well documented and can run 40% to 60% in traditional military aircraft.
But we are not dealing with traditional gravity flow liquid fuels here and the logistical and safety issues combined with the costs of developing a safe LEO pressurized refueling system are staggering.
I wonder how well people are going to accept giant fuel bombs in LEO. I think the development of flying nuclear reactors might be easier to deal with.
It's an informational sabotage attack – the better question is, who's prurient interests are put in jeopardy in NASA if there is a staff military sheep dip of the type you do when performing manned space flight using missile technology. I'd back track the data if I was involved ...
The purpose of existence is to make money.
GET THE FUCK TO MARS?
Donate here. Convince your friends to donate also.
If they can't do it on donations, not enough people actually care about doing it.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Is leaked the new catchy term?
I do
No sig for you. YOU GET NO SIG!
Rockets are easy to refuel. Here's a nice example of plans (well under way, lots of stuff already flying) to make a modern re-usable, re-fuelable rockets:
http://www.space.com/13139-space-fully-reusable-rockets-works.html
"Every time I see an adult on a bicycle, I no longer despair for the future of the human race." - H. G. Wells
Fuel is a good candidate to launch with a high-g device, but a mass driver is not the most economical way to get it off the Earth. It is fairly easy to show that a pipe will cost less per foot than induction coils and a frigging huge power supply to feed it, for the same job of accelerating a projectile. Generally, these type of devices are called "hypervelocity guns", defined as when the muzzle velocity is hypersonic (ie more than Mach 5 or 1500 m/s). This is roughly twice the muzzle velocity of large military guns.
In 1993 I was the study manager at Boeing for using a large gun to deliver fuel to a depot, which then was used to send communications satellites to GEO. The savings was you needed 75% less conventional rocket to launch the satellite dry. Hypervelocity guns are not new, they have been used for ballistic and re-entry testing for about 40 years now. NASA owns several of them. Mainly they need scaling up and "industrializing" - setting them up for regular operations, rather than research use.
To reach the highest muzzle velocity, you want to use the lightest gas (Hydrogen), and heat it, so the speed of sound is as high as possible. Speed of sound is the same as speed of pressure waves in the gas, and when your projectile exceeds that speed, there is no way for the gas at the back end to affect the projectile any more, because it outruns the pressure waves. So the gun gets very inefficient at that point. To make hot hydrogen, it is easiest to store it at room temperature in pressure tanks, then run it through a heat exchanger before it gets to the barrel. There is nothing that goes "boom" like a small gun, it's closer to natural gas pipeline operations (in fact, we sourced the gun barrel from a pipeline maker in the study). Find a suitable mountain, such as Cayembe in Ecuador (the highest point on the equator, and the right slope), and put a 2 km long x 60 cm I.D. pipe pointing up. Load a 600 kg projectile about 4 meters long into it, and it will accelerate at 900 g's, and come out with a muzzle velocity of around 5600 m/s. You lose around 1 km/s of that to air drag, and then use an onboard rocket to finish getting to orbit. Net payload to orbit is around 100 kg, which does not sound like much, but if your launcher is at the equator, you can potentially launch 15 times a day to a single depot destination. Over the course of a year that comes to 550 tons (minus downtime for maintenance).
For launching people and delicate cargo, Hawaii is the best location. Assume a 20 km pipe x 10 m diameter, pushing a 500 ton vehicle. It works out the pressure in the barrel needs to be 2 atmospheres (200kPa, 30 psi). That gives you 3 g's acceleration, safe for humans and satellite parts. Muzzle velocity is 1100 m/s (Mach 3.6), which is not a huge fraction of orbit velocity, but a nice running start before you light up your on-board rocket. Given those starting conditions, a reuseable non-cryogenic rocket should have a payload of around 35 tons, which along with a 10 meter diameter should be plenty for any cargo or people you want to launch. This is the upper end of what you might want to build, for your first low-g cargo launcher you can go a lot smaller.
Here is the beauty. You never get really good at something unless you do it often. You need lots of practice. But currently we are stuck in a catch 22 with rockets. The payloads are very expensive so you want to make sure your rocket doesn't fail. This requires lots of money typically to verify everything.
Fuel delpts turn everything upside down. Now you are launching something cheap, fuel. You can make the rockets as cheap as possible and even with a few failures it's no big deal since you are only out cheap fuel. But even with cheap rockets if you launch them often enough you will get very good at it and reliability will increase as you identify problems.
This is great for NASA too since the majority of beyond earth orbit mass is propellant. It can launch they payloads dry and do that on much smaller and cheaper rockets. Also it can just pay for fuel delivered to the depot. Any failures are on the customers dime.
I love Jesus, except for his foreign policy.
Oh grow up & recognize that pork is non-denominational, will you? Democratic sponsors of STS like Nelson show that your attempt to blame republicans making democrats shoulder their part of responsibility for this flying pig are futile.
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
Did you read the report? It was comparing the cost of SLS launched missions to the moon or an asteroid, with depot enabled versions of missions to the moon or an asteroid. They weren't trying to argue that every rocket in the world is refuellable, nor even most, they were saying that launching a LTO transfer stage empty, then fuelling it in orbit, is cheaper to develop and fly than building a Really Big Rocket.
You can launch a 100 ton lunar transfer stage on SLS, say, with a 25 ton dry weight and 75 tons of fuel.
Or, you can launch the 25 ton stage empty on a Falcon Heavy or a Delta IV Heavy, plus three fuel missions on similar rockets, and it will cost billions of dollars less. (Their scenario is more detailed, obviously.)
SLS is an expensive and harmful way to do these missions. It actually makes us less likely to go beyond Earth orbit, and wastes two to three decades and many tens of billions of dollars doing so.
Science is all about firing a drunk pig out of a cannon just to see what happens.
Fuel depots seem like an interesting idea. Except for the boil off of cryogenic fuel.
Makes me wonder though about collecting solar wind and distilling the ions down to something that could be used for reaction mass, perhaps less than a fluid more like a plasma. Then accelerating that for drive thrust.
On the other hand (due to the recent viral video on youtube) what about using the Meissner effect to collect and redistribute magnetic flux tubes already in space. If I understand the idea.. chilling something down to make it superconduct could act as a drive plate and generate thrust when it expels magnet fields in various ways. Probably not great for human space flight but maybe a way of generating a reactionless space drive while within a magnetic field.
He died 11 miles away from his next depot/supply dump in Antarctica.
This does not come up in a lot of these conversations, but we have a "fuel depot" in orbit right now. It uses storable propellants, not cryogenic ones, but nobody says you cannot leave LEO with nitrogen tetroxide and unsymmetrical dimethylhydrazine (UDMH). In fact, that propellant combination was exactly the one being used to land on the moon in Apollo program.
The fuel depot on orbit of course is ISS Zarya or better known as FGB. It gets fuelled up by Proton's on a regular basis, and ISS uses the propellant for station keeping. Considering the mass of ISS, boosting its orbit is no small feat.
Russians also have a spare module, used to be called FGB-2 sitting somewhere in the hangar. It was proposed as various additions to ISS at some point.
In summary, storable hypergolic orbital propellant transfer is a well known, well developed and currently used technology. Yes you need quite a bit more of it to do burns with delta-v in order of km/s, but the maturity of the solution and abundance of off the shelf engines and propulsion module designs using hypergols may well outweigh cryogenics in overall system designs.
Propellant is also relatively cheap, even nasty stuff like hydrazine, and just lifting more of it would provide the much needed demand side for the globally stagnant launch industry, which has been in the oversupply mode for years, i.e. there are far more operational rockets than there are paid payloads.
The point that "propellant depots" is nothing new, and in fact NASA's current flagship HSF program uses it needs to be made more often. Switching to cryogenics would be a new development even if not that complicated, and may or may not be worth it, depending on overall mission requirements and other elements of system architecture.
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I was always running out of fuel!
Has everyone forgotten that corrupt congresscritters have MANDATED BY LAW that NASA develop the new, poorly designed rocket system. http://news.slashdot.org/story/10/05/15/1237208/senators-demand-nasa-continue-spending-on-ares
They're the problem, so far it appears they still need to be machined out of aerospace grade Unobtainium, and have some pixie dust sprinkled in the intakes for good measure.
Why build one when you can have two at twice the price?
With a new rocket and fuel depots, we can get to freakin' Pluto.
And for those Sea Steaders, the ocean platform based variant (which might be much cheaper to locate/build but suffers from being at sea level atmosphere pressure), using a neutrally buoyant gun pipe, see
http://www.quicklaunchinc.com/
Instead of Hawaii (you really want to be *that* close to active volcanos?!), what about a tunnel built through the rockies, say Las Vegas to Tulsa and increasing the acceleration to 5Gs? That'd give you 13km/sec on a 1072 mile tunnel. Make it a maglev and you could call it "high speed rail" for tax breaks.
We all know the preeminent rocket design group is Congress. Stop it with this "science" and "engineering."
I've lost count of the number of times I've posted the following to /., well anyway another try with my idea, a further thought, if we can control robots 70 odd million miles away on Mars, why can't we control mining robots an average of 238,857 miles away on the moon, some estimates have put the amount of oxygen in moon rock at 40%, there is also aluminium in moon rock. As well as being able to create rocket fuel from water, you can also create rocket fuel from oxygen + aluminium.
The high cost to the human race's colonisation of space is caused by the complexity and danger of reaching and leaving escape velocity within the earth's atmosphere.
The Space Shuttle turned out to be an expensive and dangerous white elephant, the reason the Shuttle was so expensive is, because of its complexity with millions of different manufactured parts, and the need to cover it with the equivalent of bathroom tiles.
There is another route, we can reach the edge of space no problem Burt Rutan proved this with Space Ship one, when he won the 'X' prize by reaching over 100 km twice in one week.
Yes the Shuttle was 'reusable' but in name only. They could not have turned that around in a week.
What NASA should be doing is creating rocket fuel on the moon, there is lots of water on the moon, use solar energy to split water into hydrogen and oxygen, which when combined make very good rocket fuel, because of Newton's third law.
Use the rocket fuel to fuel a space tug, use the space tug to accelerate and decelerate Space Ship one, to and from escape velocity in the safe vacuum of space, no atmosphere = no friction = no heat = no bathroom tiles and no foam shielding on the external fuel tank.
Less bathroom tiles + insulation foam = less rocket fuel = less pollution in the Mexican Gulf.
Once we can accelerate and decelerate space craft with rocket fuel that is obtained from outside of the earth's gravity well, space travel becomes cheaper by many orders of magnitude, ok the capital cost would be very high, but once the systems are in place, the number of human beings, living in space increases exponentially.
A good example for the way very high capital cost projects work, is the Panama canal.
It's called an elephant's trunk whereas it is in fact, an elephant's nose, a nose by any other name would smell as sweet
Or at least build a factory for the oxydator (liquid O2) on the moon and launch the kerosene or hydrazine fuel from earth. The Oxygen atoms are the heaviest so to launch those fuel tanks from a surface with 0.16 g gravity would save a lot of the tanker launch costs. Could be almost half as cheap as launching both together from the 1 g Earth gravity well like in the propellant depot study. :-(
You'd need to build the lO2 tanker rockets on the moon, though
To be, or not to be: isn't that quite logical, Slashdot Beta?
Yeah marvellous idea, but surely it would be cheaper to send up hydrogen in a balloon from the surface of the earth, it seems to want to head in that direction already.
Thanks for the improvement to my idea!!
Many years ago I read a scifi story, that proposed a big dome on the moon full of breathable air, that because we would only weigh a 6th of what we do on the earth, we could strap on a big pair of wings on and truly fly like a bird.
Let us make it so.
It's called an elephant's trunk whereas it is in fact, an elephant's nose, a nose by any other name would smell as sweet
I find it incredible that one of the most amazing feats that a civilization could hope to achieve (ie manned space exploration), is such a highly polarized topic. Do you think if the economy wasn't in the shitter that people would be complaining as much?
We can't fully automate mining here on earth. I doubt it's going to work 238,857 miles away. We need a manned base on the moon for that (not that you wouldn't want to automate as much as possible.
I for one would be glad to serve a tour as a moon miner.
The DoD space budget is already around $17 billion (fluctuates higher and lower). The money that isn't, or wasn't, directly paid to NASA for launches and such basically takes over what NASA would have had to pay for if the DoD hadn't. So consider NASA's budget effectively doubled.
So, so, so, so, so, so, so, so many technologies can be traced back to the defense spending too. The DoD budget even pays for building, launching and running our GPS system.
Did you plan to use a ramjet or scramjet stage and how would that affect the cost?