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Innovations in Space Launch Systems
WolfWithoutAClause writes "Its long been a dream of people to just fly into space in an airbreathing aeroplane, however this has sadly remained as science fiction. The main problems have been a) collecting air at mach 23 requires that most expensive material: 'unobtainium' ; and b) having to carry extra airbreathing equipment into orbit. New Scientist has an article on a new study that NASA is funding to investigate whether an airbreathing launch vehicle might in fact be possible."
Inexpensive space travel is well within our reach if we but take heed of the lessons taught by ancient sci-fi classic Flash Gordon.
All you need to get to another planet, never mind just into orbit, is a toilet roll tube, a sparkler and a funnel or perhaps a bit of rolled card to make the nosecone of your intergalactic spacecraft.
Of course they used old-fashioned sparklers back then, modern ones would be too feeble compared to the old ones that would take your arm off if you weren't careful lighting them...
grab your ankles bitch
Water is extremely heavy. I guesstimate that you'd have to have at least one body mass of water per human. (yes, I did pull that number out of my arse. Thanks for asking.) This halves your human carrying payload capacity. The advantage, of course, is that you now have water in orbit, which is a very useful commodity. (we'll assume that the scrubbers and such can purify the water from when people piss themselves on takeoff...)
The bottom line is this...it takes a certain (and very large) amount of energy per pound of stuff to get said stuff into orbit. Right now, chemical rockets are the most cost effective way to do it. I think that until skyhooks and/or space elevators come into the picture, space travel is going to have a hard time breaking the $100/lb barrier. (Right now, the cost to launch stuff in the Shuttle is in the neighborhood of $10,000/lb, and the next generation SSTO craft are around $1000/lb IFF they meet their performance goals, which they almost certainly won't.)
Why yes, I AM a rocket scientist!
Keith Henson got a patent on a very clever space launch technique. You put the payload on a several mile-long tether trailing behind a large, heavy aircraft like a Boeing 747. You then fly the plane in an arc that cracks the whip. The payload goes into LEO. The cable isn't re-useable (it tends to burn up), but cables are a lot cheaper than many alternatives.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
There's no way to add extra padding to your brain. It still has to slosh up against your hard skull. Also, your organs slosh against your rib cage, et c.
This sets a hard maximum limit on the level of acceleration that a human can survive.
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Gathering while on the back of the 747 seems like it's going to cost you most of the advantages of collecting the oxygen in the air. About the only reason I can see that this might actually work is that you can replace the weight of the 747's fuel with the oxygen while you're doing the gathering. On the other hand, I'd expect that more energy goes into the speed than the 5 mile altitude, so you're still going to need a lot of fuel to make it the rest of the way into orbit.
An effective 50-75% reduction in effective fuel volume could make for a big gain with realtime oxygen harvesting. (I don't have the math, but I'm sure that someone else could do it).
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Free Software: Like love, it grows best when given away.
Perhaps the best article (4 pages easy reading) for the average slashdot reader is the one that How Stuff Works put up here.
Some information: It takes $10,000 per pound to put something in orbit. NASA's intent is to reduce it to below $1000/pound in 25 years. They way to do this is to get rid of the ~1,000,000 pounds of liquid oxidizer that wouldn't be needed for air-breathing rockets (which will use air instead, duh).
An air breathing rocket is very similar to a jet engine, except that a jet engine overheats at about Mach 3-4.
MOST IMPORTANTLY, Air-breathing rockets DO NOT have the thrust to achieve lift off. The intent in the future is to use conventional rockets up to Mach 3-4. Then switch to air-breathing until Mach 10, then return to conventional rockets for the spaceward journey.
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I'm just an ordinary man with nothing to lose.
Actually, this has already been proposed from NASA. The following is from here:
Further out, NASA is developing a plan to launch the air-breathing rocket vehicle by using magnetic levitation (maglev) tracks. Using maglev tracks, the vehicle will accelerate to speeds of up to 600 mph before lifting into the air.
Following liftoff and after the vehicle reaches twice the speed of sound, the air-augmented rockets would shut off. Propulsion would then be provided by the air-breathing rocket vehicle, which will inhale oxygen for about half of the flight to burn fuel. The advantage of this is it won't have to store as much oxygen on board the spacecraft as past spacecraft have, thus reducing launch costs. Once the vehicle reaches 10 times the speed of sound, it will switch back to a conventional rocket-powered system for a final push into orbit.
Because it will cut the weight of the oxidizer, the vehicle will be easier to maneuver than current spacecraft. This means that traveling on an air-breathing rocket-powered vehicle will be safer. Eventually, the public could be travelling on these vehicles into space as space tourists.
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I'm just an ordinary man with nothing to lose.
I've seen this type of device described in Ben Bova's _Welcome to Moonbase_ book. Later I read about it in Heinlein's _The Moon is a Harsh Mistress_. Heinlein's reference is the oldest I've found. Does anyone know who originally thought it up?
Speaking of the moon, I thought I'd revive a legendary /. troll classic from the immortal streetlawyer, Have fun!
.. the next time you're out in the backyard exercising your Second Amendment rights, the liberals will see it! These satellites are sensitive enough to tell the difference between a Colt .45 and a .38 Special! And when they detect you with a firearm, their computers cross-reference the address to figure out your name, and then an enormous database housed at Berkeley is updated with information about you.
The "Moon": A Ridiculous Liberal Myth
It amazes me that so many allegedly "educated" people have fallen so quickly and so hard for a fraudulent fabrication of such laughable proportions. The very idea that a gigantic ball of rock happens to orbit our planet, showing itself in neat, four-week cycles -- with the same side facing us all the time -- is ludicrous. Furthermore, it is an insult to common sense and a damnable affront to intellectual honesty and integrity. That people actually believe it is evidence that the liberals have wrested the last vestiges of control of our public school system from decent, God-fearing Americans (as if any further evidence was needed! Daddy's Roommate? God Almighty!)
Documentaries such as Enemy of the State have accurately portrayed the elaborate, byzantine network of surveillance satellites that the liberals have sent into space to spy on law-abiding Americans. Equipped with technology developed by Handgun Control, Inc., these satellites have the ability to detect firearms from hundreds of kilometers up. That's right, neighbors
Of course, this all works fine during the day, but what about at night? Even the liberals can't control the rotation of the Earth to prevent nightfall from setting in (only Joshua was able to ask for that particular favor!) That's where the "moon" comes in. Powered by nuclear reactors, the "moon" is nothing more than an enormous balloon, emitting trillions of candlepower of gun-revealing light. Piloted by key members of the liberal community, the "moon" is strategically moved across the country, pointing out those who dare to make use of their God-given rights at night!
Yes, I know this probably sounds paranoid and preposterous, but consider this. Despite what the revisionist historians tell you, there is no mention of the "moon" anywhere in literature or historical documents -- anywhere -- before 1950. That is when it was initially launched. When President Josef Kennedy, at the State of the Union address, proclaimed "We choose to go to the moon", he may as well have said "We choose to go to the weather balloon." The subsequent faking of a "moon" landing on national TV was the first step in a long history of the erosion of our constitutional rights by leftists in this country. No longer can we hide from our government when the sun goes down.
Cui peccare licet peccat minus. -- Ovid, Amores.
The problem with these technologies is the amount of money it takes to develop them to working examples. The solution? Make it _worth_ investing the large sums of money.
The current launching market is too small to support large R&D efforts. The rate of commercial launches is dropping steadilly with the dissolution of market drivers like Iridium. To make it worth the while of companies like Lockmart to spend big bucks on space you need to make space appealing to the industries that would purchase cheap access to space.
The first step is not to spend $10 billion for a Venturestar (which will never get congressional approval). The real step is to make the Space Shuttle as cheap as possible in the short term so that business in space can get started. Here's how:
1. Remove government restrictions on using the shuttle fleet for commercial operations. This reactionary restriction that came in the wake of the Challenger incident hurts our future in space and forces companies to use expensive ELVs.
2. Give NASA the chance to profit. Any commercial money NASA ever makes is funneled straight back into a general slush fund. If they had a direct incentive to operate more like a business, they would start innovating.
3. Switch from toxic hydrazine to high energy cryogenics for the OMS. Hydrazine safing is part of the huge delay and costs in maintaining the shuttle. Insulative technology has progressed in the 30 years since Hydrazine was chosen to a point where LOX and Hydrogen (or higher temperature fuels) can be stored on orbit for the duration of a shuttle flight.
4. Remove the expensive to maintain and toxic fueled APUs that (among other things) run the hydraulics that power the control surfaces during gliding flight. Use electric pumps powered off of fuel cells instead. After this, Hydrazine would be limited to the RCS and much easier to safe.
5. Convert the Enterprise into an unmanned cargo launcher. Removing the life support, crew cabin insides and so on and automating it would drop the between flight costs and increase payload significantly. Use this to deliver things that don't need human interaction to orbit.
6. Re-activate the Centaur upper stage project and install the plumbing in at least two of the OV fleet. Cryogenic upper stages increase your payload to geosynchronous orbit and let you build things like transfer vehicles to the moon. The shuttle uses IUS solid upper stages that have a fraction of the performance.
7. Last and more importantly, commission the development and construction of LFBB (Liquid FlyBack Boosters) to replace the dangerous and low performance SRBs. Liquid fueled boosters would increase the payload to orbit, offer abort modes during the first 2.5 minutes that the SRBs don't (see the Challenger disaster for an example of where this would have helped) and could be a lot cheaper then dragging the solid steel SRBs out of the ocean and rebuilding them. Boeing wants to make LFBBs. They would land themselves on a runway and be ready for launch shortly afterwards. LFBBs could lower costs for other boosters like the Titan V, the EELV, Ariane 5 and more.
Once companies can afford to get stuff to orbit, the market will exist to develop the new space craft that will drop costs to where we want. Until then, it will be entirely dependent on how much pork a congressman will get.
I would add a third thing more critical thing:
3) launch often
Economies of scale nearly always reduce cost; there's no known reason why that won't extend to space also.
The question is, is there anything about this idea that can reduce the standing army normally needed with rocketry? Clearly there is because this technology seems fully reusable, unlike the space shuttle; secondly this launch platform may well be further away from the bleeding edge of performance because it has two liquid fueled engines. That will help to keep costs down.
Incidentally, energy isn't the problem in rocketry; the real question here is takeoff mass- is it reduced or increased with all this mucking about? I expect that that's really what the study will be looking.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"Actually, they don't, and haven't for some time. This is an old myth that's trotted out anytime someone brings up the Space Pen, but the Russians use it too. Here's a link that both talks about the Apollo 11 story and shows Russian cosmonauts with the pens:
Apollo 11 Space Pen Story
I've heard (although this is unverified) that the problem with the pencils was graphite dust getting into the machinery--or at least the potential for it.
No relation to Happy Monkey
>you still have the same volume of stuff to get into orbit
Not true:
a) you're higher up (this is hardly any help- 93% of attaining orbit involves going sidewise very fast, the other 7% is going up 70 km or so.)
b) the atmosphere is thinner so there are less aerodynamic losses
c) rocket nozzles generally like less backpressure which you get at higher altitude
Other points:
1) energy budget is irrelevant for rockets- rockets don't conserve energy in the sense that most of the energy ends up in the exhaust.
2) takeoff weight is crucial for the aircraft part- once in the air the weight of fuel is often supported by aerodynamics, on the ground it has to be supported by metal that you have to carry with you later
3) range control is going to be a lot easier, the rocketry can happen over ocean and it won't land on someones head
4) this proposal is fully reusable, normally rockets are not very reusable
Scramjets? That's where unobtainium comes in doesn't it?
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"you should read all those links man
I am become Troll, destroyer of threads
Yup, that's the idea behind Mitchell Burnside Clapp's Black Horse rocket plane. It was published in the 1995 Analog. I guess it made too much sense for NASA to even give it a try.
Rather than use LOX, his original plan called for burning JP-5 and highly concentrated hydrogen peroxide. That was the densest combination of propellants he could find, so would take the smallest amount of tankage. And, because it didn't involve any cryogens, it could use lighter non-insulated tanks. Lighter spacecraft == a chance at single stage to orbit. Here's an excerpt from the Analog article:
Because off-the-shelf rocket engines that use H2O2 are few and far between, he later changed his plans to use LOX. This would mean more changes in the tanker, but would avoid using unproven engines.
Clapp eventually founded a company to develop the concept, Pioneer Rocketplane, but I haven't heard much from it lately. That's too bad. It was (is) a great concept.
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"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
The "Avatar" script has been floating around the net for a while. Anyone care to post a link?
Free Hans!
According to FOX we didn't even go to the moon, so what makes you think airplanes can fly above the atmosphere?
"TV said that?!" -- Homer Simpson
std::disclaimer<std::legalese> sig=new std::disclaimer; sig->dump(); delete sig;
It doesn't sound perfect.. First, you have to fly around for a few hours, collecting oxygen.. Then, you still have to carry all that collected fuel into orbit. Finally, the complexity of the "breather" will cause a lot of flights to fail in the "flying around" stage, and that's a big no-no for space tourism. Imagine cancelling the flight after you've been circling for 6 hours already?
The ideal "breather" vehicle would be making liquid oxygen in "real time", i.e. as it's flying toward the orbit. That way, it would never have to carry any extra LO around, making things cheap for real.
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Never underestimate the bandwidth of a 747 filled with CD-ROMs.
There has been extensive research on this:
;-)
Including, but not limited too:
1)This Article in Scientific American
2)This Reasearch Paper
3)This NASA report
Just FYI
I am become Troll, destroyer of threads
I hear they'll have to make the ship out of Adamantium, and use some Vibranium in the engine room.
What is this with Science imitating Comic Books, these days; I kept looking for the "It's Funny, Laugh!" section on this one!
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pb Reply or e-mail; don't vaguely moderate.
pb Reply or e-mail; don't vaguely moderate.
The last paragraph says a lot about this concept. They may end up with a net energy loss.
The problem with Horizontal Takeoff, Horizontal Launch designs is resident time in air. Most boosters launch on a pretty vertical trajectory to get above the energy-robbing atmosphere. They do pitch over in the air, but only to use gravity to do most of the work for them. Boosters even launch up, reach a local maximum altitude, then decend under power in order to obtain the very large velocity required for orbit. Getting this velocity in air gives a lot up to drag.
This idea gets around the mass penalty for heavy landing gear by gaining weight in the air. Aircraft landing gear accounts for about 3% of the maximum total takeoff mass. This is for sufficient strength in a takeoff abort situation.
Pretty clever, but I think complicated machinery that requires extensive maintainance won't get us into space cheaply. The price of space travel is largely the cost of people on the ground. It takes about 10,000 people to service the Space Shuttle, hence its cost. LOX is cheap, and so is LH2.
It will be interesting technology, but I disbelieve that it will lower the cost. To get into space cheaply, I think we need to do two things:
1.) build it big.
2.) build it simple.
After all, NASA spent thousands to get an ink pen to write in space. The Russians used a pencil...
SatelliteBoy
Dump NASA!
NASA has been screwing up space flight for decades.
Private companies have long been willing and able to develop cheap commercial space flight, if only NASA wasn't involved. They wrap fifty tons of red tape around any project. Similarly troublesome agencies exist in practically every country with a space program. Since NASA went to the moon, every government thinks they must be doing things right, so they model their agencies after them.
But just look at the space shuttle: the ultimate hangar queen, and so damned complicated that one little easily-overlooked mistake causes the whole thing to blow up. Just look at that monstrosity: underpowered main engine, so solid rockets are needed to launch, extremely heavy frame drastically cutting down payload, etc. . Now, it's pretty good for their first try at a reuseable vehicle, but instead of learning from their mistakes and building something better they decided to build several copies of this disaster. Hell, even the Russians beat them at it: building one that could fly without humans onboard (sure they had the advantage of seeing the American one, but so did the Americans, after building the first one!).
Don't get me wrong, there are lots of smart people at NASA, but they are all stepping on each others' toes on a handful of projects. Every damned NASA toy is designed by committee, guaranteeing inefficiency and lots of failures.
Space flight isn't that hard! The V2 rockets were space-capable, and the Nazis were pumping them out by the thousands during war-time shortages, 60 years ago. All these years later, we ought to be able to produce orbit-capable rockets for the same price or cheaper. We would be able to, if a small team of good rocket scientists were given sufficient freedom and money to build a factory for these things (the price of one shuttle-launch would suffice).
Except for government intervention, any number of companies would have already done so. Wilder plans, such as beam propulsion and space catapults would follow quickly. We'd have people living on the moon and mining asteroids within the decade.
The question is, is it unintentional incompetence, or do governments prevent space travel because of their love of "stability"? It's all well and good to have one tangled bureaucracy sending out the occasional Mars probe, but having a million people living free up there who could drop big rocks on the old countries is enough to give anyone concerned with defense the screaming heebie-jeebies.
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Isn't that how it was done in the "Rama" series by A.C. Clarke?
I am become Troll, destroyer of threads
Also, the strain on the capsule and it's contents would be IMMENSE. This method would pretty much be suitable only for delivering durable, non-mission critical, components to orbit.
That said, this would still be of immense use for delivering structural components to orbit, like strusses for the ISS. But think of the logistics of this. The "barrel," the initial propulsion corridor, would have to be parallel to the equator, to avoid complications with the rotation of the earth perturbing the trajectory of the projectile. To avoid complications arising because of the curvature of the earth, you would want to construct it as close to the equator as possible. This means south america, or africa. Areas that have neither the infrastructure nor the political stability to bear a two to five mile long shaft, propelling by some means, a capsule.
Add that to the fact that the area immediately under the barrel's mouth, and the area under the capsule's flight path until it reached high atmosphere, would be regularly devastated by the sonic boom, and the fact that the elictricity neccesary to power such a maglev tunnel would be prohibitively expensive, and you'll find that this plan, while it sounds nice at first, is not going to fly. It's been being batted around since Jules Verne used a cannon to shoot a man to the moon in one of his stories, but the sad truth is that the future of orbital transport does not lie with the cannon.
--Use this space for notes--
After all, NASA spent thousands to get an ink pen to write in space. The Russians used a pencil...
[Spider Robinson story about space pen replacing switch snipped; read it at the Official Space Pen website. For the record, there's no mention of this incident in the exemplary resource Apollo Lunar Surface Journal.]
In the rest of his article, Spider uses the space pen, and other by-products of space-race research, to justify the support of basic research by government in the face of opposition from pork-barrelling politicians like Senator Socksdryer.
But the Space Pen was developed entirely by private enterprise. Fisher does claim that they spent $2 million (in 1960s dollars? doesn't say) to develop the pen, but we can assume those development costs have been repaid many times over.
Also, many Russian cosmonauts now use the Space Pen; and American astronauts have used a variety of writing implements, generally chosen by the astronauts themselves. The ALSJ does relate one mention of the Space Pen: Aldrin says he had a felt-tip pen that put out more ink than the Fisher pen.
The space pen is neither an example of government procurement gone mad, nor an example of return on investment, except for the Fisher company.
The original Spider Robinson article. Despite the attribution to Aldrin, I believe we have to take this one with a grain of salt. The Apollo 11 mission has been very closely studied for a generation.
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lake effect weblog
{Network engineer in Chicago--looking for work!}
Chairboy wrote:
3. Switch from toxic hydrazine to high energy cryogenics for the OMS. Hydrazine safing is part of the huge delay and costs in maintaining the shuttle. Insulative technology has progressed in the 30 years since Hydrazine was chosen to a point where LOX and Hydrogen (or higher temperature fuels) can be stored on orbit for the duration of a shuttle flight.
4. Remove the expensive to maintain and toxic fueled APUs that (among other things) run the hydraulics that power the control surfaces during gliding flight. Use electric pumps powered off of fuel cells instead. After this, Hydrazine would be limited to the RCS and much easier to safe.
I wrote:
Hydrazine replacement is being considered for Phase III of the ongoing Shuttle Upgrades program. It should be noted that the decision tree NASA uses for Shuttle upgrades places safety first, supportability second, reliability and maintainability third, and cost-reduction last.
That last remains true, but I was wrong about the upgrade status. The $1.6 billion upgrades program that Congress approved last fall includes $224M to eliminate hyrdrazine in the Shuttle APU and $208M for the SRB, though the OMS will apparently continue to use it.
Look for these upgrades to be incorporated into flying orbiters late in the coming decade.
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lake effect weblog
{Network engineer in Chicago--looking for work!}
I have not much experience with kites except for my own childhood experiments, but it seems to be difficult to get a kite to fly really high. The problem is that the wire will be dragged by the wind, so when you release more wire it will not necessarily make the kite fly much higher (most of the movement will be horizontal).
Now, using a really big kite, you will of course be able to get higher, as you don't need to double the surface area of the wire to double it's strength. I wouldn't know, anyone who knows enough physics to do some calculations? How about atmospheric conditions, etc...
Still, I can't start to imagine the size and forces involved in this, we are talking about using a kite as a launching platform, right? You are going to launch rockets from this thing. In a jet-stream... Or were you just thinking about putting wings and a big wire on a rocket, and drop them when you were high enough?
Seriously, a former USAF captain proposed a hybrid air-breathing vehicle which would be fueled with LOX once in the air by a modified KC-135 at least 7 years ago.
The guy who came up with the idea has since left the USAF and founded a company solely for the purpose of commercializing the concept.
The primary difference between the Black Horse concept and the one proposed in this article is that it wouldn't take three hours for a Black Horse-type aircraft to collect the LOX necessary to fire its rocket motor(s). They'd take on the LOX from the KC-135 while airborne in presumably less than three hours.
Put simply, you build a long (2 miles?) maglev shaft and then fire a capsule atlong it. It should reach escape velocity and at the propitious moment be flung of the end of the tube at a speed allowing it to reach geostationary orbit.
NASA have done research showing that although building the long shaft would be expensive initially, thereafter, per flight, costs would be very low.
I think that it is really the concept to replace the space shuttle, as it would give us a cheap way of getting into space for an expensive initial investment.
--Anticipation of a New Lover's Arrival, The
It is too obvious a joke to have originated in an unproduced movie script. I've heard it from so many sources that I suspect any "definitive" claim about its origin is constructed from pure weapons-grade bolognium.
Anyway, upsidasium is a far superior material for building spacecraft.
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Some applications don't care about this, and I expect you're correct in thinking that if the actual launch cost went down, that might lower the barrier to some companies, and of course there are some things where you actually need the Shuttle, but there will still be many, many applications for which the Shuttle is not a cost-effective launch vehicle. It's a two-edged sword: the Shuttle is great because it's a manned vehicle, but it's also terrible for the same reason, and there's no good way around that.
Just my 2 cents. :-)
Snopes has the true story of the space pen. Interesting story, it's nice to know the truth.
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Xenu loves you!
Okay, so we have to worry about how much fuel is used up trying to fuel up the orbiter. We also have to worry about the launch vehicle's aerodynamic qualities both with and without the orbiter attached. Sure, the project is getting funded decently, but would that money be better spent trying to get a launch vehicle that can also enter orbit (like the space plane that we have already spent quite a lot of money on)?
Perhaps an aerospace engineer can explain to me whether this would be workable or not.
Disclamer - Opinion of Person