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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!
I don't know about anyone else, but I remember reading about an Alchemist device in the book "Reality Dysfunction", and it was an anti-matter drive. Just a thought... =)
"To many, a tux is something you wear for formal events, to those of substance, Tux is a symbol of freedom." --sandalle
actually we call it unobtainium also. Kind of like titanium
Ryan
This idea doesn't make a hell of a lot of sense to me. (and it should...I'm in my senior year of aerospace engineering...)
There is a certain amount of LOX that you have to have to combine with your H2 to sling a pound of stuff into orbit. If you harvest that LOX from the atmosphere (schlepping your LOX generation along with you as dead weight) or tank up on the pad (and leave said dead weight on Earth) you still have to have the same volume of stuff to get into orbit. OK, you do get a nominal advantage in that you don't have to lift your LOX from 0 to, say, 60,000 feet, but considering you're needing to go up about 10x that far, this is not a big advantage. (I have the same objection to piggyback rockets like Pegasus and Burt Rutan's X-Prize entry...the air breathing craft does not give your spacecraft a substantially better energy budget than just launching from the surface. I guesstimate that you might get 10% more useful payload by using an air breathing first stage)
Scramjets (supersonic compression stage ramjets) are nice, because they have very few moving parts. (like, about zero.) They are not nice because you have to have a very large frontal area to collect enough air to combust the fuel, AND you still have to carry a conventional rocket engine to boost you into orbit (where there ain't no air to breathe). The key problem is that you cannot use the area rule to decrease your supersonic wave drag...the frontal area of your craft must be large relative to its weight. (Area ruling occurs when you keep the cross sectional area of an airplane close to constant along its length. I don't know why it works, but in the 60's the Convair Delta Dagger was converted into a supersonic interceptor simply by giving the fuselage a little bit of a coke-bottle shape)
Anyhow. Conventional rocketry is messy and expensive, but it's currently the best thing going. I hope that this will change in the future...I've got high hopes for electric and light powered spacecraft. But I don't think we're going to get away from chemical propellants and oxidizers in the near future.
Why yes, I AM a rocket scientist!
well, before you use it for commercial flights you make sure the breather (condenser?) is reliable. Complexity!=high failure rate. It's an engineering problem. And I'm not sure, but some fuel is saved by using the air breather to get some speed and a lot of altitude right? Not to mention the taking off from regular airports thing. and on a side note != is three keystrokes only one keystroke savings over not equal and really takes longer. Strange finger reach. Oh well.
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).
--
Free Software: Like love, it grows best when given away.
If filled with vacuum, then you have a real problem when the spacecraft hits the heavy metal plug sealing the end of the tunnel.
If it's sealed with an amazing plug that disappears just at the right time, then you have a problem finding all the pieces when the craft explodes having hit the equivalent of an air brick wall at mach 25.
If the tunnel is constructed vertically so the other end is in an area of very low air pressure, then it needs to be much more than two miles long, and it would be very, very difficult to build. Where 'difficult' tends asymptotically towards 'impossible' for current values of 'today' tending towards 'tomorrow'. This is the hazard of reading these sorts articles in discarded copies of "modern biker". :)
If at 'regular airliner' speeds, then all you've done is buy yourself 8000m and (say) 600 kts, which is pretty insignificant. For traditional vertical launchers, this is not a huge part of where their delta-v goes.
If the two craft stay attached and generating oxygen until they reach orbital speeds before the orbiter 'zips into orbit', then how does the launch craft prevent itself burning up? If it has thermal tiles and all that stuff, and it's right there at orbital speed (or close to it), then why not just have a single craft.
There is no valid argument that the cost saving comes in the self-production of fuel oxidizer, as LOX is incredibly cheap.
The only saving seems to come by having smaller landing gear on the orbital vehicle than would be required if it carried the oxygen generator itself - a saving that is probably outweighed by the additional complexity of the whole arrangement. If they separate at airliner speeds, then the orbital vehicle needs to carry a huge amount of oxidizer anyway.
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?
Its the expensive initial investments that stop all too many good ideas from getting past bugeteers in congress.
is that plain cream cheese tastes a lot better and is not prone to explosions. huh?
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!"It would be a great idea, except for this pesky atmosphere. You'd have to be at orbital speed+enough extra to get thru the atmosphere, and since you can't launch straight up (unless you want to build a 2 mile high tower strong enough to take accelerating the vehicle at 5-10+Gs at launch.) you're going to have alot of atmosphere to punch thru. Ever tried doing Mach 40 at ground level? Things would get a bit warm, not to mention the shockwave.
/.ers and the other responces to the lover's arrival's post
but this would seriously be a great technique once we get to the moon in a profitable way
P.S. I'd like to apologise on behalf of my fellow horny
P.P.S. is that nick a Culture refrence?
The force of gravity at orbit is not negligible if you are trying to move against it. Sure, Fg = Gm1m2/r^2 makes Fg pretty small at a big r, but r at orbit is not so big that trying to move away from a planet when you are just above it's atmosphere is easy. You would definetly need a bit of fuel other than air to manuver and change orbit. Thanks, Travis forkspoon@hotmail.com
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
Their idea is to use standard hydrogen-oxygen rockets with the O collected from the atmostphere.
Mode (3) smart-aleck mode. Press * to return to main menu.
After all, NASA spent thousands to get an ink pen to write in space. The Russians used a pencil...
Oh, for crying out loud. Here we go ago. See my above referenced article. NASA paid not a dime to get an ink pen to write in space--it was an independently developed invention that was then purchased for the astronauts (who also used pencils at the time) and later by cosmonauts (who no longer use pencils).
No relation to Happy Monkey
duh
How dare you explain and advise the community at large of the ULTRA - SECRET PROJECT MOON BALLON
We thought we deleted every reference. Therefore we must find you and delete this reference again.
You will be delt with shortly
... activate moon glow
... activating trace program
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So you're arguing that in developing a $2 million pen, NASA was showing great foresight and flexibility, spending all that money for a pen that writes in space and doubles as a screwdriver? If NASA really wanted their astronauts to be prepared for anything, they would have issued each one a paperclip.
You need to get to at least 7 km/s to get into orbit. THat's 1000 times more than a "jet liner" flies.
Energetically speaking, there is negligible "weight" saved by collecting Oxygen from the atmostpher flying at "jet liner" speed.
The actual calculations are left to the student. But I bet a lot of pop (I don't drink) on it.
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Mode (3) smart-aleck mode. Press * to return to main menu.
! == 2 keystrokes, a 1 and a (shift).
= == 1 keystroke.
thus, != == 3 keystrokes. I got that far.
But what is this 4 keystroke (not equal) that you're talking about? Is it like Alt-1-7-1 produces a ½? If so, what's the keycode?
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IANASRP- I am not a self-referential phrase
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IANASRP- I am not a self-referential phrase
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email: proprietary becomes free, org to com
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.
--
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
Goodwin's Law: you lose!
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C'mon, flame me!
No sig for the moment.
think about it, you can drink it, you can use it to grow plants, bathe in it, protect from radiation, create a gelatin out of it to contain it with the people in it. sure, it would decrease the number of people but the benefits are far greater. just think how much less radiation people would absorb if the walls of the spacestation stored their water. couldn't it act as an insulator too?
http://www.livejournal.com/users/cixel
there was no increase because they were already devoting 15-20% GDP to defence. To increase this would mean economic collapse
You forgot the real reason for SDI - the pork barrel. Here the US taxpayers can be repaid to those entities responsible for electing the officials.
See my journal, I write things there
The "Avatar" script has been floating around the net for a while. Anyone care to post a link?
Free Hans!
I thought this was a joke at first with the "unobtainium" and all, but I have to admit, even though newscience has some very strange articles sometime, it looks as if an air breathing launch vehicle would be pretty neat. The ideas are somewhat sketchy, but it looks pretty interesting, I hope that NASA pursues this.
The anti-salmon
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'd hate to be a troubleshooter for that, it'd be like in "Paranoia" when the dome cracked, and they were sent to investigate and destroy the large yellow thing in the sky...
But wouldn't it suck to be sittin' there and suddenly find the seat a bit too warm?
"Titanic was 3hr and 17min long. They could have lost 3hr and 17min from that."
IBM had PL/1, with syntax worse than JOSS,
And everywhere the language went, it was a total loss...
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
The problem is that if you want to develop a new launcher, and you're neither NASA nor Boeing or Lockheed, you aren't really credible. What NASA wants is to fly the Space Shuttle and keep a monopoly on human spaceflight (at least in the US), and develop new space technology as long as it can't compete with the former before a decade or two. What the big aerospace corporations want is to sell their existing expendable lauchers and maybe develop bigger ones at taxpayer expense. It looks like none of these players want CATS.
Look at their projects aimed at reducing launch costs. The DoD/McDonnell-Douglas Delta Clipper demonstrated a reusable rocket-based vehicle capable of quick turnaround by 1994; NASA sat on the funding before taking over the project, modifying the vehicle until it crashed. A competition was held for a follow-on, the X-33, whose stated goal was building a prototype of cheaply reusable, quick-turnaround suborbital vehicle using off-the-shelf technology; of the three competitors, the winner (Lockheed Martin's) was the one who most depended on new technologies; the vehicle is now two years behind schedule, over budget, underpowered and obsolete, and quite a number of people wonder whether Lockheed didn't fail on purpose ("see, it can't be done, buy our Titans!")
Finally, while a number of small companies are trying to get business done on inexpensive lauchers, they can't find investors as they are competing with NASA, especially with the recent Space Launch Initiative (SLI), aimed at subsidizing new launchers' development - favoring, as everybody expects, those which can meet NASA's requirements (one-size-fits-all, man-rated, heavy payloads) over commercial businesses' (cheap launchers aimed at a single market).
Where does all this leave us? Space is expensive, thus the market remains small, controlled by few players who ensure new ideas won't fly before twenty years and not cost less than what we have now, much less what IMHO we could do now. Sad, isn't it?
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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...seems someone at NASA has been watching too many episodes of the Thunderbirds
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"I'd never want to join a club that would have me as a member" - G. Marx
Why not just launch a second plane already full of liquid oxygen, the do an in-flight refueling job once they are both airborne? Seems much easier than carrying around all that extra gear to convert oxygen, and the extra fuel to fly around for 3 hours generating it.
"Freedom in cyberspace'd be fine and dandy if we happened to live there."
Isn't that how it was done in the "Rama" series by A.C. Clarke?
I am become Troll, destroyer of threads
The Plate Class GSV "The Anticipation of a New Lover's Arrival" from "Excession" would be my guess.
But you shouldn't apologize much for the other responses to NLA; she (if it is in fact a she) is one of the worst trolls I've seen around here for months. Gives other Banks' fans a bad name.
No relation to Happy Monkey
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!}
You mean UranIum? Such as U-235 and the like?
Problem with suspending people in liquid (as summed up by Joe Haldeman in "Forever War": 'What happens if drop a wrench in a submarine?' You overall might not be a puddle, but your guts would...
Pluses:
Minuses:
Got time? Spend some of it coding or testing
Perhaps I should mention that it doesn't actually have to fly, as such, just fall past the planet faster than it falls onto it. (-:
That said, the use in a magcannon would not be firing things at orbital velocities; the cannon would be firing things at only a few thousand miles per hour. The business end would be at the top of a mountain, a couple of miles above sea level, having run up a nice straight Western ridge, and would be hurling capsules into reasonably thin air; you would either use a tunnel at or near vacuum, or suffer the drag of full pressure at lower speeds/altitudes working up to high speeds and altitudes. The idea is to do the hardest part (getting started and getting above most of the atmosphere) on the ground, as it were, so making the actual flying bits much lighter and smaller.
The big problems would be dissipating the heat from the power source and maglev track if you launch stuff often enough to be profitable. Perhaps run a power station from the waste heat? Once you had run it for a few years and built yourself a powersat, the first big problem would be over 80% smaller.
BUT what's actually being discussed by the original poster is not a magcannon, but a laser ablation launcher. Part of the purpose of rocket fuel is to provide energy, the other part is to provide reaction mass. By providing the energy from a ground-based laser instead of lofted fuel, the reaction can be made denser (means smaller so lighter and cheaper vehicle) and cheaper (water or even rock(!)).
Laser ablation is usually teamed with a magcannon to fling the payload into the air in the path of the laser, but there is no particular reason not to use an airborne launching platform like a modified 747, other than most pilots being nervous about flying through the field of fire of a really big laser...
Got time? Spend some of it coding or testing
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
Liquid water is a lot easier and safer to obtain than liquid oxygen. We should use it instead. Basically, you use ground based lasers and train them on the bottom of the launch vehicle - this causes the water stored inside to vaporize, providing thrust.
Nasa has done some research on these systems, but I haven't heard anything recently. Have any of you?
--Kara
--Kara
Before you ask, I already have a boyfriend and he's more of a man than you'll ever be.
...and suffered from respiratory ailments as a result of inhaling fine graphite dust.
DNA just wants to be free...
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 info for our American friends; The American name for Unobtanium is Unobtanum, analogue to Aluminum and Uranum.
Hope this help you better understand this rather complex matter.
"The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
Of course, Pioneer seems to be dying of neglect as far as I can tell. Sad, really, since it was a great idea. Their original idea was even better.
Currently, they fit rockets using hydrogen and oxygen, and only carry enough LOX to get up to the tanker, plus a reserve for powering back to a landing. Originally, they planned to fit two air-breathing engines, plus the rockets. The air breathers would use kerosene fuel, which could also be used (with LOX taken on at altitude) with the rockets. This means that they could land more safely during an abort, because no LOX would be on board. The extra dead weight of the engines once the vehicle started running on rockets would be an issue, as would the lower energy density of the fuel. However, the extra safety and simplicity would be worth it in my opinion.
Once this kind of system gets going, it will be possible to build larger rockets which could actually get orbital (rather than using an expendable upper stage - the heat protection has to be there regardless since the vehicle leaves the atmosphere). Original versions would be great "4 hour delivery anywhere in the world" vehicles, as well as LEO launchers. Later versions would be a dirt cheap way to get payloads to orbit.
-jeff
-- Two men say they're Jesus. One of them must be wrong. - Dire Straits
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. :-)
With all the current debate in the soundness of our current physics model, I can't understand the continued funding, implementation, and developement of such antiquated devices as are currently used in the spacefaring arena.
To put this in perspective, our current model of physics insists that anti-gravity is an "impossibility" due to the accepted fact that the electric and gravity forces are unable to interact. Yet a recent article on MSNBC indicates that researchers are now discovering that certain particles (muons) do not react as is predicted by current physics. The article even goes so far as to say that these new discoveries could lead to the obsolesence of the current physics model. Imagine that. What happened to the Newtonian model may happen to the Einsteinian model!
One profound point made within the article is that only three of the four known forces are considered within todays accepted physics model. Currently, gravity is not covered within dynamic force interaction principals.
Further, an article publishing a documented case of an anti-gravity device came to my attention a few months ago. In the article was proof that anti-gravity is a reality though the device in question created a field of negligible power( measured at somewhere around 0.09% decrease), the field measured to be uniform directly above the device through the several upper floors of the building.
In all fairness, I must say that none of the recent discoveries are "here and now", nor directly affect current spacefaring as the original story topic may, but the spaceprogram we have is certainly doing fine with what it has already, so I say lets look to what comes next in technology rather than refine the technologies currently in use.
In conclusion, all of these new developments lead to many thoughts of what the future has in store for us. Whether science fiction or science fact, if we don't take the chance and try as the true space pioneers did, we may never know. I say, lets take the chance of embraceing our future and the new discoveries inherent therein.
[Sorry I don't know the links to the documents in question, but the one on MSNBC shouldn't be that hard to find. The one about the anti-gravity device may prove to be a little more difficult to find. I believe I got the link in the Langa List, but could be mistaken. It may even be one of the links on this page ;)http://www.amasci.com/freenrg/antigrav.html ]
That's the stuff we've been looking for to get our robot working! (See US FIRST)
Sheepdot: Open Source good, Closed Source baaaaaaad!
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!
Since all the heat energy in space is radiant, it's easy to insulate. Just use a mylar film. Since there's no atmosphere to take heat out of the vehicle, you don't lose a WHOLE lot of heat that way (some, yes, but it's a relatively easy problem to stay on top of with air heaters inside the station).
The big problem is differential heating. And for that, a giant radiator on the outside of the hab module might be just the thing. The problem is, water is WAY useful for drinking and washing...I don't know if it would be "worth its weight" as an insulator/heat distribution apparatus...but it's a very interesting idea.
Why yes, I AM a rocket scientist!
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
If you go fast enough at any point, there will be enough gas collected in that instant for the propulsion process. The problem is that the amount of air decrease as you move higher in altitude, so you will correspondingly have to increase your velocity to collect the needed gas. So the rocket-plane would have to have an acceleration requisite to collect enough gas in an instant. The good news is that at lower altitudes, most of the accelerating will be done to escape gravity, and as your altitude increase and the force of gravity on the ship decreases, you don't have to accelerate as much just to counter gravity, but you will have to continue accelerating your acceleration ;) the higher you go in the atmosphere, until at least you reach space, at which point you better have some other plan for propulsion or you're never coming back! So instead of you simply having the provide enough thrust to reach escape velocity or something near it, you will have to apply extra thrust the higher you go in Earth's atmosphere to keep the rate of air intake constant. But if the rate of air intake is constant, how are you going to accelerate? Perhaps you must have a higher than 1 degree acceleration. This is obviously a challenging problem, given the fact that no one has solved it yet. So basically, you will need tons of crazy acceleration all the way up, perhaps extreme acceleration so that as you move higher a = h^n, n being some number higher than 1. This would probably kill everyone riding in the ship, but perhaps if the ship was made out of extremely strong and/or flexible material such as titanium, the ship could survive such internal stress of the thrust production assembly pushing up on the rest of the ship.
Thanks,
Travis
forkspoon@hotmail.com
Great. I'll pay for the first class ticket. You all get on and fly around for three hours. Then, when you've got all the oxygen you need, come back and pick me up. :)
forth ?love if honk then
yes, that would work but you'd wind up a puddle. what i still havent understood is why they couldnt put people in water or some sort of gelatin to distribute the incredible force and allow them to survive a trip to orbit.
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