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Blimps... In... Space...
LandGator writes "MSNBC reports a California company with an alternate launch site in Texas, JP Aerospace, is on their third test of a blimp system specifically designed to fly to space. Blimps. To Space. At payload costs around a dollar a ton to LEO. Their concept, first unveiled at the Space Access '04 conference in Phoenix last month (with a blog report here, include the Ascender, a ground-to-near-space blimp, which docks to a helium-inflated two-mile-long station at the edge of space, over 20 miles up. Another ship, also a blimp but specifically designed to reach orbit, takes the payload from there to LEO, using well-proven electric propulsion (AKA 'ion drive'). That trip to LEO would take up to nine days, but that's a good thing; for, what goes up fast, must come down fast, and speed is energy which must be bled off by either massive amounts of expensive and explosive rocket fuel, or through ablative heat transfer which has its own problems (as we have seen before). JP Aerospace has flown many PongSats -- micropayloads the size of a ping-pong ball -- for balloon or rocket-launch. Over 1,500 PongSats have flown to date, which demonstrates a track record in near-space few of the X-Prize contenders can approach. Oh, yes, the Air Force is interested."
Well, if they can truly get cargo to space at a single US dollar/ton, this is orders of magnitude cheaper than current costs which run approx $10k/kg. Which could very well result in a total destabilization of the space launch business. (a little chaos now and then is a good thing.....yes?). Of course we also have maglev and space elevators which could also provide this a run for the money, but I suspect maglev would be more expensive and due to helium costs, space elevators might be cheaper still.
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What's even more amazing is they have only been around since 2002. Going from start-up company to your 3rd test flight in that amount of time is.. well.. impressive.
Hmmm.
Eh? That's the coolest thing I've seen in a while, if it's at all possible. Kinda blows the x-prize away.
Quid festinatio swallonis est aetherfuga inonusti?
Africus aut Europaeus?
And then when Indiana Jones is travelling on the blimp he will figure out that the blimp changed direction by doppler shift!!!
i can see the marketing folks rubbing their palms now...
mmm...mass advertising...
R.I.P.
on their third test of a blimp system specifically designed to fly to space
"Now, the object of this expedition is to see if we can find any traces of last year's expedition."
I watched C-beams glitter in the dark near the Tannhauser gate.
Incase there are actually people not reading the linked article, the interesting part is quoted here:
Karma: SELECT `karma` FROM `users` WHERE `userid`=138474;
Blimps in space? Now we're one one step closer to Pigs In Space!!
Come on now, if we're really tipping our hat to The Muppet Show, let's do it right...
Blimps... In... Spaaaaaaaaace!
I would love to see huge balloon animals in the night sky..
What the hell is LEO?
Without music, life would be a mistake. --- Nietzsche
This suckers sound pretty big. Is it possible that they'll be subsidized by giant ads placed on the blimps? Will the sun be blocked out by the tri-color Pepsi logo?
Or maybe I'm the only person who remembers F-troop. Seriously, this is going to be a bit weird, because at that size, it's going to be quite visible all the way up, even in orbit.
Am I part of the core demographic for Swedish Fish?
Blimps into space looks insane but they have flown some of the parts of a 3 stage to orbit system and they are talking about costs to space of a dollar a ton/mile. Ton mile.
Still.
Defense Tech has a blimpload of material on high-altitude airships.
OH THE HUMANITY!
Fortunately this time we should have the sense not to paint the blimps with highly flammable doping.
Saskboy's blog is good. 9 out of 10 dentists agree.
Second, LEO isn't just *up*, it's also speed that keeps you falling back to earth. That kills the up-fast-down-fast idea. Are these space blimps (inflatible tech! Dr. Schlock would be proud) going to manage to accelerate a load from a relative standstill to LEO speeds using an ion engine (which has very weak acceleration) in just a few days? Unless I'm missing something, that doesn't seem very likely.
That aside: Cool idea. This sort of infrastructure wouldn't be as awesome as a space elevator would be, but it sure seems a hell of a lot more likely (cheaper, safer, possible without huge leaps in materials, etc). Once you're moving tons of material to orbit for a very small price (costs more to ship something across the ocean!), it seems like space exploration is ready to take off (no pun inte... oh, who am I kidding?) in a very real way.
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
I can't way until they offer nine day cruises to near-space.
Imagine the view...
Seriously, this is a good stepping stone to space tourism.
LEO = Low Earth Orbit
Hmmm.
This is neat, but too bad it wouldn't work for the X Prize. If it takes 9 days to get up there, then comes back slowly too, they wouldn't be able to relaunch the same craft in time. That's a shame, as this sound promising and could really use the extra funding from the prize itself and that the prize's notoriety would help it get.
Hopefully this solution will be developed and used commonly when fats times to orbit aren't a must.
So the first word visiting aliens will see will be "Goodyear."
The coolest voice ever.
Good catch. Even a $/ton/mile price seems way too low for me. That just means a 20X increase. So a 100 ton craft to LEO would be something in the tens of thousands? I doubt it.
Sorry but that just stinks of "too good to be true". What about the cost of the blimp, gas, maintenence, workforce, insurance, and everything else.
$100/ton/mile sounds like something real but this, I don't know.
Blaze a trail to the New World
Blimps in space?
Hindenburg, anyone?
(Sorry, but the idea of airships in space seems insane and unsafe to me)
By summer it was all gone...now shesmovedon. --
I'm sure they have thought this out, but:
Can you really accelerate a big inflated condom to escape velocity with an ion drive? I mean, it can only get so high on He, and I'm assuming that at its apogee there will still be an appreciable amount of atmosphere. Would an ion drive be able to overcome the drag force? Anyone willing to do the math?
This shatters the "space access is expensive" problem that we've been battling with for aeons. This would absolutely revolutionize the concept and bring about the golden age of near-earth space access. This is better than science fiction - and makes the previous holy grail - the space elevator - seem klunky and expensive in comparison.
I can see the biggest problem is going to be transitioning from simply "being really high up in the atmosphere" actually travelling at an orbital velocity. At some point you've got to kick in an awful lot of energy - I'm not sure that would so easily be solved by ion drives (they're really, really efficient, but they're also really, really weak) when you're skimming the edge of the atmosphere trying to get up to speed.
I imagine there will still be a need for high-energy launches for time critical stuff (ie: the military, emergency rescue, short duration human transport, sport & entertainment, racing, etc), so more "conventional" rocket science would still have it's place.
from the article~
JP Aerospace, self-billed as a volunteer organization, has operated since 2002. PongSats are micropayloads the size of a ping-pong ball. Over 1,500 PongSats have flown to date
~The only thing they forgot to mention is the launch vehicle is a 500 foot long baseball bat and costs 2 million dollars.
------
beware he who would deny you access to information, for in his mind he dreams himself your master
Space elevators are something we will need better materials science to accomplish. Blimps we can do now. Space elevators also have a problem evading space junk and satellites, although I have read a proposal to introduce harmonics to the cable so it vibrates around them. I suspect that giant, slow moving blimps may have a real problem with space debris.
;-)
Pop, pop. Hiss, hiss, oh what a release it is.
Sorry, I can never resist a dumb joke
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
They actually claim one dollar per ton per mile. And I'm sure that doesn't include accelerating it to an orbital velocity... So it's cheaper, to be sure... but not quite that cheap.
Have you been touched by his noodly appendage?
Ion propulsion typically doesnt work in an atmosphere. Let alone that its going to have to overcome gravity and the drag of the upper atmosphere to get its payload into orbit.
I wish them well, but I'm not holding my breath.
"Open the pod by doors, Hal" > "I'm afraid I can't do that, Dave" sudo "Open the pod bay doors, Hal" > alright
That trip to LEO would take up to nine days, but that's a good thing; for, what goes up fast, must come down fast
What goes up fast must come down fast? Unless I'm missing something, low earth orbit still means going several thousand miles an hour. The rate you ascend at has nothing to do with how quickly you'd come down at.
AccountKiller
Whether you reach orbital velocity in 9 days or 9 minutes, you're still travelling at orbital velocity.
Where the hell's my flying car? They promised me a flying car in the future! Without flying cars, the future sucks.
See, a Viking Funeral!
[insert mourning vikings]
See, Hitler on Ice!
[insert Hitler on, well, ice]
See, Jews... In... Space...!!
[just picture it]
Recall in the very beginning where the Vickis are riding in a blimp where the bag is full of vaccum instead of any gas? It seems to be that this would be an elegant one-stage-to-orbit vehicle, since you don't have to worry about things like gas expansion.
Anybody care to take a guess as to what sort of advanced materials would be needed for this sort of structure?
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"From the Oh!-The-Humanity department....."
---
IMHO, of course.
May the SOURCE be with you.
Pong statistics for leo.space.com:
Balls: Sent = 2002, Received = 1001, Lost = 1001 (50% loss)
Striving to be common
Striving to be common...
Hydrogen is half the density of Helium, not 1/4. And it wouldn't give anything like twice the buoyancy, either. If you're confused as to why this should be so, I recommend doing a little web research on the following terms: "monatomic gas", "chemical mole", "ideal gas law". "density of air".
-Mark
Folks, you can't just lift something up to a few hundred kilometers for it to be in 'orbit' -- you have to accellerate to around 8 km/s at altitude. Show me a blimp that can do THAT!
This isn't competition for rockets, it's an alternative for hoisting a sensor platform to an altitude which would serve as well as if it were in orbit.
If anything, should tools like this prove successful, there will no longer be a commercial or military need to lift heavy payloads into 'permanent' Earth orbit. If that happens, say goodbye to those space dreams.
You might very well be witnessing the beginning of the end of the space age.
Like Armadillo, Carmack's company the best thing about them is that they don't have one great idea that they are basing their company on (or bust), instead they are taking small steps to a large goal, sometimes failing but learning from that failure and moving on a little at a time. Of course it helps to have mob of volunteers around just itching to help :-)
A big inflatable boomerang? Come on. Where is the Cow Bell?
MadOgre.com
but we managed to ditch him by speeding. Just thought you might want to know.
That's a long trip- 9 days to go 100 miles or so. But at $1/Ton/Mile, I'm sure it would be possible to create a single-man spacecraft that could be attached to this launch system-say just a space suit, a titanium box, and enough food/water/air for 9 days.....
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
(but why not hydrogen is good question. hydrogen is cheap & renewable....)
I thought the edge of space is generally considered to be at 70 miles up (i.e., if you could turn your car upwards, you'd be there in an hour)
Damn that's big. "That's no space station..."
Oh dear... my poor friends over on the Atlas program. But I wonder if this methodology is extendable to reach higher orbits. It's a long ways to get from 350 miles up to 19,000 miles up.
this thing will enable.
I mean if it isn't this, it's one of the other launch technologies. There are already free-to-air satellite feeds in Asia and Europe. This is a greater danger to the MPAA, RIAA than the wired Internet will ever be.
I can see your house from up here!
i had a dream a while back where the earth was attacked by aliens and just when they were about to reach earth to destroy it a large blimp-net surrounded the earth creating a blimp cage around the whole world. on this blimp-net there were many laser gun and missle launching platforms. on the side of blimp-net it said "for all the people of earth from the lockheed martin company." it was quite disturbing but now it seems to be begining. i knew i was psychic.
And don't forget drag -- if you're high enough to float a blimp, you're still floating on some amount of atmosphere.
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
Okay let's say it costs $1/ton to put something in low earth orbit. It would actually cost more to get what you were launching to the launch facility than it would to launch it. A quick check with FedEx showed a rate of about $4500 to ship one ton about half way across the country.
This sig has been temporarily disconnected or is no longer in service
yes - the lack of groundable rigging lines on the very flamable oxide painted cloth panels creating insufficient discharge once the moring lines were dropped were a disaster for the aircraft.
I hope that the next hydrogen powered aircraft that's the size of 2 football fields takes note and insures that it doesn't use flamable paint on the outer surface and makes sure that static can discharge without impedence.
You know - car fires usually don't start around the gas tank - unless it's a pinto - bozo. Do a google search once in a while before spouting outdated science on aircraft disasters.
Many of the reports site a very large triangular shaped vehicle that makes almost no sound... I wonder...
01100101 01111001 01100101 01100010 01101001 01110100 01100101 01110010
I'd pay good money to to watch that thing go up in flames. I wonder what effects it would have on the atmosphere?
YOU'RE ON THE LIST
IMO the best browser game ever http://wittyrpg.com
when does Cowboy Neil blast off?
Why don't you embrace your slashbotness instead of living in a dreamworld?
Just in case you missed it . . It's particularly appropriate, because the episode is about . . ballast . . *snort*
A very readable John McPhee nonfiction book.
Synopsis: Zealots (both religious and technological) try to revive airships for use in inexpensive air transport, fail badly a couple of times, succeed technically on last dime, go broke. No one pays attention afterward.
Proponents were plagued by systemic resistance to lighter-than-air technology (in addition to many, many other problems.) Interesting accounts of how the last Navy airship pilots proved their ships were capable of much more than heavier-than-air -- just before the DOD pulled the plug on military LTA vehicles.
Indiana Jones is an expert in archeology, not physics
Well let's make a brief calculation Of course, atmospheric pressure is by area. "using the ISA standard sea level conditions of P = 101325 Pa and T = 15 deg C, the air density at sea level, may be calculated as: D = (101325) / (287.05 * (15 + 273.15)) = 1.2250 kg/m3 " so say we have an ultra strong and light material that is about as dense and strong as aluminum and is 2700 kg/m3. Wow that's a lot! So let's say our balloon is only 1mm thick, the balloon need about 2200 times the amount of volume the material used in vacuum to be able to float up. 2200 times the volume, we know that the volume of a sphere is 4/3pi*R^3, so we can take R and find cross sectional area. Now we have the amount of pressure exerted on ALL sides (proportional to cross sectional area), 14.7 pounds per square inch of pressure at sea level. The math is long and tedious, but basically we are talking about no material known to man, needing something 1000's of times stronger than steel which comes to the point that the forces applied at this strength would probably be actually tearing apart molecular bonds much less the actual crystaline structure of most structural materials, in short it is impossible.
People have a misconception that if you put a hole in a blimp, that it crashes. If properly designed it will not.
It all comes down to the pressure difference between the insides and the outsides of the blimp.
Reading their promotional literature, they do not maintain much of a pressure difference between the insides of the blimp and the outsides. Thus, a hole will not really result in the helium being replaced with the heavier atmospheric gases.
Most blimps can manage a safe emergency landing if even significantly damaged.
Last but not least, I suspect that their choice of helium was more due to the dramatic reduction in safety precautions they have to take with the stuff on the ground. There are real advantages to using diatomic gases over monotomic gases (for example, they leak much more slowly through micro-pores). But the advantages do not make up for the disadvantage of the risk of explosion on the ground or at low altitudes.
See also: other posts explaining the nature of the Hindenburg fire.
As far as i understood until now the main cost to put something in orbit is to vainquish the gravity potential well. So if the "blimp" put you at the right altitude even if it is a slow-mo ascent, the only stuff you have to have afterward is a slighty ascending booster to finish putting the payload in orbit.
In other word you would only need to lift a far smaller rocket up there , orient it correctly, and have it put payload easily in space. Thus far less cost in needed boost overall. Am I missing something ? Is it a naive thinking ?
C. Sagan : A demon haunted world:
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visit randi.org
Gibson Wrote a short story called Red Star, Winter Orbit, where at the end, people used near-leo ballons to launch sounding rockets to achieve higher orbits. Sounds like this company might be able to do something similar for cheap.
Second, to stay in orbit you need to be going at orbital velocities - i.e 7.6 km/s. That's fast, so doing it in the atmosphere creates lots of drag and spectacular fireworks. It takes energy to maintain orbital velocity in an atmosphere - much more than you can supply with a puny ion drive.
This just doesn't hold water.
Human genome = 3 billion base pairs = 6 GBit. Windows + Office = 20 Gbit. Which is more impressive?
POP! .... fssss .... Ahhhh!
;)
That's all I've got to say
"Things are more moderner than before- bigger, and yet smaller- it's computers-- San Dimas High School football RULES!"
... perhaps it was the incredibly clear camera shot of the wine glass shadow rapidly moving on the table; meaning that the relative position of the sun was changing. As the sun doesn't move a whole lot within the 20 seconds that the wine glass shadow was moving, that meant THEY were rotating, e.g. changing direction.
Watch the scene again, and THEN comment.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
http://www.jpaerospace.com/atohandout.pdf
Here are the details:
Atmospheric airship with crew of three takes payload to 140,000 ft. Airship uses lift and buoyancy, and driven by propellers designed to operate in near vacuum.
Dark Sky Station (DSS) at 140,000 ft. Permanent, crewed facility.
Airship that flies from DSS to orbit. Over a mile long. Uses buoyancy to climb to 200,000 ft. From there uses solar/electric propulsion to reach orbital velocity over several days.
Continuing to use solar/electic propulsion, it can keep on going to anywhere in the solar system.
Several "DSS" platforms have been flown. All equipment has been flown at 100,000 ft. and tested in the environment. Ion engine tests of the orbital airship at 120,000 ft. will occur in the next five months.
Every segment of the plan has funding. DoD is funding the atmospheric airship for reconnaissance. Telecom companies are funding DSS.
I know what their fist ship should be named: The Vulture, after the old TV show, Salvage, about a junk yard owner whe builds a ship to salvage moon-junk. His ship, The Vulture, used low-acceleration to allow him to use safer fuels. Neat idea, although the writers got a tad carried away with the possibilities after a few shows.
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FYI.
http://en.wikipedia.org/wiki/2004_U.S._Election_c
Congrats!
If enough money is put into the project, we can start space industrialization in a year or three, we don't have to wait until we find out if the space elevator is actually possible, we don't have to build giant rail guns for cheap space launches if the Elevator is unworkable.
It's time to start work on actually building Space Power Satellites at the "proof of concept" level. For more info, click here
Tech Public Policy stuff
Ummm, if high winds are a problem, maybe Texas isn't such a hot place for them to be launching these things???
The best part about watching these launch would be you could show up an hour late and it would still be visible :-)
I Am My Own Worst Enemy
If you've not read the "Deltoid Pumpkin Seed" it is worth reading for the insights into technology and culture it gives.
That after failing to get a Darwin award using conventional baloons, someone would come up with a version that would guarantee you get the award. If you use a lawn chair as payload, anyway :-)
First, the article does mention using 2 stages to orbit -- a heavier lifting balloon and a lighter, larger space balloon. Between the two of them, the engineering and materials exist (apparently) to accomplish the target height.
Now, you're right: No matter how big the space balloon is, it can't lift you completely out of the atmosphere. But it can get you *real* high where the air is very, very thin and provide a neural overall buency (I can't spell). From there, the thrust of the ion engine will apparently be sufficiant to lift the payload up while accelerating it to orbital velocity. Sure, drag's an issue, but we're talking near-vacuum here so once you get moving it's not a big problem given the long firing time of the ion engine.
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
Hot air works as a lifting method in hot air balloons.
How about heating helium? Would that add additional lift? I hesitate to propose this with Hydrogen, but... ?
emt 377 emt 4
about the "Another ship" jpg link above: why does the near space-to-leo blimp look like a star trek insignia?
you could read the question as a joke, but i'm asking it seriously as well
and, btw, if this whole scheme works, it kinda makes the x-prize and its roster of contenders look like a joke, seriously
this whole idea, which, quite frankly, utterly smacks of a smack-me-in-the-forehead "why didn't i think of that!?" moment, makes me wonder about history:
before the hindenberg, the world was seriously in love with blimps... the empire state building in new york city was built with the notion in mind that blimps would moor to the top
so if our love affair with blimps had not been so tragically and rapidly abandoned, in favor of fixed-wing aircraft and rockets, and if blimps had remained in the mix on the world stage as a versatile and viable and important mode of air travel, then i seriously wonder if someone could not have thought of this scheme back in the 1940s
then we could have been, quite possibly, since the tech to make this blimps-to-space scheme work was easily within the grasp of 1940s tech (hmmm... fabrics/ blimp skin tech too?), then we could have been CHEAPLY spaceworthy in the mid 1950s... in a totally retro-futuristic manner at that!
and the whole history of humanity as spacefaring creatures could have and probably would have looked FAR different today, with us being far more advanced and much further along in a trajectory to reach other planets and beyond
god i really hope this get-to-space-cheap scheme works
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Its too bad my hot air was not able to propell me to the sub space level, it was also kinda stinky.
Rocco
on an earlier blimp story, you look up at the giant blimp passing overhead. A voice from the sky intones, "Spawn More Overlords."
Some mornings it's hardly worth chewing through the restraints to get out of bed.
We're Jews out in space
We're zooming along protecting the Hebrew race
We're Jews out in space
If trouble appears
We'll put it right back in its place
When Goyim attack us
We'll give 'em a smack
We'll slap 'em right back in the the face
We're Jews out in space
We're zooming along
protecting the Hebrew race!
...I guess we'll be seeing some DoomSats, GTA3Sats, and maybe, dare I dream, a few Master Of Orion 4 Sats, as the natural progression from this new industry's meager start with PongSats? And will the /.ers of the 2020's fondly recall the early days of the space blimps as they're floating past the moon?
Second, escape velicity is a ballistic value, ie. the speed required to kick your butt off the planet from ground level going straight up.
No, escape velocity is actually misnamed. Velocity implies speed and direction. But escape speed is what it really is, since direction doesn't actually matter. The planet is round. When you go far enough, all directions become "up".
As long as you're pointed above the horizon, and as long as you have enough extra speed to overcome the friction due to the air you happen to be travelling through, then all you have to do to get off the planet is to go at escape speed.
Rockets go straight up to get out of the atmosphere in the fastest possible way, reducing drag and thus requiring less fuel. If fuel wasn't an issue (hah!) it doesn't matter which way you point the thing.
Now, getting into an orbit means going at a certain speed in that orbit, relative to ground. The original post is incorrect about the "what goes up fast, must come down fast" bit because, if you're in orbit, you *have* to be going at some given speed. That speed depends on the height of your orbit. That's kinda what "orbit" means.
It doesn't matter if it takes you 4 minutes or 9 days to get into a given orbit, you are still going at the same speed once you actually get there either way. You have to be. Otherwise you wouldn't be able to get there. Anything that falls to the earth from a non-orbital position hits the earth at 11 km/sec (escape speed), minus the speed that it bleeds off in the atmosphere.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
actually, a blimp is a nonrigid airship -- it's not a zeppelin.
err .... out.
Just to quibble: Helium is a noble gas, so it won't be diatomic above ~4K. (Diatomic gasses are gasses with molecules formed by two atoms joined by chemical bonds.)
I see your point, though. Helium has a nucleus that is four times as heavy (two protons and two neutrons versus a lone proton for most hydrogen), and has another electron in its orbitals. These factors greatly reduce the diffusion rate. Diatomic gasses would have some added advantages of greater size per unit weight but would have some disadvantages such as pressure buildup upon decomposition and less buoyancy due to greater weight.
I'm not a rocket scientist, but this seems nonsensical. You don't need to "bleed off" the speed of something going into orbit--gravity will do it for you. The kinetic energy (speed) is turned into potential energy (gravitational). Any speed short of escape velocity will fail to escape earth orbit, so any speed short of escape velocity doesn't need bleeding off. (It's true that if you throw a ball up at higher speeds it comes down at higher speed [ignoring air resistance], but this has nothing to do with throwing a self-propelled ball into orbit.)
You can maybe naively figure work is energy, and work is force times distance, and a reduced force through the same distance is less work, but it's not actually less energy. Try going into low-earth orbit and not orbiting, instead hover without orbiting. I guarantee you'll be spending energy hovering, even though naive work of force-times-distance is 0 (since distnace is 0). No matter what speed you go getting into orbit, you'll need to increase your potential energy by the same amount--but a nine day trip to orbit is like nine extra days spent hovering.
Please note that I'm saying this without having read "the" article, since I don't know which of the twelve links this claim might have came from.
Hell, Frank Read did this in the 1800s.
A big bag of Helium won't stay filled long in the low pressure environment. Probably half the trips would be to just keep the Helium topped off.
Dammit. I saw the headline and thought Michael Moore had "won" a "vacation on Venus", a' la Cyril M. Kornbluth.
Figure a fully outfitted luxury passenger module, including oxygen and other facilities, is ten tons per passenger.
That's $200 per passenger to get to the "edge of space", or $9000 per passenger for low earth orbit.
Space cruises for civilians now become feasible.
Pretty exciting.
Finding God in a Dog
How are you going about making that assumption? To achieve that sort of acceleration, how much of the ship's weight has to be fuel? Do you have a link or anything?
I think you mean a net Acceleration of 0.01G.
This blimp needs air for bouyant lift, so you are inevitably going to be in the atmosphere. Ion engines, unfortunately, only work in a vacuum. And even if they did work at that altitude, the drag would so high that they wouldn't accelerate the ship at all.
.01, then the drag force at 5000 fps, 1/5 of orbital velocity, is: .5 rho Cd V^2 A
.01
If the ship was, say, 50 ft wide and had a rediculously low drag coefficient of
where
rho is density (about 1.7x10^-5 slugs/ft^3)
Cd is
V^2 is velocity squared. At 5000 fps, that's 2.5x10^7
A is area, 50 ft
This yeilds a drag of a little more than 100 lbf.
The most powerful ion engine is Nasa's new HiPEP that has a thrust of about 1/10th of a pound.
Now, I'm a big fan of JP Aerospace, and wish them all the luck in the world. Their program of launching sounding rockets from high-altitude balloon platforms was quite exciting. Hypersonic blimps, though, are just not going to happen.
Thad
I love Mondays. On a Monday, anything is possible.
thats the reference to all the non-muppet lovers.
Sigs? We don't need no stinking sigs!
All you have to do is make the gas bags out of a black material. The sun will heat it up and you get an additional boost to the lift produced.
S olar-Air ship.asp
In fact, you can make a solar hot air balloon out of nothing more than black bin bags.
e.g.
http://www.gadgetstuff.com/gifts-gadgets/
Deleted
what goes up fast, must come down fast
Fascinating. Nothing to do with that whole 9.8 m/s^2 stuff, nope, gravity remembers how fast you got there in the first place.
"That trip to LEO would take up to nine days, but that's a good thing; for, what goes up fast, must come down fast, and speed is energy which must be bled off by either massive amounts of expensive and explosive rocket fuel, or through ablative heat transfer which has its own problems (as we have seen before)." That's not true. It doesn't matter how fast you send something up, things will fall at the same rate, and you'll have the same problems. Using an ion drive is probably a lot more efficient than chemical rockets, but once two objects are in similar orbits they have the same potential and kinetic energy, regardless of method of delivery. And it's this energy, (mainly the potential energy) that needs to be shed to land safely on the Earth again.
Good analysis. In reality, the drag coefficient is going to be more like .2 due to the "dirty" truss structure that supports the engine and keeps the v-shape - even that's giving them some leeway. So, at 100,000 ft, the average wind velocity is 40-knots (take my word for it). This produces a drag force on the balloon of:
.5 * rho * Cd * A * V^2
.5 * 1.7E-5 * .2 * 50 * (40kt * 1.69(ft/sec)/kt)^2 = 0.4lb.
.
This means that they would need four ion engines just to keep station over a geographic point. It also means that 40-knots is their terminal air-velocity with said engines. Ya ain't gonna to get to orbit that way! Plus, their actual "orbital" craft has a MUCH bigger planform. .
This sig is a test. If this had been an actual sig, you would be reading something quite a bit wittier than this now.
That may be. I do have question -- perhaps some of you have the knowledge to speculate -- could one of these LEO objects be an anchor for a space elevator, to get one going sooner rather than later in this century?
I could a trip around the world for 3 or 4 thousand bucks. Dang!
If you post it, they will read.
Carbon nanotube ribbons as mentioned might very well work (not an endorsement on my part) for the tension loads, but you have to consider the wind loads and oscillations they will induce. Does the name Tacoma Narrows ring a bell?
Wind engineering is serious business for just this reason. If the profile of the tether increases drag (thereby reducing terminal velocity), there will be a corresponding increase in susceptibility to wind forces.
Consider the tethered balloons (aerostats) in various US locations.
Faith is the very antithesis of reason, injudiciousness a critical component of spiritual devotion. Jon Krakauer
I'm worried about the temperature of the airship skin. Granted, at very high altitudes, the air will be thin, but at mach 20, the air temperature (actually kinetic energy) will be very high. Since the ship will be accelerating for days from mach 1 to mach 24 orbital speed, the thin skin will have plenty of time to heat up and melt. Active cooling would be too heavy for the airship's huge surface area. Likewise for ablative cooling.
> So, once we use the helium we have, we aren't getting any more. One source says this may happen by 2030.
Well, that's a very good argument for using H2 in the orbiter rather than the ground-to-station shuttle.
Of course, all we need to do is to get fusion spun up here, and we will have a bit more He to play with.
However, there was no authoritative source listed on the 'may happen by 2030' quote, so I think digging a little deeper may be justified.
Just think... Supra-NewYork Station (yes, Heinlein did write about it in the Fifties, didn't he?)
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Having a small percentage advantage by using H2 rather than He could have a major advantage on the second stage. Besides, there's only so much He in the Texan helium wells, so conserving it until fusion gets going is a good idea.
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Hasn't this already been done?
Your relation needs to be flipped. Hydrogen (helium/4) makes the denominator larger and lowers the relative buoyancy.
One guess is licensing and permits, in which case why do we have beauracracy inhibiting innovation? Another might be rental of a hangar to prepare this thing, but that still seems a little odd.
Bleh!
I came up with a similar result. Maybe we should just shut up and short the stock later on. :)
I understand that at in the automotive world, a very rough approximation used is that drag is proportional to v4. That calculation breaks down as you approach Mach 1, but I dunno what the situation is at supersonic speeds and the very low pressures at these very high altitudes (well beyond the range I thought you could lift a blimp to, to be honest).
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
No matter how far *vertically* you lift something, you still need significant *horizontal* velocity in order to reach, and stay, in orbit. Blimps get you high, but not fast. Airbreathers get you fast, but nowhere near fast enough, and nowhere near high enough. In the end you don't save all that much because the size of the actual booster required isn't reduced all that much. (Something like 75% of the fuel in an orbital launch is used to generate that horizontal velocity.)
apparently such things have been done for a long time by the US government in some capacity.
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
Reaching space? I think not. Some conjecture that such a thing could be accomplished with rockets, but this is clear fallacy: once outside the atmosphere, there is nothing for the rocket to push against.
WWJD for a Klondike Bar?
Lest anyone harbor visions of floating to orbit, you can't achieve orbit without accelerating to orbital velocity. Don't have orbital velocity? Down you come.
-- Slashdot: When Public Access TV Says "No"
How will such a big, flying-wing shaped balloon support loads of several tonnes without deforming?
"We also do some bread-and-butter work with rockets to pay the bills," Gee, these guys do rocket science JUST so that they can pay their bills....
First, escape velocity is about getting you permantly out of earths gravity well. Not something you want if your destination is a stable orbit around the earth.
The average kinetic energy of an orbiting object will be half it's total energy. So the parent post was off by a factor of two, not something I would bitch about. For some numbers, the escape velocity at that altitude is ~10km/s. The orbital velocity at that altitude is ~7.5km/s.
escape velicity is a ballistic value, ie. the speed required to kick your butt off the planet from ground level going straight up.
Escape velocity has nothing to do with going straight up at all - merely going at that speed in any direction will get you away from Earth's gravity at a given altitude. It's simply a matter of having enough kinetic energy to account for the potential energy well you are in. Direction only matters when you want to get a extra kick from the rotation of the earth.
Third, pushing "a big inflated condom" around in the upper atmosphere is not really a problem since there isn't much air to create drag.
And floating a big inflated condom around in the upper atmosphere is totally impossible because there isn't much air to create bouyancy. I hope you see how your totally vaguish statements are completely useless.
Further, the higher you go, the less drag you feel, hence the "launch" of the orbiter from a platform already 20 miles up.
The higher up you go, the less lift you feel for a given volume of low-density gas, hence the need for increased size which translates into increased drag. A very naive approximation of drag goes as the frontal area ~ R^2, while lift will go as R^3 - so you might think that you can win by making things really big, but in all practicality it's hard to imagine a huge object, supported by the weight of the atmosphere around it, going at any appreciable speed through that same atmosphere.
With regard to the ion drive, the force provided is so incredibly minimal I wouldn't count on the terminal velocity of the blimp to even be measurable.
Too dumb to be funny.
Tech Public Policy stuff
Yes, I know you won't get aerodynamic lift without air, so there will be some drag, but your back-of-envelope calculation doesn't tell enough of the story to know if it's a showstopper.
My question is how the heat gets dumped on the way back. I guess it has so much surface are the heat load at any given point is small, but we're not talking about titanium here.
Piiiggsss iiinnn spaaaacce.
Mayeb a bit off topic, but maybe we should ask a little help from the Russians. They seem to have been using charged gas engines for quite a while. Maybe a hall effect thruster? They use more power, but seem to generate more thrust as well.
Bill G. digs a few million out of his pockets, buys JP Aerospace, and finishes the blimp program.
MS Blimp Services (running Windows of course), puts NASA and everyone else out of business, then jacks the price back up to $10K/kilo once all of the competition is gone.
You forgot about lift. If you shape yoru baloon in such a way that it produces lift if it has forward momentum, you can get around the drag. You start at say 100,000 feet with zero velocity. You turn on your ion engine, and accelerate to a few fps. Yes you have a big drag area, but you also have a big lift area. You use the lift to move higher than the buoyant force can move you. As lift brings you higher, you accelerate, because dynamic pressure will remain a constant (so that drag cancels out thrust and you still have net lift) The only problem I can see is that at very high altitudes you have rarefied gas dynamics and effective temperatures of the air is very high, so you need to have some sort of TPS even if youre moving very slowly. Its worth a shot to try it though.
Quid festinatio swallonis est aetherfuga unonusti?
That's Latin in dactylic hexameter, by the way.
The 5th foot seems a bit of a stretch as a dactyl to me. (Though so do some of Vergil's verses, so what do I know?) And the Romans didn't have the letter "w" so I take that word as an English retrofit (as well as the prefix un- rather than the Latinate in-).
You're allowed to use spondees here & there y'know. How aboutQuid festin|atio | swallonis | est aether | fuga un|onusti?
What haste of the unburdened swallows is air-flight?
Quid festin|atio | fugae | avis | liberae | est idem?
What haste of the free bird's flight is this?
Sounds more like Vergil to me.
Does this post make me fascetor grammaticalis?
So use more than one ion engine.
I don't know if anyone has noticed this, but at the "dark sky station" stationed at 100,000 feet up, since the station is floating rather than orbiting, there is no issue with zero gravity. Weightlessness is caused by the fact that an object in orbit is "falling" to the earth--and missing. But the "dark sky station" is not in free-fall; it's held aloft via bouyancy, and so workers on the "dark sky station" will experience full gravity. No problems with muscle atrophy.
Furthermore, it's not like poeple haven't flown up to 100,000 feet up in balloons; what becomes technically interesting is building a permanent or semi-permanent station as a balloon at that altitude.
The best part is that the worlds record for the highest skydive is above that altitude. So theoretically in the case of a catestrophic emergency, people could simply get into their skydiving space suits, and jump.
Beware the horrible approximations that follow. . .
Assuming. . . . 100 Tons of Blimp (1x10^5 kg)
Assuming. . . . The ion drives expend 0.1kg of fuel per second (absurdly high for ion drives).
Recall conservation of momentum.
Recall kinetic energy. (k = (1/2)mv^2)
Plug some numbers. . . We need a force of (F = ma = (1x10^5kg)(0.1m/s)) 10,000 newtons.
Rocket thrust is roughly (dm/dt)(V)
dm\dt = 0.1kg
V is dependant upon our accelerating potential, but must be high enough to give 0.1kg enough momentum such that 10,000n = (0.1kg)(V), v = 100,000 m/s. Luckily this is non-relativistic which makes life easier. k = (1/2)mv^2 = 0.5 * 0.1kg *100,000m/s^2 = 5x10^8j
To summarize.
In order for a 100 ton blimp, to achieve an acceleration of ~0.1g, and a fuel expendature of 0.1kg/s (360kg/hour -> 8.64 tons/day). It would require 500MW of power generation.
The moral of the story?
Ion engines are useful only for low thrust applications. If you want to drop the mass expendature of that engine further, it will require an unfortunatly large amount of energy to power the damn thing and get a large thrust out of it.
Building a better backup.
Zettabyte Storage
Thank you. I've been sitting here trying to figure out how you could use the atmosphere for lift while accelerating to orbital velocity without massive drag. Funny how hundreds of people can read and discuss a concept without noticing that it is fundamentally impossible.
(This was really cool, btw.)
Karma: Excellent (My Karma? I wish...:-( )
I suddenly have this image of a Kirov blimp from Red Alert 2 slowly rising into space to drop bombs on weak capitalist fools!
"Last but not least, I suspect that their choice of helium was more due to the dramatic reduction in safety precautions they have to take with the stuff on the ground. There are real advantages to using diatomic gases over monotomic gases (for example, they leak much more slowly through micro-pores). But the advantages do not make up for the disadvantage of the risk of explosion on the ground or at low altitudes. "
You have your facts backwards. Helium is the monoatomic gas and Hydrogen is the diatomic gas. Helium has an atomic number of 2, and is a noble gas, thus doesn't need to combine with any other atom to be stable. Hydrogen has an atomic number of one and comibines with itself to form H2 molecules -- thus diatomic -- two atoms.
So your assertion that Helium is safer b/c it's a diatomic gas is false. Hydrogen is the diatomic gas.
Helium may or msy not be safer, but it's certainly not for the reason you stated.
for, what goes up fast, must come down fast, and speed is energy which must be bled off by either massive amounts of expensive and explosive rocket fuel, or through ablative heat transfer which has its own problems (as we have seen before).
the part I don't understand in this statement is if it goes up fast, why does it have to come down fast? why can't you get things to come down slow? if there are problems with heat transfer like on the space shuttle, why don't we have them come down at a slower speed, like say half-speed? wouldn't that be well-within the safety margins?
someone want to try and clarify this for me?
I'm good with numbers -
Firstly giving the amount produced as atoms/molecules a second (the same thing for helium) was quite unhelpful of me but I think producing all the worlds power by fusion would yield about 5.5 billion litres of helium at standard temperature and pressure (atmospheric pressure and 0 degrees celsius) a year. That corresponds to about a million killograms of it a year. This assumes the reactors are 100% efficient which is obviously not the case (since we are currently unable to actually get out more than we put in they currently have negative efficiency) so in reality many times this would be produced (100 times if they turn out to be as inefficient as coal power plants used today). The Texas oil fields (the world's largest producer of helium) were producing about 4 billion litres a year in the 70's so the amount produced by fusion would probably be enough to cover our current demand (assuming we don't manage to make highly efficient reactors)
I forget, or actually, I've never received a good objection to just launching rockets from 100k+ feet, why aren't we just doing this to start with? Seems like a no brainer, but IANARS. I'm assuming removing the part of the trip that uses up %90+ percent of your rocket fuel will allow you to accelerate to the requisite 17.5k mph rather easily, and considerably safer than dragging a few metric tons of expolosive propellant through the atmosphere.
Ion drives are rather new than well proven. The ESA is still having their SMART satellite out there, on its way to the moon. Will probably arrive in 2005. It only uses an ion drive to get there and spirals its way out of earth's gravity field. Not as fast as the Apollo missions, but the first real test for ion drives I would say.
Btw, low earth orbits usually means well below 1000km and that means you are still within the earths thermosphere. A part of the atmosphere which contains mostly hot, ionized gas. Using an ion drive there might look completely different.
Sven
There has been a long discussion about this topic in the
sci.space.policy news group.
The people in there are usually extremely well informed, and none of them could see a plausible way how this could work. The problem is that there is no way to get lift without drag, and even with a very good supersonic lift to drag ratio the drag would be bigger than the thrust of the ion engines.
If they can pull it off anyway, they will get richer than bill gates. But I am not holding my breath.
Private property is the central institution of a free society (David Friedman)
Coat them with aerogel that'll trap the offending paint chips and pose no threat thanks to its low mass.
-C
why not a lighter than air rocket? By making a really long rocket with a big chamber for He (or why not H if it's significantly lighter, just be sure and post a no smoking sign), and let the helium take it as high as it can before turning on the conventional rockets? I'm sure it would require a lot less fuel than a conventional rocket, would have a naturally slowed descent, and it would allow the blimp to go to the moon.
Help! I'm being repressed!
The problem with getting to orbit isn't altitude, it's velocity. From your handy-dandy high-school physics book: E_altitude = mgh (mass times gravity times altitude) = 1 kg * 9.8 m/s2 * 100 km = 9.8*10^5 J. Whereas kinetic energy is E_kinetic = 0.5*m*v^2 = 0.5 * 1kg *(7.6 km/s)^2 = 2.8*10^7 J.
So getting to altitude takes only 3% of the energy required to reach orbital velocity. This is again why all these schemes that have you starting on a balloon, or a tall tree or whatever just won't work. Saying I lack vision is idiotic; I just happen to know some physics.
Human genome = 3 billion base pairs = 6 GBit. Windows + Office = 20 Gbit. Which is more impressive?
How these blimps will handle all the floating small debris that rains downwards?
I prefer the "u" in honour as it seems to be missing these days.
If the above gapemouth took time to read all the connected websites including the companie's site at www.jpaerospace.com, then he would have found out that all the testing to date on these systems have been done with helium as the lifting gas. The Ascender, the lifting ship that will provide the primary lift to the large 'Strato Station' appears to be designed with the use of helium as the lift fluid.
Inasmuch as the United States Air Force has subcontracted JP Aerospace, the holder of the above website, to build prototypes of the Ascender for them; and inasmuch as they have built three of them including a closer to scale version of it that is 175 feet long (350 feet if you include both arms of the 'V' shape) and over 50
foot in diameter; it is a given that this is a very serious effort. By the way, the Air Force does not send its men up in hydrogen balloons. I spent over 10 years in the Air Force and we know about the Hindenburg as well.
This company is on a long term research project concerning this and is not playing games. It is going slowly and methodically, testing each piece of the project before going on to the next step.
Personally, I would like to be able to walk the halls of the 'Strato Station' when it gets built. They envision a 2 mile wide structure that will float at 140,000 feet, having 5 arms in a 5 pointed star like the interior arms of Chrysler's old pentagon symbol on their cars. Visions of Star Trek's 'Deep Space Nine' assert themselves.
This would be a terminal in the true sense of the word. At less then a dollar/pound/mile of ascent, the private industrial world would become players as well.
This technology is not limited to our planet.
New materials for balloon envelopes have made this
possible, and other new materials have made possible other parts of the structure. Computers have made possible station stabilization methods unthinkable even 20 years ago. Other nations will build this as well. So if we do not go this way or at least explore it, we will just get left behind. Maybe we need another shock like Sputnik to ignite our efforts that I know we are capable.
And to think we're giving all that precious Helium away to children inside silly ballons!
Won't somebody please think of the blimps?
I wouldn't mod you a troll, but maybe a -1 DRTFA. One of the outstanding questions in the project is: "Can the vehicle accelerate to the Mach 25 necessary to reach orbit?" So whether its prior posters who didn't read, or yourself, it does clearly state that the blimp team is aware of the need for speed.
The speed is achieved through a bizarre combination of tech:
In theory, despite the extremely thin atmosphere, the airship will act like a lifting body as it accelerates to orbit velocity over several days. As it climbs, it relies less on aerodynamic lift & more on the propulsion from the ion drive. Certainly seems odd to me, but they claim there's a fairly wide window to be hit.
http://slashdot.org/comments.pl?sid=108858&cid=925 4503
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The paper (on PDF, downloaded) states they rely on buoyancy up to a specific point, and then use the ion drives to push up from that equilibrium point up to LEO.
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The physics is a bit more complicated than some here realize. The airships are shaped like wings for a reason. We intend to use both buoyant and dynamic lift for each of the Ascenders.
And... yes... Drag is a significant issue. The power you need to increase the speed depends directly on the drag force. Obviously we must use dynamic lift as much as possible to fly high enough for our engines to be able to add the delta-vee we need. If we don't have enough power, it can't be done. If we do, it can be done. It's that simple.
Also, be aware that the ion engines we have in mind are the third place finishers for job. The first place engines are ones we can't talk about yet without spending time in jail. 8)
--Be The Alien.
Two gold stars for you!
We will be using dynamic lift. That is an absolute must. We will also be bringing the truss structures inside the envelope, so the drag coefficients should become more comparable to regular flying wings.
The heat loading issue on the way back down is no worse than it is on the way up. We can go into a high drag profile at a very high altitude and spread the loss of kinetic energy over a very long time frame. Skin heating is proportional to the power dissipation rate, so a long time frame keeps that number low.
--Be The Alien.
There is something subtle they've missed.
I am the teams physicist if you have any direct questions. I won't answer everything because a competitor with more cash could displace us, but I do intend to open source the simulator I've built.
--Be The Alien.
No Sputnik needed. Just buy t-shirts, hats, and so on. Volunteer to help if you can. Be patient otherwise because we won't stop.
--Be The Alien.