Slashdot Mirror
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.
Visit Jonesblog and say hello.
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?
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;
I would love to see huge balloon animals in the night sky..
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.
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.
Low Earth Orbit.
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.
It's like a Sagittarius, only friskier.
Low-earth Orbit
On Apple Input Peripherals: They're okay, I guess, but I was really hoping for a one-key keyboard and a 109-button mouse
So the first word visiting aliens will see will be "Goodyear."
The coolest voice ever.
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?
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?
The Hindenburg was filled with hydrogen, not helium. Hydrogen burns, helium does not. Besides, the Hindenburg was painted with some rather flammable compounds..
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.
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?
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
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
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.
That is what the ion engine is for. They calculate it will take 9 days to acclerate the craft to 8km/s.
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
Or Law Enforcement Officer, but I dunno why you'd want to fly a blimp to the local police station.
LOAD "SIG",8,1
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.
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.
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:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
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.
Hindenburg, anyone?
Man, I'd hate to be in the blimp industry. Give a dog a bad name, or what? One big accident almost seventy years ago and every time somebody suggests a blimp as a solution to anything, everybody assumes it's a fiery disaster waiting to happen. It's as if we'd all given up on ships after the Titanic.
Please donate your spare CPU cycles to help fight cancer and other diseases
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
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.
You forgot to figure in the ion drive- which very slowly accelerates the blimp as it goes up. In addition, we're talking blimps, not balloons (rigid structure, not inflateable tech) which, supposedly, can handle the vaccuum. You're not at orbital velocity until you're already in near-vacuum.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
Actually it is. Any Nuclear reactor can be tuned to produce Helium. I think they did this briefly at the Laurence Livermoor reactor for a short time before decomissioning it.
"Curiosity killed the cat, but for a while I was a suspect."- Steven Wright
This is stupid, I swear noone has any vision.
First, they're talking about 20 miles up for this two-mile 'lily-pad'. At 20 miles, we still have atmosphere, so we still have buoyant(sp) forces acting. Since there's a buyoant(sp) force at work, orbital mechanics can be damned. Your airship doesn't fall back to Earth because it's lighter than air.
Are you with me, then? You have a lovely two-mile long launch platform. From here, you launch another, smaller balloon with even less density and a few ion engines. This smaller balloon floats up as high as the remaining atmosphere allows. At this point, we'll say that the balloon is 'floating' on the very top of the Earth's atmosphere. It won't go down (buyoant[sp] force) and it won't go up (gravity). At this point, as long as the ion engines can beat the force of gravity, you have acceleration.
Acceleration, even small amounts of it, mean a lot in a vaccum. Give it a couple weeks and you'll find yourself speeding along at 8 km/s. Let go of the object you want in orbit and use the same ion engines to slow down. Physics being what they are, you should wind up back where you started with the same amount of velocity as when you left. At which point, you'll be 'floating' on the top of the Earth's atmosphere and you can manipulate your airship to get back down to the 20-mile-high 'lily-pad'.
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.
Hell, Frank Read did this in the 1800s.
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
Hindenburg, anyone?
No oxygen to burn?
Helium, not hydrogen?
In the Hindenburg it was the blimp material and not the hydrogen that caused the flames?
Ignorant Comment Of The Week, anyone?
--- Ban humanity.
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.
"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.
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
Losses due to mass? Back to Physics Jail with you!
Why yes, I AM a rocket scientist!
I came up with a similar result. Maybe we should just shut up and short the stock later on. :)
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.)
You're right that "thrust" should be "acceleration", but you're wrong about g. G is the gravitational constant; g is the acceleration due to gravity at the Earth's surface.
The shareholder is always right.
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.
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?
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
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?
At this point, we'll say that the balloon is 'floating' on the very top of the Earth's atmosphere. It won't go down (buyoant[sp] force) and it won't go up (gravity). At this point, as long as the ion engines can beat the force of gravity, you have acceleration.
Wrong! As long as the ion engines can beat drag, you have acceleration. But they won't, and you can show that in a few lines - though I wish it were easier to write equations here...
At 50 km altitude the atmospheric denisty is something like 1 gram per cubic meter. So to lift 1 kg of mass with a balloon you need something like 1000 cubic meters of volume (actually more since you're using hydrogen and not vacuum, but whatever). That will mean a balloon with a radius of 6 meters. It will have a frontal area of 120 square meters. Now, the drag equation is: F_drag = Cd * Area * density * velocity^2, where Cd = 0.2, Area = 120 m2, denisty = 0.001 kg/m3, velocity = 8 km/s. So, F_d = 1.5 million Newton. The ion engine on DS-1 produced 0.09 N of thrust, and massed about 10 kg.
So this idea is cracked by a factor of 10 million or so. I'm sure I'll get lots of indignant, anonymous replies saying how it's actually at 60 km, not 50 etc etc. But the point remains, this is an idea anyone who passed high school physics should be able to see through. Sorry, but that's life. Don't moderate down the messenger....
Human genome = 3 billion base pairs = 6 GBit. Windows + Office = 20 Gbit. Which is more impressive?
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.