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."

Cost to orbit

[BWJones]

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.

Re:Cost to orbit / quote

[Anonymous Coward]

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.

Re:Cost to orbit

[confused one]

ahhhh Helium... Why oh why must we always use Helium... Hydrogen is 1/4 the weight & therefor would have close to 4 times the buoyancy. Hydrogen is good...

Re:Cost to orbit

[the_mad_poster]

Yea, good and explosive. While it may not be particularly dangerous to people, losing payloads to accidents involving hydrogen explosions in the atmosphere would jack the potential cost up.

Re:Cost to orbit

[kpansky]

Right... because ROCKET FUEL is much more stable...

Re:Cost to orbit

[JabberWokky]

No, but Helium, having a filled outer electron shell, is *very* stable, and since the comparison was between Hydrogen and Helium, the fact that Hydrogen is unstable is applicable.

Which brings up the interesting question of what there is in the upper atmosphere... is there enough oxygen for hydrogen to burn?

--
Evan "Not a meteorologist"

Re:Cost to orbit

[Coz]

Yes. Atomic oxygen (O1), standard diatomic oxygen (O2, the kind we breathe), and ozone (O3, the kind the blocks UV and gets eaten by fluorocarbons). O1 and O3 are very reactive, but nothing that a hydrogen balloon should have to worry about, so long as it contains most of its hydrogen.

Of course, one of the other great benefits of helium over hydrogen is that helium is MUCH more containable - He stays inside Mylar envelopes a lot longer than H, which has been known to burrow its way out of multi-layer met

Re:Cost to orbit

[Greedo]

Also, I remember reading a while ago that the earth's helium resources are pretty limited. Any helium that escapes into the atmosphere isn't coming back. Ever.

So, once we use the helium we have, we aren't getting any more. One source says this may happen by 2030.

Found some googled info here [anl.gov] and here [omsi.edu] and here [gopbi.com].

Re:Cost to orbit

[ahfoo]

WElp, I did a bit of research as well and you're right that it does leave the Earth, but your tone of urgency, which I'm assuming, may be a bit displaced.

Helium makes up about 0.0005% of the earth's atmosphere. This trace amount of helium is not gravitationally bound to the earth and is constantly lost to space. The earth's atmospheric helium is replaced by the decay of radioactive elements in the earth's crust. Alpha decay, one type of radioactive decay, produces particles called alpha particles. An alpha particle can become a helium atom once it captures two electrons from its surroundings. This newly formed helium can eventually work its way to the atmosphere through cracks in the crust.

Quoted from education.jlab.org [jlab.org]

So, yeah, you're right it's leaving, but it's also being replaced by natural radioactivity so that even after all the hydrocarbons are used up, natural gas wells will still be producing helium for millions of years.

According to Praxair, fifty percent of current natural gas consists of helium. So, it's not all that rare which helps to explain why it's not all that expensive.

Re:Cost to orbit

[portforward]

Actually the Hindenburg probably wouldn't have blown up or burnt nearly so quickly IF THEY DIDN'T PAINT IT WITH ROCKET FUEL. (oh the irony) Hydrogen will burn with a flame that travels upwards.

No, the only safety concern that I have with Hydrogen is that it tends to escape from a confined space much more quickly than does Helium.

Re:Cost to orbit

[Ungrounded Lightning]

No, the only safety concern that I have with Hydrogen is that it tends to escape from a confined space much more quickly than does Helium.

It also burns with an invisible (ultraviolet) flame - and a leak is essentially ALWAYS lit. (NASA used to find them by having a worker walk slowly forward holding a big piece of cardboard edge-on in front of him, stopping when it caught fire. B-) )

Re:Cost to orbit

[Oculus Habent]

I'm more worried about the massive debris field we've strewn around our planet. Blimps may be cheap, but if we blow holes through them with paint chips from the 70's, the worth suddenly drops.

Maybe this will make it affordable to launch garbage collection in space, though.

Blimps do not necesarily crash due to leaks

[tarranp]

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.

Re:Blimps do not necesarily crash due to leaks

[Oculus Habent]

I suppose that once you get to LEO, it's not so much of an issue, as whatever the blimp is carrying may be able to propel itself into higher orbit.

My understanding of blimps is that they use equivalent pressure - hence the airsacs that allow pressure changes as they rise - and rely on the buoyancy of lower weight at the same pressure.

I'm just thinking of a blimp on the edge of space suddenly getting hit with a small projectile traveling 1000+ miles per hour. That could do some serious damage. Aside from making a hole, the force of impact might well deform the ballon, rapidly forcing gas from it. This is unlike most damage that occurs with conventional blimps. And, the additional height exacerbates the issues with blimps, giving them more time to slowly leak as they descend and more time to accelerate.

helium != diatomic

[pwarf]

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 disad

Re:Blimps do not necesarily crash due to leaks

[Dyolf Knip]

Helium _might_ make sense for the first leg of the trip, if only to placate the "But the Hindenburg!" crowd. But past a few dozen thousand feet, there's no point. As you said, there's not really enough internal overpressure for the incredible diffusive properties of H2 to matter so much, and there's not even enough oxygen around for it to combust with! You'd quadruple your payload capacity at a stroke. And both H2 and He have liquification points far below the temperature around LEO, so no worries there

Re:Cost to orbit

[mindstrm]

Seems not to be a problem.

When the blimp is staying up via buoyancy, it's still in atmosphere by definition. If there is atmosphere of any sort, it's rather unlikely you will find high velocity paint chips or other things.. they would quickly slow down, burn up, etc.

When the blimp is OUT of the atmosphere, at orbital velocity, it is no longer staying up there via buoyancy, and puncturing it's gasbags would not really be an issue as far as staying up there goes.

Re:Cost to orbit

[jlaxson]

Because... [wikipedia.org]

Re:Cost to orbit

[afidel]

Thank you. The stupid Hindenburg was the begining of bad science in the media. Due to the radio reports and the worldwide viewing of the recorded images of the disaster no formal inqury into the cause of the disaster was done. As we know now the skin of the Hindenburg was painted with what was essentially ROCKET FUEL. A small static discharge along a seam is the most likely cause of the disaster, the skin almost exploded and it wasn't until much later in the disaster when the envelopes tore open due to loss of internal structure that the Hydrogen had any affect on the fire. Not only that but no people were hurt by the hydrogen fire because due to hydrogens boyancy it would have risen to the top of the structure and burnt there.

Re:Cost to orbit

[Sparr0]

uhm... no. hydrogen is 1/4 the weight and therefore has ((airdensity)-(heliumdensity))/((airdensity)-(heli umdensity/4)) the buoyancy. In this case the density of air is so much higher that the increase in buoyancy isnt even 25%, let alone the 300% you say.

Re:Cost to orbit

[another_henry]

Incorrect. The blimp expands until the pressure inside is the same as the pressure outside, so any change in air density will be reflected as a proportional change in helium/hydrogen density. See my other post for a longer explanation of that.

Re:Cost to orbit

[kmac06]

Half the weight. Hydrogen is diatomic.

Re:Cost to orbit

[MrNovember]

Really. It's not like sitting on top of many tons of pressurized, igniting liquid oxygen and hydrogen is any more dangerous than sitting under a hydrogen blimp.

I bet people just keep thinking of the Hindenberg.

Re:Cost to orbit

[Dark Paladin]

Oh, the humanity!

Helium vs. Hydrogen

[mbessey]

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

Re:Cost to orbit

[another_henry]

Actually I thought that, but when you run the numbers you find that helium is very close in terms of buoyancy for a couple of reasons.

Firstly, helium gas goes round as a single atom, He, because it's a noble gas. Hydrogen goes as pairs, H2. This means that in a given volume at fixed pressure, you would have twice as many hydrogen atoms as you would heliums, so that brings the difference in weight down to 1/2.

Secondly and more importantly, it's not actually the weight that counts. (Please if I've got this wrong, correct me, this is just from me thinking about it) The important thing is the difference in weight between e.g. a liter of air and a liter of helium/hydrogen.

Air is mostly nitrogen which has mass no. 14. This means that 1 mole of N2 molecules weighs 28g. A mole of any gas occupies 24 liters at STP so air weighs about 1.17 g per liter. Running the numbers for He and H2 gives 0.16 and 0.08 respectively.

Now, looking at the difference in weight, which is what determines buoyancy, helium gives about 1.01 g per liter while hydrogen gives 1.09 g per liter. Not such a big difference after all! I think that the advantage of non-flammability probably outweighs this minor difference in buoyancy. On the other hand, it may very well be easier and cheaper to produce hydrogen in bulk than helium.

Re:Cost to orbit

[angst_ridden_hipster]

Although the Hindenburg is often perceived as an advertisement against hydrogen, it was, in reality, more of an advertisement against using cellulose nitrate or cellulose acetate to add rigidity to the skin of a dirigible.

In all likelihood, it was the flammable nature of the skin that led to the ignition. Sure, having all that hydrogen there didn't help once the fire started, but there were a lot of successful hydrogen-filled blimps and dirigibles up to that point (the survival ratio was at least as good, if not better, than that of hydrazine or solid-propellant rockets).

Re:Cost to orbit

[techno-vampire]

Although the Hindenburg is often perceived as an advertisement against hydrogen, it was, in reality, more of an advertisement against using cellulose nitrate or cellulose acetate to add rigidity to the skin of a dirigible.

It's much worse than that. In order to make it look better, they covered the skin with a mixture of iron oxide and aluminum powder. That's right, boys and girls, they covered it with thermite! No wonder it burned so fast!

What's that hissing sound?

[spun]

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 ;-)

Not a dollar a ton...

[Chmcginn]

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.

Re:Cost to orbit

[georgewilliamherbert]

Space Elevators == folly.
The problem is, you have to keep it up and stable. Major danger given the forces involved.

I wish ignorant people would stop saying that.

They're almost certainly dynamically stable in position and tension.

And when it fails, it's a total catastrophe.

I wish ignorant people would stop saying that, too.

It's going to be a thin ribbon of probably carbon nanotube fibers. How much ribbon do you need to drop on someone to hurt them?

Common retort: Oh, but it's falling from orbit

What is the terminal velocity of a strand of ribbon? Do you have a one story building's roof available to demonstrate this to yourself?

Most of it, falling down, will burn up in the upper atmosphere. That which does not, will fall so slowly by the time it reaches ground level as to pose no threat to anyone on the ground, unless you tangle yourself up in it after it lands or it happens to catch an airplane on the way down.

Screaming terror scenarios of huge swaths of land ruined by explosive impact are bad science fiction not fact. No competent professional has ever said such a thing. It just plain will not happen.

Re:Cost to orbit

[Thuktun]

What is the terminal velocity of a strand of ribbon? Do you have a one story building's roof available to demonstrate this to yourself?

While I tend to agree with your overall claim, this particular comparison doesn't seem all that straightforward. That's the terminal velocity of an infinitesimal fragment of the overall tether.

Small pieces tend to flutter in the breeze. Would a mile's length of tether also flutter? Much less so, at least in the middle, since any given small length of the tether would need to pull on the parts above and below it to move out of position. I'd be interesting to see a computer simulation of this.

Re:Weight, profile and wind

[barawn]

Does the name Tacoma Narrows ring a bell?

Yes, it does. And it did to the people who looked at the space elevator as well. The Tacoma Narrows bridge fell because the period of its resonant frequency happened to be close to a naturally occurring oscillation.

In order for resonance to be a serious problem, the induced oscillation has to occur over the entire object, and it has to be close in period to the natural frequency of the object.

The fundamental period of the space elevator is 7 hours. There's nothing which occurs on the full scale of the elevator (hundreds of thousands of kilometers) which is near to 7 hours.

So induced oscillations aren't a worry.

(Wind oscillations are a non issue if they don't rip the ribbon. The ribbon is huge. The atmosphere is just a tiny sliver compared to its full length.)

Re:Weight, profile and wind

[blair1q]

When you pluck a guitar string, do you stretch your fingers from capo to bridge? Or is your pick just a tiny sliver compared to its full length? The latter, I think. Which should open your mind a little. Here's what to allow into it:

The wind at the bottom will act more like a violin bow, and the harmonics of the primary mode of vibration (i.e., all the multiples of f=1/(7*3600) cycles/second) will be induced into the cable in the stable state.

These vibrations won't be simply transverse, but helical as

Re:Cost to orbit

[Spoticus]

What is the terminal velocity of a strand of ribbon?

African or European ribbon?

Only since 2002?

[Mz6]

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.

x-prize

[Capt'n Hector]

Eh? That's the coolest thing I've seen in a while, if it's at all possible. Kinda blows the x-prize away.

Re:x-prize

[confused one]

That's the coolest thing I've seen in a while

That was exactly my response. Amazing. Why hadn't anyone thought of this before!

Oh the humanity

[daeley]

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."

Re:Oh the humanity

[daeley]

I am imagining this thing getting a hole from a micrometeorite and going fllurruurpptpppthhh around the globe like a punctured balloon in your living room, whacking into San Francisco, slobbering over Addis Ababa, sliming Machu Picchu, bouncing off Sidney before coming to rest sadly draped over the Eiffel Tower. Of course.

Re:Oh the humanity

[dmaxwell]

Even regular blimps use multiple gas cells so that a problem with one doesn't bring the whole thing down. Granted, debris is a concern but it needn't be a deal breaker.

NOT a dollar/ton

[SeanTobin]

The price is NOT a doller/ton. It is a dollar per ton/mile.

Incase there are actually people not reading the linked article, the interesting part is quoted here:

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.

Re:NOT a dollar/ton

[rmohr02]

The price is NOT a doller/ton. It is a dollar per ton/mile.

Correct. However, it is still an order of magnitude cheaper than conventional ways of getting cargo into orbit.

Re:NOT a dollar/ton

[Bingo Foo]

Which is pretty close to an order of magnitude of orders of magnitude.

Re:NOT a dollar/ton

[DeepDarkSky]

That is still damn cheap. How many miles to space?

Re:NOT a dollar/ton

[linzeal]

Well around 10,000 miles [nasa.gov] so around 16,093 km [google.com], for all you science types and Europeans.

Re:NOT a dollar/ton

[SEE]

Well, what do you mean by "space"?

The U.S. definition is 50 miles high (80 km). The FAI uses 100 km (62 miles).

Mercury 3 (Freedom 7) reached 186.2 km (115.7 miles) at its greatest distance from Earth, while Vostok I perigeed at 169 km (105 miles) and apogeed at 315 km (196 miles) in its orbit.

The exosphere goes out to 10,000 km (6213 miles); the only humans to ever go beyond it were in Apollo mission 8 and 10-17.

Re:NOT a dollar/ton

[Capt'n Hector]

So that makes it ~$1,000 per ton to LEO. That's still WAY cheaper than current rates.

Too good to be true.

[kippy]

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.

Re:NOT a dollar/ton

[NoMoreNicksLeft]

Wow. Here I was, ready to put a 1 ton satellite into orbit for $1. Instead, I find out it costs nearly $200. You've dashed my hopes of becoming a private space power. Damn you.

Can I have a Giraffe?

[g0nk]

I would love to see huge balloon animals in the night sky..

Re:Can I have a Giraffe?

[confused one]

OMGROFLOL. I hadn't thought of that. Why not...

Ads in space?

[macshune]

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?

It... is... BALLOON!

[pedantic bore]

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.

Crossing fingers that this won't lead to another..

[saskboy]

OH THE HUMANITY!

Fortunately this time we should have the sense not to paint the blimps with highly flammable doping.

Couple of things...

[Skyshadow]

First, an error I noticed: It's not $1/ton to LEO, it's $1 per ton/mile. It's still really low, but it's a pretty significant difference.

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.

Re:Couple of things...

[Tyler Eaves]

Well, let's work it out. Assuming an ion Drive can produce a net thrust of 0.01g (.0931 m/s). LEO is around 7600m/s. That gives 81362 seconds, or 22 hours. Obviously they're planning on much lower accelerations than even that, but low forces build up over time.

Re:Couple of things...

[confused one]

Are these space blimps ... going to manage to accelerate a load from a relative standstill to LEO speeds using an ion engine

a few days... a few weeks... does it really matter? It still gets you to LEO for peanuts.

Re:Couple of things...

[Penguinshit]

Congratulations on working a Sluggy Freelance [sluggy.com] reference into your post!

I'm also bitter because I was too late to do it first.

Fear the rabbit!

Blimp Cruises

[ChowyChow]

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.

Re:Blimp Cruises

[Unordained]

Compared to having your ass embedded in a chair during lift-off ... yeah, I'd say this would be more family-friendly. With catering all the way up. And down. Then the bulk of your cost is managing the customers, not the hauling itself.

9 days might be a bit long though -- 18 day round-trip? That, and when you get to LEO ... are they just going to announce "uh, welcome to LEO. it looks just like it has for a few hours, but we're at the top now. and going back down. slowly." Won't be very impressive in that s

Probably not X Prize contenders.

[mr_mischief]

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.

Re:Probably not X Prize contenders.

[g0nk]

just carry a saftey pin with you on the way up, that'll get you down quicker... ;)

Great...

[Faust7]

So the first word visiting aliens will see will be "Goodyear."

WTF?

[wwest4]

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?

Re:WTF?

[Froze]

Your question begs multiple misconceptions.

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.

Second, escape velicity is a ballistic value, ie. the speed required to kick your butt off the planet from ground level going straight up.

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.

Further, the higher you go, the less drag you feel, hence the "launch" of the orbiter from a platform already 20 miles up.

This one isnt going to be easy

[Manhigh]

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.

I'm a bit confused by this statement:

[Vellmont]

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.

Up-fast-down-fast?

[Syberghost]

Whether you reach orbital velocity in 9 days or 9 minutes, you're still travelling at orbital velocity.

Advanced Materials

[Skyshadow]

I was just mulling this over thinking about how cool it is -- seems more realistic than something like a space fountain -- when I remembered the Diamond Age.

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?

Re:Advanced Materials

[LaCosaNostradamus]

The blimp in Stephenson's The Diamond Age was filled with vacuum, and a cyberpunk author did something similar with tall buildings in one of his books (building tops were large balloons whose lift helped support the building weight so the thing could carry more floors).

This is different than a gasbag put into a vacuum. Stephenson's blimps were under compression, and the proposed blimp-in-space is under tension.

Compression's a bitch. Holding a 500-foot-dia sphere in enough equalized compression to avoid buckling and collapse is insanely difficult, which is why nanotech was the narrative used to justify it. But tension? Ha, tension's a walk in the park particularly for materials formed into skins.

Just eyeballing it, we have more than enough common materials like mylar that can produce a gasbag of sufficient size (i.e. common Goodyear blimp). If the tension proves too much for mylar, then some strenghtening can be done like sail makers do all the time, with carbon-fiber thread wrappings, etc. But my rule-of-thumb gets hazy for things that are kilometers in size under the gas pressures they must contain, since tension rises appreciably with the radius of curvature.

Pong Stats

[proudlyindian]

Pong statistics for leo.space.com:
Balls: Sent = 2002, Received = 1001, Lost = 1001 (50% loss)

Striving to be common [blogspot.com]

9 days to LEO

[Marxist Hacker 42]

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.....

Odd economics...

[sterno]

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.

Might be a stupid celestial mecannic question but:

[aepervius]

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 ?

Re:Might be a stupid celestial mecannic question b

[DerekLyons]

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 ?

It's naive thinking. (The same kind of naive thinking leads to proposals for air breathing first stages.)

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.

RTFM...

[TheSync]

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.

NOBODY'S SEEN THE IMPLICATIONS?

[alizard]

From what I've seen here, what's left to do on the project is development, the proof of concept is already done.

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 [ecis.com]

Re:NOBODY'S SEEN THE IMPLICATIONS?

[alizard]

Given 1% of NASA's budget, I think their timeframe to orbit could be compressed a hell of a lot.

This suggests that it's time for NASA to get out of most of the space transportation business and fund this instead.

Given that money spent on a transportation and platform system that is almost a slam-dunk (a big-D sort of R&D project), NASA should then refocus its priorities onto getting the "proof of concept" demo for the Space Power Satellite system together and the lunar industrial facilities which will

As someone else noted...

[Kozar_The_Malignant]

on an earlier blimp story, you look up at the giant blimp passing overhead. A voice from the sky intones, "Spawn More Overlords."

Been done.

[Medievalist]

Hell, Frank Read [bigredhair.com] did this in the 1800s.

Space cruise?

[MAXOMENOS]

$1/ton/mile for cargo.

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.

No way. Unfortunately. Way too much drag

[Thagg]

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.

If the ship was, say, 50 ft wide and had a rediculously low drag coefficient of .01, then the drag force at 5000 fps, 1/5 of orbital velocity, is: .5 rho Cd V^2 A

where

rho is density (about 1.7x10^-5 slugs/ft^3)
Cd is .01
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 [nasa.gov] 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

Re:No way. Unfortunately. Way too much drag

[wwest4]

I came up with a similar result. Maybe we should just shut up and short the stock later on. :)

Re:No way. Unfortunately. Way too much drag

[tsotha]

You are assuming this thing is going to be a bigger, thinner Goodyear blimp. According to what I've read (and look at the picture), part of the idea here is the shape of the craft is supposed to generate lift. So by the time it's going 5000 fps it'll be far above its original altitude with very little drag.

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 i

Re:No way. Unfortunately. Way too much drag

[cybercuzco]

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

Gravity in the blimp space station

[w3woody]

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.

Re:LEO?

[apraetor]

Low Earth Orbit.

Definition...

[Mz6]

LEO = Low Earth Orbit

Re:LEO?

[Anonymous Coward]

It's like a Sagittarius, only friskier.

Re:LEO?

[jlaxson]

Low-earth Orbit [wikipedia.org]

Re:Potential for a disaster

[apraetor]

The Hindenburg was filled with hydrogen, not helium. Hydrogen burns, helium does not. Besides, the Hindenburg was painted with some rather flammable compounds..

Re:Potential for a disaster

[Mannerism]

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.

Re:Potential for a disaster

[HarveyBirdman]

Blimps in space?

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?

Re:Altitude != orbit -- The beginning of the end

[stripe]

That is what the ion engine is for. They calculate it will take 9 days to acclerate the craft to 8km/s.

Re:Crap?

[Marxist Hacker 42]

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.

Re:Crap?

[Anonymous Coward]

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'.

Re:Crap?

[RayBender]

I swear the moderators are on crack today, and I know I'll end up paying for this in karma, but someone needs to be the voice of sanity here. Does no-one know any physics? Lets break it down:

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 h

Re:Crap rockets?

[RayBender]

I know I'm going to end up being modded a troll for this - it seems anyone who actually thinks critically about this stuff does. But seriously, I haven't lived under a bridge in years, and last time I went sunbathing I didn't turn to stone.

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 *(

Re:Helium non-renewable

[Teahouse]

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.