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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."
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?
Incase there are actually people not reading the linked article, the interesting part is quoted here:
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I would love to see huge balloon animals in the night sky..
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.
It's like a Sagittarius, only friskier.
So the first word visiting aliens will see will be "Goodyear."
The coolest voice ever.
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.
Half the weight. Hydrogen is diatomic.
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?
just carry a saftey pin with you on the way up, that'll get you down quicker... ;)
The Hindenburg was filled with hydrogen, not helium. Hydrogen burns, helium does not. Besides, the Hindenburg was painted with some rather flammable compounds..
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.
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.
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Whether you reach orbital velocity in 9 days or 9 minutes, you're still travelling at orbital velocity.
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).
Eloi, Eloi, lema sabachtani?
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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.
I watched C-beams glitter in the dark near the Tannhauser gate.
That is what the ion engine is for. They calculate it will take 9 days to acclerate the craft to 8km/s.
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.
"Studies have shown that people who eat peanuts live longer than those who do not eat."
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.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
They're almost certainly dynamically stable in position and tension.
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.
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.
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.
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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
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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 and here and here.
Tuus crepidae innexilis sunt.
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.
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'.
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.
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.