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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.
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.
So the first word visiting aliens will see will be "Goodyear."
The coolest voice ever.
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..
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."
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.
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'.