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."

Comments

Crap?

[RayBender]

Can somebody please explain to my why this isn't total crap? First of all, a typical balloon tops out at 140,000 ft (= 40 km) which is very different than the 100-300 km for LEO. While you might be able to stay aloft from buoyancy at 140kft, since the pressure drops with increasing altitude, so does your buoyancy force. After all, space is a vacuum, and it's hard to be lighter-than-vacuum.

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.