But for an accident of history, this is how space science would have been done:
This is the launch a few days ago of the Compton Spectrometer and Imager, a soft gamma-ray (0.2 to 10 MeV) telescope designed to look at what’s happening around the galactic black hole and in supernova remnants. You can follow its track and get views from its camera:
For a couple of million bucks these super-pressure balloons let you fly close to the edge of space – 33 km (110,000 feet) up, above 99.5% of the atmosphere. The balloon is meant to stay up for at least 100 days, and will circle the earth several times at the latitude of New Zealand. Super-pressurizing means that there is extra helium in the balloon, so that even when it cools off at night it still has the same volume, and therefore the same lift. The pressure difference between day and night is very small, only 0.03 psi, but that adds up over the 22 acres of surface.
They’re tricky to make because the extra pressure tends to make the envelope leak and then tear. They’re made of 20 um thick polyethylene, the same as Saran wrap, with lines that run from top to bottom to keep the force off the film. More design info here. This pumpkin-style super-pressure balloon was invented by Julian Nott, who flew one from Perth on the west coast of Australia to Broken Hill on the east in 1984. Google is using them for Project Loon, their attempt to build a world-wide wireless network by having thousands of these balloons floating around 20 km up with links to the ground and to each other. This one was built by NASA’s Columbia Scientific Balloon Facility in Palestine TX, which is managed by the rocket company Orbital ATK. They’ve done over a thousand launches, including missions that do great science like the BLAST far infrared telescope and the BOOMERanG cosmic microwave background instrument. The program costs about $34 million to do a dozen launches a year from Texas, New Mexico, Antarctica, and Sweden.
So how is it that this elegant and cheap method of flight doesn’t dominate space science? You could launch twenty missions like this for the cost of a single satellite. Plus you can retrieve your instrument at the end, if the parachute landing isn’t too hard. Plus you get to visit New Zealand!
Balloons like this could have been built in the 1960s, and in fact small ones were as part of the GHOST program for world-wide weather monitoring. One of those balloons stayed up for two years, circling the earth dozens of times, and there was an unconfirmed sighting of one 15 years later. Yet somehow they’re a neglected corner of the field.
I blame Walter Dornberger, the project manager for the V-2. In 1942, after showing Adolf Hitler a test firing, he convinced Hitler that the rocket should be the top priority of the German economy. The whole program cost 50% more than the Manhattan Project. It killed more people in its construction, 12,000, than it did in its use, 9,000. It so exhausted Germany that it probably shortened the war.
Rocketry would have taken decades longer to develop without that vast war-time investment. Without the example of the V-2, the US and USSR would never have made the even vaster investments in the ICBM, and that’s what ultimately made orbital rocketry possible. One successful demo in 1942 by a hard-charging startup CEO to a VC with particularly deep pockets, and the whole direction of science changed.
This isn’t a good way to make technical decisions. Rocketry has not turned out to be all that technically important if you compare it to, say, plastics or electronics. Those affect daily life vastly more than anything to do with space. Nuclear fission, the other great distortion that came out of WW II, hasn’t turned out all that well either.
Ballooning really does depend on plastics and electronics, but it got short-changed. Maybe that was inevitable. There’s something primal about a big rocket launch. It tickles that instinctual pyromania that hominids have evolved over two million years of handling fire. Maybe the graceful bobbing of a balloon as it lifts off just can’t compete with the glamorous roar and blaze of a rocket. But now that super-pressure tech is finally working, maybe balloons will take their rightful place in supporting good, cheap, diverse science.
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