This week’s entry: Non-rocket spacelaunch
What it’s about: Since the beginning of space travel, we’ve really only had one method of getting to space: giant explosions. Preferably the controlled kind that propels a rocket out of Earth’s gravity. While rocket launches have gotten us a fleet of satellites, a space station, a few telescopes, and a trip to the moon, they’re not without their problems. At the top of the list, they’re dangerous, and expensive. It can cost up to $25,000 per kilogram to get materials into orbit, which is probably why the only people eager to launch a Mars mission are billionaires. But there are lots of proposed methods of getting off this crazy planet that don’t involve rocketry, some of which are plausible and some of which are delightfully nuts.
Strangest fact: The launch loop we mentioned last week—essentially a 50-mile-high, 1,200-mile-long conveyor belt into space—was gigantic by building standards, but small by non-rocket space-launch standards. Consider the orbital ring, a track (or even a space station) that encircles the entire Earth at orbital height, making it significantly longer than the Earth’s 24,901-mile circumference. The ring would be connected to the ground at at least two points—essentially space elevators on opposite points of the Earth’s surface.
Wikipedia doesn’t get into this, but there actually aren’t a lot of land masses directly opposite one another in this way, or antipodal. If you built the ring around the equator, virtually the only place to build the elevators would be Indonesia on one side and the Colombia-Brazil border on the other. If you don’t stick to the equator, you could go from northwestern Spain to the South Island of New Zealand, Beijing and eastern Argentina, or Hawaii and Botswana, but those are just about your only options.
Thing we were happiest to learn: Getting halfway to space is far more than half the battle. Besides gravity, one of the main forces that has to be overcome in a launch is resistance from the air. Fortunately, the atmosphere gets thinner as it goes, so the higher up you start, the easier a launch will be. Fifty percent of the weight of the atmosphere is in the bottom six kilometers (3.7 miles); by comparison, the tallest mountains can reach nine kilometers (5.6 miles), so simply launching from a mountaintop would save a lot of effort. Soviet rocket scientist Konstantin Tsiolkovsky, who first conceived of the space elevator, also imagined a solid tower so high it would reach into space. Of course, no material exists that could support a construction so high, but if such a building were possible, spacecraft or satellites could essentially be pushed off the roof and into orbit.
If your only issue with the space tower is that it isn’t insane, look no further than the space fountain. Instead of inventing some incredibly strong material that can support a tower up to space, the space fountain would support itself by a constant stream of “fast-moving pellets” that would hold up the building the way a stream of air holds up the inflatable guy in front of the car dealer. Materials intended for space would either be shot up with the stream of pellets, or would scale the side of the building. The whole apparatus would take an incredible amount of energy to maintain, and of course there’s a chance of a mishap that sends pellets rocketing across the landscape at high speeds.
Thing we were unhappiest to learn: The only thing to get us off this planet without a rocket might be a good man with a gun. All the way back in 1865, Jules Verne proposed in his book From The Earth To The Moon that a large enough cannon could fire a projectile into lunar orbit. Reaching Earth orbit should be much simpler, but it still has problems. First and foremost, the G-force generated by being shot into space would be too much for a human to withstand, and most inanimate objects would burn up in the atmosphere at the speeds involved. However, in the 1960s, U.S.-Canadian venture Project HARP did succeed in firing a 400-pound projectile 110 miles up into suborbital space. So while a space gun has never fired anything into orbit, it seems like a reachable goal.
Also noteworthy: Two of the more realistic options already exist. One is a spaceplane—an aircraft that flies like an airplane, but can ascend to beyond the atmosphere. (Technically the Space Shuttle was one, as is SpaceShipOne, which became the first manned private spacecraft in 2004.) However, every existing spaceplane has gotten a boost from a rocket before flying under its own power. The dream of a standalone spacecraft would involve an airplane that could use a jet engine to get to the top of the atmosphere, and then use a rocket engine once the air is too thin for jets to work.
The other option is balloons. Weather balloons have already been known to reach the edge of the atmosphere, and a big enough balloon could, in theory, lift a payload high enough to be easily launched the rest of the way into space. Alternately, very large balloons could support a spaceport in the upper stratosphere, although to carry any significant weight, they’d have to be ridiculously large balloons.
One alternative to giant balloons is the SpaceShaft. (It doesn’t have a Wiki page of its own, but we sincerely hope Bowie and Isaac Hayes collaborated on its theme song at some point). It would be a buoyant vertical tower—essentially a lighter-than-air skyscraper, or the upper-atmosphere version of a space station, which could serve as a launchpad for ships making a much shorter trip to space.
Further down the Wormhole: Early on in this feature’s history, we seemed to be invariably drawn back to space travel or Nazis, so perhaps it’s inevitable that we’ve arrived at Nazi space travel. The spaceplane page’s list of proposed projects includes the Third Reich’s Silbervogel (Silver Bird), a proposed bomber that would reach suborbital space and have enough range to take off from Germany, bomb the United States, and land in allied Japan. It was one of several competing plans for an Amerikabomber, a plane that would fulfill Hitler’s sometime dream of seeing New York in ruins (not to mention airplane and tank factories across the country). While der Führer publicly professed no plans to invade North America, he knew well before we entered the war that he’d eventually have the USA to deal with. In a Wiki Wormhole first, we’re going to look at just part of a much longer page when we examine Hitler’s plans for North America, next week.