For all the rabid speculation in 1950s space-age expos, rockets actually haven't changed that much in the last 60 years -- at first glance, anyway. For the vast majority of orbital missions, the stuff on the launch pad today looks pretty much the same as it always has.
The situation might evolve eventually. But change is likely to be gradual, as Trace Dominguez explains in today's DNews dispatch.
A British company called Reaction Engines Limited is one of several entities working on spaceplane hybrids that fundamentally change the strategy of getting people and things into orbit. The company's Synergetic Air-Breathing Rocket Engines -- or SABRE -- is designed to work both in and out of Earth's atmosphere.
Jet engines require oxygen to combust fuel and generate thrust, and the SABRE engine does double duty in that regard. When the space plane is still low enough, it uses oxygen in the atmosphere to ramp up to speeds approaching five times the speed of sound. Once it's too high to use available oxygen, the SABRE engine switches over to onboard liquid oxygen. By employing a reusable engine for both jobs, the vehicle saves on money and weight.
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The U.K. aerospace company Airbus takes a similar approach with its Adeline system. But instead of saving and reusing the whole rocket, the Adeline module sits at the bottom of the rocket stack and returns to Earth with critical and expensive components, like the avionics, computers and main engines.
The basic idea of a spaceplane isn't new -- alert citizens may recall a little shuttle program operated by NASA for many years. Today's various rocket technologies are essentially updates and upgrades to core technologies that have been around for a long while. NASA's new Space Launch System -- designed to replace the shuttle program -- is built around proven rocket technologies, so it might look familiar. But underneath the hood, power and efficiency are maxed out with 21st-century specifications.
Beyond rockets, there are other ways to get into space -- theoretically, anyway. Like, say, an elevator. Seriously. But until these next-era technologies become practical, rockets and spaceplanes will continue to look like rockets and spaceplanes. You know what they say about things that ain't broke.
-- Glenn McDonald
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