Microsoft co-founder Paul Allen wants to revolutionize space travel, and he's betting that the upcoming Stratolaunch can dramatically cut costs and improve the number of launches we can perform on an ongoing basis. The Stratolaunch is a giant aircraft with a 117m / 386 foot wingspan -- larger than the Spruce Goose or the Saturn V, and nearly half the length of the massive Hindenburg-class airships built before WW2. The Stratolaunch is built around a pair of retired 747s, and will utilize their engines, landing gear, avionics, and flight deck to cut down on initial costs and speed development time.
The plane is expected to begin flight testing in 2016, though the difficulty of developing both the aircraft and its infrastructure could delay that further. The Stratolaunch requires a 12,000 foot runway, which is substantially longer than an average commercial jet. A standard plane can land on a runway roughly 7000 feet long, while a larger widebody typically requires at least 8,000 feet. Available statistics tend to cut off above 10,000 feet, which remains the number of existing facilities that can accommodate the Stratolaunch are few and far between.The pros and cons of air launches
The process of launching a rocket from a parent aircraft is known as an air launch, and there are advantages to launching in this fashion. An air-launched rocket deploys higher in the atmosphere where the pressure is lower and at considerable height, which means it doesn't have to start moving from 0 mph. Using a plane as a launch vehicle can also cut long-term costs by allowing the same airplane to be used on a number of launched. With its 1200 nautical mile (2200 km) range, the mothership has more flexibility to launch the payload at the best point for orbital insertion rather than relying solely on the rocket to maneuver the payload. It's also easier to build rocket components like engine nozzles that are tuned to the air conditions at 40-50,000 feet.
1,000 nautical miles is approximately 1,151 miles.
These gains are somewhat offset, however, by the limited payload and performance requirements for the aircraft itself. The plane has to be able to both take off and land with the payload attached, and it has to be able to maneuver at speed without losing the payload en route to the launch site. Because airplanes travel horizontally while spacecraft launch vertically, there's a noted delta-v lost when you drop a rocket off an airplane -- though you can compensate for that somewhat depending on where the rocket is heading to and how much fuel is required to reach its destination. Despite plenty of high-profile testing, including SpaceShipTwo, air launches haven't really taken off as a serious competitor for ground launch.
Paul Allen wants to change that, and he's counting on the Stratolaunch to deliver. The company has been through a variety of partners in recent years, from SpaceX to the Sierra Nevada Corporation. Right now, Stratolaunch is reportedly evaluating multiple designs and will choose a winner in the near future; the company isn't expected to begin manned flights until the 2020s.
A video demonstrating the size and launch capability of the Stratolaunch can be seen above. While it's a 3D rendering, it does give some sense of just how huge this aircraft is. If Stratolaunch succeeds, it might allow companies to tap the vehicle more small to midrange payloads. That would be larger than previous air launch systems, and it could allow Stratolaunch to compete against established companies for relatively cheap rocket launches.Tagged In
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