This week, private spaceflight company Stratolaunch tested out the turbofan engines on its aircraft for the first time – all six of them. The engines were filled with fuel and allowed to idle one at a time at the company’s facility at the Mojave Air and Space Port in California. All six worked as expected, according to Stratolaunch.
The Stratolaunch megaplane, built by Scaled Composites for Paul Allen's aerospace company Stratolaunch Systems and unveiled in May, is an enormous twin-fuselage aircraft designed to carry rockets up to altitude and drop them. The rockets will then ignite and carry satellites the rest of the way to orbit. It's a novel way of launching payloads to space that saves fuel by bringing the rocket up to high altitude before launch. Rival Virgin Galactic is working on a similar launch system, though Richard Branson's rocket-carrying aircraft is a modified 747.
The first phase of engine testing was carried out in three steps. The first was a "dry motor" test, where technicians hooked up the turbofans to auxiliary power and fired them up. "Wet motor" tests followed, where fuel was introduced to the system. Finally, Stratolaunch Systems started up the engines one at a time and allowed each to idle. The six engines operated as expected, according to the aerospace company.
However, the company is going to start out small at first. Stratolaunch signed a deal last year to launch Orbital ATK’s Pegasus XL rocket from the plane. Designed to launch from the air, the Pegasus is a fairly small rocket, capable of launching satellites weighing up to 1,000 pounds.
"Over the next few months, we will continue to test the aircraft's engines at higher power levels and varying configurations, culminating to the start of taxi tests," writes CEO Jean Floyd announcing the successful tests. The Stratolaunch is undoubtedly a massive feat of aircraft engineering, with a giant wingspan of 385 ft (117 m), the company plans to continue engine tests over the coming months with the next milestone being taxi tests.