Reflying rockets: A concept of SpaceX’s approach to developing a reusable rocket that would land vertically by extending a set of legs from its base.
For decades, companies and space agencies have sought to develop launch vehicles that can be reused. A rocket that could be used dozens or even hundreds of times would reshape the economics of spaceflight by slashing the cost per launch. NASA aimed to do just this with the space shuttle, but the vehicle failed to achieve the promised cost savings. Now two prominent commercial space companies have announced plans for reusable launch vehicles, and their progress is notable.
In a speech at the National Press Club in Washington, D.C., in late September, Elon Musk, the CEO and chief technology officer of SpaceX, announced plans to develop a fully reusable version of the company’s Falcon 9 rocket. First launched last year, the Falcon 9 is a two-stage rocket designed to carry satellites as well as SpaceX’s cargo and crew capsule into space. “It’s a very tough engineering problem, and it wasn’t something I was sure could be solved for a while,” he said about the prospects of building a reusable launch vehicle. “Relatively recently—in the last 12 months or so—I’ve come to the conclusion that it can be solved, and SpaceX is going to try and do it.”
NASA’s space shuttle is the only orbital reusable launch vehicle that’s flown to date, and it was retired this summer after falling far short of its original goals to launch frequently and inexpensively—the agency projected it would fly up to 50 missions per year at an operating cost of $10.5 million per flight. It turned out that the shuttles flew less than five times per year at an operating cost 20 times that.
SpaceX’s approach is to convert the two stages of the Falcon 9 rocket into independent vehicles capable of making return landings at their launch site. The first stage, after separating from the rest of the rocket, would fire its engines to guide itself back to the launch site, extending a set of legs from its base to land vertically. The upper stage, outfitted with the heat shield that SpaceX developed for its Dragon spacecraft, which was designed to transport cargo and eventually crews to and from the space station, would reenter after deploying its payload in space. It would also use its engine for a powered vertical landing.
Musk is backing up his speech with development work. SpaceX has been quietly building an experimental vehicle called Grasshopper to test the vertical landing technology. Grasshopper is a Falcon 9 first stage outfitted with a single engine and landing legs to allow it to take off and land vertically. The vehicle was publically disclosed for the first time the week before Musk’s speech in a regulatory filing with the U.S. Federal Aviation Administration’s Office of Commercial Space Transportation.