11 September 2013

SpaceX’s Grasshopper, the future of cheap spaceflight, performs perfect test flight

SpaceX has released a spectacular new video of its vertical-takeoff-and-landing (VTVL) reusable launch vehicle (RLV) Grasshopper. In the video, Grasshopper uses its single rocket engine to shoot up to an altitude of 250 meters (820 feet), perform a 100-meter (330-ft) lateral maneuver, and then slowly return to the exact same spot that it took off from… while simultaneously scaring a herd of cows. Grasshopper is the first stage of SpaceX’s efforts to create a reusable space launch system that, by virtue of not wastefully dropping everything into the ocean, will massively reduce the cost of spaceflight — like, to the point where you and I could visit outer space for less than a few months’ salary.

Grasshopper is a simple, single-stage 32-meter (108-ft) tall VTVL RLV powered by a single Merlin-1D rocket, and four steel legs that act as landing gear. In many ways it’s very similar to the first stage of the Falcon 9 rocket, which has been successfully launching spacecraft (such as the Dragon capsule, which resupplies the International Space Station) for the past year. The similarity is intentional, as Grasshopper is a tech demo that will later be used to build reusable versions of the Falcon 9.

The main difference between Grasshopper and the first stage of normal launch systems is that the Grasshopper gracefully lands back on the ground. Basically, while most rockets blow all of their fuel to get as far away from the launch site as possible, Grasshopper uses some of its fuel to gracefully return to the launch pad. This is fairly complex, as slow-moving and non-rotating rockets aren’t the most stable of creatures. Grasshopper maneuvers by way of its Merlin-1D engine being gimbaled, where the rocket’s nozzle can be angled to alter the thrust vectoring (see image below). It lands by way of four legs, which look a lot like the legs on Apollo’s Lunar Lander (which also had to launch and land on the same surface).

Up until this point, every orbital space launch system has been expendable, with most of the rockets and the fuel tanks tumbling into the ocean. The Space Shuttle itself was somewhat reusable, but its main fuel tank was expendable and each Shuttle still had to undergo months of rejuvenation to prepare it for the next mission. SpaceX’s plan for a reusable launch system would eventually see first- and second-stage rockets that are reusable within “single-digit hours” after returning to the launch pad. This could eventually lead reasonably priced space travel. The next version of Grasshopper, version 1.1, will be outfitted with nine Merlin engines — just like the Falcon 9 rocket. It is hoped that Grasshopper 1.1 will begin testing sometime between now and the beginning of 2014, and will slowly work its way up to an altitude of 91,000 meters (300,000 ft). By mid-2014, SpaceX may start bringing actual Falcon 9 launch vehicles back to the launchpad.

SpaceX isn’t the only company looking at reusable space flight, of course. The Skylon spaceplane, based on the British-designed and highly novel SABRE engine, is a normal plane that flies to an altitude of around 25 kilometers (15.5 miles) — and then effectively turns into a rocket, shooting up into outer space.

Now read: The future of airplanes: Perpetual flight


Post a Comment

Get every new post delivered to your Inbox.


Copyright © 2018 Tracktec. All rights reserved.

Back to Top