Grasshopper is an experimental technology-demonstrator, suborbital reusable launch vehicle (RLV), a vertical takeoff, vertical landing (VTVL) rocket,[1] built to support development and test of a subset of the technologies required for the SpaceX reusable rocket launching system.[2] Grasshopper was announced in 2011[3] and began low-altitude, low-velocity hover/landing testing in 2012. The initial Grasshopper test vehicle—the 32 metres (106 ft)-tall Grasshopper v1.0—made eight successful test flights in 2012 and 2013 before being retired. A second Grasshopper test vehicle—the larger and more capable Grasshoper v1.1—is currently being built and will be used for testing at higher altitudes and supersonic speeds.
Grasshopper is being developed and tested by Space Exploration Technologies (SpaceX) in order to assist development of the reusable Falcon 9 and reusable Falcon Heavy rockets, which will require vertical landings of the near-empty Falcon 9 and Falcon Heavy first-stage booster tanks and engine assemblies.
Grasshopper is one element of the multi-element, incremental SpaceX reusable rocket launching system test program, a program that includes Grasshopper testing both in low-altitude, low-velocity situations at the SpaceX Texas test site and high-altitude, mid-velocity testing of the larger second-generation Grasshopper test vehicle with all nine engines at Spaceport America in New Mexico, as well as high-altitude, high-speed controlled-descent tests of post-mission (spent) Falcon 9 booster stages on Falcon 9 missions beginning in September 2013.
Grasshopper v1.1—also known as Falcon 9 Reusable (F9R) development vehicle[14] —was initially announced in October 2012, when SpaceX indicated that a second Grasshopper vehicle with fold-up landing legs would be built on the longer Falcon 9 v1.1 platform.[11]
In March 2013, it was announced that the v1.1 Grasshopper suborbital flight vehicle would be constructed out of the Falcon 9 v1.1 first-stage tank that had been used for qualification testing in Texas at the SpaceX Rocket Development and Test Facility prior to March. It was to be rebuilt as the next Grasshopper "with flight-like landing legs."[15] In May 2013, the design for the retractable landing leg was shown to be a telescoping piston on an A-frame. The total span of the four legs will be approximately 18 metres (60 ft), and the landing gear will weigh less than 2,100 kilograms (4,600 lb); the deployment system will use high-pressure Helium.[16]
Test plans call for the v1.1 Grasshopper to be high-altitude flight tested only at Spaceport America, New Mexico,[9] at altitudes up to approximately 91,000 metres (300,000 ft).[15] SpaceX began constructing a 30 by 30 metres (98 ft × 98 ft) pad at Spaceport America in May 2013, 7 kilometres (4.3 mi) southwest of the spaceport's main campus, and will lease the pad for US$6,600 per month plus US$25,000 per Grasshopper flight. As of May 2013, the spaceport administrator expected SpaceX to be operational at the Spaceport sometime between October 2013 and February 2014, and that is the time that the lease payments were expected to begin.[17]
In August 2013, SpaceX announced that the Grasshopper v1.1 test vehicle would fly in New Mexico with all nine engines of the fully loaded Falcon 9-R, whereas Grasshopper v1.0 had flown exclusively with only a single Merlin 1D engine in place, the center engine which is planned to be used to complete the last phase of the deceleration and landing.[18] The testing is expected to start in New Mexico only after low-altitude initial flight tests of the Grasshopper v1.1 are accomplished in Texas at the SpaceX Rocket Development and Test Facility, sometime after October 2013.[14]
A rocket is a missile, spacecraft, aircraft or other vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed entirely from propellants carried within the rocket before use.[1] Rocket engines work by action and reaction. Rocket engines push rockets forward simply by throwing their exhaust backwards extremely fast.
While comparatively inefficient for low speed use, rockets are relatively lightweight and powerful, capable of generating large accelerations and of attaining extremely high speeds with reasonable efficiency. Rockets are not reliant on the atmosphere and work very well in space.
Rockets for military and recreational uses date back to at least 13th century China.[2] Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the moon. Rockets are now used for fireworks, weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight, and space exploration.
Chemical rockets are the most common type of rocket[citation needed] and they typically create their exhaust by the combustion of rocket propellant.
