SpaceX Falcon Rocket to Test Landing Legs
The SpaceX "Grasshopper" rocket hovers over McGregor, Texas, on April 19, 2013, during a test flight (left). One of the Falcon 9 rocket landing legs on display at the SpaceX headquarters in Hawthorne, Calif. (right)
On April 19, 2013, the Grasshopper rocket, designed and built by SpaceX, took to the skies over the company's rocket development facility in McGregor, Texas. The rocket climbed to 250 meters (820 feet) where it hovered for a short time and then returned to Earth in a controlled descent.
The prototype rocket, that is being developed to launch payloads into orbit and then return to Earth in a controlled manner, tripled its previous altitude record (80 meters) during the April 19 one-minute test.
During the test, the private spaceflight company used a six-bladed "hexacopter" to fly around the rocket, capturing breathtaking video for further analysis by the team.
The rocket is around 10 stories tall and uses the company's Falcon 9 rocket first stage to accomplish its controlled flight.
Seen standing at the base of the rocket, "Johnny" (a cowboy mannequin) is "keeping things under control" according to the company's Twitter account.
The Grasshopper's single Merlin engine provides the thrust, while the four metallic legs support the rocket during launch and landing.
Space Exploration Technologies is installing landing legs on its next Falcon 9 rocket, part of an ongoing quest to develop boosters that fly themselves back to the launch site for reuse.
For the upcoming demonstration, scheduled for March 16, the Falcon 9’s first stage will splash down, as usual, in the ocean after liftoff from Cape Canaveral Air Force Station in Florida.
This time, however, SpaceX hopes to cushion the rocket’s destructive impact into the Atlantic Ocean by restarting the Falcon 9’s engine and extending landing legs that will be attached to the booster’s aft section. The goal is a soft touchdown on the water.
Falcon 9 “will continue to land in the ocean until we prove precision control” from hypersonic all the way through subsonic regimes, SpaceX founder, chief executive and design engineer Elon Musk said on Twitter.
SpaceX has been chipping away at that challenge in a related series of technology development initiatives.
In October 2013, SpaceX completed a program called Grasshopper to develop precision landing techniques. From a launch pad in McGregor, Texas, SpaceX flew a 10-story, first-stage Falcon rocket that ultimately reached an altitude of .46 miles (744 meters) before touching back down.
An expanded program is due to begin this year from a new test site at Spaceport America in New Mexico. The new prototype, known as Falcon 9R, will be outfitted with nine Merlin 1D engines, rather than just the single motor flown on Grasshopper, to reach higher altitudes and faster descent rates.
Next month’s test will be SpaceX’s second using an operational rocket.
The company’s September 2013 debut of its upgraded Falcon 9 rocket (flying for the first time from California) included a restart of the spent first-stage to slow the rocket’s descent.
The first of two planned engine restarts was successful. The second one failed because the rocket was spinning. Centrifugal force cut off the flow of fuel.
Musk said afterward that landing legs should help stabilize the rocket.
Four legs, which are made of carbon fiber with aluminum honeycomb, will be placed symmetrically around the base of the rocket. They will be stowed along the side of the vehicle during launch and extended down and outward for landing, SpaceX’s website shows.
Musk said the legs used for next month’s test will have a span of about 60 feet.
"Given all the things that would have to go right, the probability of recovering the first stage is low ... but we’re getting closer," SpaceX spokeswoman Emily Shanklin wrote in an email to Discovery News.
The Falcon 9 rocket due to fly on March 16 will be carrying a Dragon cargo capsule for the International Space Station. The mission is the third of 12 under SpaceX’s $1.6 billion contract with NASA.
The company, based in Hawthorne, Calif., also is working on version of Dragon to fly people.