UPDATED at 5:12 EDT Nov. 5
WASHINGTON — Space Exploration Technologies Corp. (SpaceX) flew its experimental Grasshopper vertical-takeoff, vertical-landing rocket Nov. 1 for the second time, according to footage of the test posted by company founder Elon Musk
The Grasshopper flight was the “[f]irst flight of 10 story tall Grasshopper rocket using closed loop thrust vector & throttle control,” Musk said in a Nov. 3 Twitter message. The note contained a link to a video of the flight, which took place at the company’s McGregor, Texas, rocket test facility.
Grasshopper burned its single Merlin 1-D engine for eight seconds, boosting the craft about 5.4 meters above the ground, according to a note posted on SpaceX’s YouTube channel Nov. 5.
The latest Grasshopper hop was an interim step toward the vehicle’s next major milestone: a hover test at 30.5 meters. SpaceX publicly announced plans for the hover test in a press release after Grasshopper’s first flight in September.
“Testing on Grasshopper is ongoing and we expect the extended hover before the end of the year,” SpaceX spokeswoman Katherine Nelson wrote in a Nov. 6 email.
One of the largest vertical-takeoff, vertical-landing rockets ever built, the 40-meter-tall Grasshopper is a testbed for technology SpaceX is developing to make the first stage of its Falcon 9 rocket reusable. The company eventually wants Falcon 9 stages to be able to return to the pad under their own power after launch. The rocket has flown to orbit four times to date, each time in an expendable configuration.
Grasshopper is essentially a Falcon 9 first stage with landing legs that is powered by a Merlin 1-D engine. Merlin 1-D, an upgraded version of the kerosene-fueled rocket engine that currently powers SpaceX’s cargo delivery missions for NASA, has yet to fly in space.
Grasshopper first flew Sept. 21. In that test, the rig reached an altitude of about 1.8 meters. SpaceX was testing the systems that allow remote operation of the rocket, and the ability of the craft’s landing gear to withstand the impact of a hard touchdown on the pad. SpaceX declared the test a success.
In a 2011 Federal Aviation Administration document, published as part of that agency’s due diligence for licensing Grasshopper flights, SpaceX said the Grasshopper test program could last up to three years. Grasshopper might make as many as 70 suborbital flights a year, SpaceX said at the time.
SpaceX is performing Grasshopper tests even as the company moves into the operational phase of its space cargo hauling contract with NASA.
On the same day Grasshopper made its second flight, SpaceX’s Dragon capsule arrived at McGregor for postflight processing after a successful cargo delivery mission to the international space station. Dragon returned to Earth Oct. 28 with 720 kilograms of return cargo, marking a successful end to SpaceX’s first contracted cargo run to the orbiting outpost. SpaceX has 11 more delivery flights remaining under its $1.6 billion Commercial Resupply Services contract, which it got from NASA in 2008. The next SpaceX resupply flight is slated for liftoff in mid-January from Launch Complex 40 at Cape Canaveral Air Force Station, Fla.
In addition to delivering space station cargo, SpaceX is one of three companies that in August got an infusion of NASA money under the agency’s $1.2 billion Commercial Crew Integrated Capability program. NASA is funding designs for competing, privately operated crew transportation systems in the hope that at least one of them will be ready to transport astronauts by 2017.