Rocket racer remade
Posted: Wednesday, August 27, 2008 1:42 PM by Alan Boyle
Mike D'Angelo / Rocket Racing League ® |
Click for video: Watch the Armadillo-powered
rocket plane take off for a test flight in Oklahoma.
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Less than a month after its public debut, the Rocket Racing League is putting a bigger, more powerful prototype plane through its first flight tests - and the results are so impressive that the craft's rocket engine will be adopted as the standard for another five racers, the league's chief executive officer says.
"Everything was exactly as we had drawn it out," CEO and league co-founder Granger Whitelaw reported from Burns Flat, Okla., where the second-generation plane had its first outing on Monday.
The first-generation plane, which was demonstrated at the EAA AirVenture experimental air show in Oshkosh, Wis., was equipped with a kerosene-fueled, pump-fed, 1,500-pound-thrust rocket engine provided by California-based XCOR Aerospace. In contrast, the plane being flown this week at the Oklahoma Spaceport has an alcohol-fueled, pressure-fed, 2,500-pound-thrust rocket engine from Texas-based Armadillo Aerospace.
The engine isn't the only thing that's bigger: The airframe is a modified version of the Velocity XL-5, which is wider, longer and heavier than the Velocity SE that was equipped with the XCOR engine. (One of the league's subsidiaries acquired Florida-based Velocity Aircraft earlier this year.)
If the demonstrations in Oshkosh and Burns Flat were meant as a fly-off, the Armadillo team - led by millionaire video-game programmer John Carmack - came away as the winner.
"The Armadillo engine is going to be the primary engine for the Rocket Racing League," Whitelaw told me. He said five more planes will be built using Armadillo's propulsion system, which is a spin-off from Carmack's years-long quest to win the $2 million, NASA-backed Northrop Grumman Lunar Lander Challenge.
Whitelaw said the planes will be offered to the league's six teams at a cost of $1.25 million each. The Armadillo-powered plane will be painted in the colors of the Bridenstine DKNY Rocket Racer, thus taking on the sponsorship that was announced last month.
"Now that we’ve successfully conducted a test flight with the Armadillo engine, we are looking forward to getting to racing and exhibiting a 21st-century sport for the 21st-century sports fan," Whitelaw said.
XCOR's engine, meanwhile, will be out of the running for the time being, although Whitelaw said he wouldn't rule out using that engine or others in the future if they meet the "specifications that we feel are required for safety, reliability and reusability in a racing format." He declined to discuss the details, citing requirements for confidentiality.
The Rocket Racing League had hoped to put the Armadillo-powered plane as well as the XCOR-powered plane into the air during the Oshkosh show, but the Federal Aviation Administration didn't approve the Armadillo version for exhibition. The bigger plane had to sit on the ground at the league's exhibit space, partially disassembled.
Whitelaw said the FAA's approval for research-and-development flights came just after the Oshkosh show was over, setting the stage for this week's first flights.
The tests involved roughly 10-minute flights to put the craft through its paces, at altitudes ranging up to 8,000 feet and speeds of up to 190 knots (219 mph), Whitelaw said. Test pilot Len Fox revved up the plane from zero to 92 knots (105 mph) in 8 seconds during Monday evening's first takeoff, and shaved that time down to 6.7 seconds on Tuesday, he said. Test flights continued today.
The Armadillo engine's rocket plume can be "seeded" with chemicals to add color to the nearly invisible alcohol flame. For this week's tests, saltwater was added, producing a "nice, bright, reddish-yellowish flame" that extended out more than 15 feet, Whitelaw said.
Fox was reportedly pleased with the performance. "Len never shows emotion, but we're all very happy," Whitelaw said.
Armadillo's Carmack was pleased as well.
"I am very happy with how the tests are going - the first three flights were done in the first 24 hours we had clearance and cooperating weather," he told me in an e-mail today. "We have been ready for a while, but the FAA held our R&D permit until after XCOR flew at Oshkosh, then two weeks ago we were up in Oklahoma and had rain or cloud cover all week."
Carmack noted that in addition to the test flights, the Armadillo engine has gone through about 75 test burns. Eventually he'd like to aim for an aviation record: the fastest climb to 3,000 meters (9,842 feet). The current record of 41.2 seconds was set in 1974 by former Russian cosmonaut Svetlana Savitskaya, and Carmack wrote that Armadillo would have to use "a slightly different engine (bigger throat, maybe more injector elements)."
Whitelaw said the current round of flight tests is aimed at providing the FAA with data that will eventually lead to the issuance of an experimental airworthiness certificate for exhibition flights. The league would need that certificate to demonstrate the Armadillo-powered plane at future air shows, such as next month's Reno Air Races. It's not yet clear whether the timing will work out for a demonstration in Reno.
"We're going to be there," Whitelaw said. "Whether we fly there depends on how we fly the test profile, and how fast the FAA moves."
Whitelaw insisted that the league was on track for a series of demo flights leading up to televised prize competitions in late 2009 or 2010. After the Oshkosh flights, four "very qualified" teams expressed interest in joining the six racing teams who have already signed up for the league, Whitelaw said. Interviews are under way.
Update for 3:45 p.m. ET: Here's a recent profile of John Carmack from Forbes (via CBC) that traces his ascent "from doom-dealer to space racer."
