When will rocket racing take off?by Jeff Foust
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| Those flights would seem to suggest that the RRL’s fortunes are back on track, but the status of the league’s flights remains uncertain. |
There were, though, no races at the 2006 X Prize Cup; the RRL instead settled on a ceremony naming the company’s first vehicle “Thunderhawk”. It wasn’t until a year later that an X-Racer flew for the first time, at Mojave Air and Space Port in California. That vehicle flew publicly for the first time at the recent EAA AirVenture show in Oshkosh, Wisconsin, with a series of successful demonstration flights on July 29 and August 1 and 2.
Those flights would seem to suggest that the RRL’s fortunes are back on track, and additional races—or at least more exhibition flights—would be right around the corner. But the status of the league’s flights remains uncertain, thanks in part to events in the weeks since the Oshkosh flights.
In April, in a somewhat surprising move, the RRL announced that it had contracted with Armadillo Aerospace to develop engines for use in RRL aircraft. At that time—and through the Oshkosh show—the decision was spun as providing the league’s teams with a choice of either the Armadillo engine or the XCOR engine that had been used on the X-Racer to date, just as auto racing teams have a choice of engines.
Just a few weeks after the EAA AirVenture show, though, the situation had changed. An X-Racer powered by Armadillo’s engine performed an initial series of test flights in late August and early September from the Oklahoma Spaceport. Now there was no mention of the XCOR engine in the releases; the press release announcing the flights included a statement from a spaceport official saying that they were proud to host the “initial flight test program” for the RRL, as if the extensive series of test flights in Mojave had never happened.
While not stated in RRL press releases, the league’s co-founder and CEO, Granger Whitelaw, suggested that XCOR’s engines weren’t up to the league’s standards. “When we feel the XCOR engines meet our standards of safety, reliability, reusability, and performance for a rocket racer, then we may bring them back into the league,” he told SPACE.com last month. Whitelaw made similar comments about the need for XCOR’s engines to meet “specifications that we feel are required for safety, reliability and reusability in a racing format” to MSNBC. In neither case did Whitelaw elaborate on the specific issues he had with XCOR’s engine. (The Rocket Racing League did not respond to requests for clarification on this or other topics last week by The Space Review.)
While performance may be an issue—the Armadillo engine generates 11,100 newtons (2,500 pounds-force), two thirds more thrust than the XCOR engine—the other concerns about safety, reliability, and reusability took many people who follow the industry by surprise. XCOR has built up a reputation over the last several years as a very good rocket engine developer, having built and tested engines ranging in thrust from 67 to 33,300 newtons (15 to 7,500 pounds-force), and safety has never been an issue.
XCOR has been subtly addressing those concerns without directly mentioning the comments made by Whitelaw. In a press release last month announcing the selection of Andrew Nelson as the company’s chief operating officer, the company emphasized its track record in safety. “Safety will determine winning or losing in the space industry, so I think that XCOR’s safety record is a firm foundation for financial success,” Nelson said in the statement. “The team has built and flown two generations of manned rocket-powered aircraft, and performed over 50 manned rocket flights without injuring a pilot or passenger, or losing or even damaging a vehicle in flight. That’s an enviable record in this industry.”
| “There is only one way XCOR could establish these records—reliability and a dedication to safety,” XCOR CEO Jeff Greason said of the company’s recent test flights. |
Last week, XCOR announced that it had set an “informal” record for the most rocket-powered flights in one day, with seven flights on October 1. The release didn’t identify the vehicle used for the record-setting flights, but other sources indicated that it was the X-Racer with the XCOR engine. The flights represented the final series of tests on the vehicle, XCOR spokesman Doug Graham later said. On the last flight, the two-seater had only one person on board, XCOR test pilot Rick Searfoss, who took the vehicle to its highest altitude ever and stayed aloft for a little over 20 minutes, according to Graham.
While the flights demonstrated the reliability and reusability of the engine, XCOR used the series of flights to again press on the safety issue. “There is only one way XCOR could establish these records—reliability and a dedication to safety,” XCOR CEO Jeff Greason said.
Since the completion of the initial flights of the Armadillo-powered X-Racer, the RRL has kept a low profile, making only one announcement since then, and that being the order of a series of aircraft by its Velocity Aircraft subsidiary not directly related to rocket racing itself. Prior to the Oshkosh air show Whitelaw said that the league had planned a number of exhibition flights through the end of the year, including the Reno Air Races, the Nellis Air Force Base air show in Las Vegas in November, and some kind of exhibition flights in Las Cruces, New Mexico, perhaps tied with the X Prize’s Northrop Grumman Lunar Lander Challenge (LLC). However, the RRL did not fly last month in Reno and is not on the schedule for the Nellis show; no announcements have been made about flights in Las Cruces, but since the LLC this year is not open to the public, any flights there would have a limited audience.
However, regardless of what RRL’s future plans are, it’s clear that the work put into the effort to date has proven beneficial for both XCOR and Armadillo. XCOR is moving ahead with development of its Lynx suborbital vehicle, with lots of lessons learned from its experience with the X-Racer. “There wasn’t any big, giant eureka moment,” Greason said in an interview at Oshkosh. “There’s been a whole bunch of little things,” such as in the vehicle’s electrical system, that they’ve learned and are incorporating into the design of Lynx, he explained.
Armadillo, meanwhile, is gaining experience with its rocket engines that it hopes will transfer over to the LLC, after two years of unsuccessful attempts to win the prize money. Last year was particularly frustrating for Armadillo, which appeared to be in good shape to win at least the less-challenging Level 1 prize after having successfully performed the required flight profile over the summer in Oklahoma (see “Hard start, tough finish”, The Space Review, October 29, 2007). “We had more problems that weekend with our propulsion system… than in the last six months of developing the engine,” Neil Milburn of Armadillo said in an interview on The Space Show in August.
The cause of the engine problems Armadillo suffered wasn’t clear, but Milburn speculated that the higher elevation of Holloman Air Force Base, where the 2007 competition was held, may have played a role, particularly if the engine was “on the ragged edge” of performance. Testing a similar engine on an X-Racer should allow them to see if changes made to the engine address the performance issues. “I guarantee you we can get to 5,000 feet [1,500 meters, the approximate elevation of the New Mexico LLC site] as soon as we can get the plane off the ground,” Milburn said. “We’ll be able to test that thing at whatever altitude that we like, well above 5,000 feet, to test its validity.” According to the RRL release about the Oklahoma flight tests, the Armadillo-powered racer got above 3,600 meters altitude, suggesting that the engine performance at the elevation the LLC will take place has been verified.
So while the debut of full-fledged rocket racing continues to stretch out into the future—as well as the demonstration of whether such competitions can be a viable business—the RRL has, indirectly, contributed to the development of two companies seeking to develop vehicles capable of flying into space. That’s not a bad legacy for the company, but the RRL is no doubt hoping it’s not their only legacy.