Graham Warwick/WASHINGTON DC
NASA has been down this road before. In July 1996, US Vice President Al Gore announced that Lockheed Martin had been selected to build the X-33 technology demonstrator - the precursor to a commercially developed replacement for the Space Shuttle.
Then, in November last year, one of the X-33's composite liquid-hydrogen tanks failed during ground testing. The structural failure, following other delays to the technologically challenging programme, ended NASA's hopes of flying the X-33 before its scheduled 2000 deadline for a decision to begin development of a Shuttle replacement.
As a result, earlier this year, NASA unveiled its Space Launch Initiative, which includes a five-year, $4.5 billion effort to demonstrate technology for second-generation reusable launch vehicles (RLVs). This time, the space agency plans to maintain competition through the technology demonstration phase and, hopefully, into full-scale development.
Under the Initiative, NASA plans to fund cost-sharing ground and flight demonstrations of technologies for competing Shuttle replacements that would be developed commercially following completion of the risk reduction phase in 2005. The agency hopes "at least two commercially competitive reusable launch vehicles" will enter full-scale development in 2005 and be ready for service by 2010.
"We will take all the lessons learned from the X-33, X-34 and other programmes and, over the next five years, get to the point where we have at least two viable contenders for competitive full-scale development of a launch system meeting our safety and cost goals," says Dan Dumbacher, NASA's second-generation RLV programme manager.
The new plan is intended to head off criticism from US Congress that NASA "put all of [the USA's] 'cheap access to space' eggs in one fragile technology basket" when it backed the X-33 and its full-scale follow-on, Lockheed Martin's VentureStar single-stage-to-orbit RLV.
The decision to sustain competition throughout the demonstration and development phases of the second-generation RLV programme has been welcomed by Congress, but concerns are beginning to emerge that NASA might find it hard to keep a minimum of two competitors in the race.
Since the Space Launch Initiative was unveiled, it has been assumed the VentureStar will be one of the competitors, ranged against a new two-stage-to-orbit RLV and a Shuttle-derived design. But, seven months after the fuel tank failure, NASA and Lockheed Martin have yet to agree how they can proceed with theX-33, raising the spectre that the company may simply walk away from the programme - and from the VentureStar.
NASA has reason to be concerned. After several years of investment, the agency was forced to cancel its High Speed Research programme in 1998 when Boeing decided there would be no near-term market for a second-generation supersonic airliner. This has made NASA, and Congress, wary of putting more money into the X-33 when there is a risk Lockheed Martin could back out of the programme.
Protracted talks between the manufacturer and NASA revolve around who will pay what to get the X-33 back on track and into the air. While industry's investment in the technology demonstrator has grown to $352 million as a result of technical problems, the government's contribution remains capped by Congress at $941 million. About 10% of NASA's budget remains to be spent, but is tied to programme milestones, such as first flight.
Lockheed Martin wants NASA to advance the remaining progress payments so the failed tank can be redesigned and the demonstrator completed and flown some time next year. The company recently submitted a revised offer in a bid to conclude negotiations with NASA, but there is no sign an agreement is near.
Congress has questioned the wisdom of advancing money linked to flight tests when there is a possibility the X-33 may never fly. Lockheed Martin, meanwhile, is wrestling with its own internal issues as it seeks to improve its financial performance.
The X-33 and VentureStar programmes come under recently restructured Lockheed Martin Aeronautics, but the reusable launch vehicle is viewed as the likely long-term successor to the expendable launch vehicles produced by the company's Space Systems division. This is posing a problem for Lockheed Martin, as it tries to make strategic decisions on investment in each of its business sectors.
Lack of a resolution on the X-33 has cast a shadow over the unveiling of NASA's Space Launch Initiative. The space agency is keeping the two efforts separate and does not intend to use any of the $4.5 billion requested for the second-generation RLV to complete the X-33 programme as currently planned.
"There will be additional funding for the X-33 only if it meets our requirements for a second-generation RLV, and only for work in addition to the current programme," says Dumbacher. There has been talk of a follow-on "X-33B", which would test advances in avionics, engines and thermal protection systems, and could be funded under the second-generation RLV programme - if the X-33A ever flies.
But the main intent of NASA's Space Launch Initiative is to support the development of other RLVs that could compete with the VentureStar to replace the Space Shuttle beyond 2010. Work on alternative concepts slowed dramatically after Lockheed Martin's single-stage-to-orbit design was selected in 1996. "Everybody's at a little bit different status," says Dumbacher. "We want to get as objective and level a playing field as possible."
Candidate second-generation RLV concepts were identified in a series of space transportation architecture studies conducted by industry and NASA over the past two years. In addition to Boeing and Lockheed Martin, these studies involved several smaller companies, including established air-launched booster specialist Orbital Sciences and startups like Kelly Space & Technology, which is is developing a towed-launch RLV.
"Anything that meets our requirements is a viable option," says Dumbacher. One substantial change from the previous RLV competition - and NASA's main justification for starting over again - is the introduction of a stringent safety goal equivalent to a risk of crew loss of one in 10,000 missions, two orders of magnitude better than the Shuttle. This is in addition to the goal of $2,200/kg ($1,000/lb) of payload into low Earth orbit - a tenfold reduction in launch cost over the Shuttle.
NASA is kicking off the Space Launch Initiative with a lengthy systems engineering and requirements definition phase. "We do not know if the cost and safety goals are achievable. We know they are ambitious, so we have to go out and validate that we can meet them," says Dumbacher. The cost and safety goals are linked. "Increasing vehicle reliability and safety has a significant impact on insurance cost, which is a big part of the $1,000/lb price."
NASA hopes to have "some level of definition of the requirements" by September, when it plans to award multiple contracts to begin the risk-reduction effort - if Congress authorises funding for the second-generation RLV programme. "We will award more than two contracts - how many more we do not know, but it will be a fair number," Dumbacher says.
As the programme progresses, NASA will narrow the options being pursued, he says. It is not known whether flight demonstrators on the scale of the X-33 will be built under the risk- reduction programme. "We have retained the capability to use the current X-33, X-34, X-37 and Shuttle, and will look at possible new flight demonstrators," Dumbacher says.
NASA has been criticised for including a Shuttle-derived vehicle among the options for a second-generation RLV. Critics of the concept argue a vehicle based on the Shuttle will never meet NASA's goals for low-cost access to space. "A Shuttle-derived vehicle will be part of the mix," confirms Dumbacher. Such an approach could take advantage of Shuttle upgrades being funded separately by NASA, he says.
Critics fear the unresolved technical and financial issues facing the X-33 could eliminate Lockheed Martin's VentureStar from the second-generation RLV competition, and discourage others from entering, leaving a Shuttle-derived vehicle as the only commercially viable option when it comes to NASA's decision on full-scale development in 2005.
Source: Flight International