X-33 faces lengthy delays

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Fuel tanks damaged after tests

WASHINGTON – Damage to the X-33’s two hydrogen fuel tanks could delay the program one to two years, government and industry officials told Space News.

“Frankly, there was very little chance of flying in 2000 prior to the damage,” said an industry official. “This just drove a stake through that.”

The X-33 is a joint project of NASA and Lockheed Martin Cory. to test technology that can be used on future reusable launch vehicles, including a commercial vehicle called VentureStar that Lockheed Martin is developing on its own. NASA hopes such a vehicle will be able to replace the agency’s aging space shuttle fleet. 

The outer skin of the X-33’s hydrogen tanks was fractured Nov. 3 during pressurization tests at Marshall Space Flight Center in Huntsville. Ala.

Artist’s concept of the NASA/Lockheed Martin single-stage-to-orbit X-33/VentureStar reusable launch vehicle.

Senior officials from NASA and Lockheed Martin acknowledged that the damage is a major setback for the program, but would not speculate about the potential impact on the X-33’s flight schedule. The initial launch had been tentatively set for mid-summer 2000.J

Jerry Rising, president of Ven- tureStar LLC, Palmdale, Calif., and a former Lockheed Martin Skunk Works vice president for X-33, cautioned against putting too much weight on unofficial preliminary assessments of the damage. “Engineers are prone to gossip and exaggeration,” Rising said. “I’ve learned over the years working these kind of programs [that] you never want to speculate and go forward without solid facts.” 

“We’ve had some conflicting reports about the nature of the damage,” Rising said. “The only thing we know for sure is [the engineers at Marshall] had seen some damage on the video monitors.”

Rising said a complete investigation of the damage could take weeks. When asked if X- 33 will fly in 2000, he said, “I can’t say at this point. I don’t have enough information to really say.”

“The program is cutting-edge,” said Gene Austin, NASA X-33 program manager. “If we didn’t suspect we were going to have surprises along the way, we were foolish.” 

The lightweight hydrogen tanks, made out of graphite-epoxy composites instead of traditional but heavier aluminum, have long been considered by program officials to be one of the riskiest elements of the $1.3 billion government and industry effort to build a half-scale prototype of the Ven tureStar single-stage-to-orbit reusable launcher. 

Although it is clear the tank cannot be used in its current condition, Austin said it is too soon to say whether the tank will have to be repaired, remanufactured or redesigned. 

“Until we understand what happened to this lobe skin, we don’t know what our prospects are,” said Austin. “It could be fairly simple or it could be we replace that tank with something different. We don’t know.” 

As of press time Nov. 5, program officials were still assessing the damage. Marshall spokesman David Drachlis said multiple fractures were found on the outer skin of one of the tanks’ four sections, which are called lobes. 

Drachlis said engineers inspecting the damage found that the outer skin of one of the tank’s lobes had peeled back from the core of the tank wall along the seam joining the four sections together. 

Austin said in an interview with Space News that the damage apparently occurred Nov. 3 after an otherwise successful day of load and pressure tests at the Hunstville, Ala.-based NASA center.

After the tanks had been purged of extremely cold liquid hydrogen and were warming to room temperature, the outer skin and inner core of one of the four lobes of the tank apparently separated, Austin said. An inspection of the tank revealed multiple fractures on the outer skin of the tank, he said. 

Gary Payton, NASA deputy associate administrator for space transportation technology, said no spare hydrogen tanks were built because of a lack of money.

 “Ideally, you want to have flight-quality spares all across the board,” he said. “Not knowing what pieces will give you a problem, you would have had to build enough extra parts to build a second vehicle.” That option would have cost an extra “several hundred million dollars,” he said.

Payton said the situation is serious, but declined to cite the odds of X-33 being ready to fly in 2000. He said prior to the tank damage, he had described X-33’s chance of flying in the summer of 2000 as “better than 50-50.” 

Payton said the White House has been notified of the problem with the tank. 

Under a cooperative agreement between NASA and the Lockheed Martin-led industry team, the U.S. space agency’s contribution to the X-33 program is capped at $941 million. The cooperative agreement officially expires at the end of 2000, but Austin said the deadline is not a problem. “We’ll let the cooperative agreement float to whatever dated needed to complete the program,” he said. 

This is the second time the program has had a major problem with the hydrogen tanks. In December, two lobes were damaged during the manufacturing process, contributing to a 12-month delay in X-33’s planned flight date.