WASHINGTON — Work on key elements of the Launch Abort System (LAS) for NASA’s Orion crew capsule has slowed — and in some cases stopped altogether — following a warning by LAS lead contractor Orbital Sciences Corp. that money for the effort would cease flowing April 30.

However, a planned May 6 flight test of LAS hardware remains on track, according to Orion industry team officials.

In an April 20 letter to Minneapolis-based Alliant TechSystems (ATK), one of two companies developing motors for the LAS, Orbital said Orion prime contractor Lockheed Martin Space Systems of Denver would restrict funding for the effort by the end of April. ATK is building two LAS motors, one that will provide the primary thrust needed to whisk the Orion capsule away from its launcher in case of trouble at liftoff, and a smaller motor for attitude control.

“Orbital Sciences Corporation is in receipt of a notice of funding limitations from our customer, Lockheed Martin, that no additional funds are forthcoming for the remainder of GFY 2010,” Gregory Pappas, subcontracts manager at Dulles, Va.-based Orbital, states in the April 20 letter to ATK. “As ATK is aware, the current run-out date is April 30, 2010.”

ATK spokesman George Torres said April 30 that work on the main LAS abort motor, which is being performed by 95 people in Utah under subcontract to Orbital, has been affected and that employees are being reassigned. “We see that as a temporary fix until this issue is resolved,” he said.

Work on the attitude control motor, being done under subcontract to Lockheed by 60 employees in Elkton, Md., “is not impacted because it’s funded through the summer,” Torres said via e-mail. Lockheed last year took over management responsibility for ATK’s work on the attitude control motor.

Aerojet of Sacramento, Calif., meanwhile, was set to halt work on the LAS jettison motor at close of business April 30, Glenn Mahone, a spokesman for that company, said April 30. The jettison motor is intended to separate the LAS from Orion  in the event of a successful launch.

In the letter, Pappas asserted that the lack of funding for the Orion Launch Abort System “does not constitute a Contract termination,” which would violate a law passed in December that prohibits NASA from using 2010 funding to cancel any contracts or activities under its Constellation program.

Constellation encompasses the hardware NASA would need to replace the space shuttle and return astronauts to the Moon under a policy unveiled in 2004 by then-U.S. President George W. Bush. These include Orion, designed to transport astronauts to the international space station and later to the Moon, its Ares 1 launcher and the Ares 5 heavy-lift rocket.

In February U.S. President Barack Obama proposed canceling Constellation, including Orion, in his $19 billion NASA spending request for 2011. In an April 15 speech at NASA’s Kennedy Space Center in Florida, the president spared the crew capsule from the ax, calling instead for a stripped-down Orion vehicle to serve as a crew lifeboat in the event of an emergency at the space station.

Although the move is viewed as a reprieve for Lockheed Martin and its Orion work force — scattered in states across the country but primarily concentrated in Colorado, Florida and Texas — as a crew-rescue vehicle the capsule will launch unmanned, leaving no need for continued development of the complicated and costly LAS.

Barron Beneski, a spokesman for Orbital, said April 30 that the company has figured out a way to keep its work on the LAS program going for another two weeks or so. He said some 80 Orbital employees could be affected by LAS funding limitations.

Julie Van Kleeck, Aerojet vice president for space programs, said April 27 that the company had begun shifting LAS employees internally rather than issuing pink slips.

“We’re in the process of reassigning people for now,” Van Kleeck said. “We’re hoping it’s temporary.”

In addition to developing the LAS jettison motor, Aerojet is providing propulsion systems for the Orion capsule’s command module and service module.

“That’s continuing,” Van Kleeck said of the command and service module propulsion work.

NASA and Lockheed Martin are preparing to modify the Orion contract in light of the different requirement set associated with the capsule’s scaled-back mission. Nevertheless, in an April 23 letter to Lockheed Martin, NASA reminded the company of its contractual obligation to set aside 2010 Orion funds to cover termination costs in the event the program is canceled in 2011.

“Previous to the letter, this was being covered off-contract at the agency level,” Cleon Lacefield, Lockheed Martin vice president and Orion program manager, said in an April 23 internal e-mail to the Orion team. “The letter changed NASA’s direction and is now requiring us to cover this contingency cost on-contract with current funding. NASA has not yet provided the additional funding for the full termination liability contingency. We are working very hard with our stakeholders so NASA will provide the necessary funding or otherwise resolve the issue so that it doesn’t impact our team’s performance. In the interim, we’re going to hold procurements to minimize impacts to the team.”

Lockheed Martin spokeswoman Linda Singleton said via e-mail April 30 that the LAS pad abort test, scheduled for May 6 at White Sands Missile Range, N.M., remains on track.

“Because certain aspects of LAS development are ahead of other systems, Lockheed Martin is planning to slow down portions of this work not related to the upcoming Pad Abort 1 test,” Singleton said. “Although Lockheed Martin’s LAS efforts may be reduced, our Orion team will proceed with LAS development for a successful Critical Design Review and delivery of the Ground Test Article components.”