WASHINGTON — NASA has delayed a planned flight test of the Orion Multi-Purpose Crew Vehicle’s launch abort system at least two years in an effort to hold down near-term costs on a $3 billion-a-year program aiming for a 2017 debut of Orion’s heavy-lift launcher.

NASA had planned to conduct a high-altitude test of the Orion deep-space capsule’s launch abort system in 2015. But NASA’s deputy associate administrator for exploration systems development, Dan Dumbacher, told a congressionally chartered review panel here Feb. 4 that because of budget constraints the abort test will not happen until after the Space Launch System (SLS) makes its 2017 debut lofting an unmanned Orion capsule toward the Moon — a possibility acknowledged back in June by Jose Ortiz, NASA’s lead systems engineer for the Orion abort system at the Langley Research Center in Hampton, Va.

“This is a development problem,” Dumbacher told members of the National Research Council’s Committee on Human Spaceflight. “You run into problems along the way, and there are things that have to be moved around and things that have to be reshaped.

“It is a more challenging problem for us now because of the flatline budget,” Dumbacher told the committee, which is due to publish a report in May 2014 containing, among other things, a list of prioritized recommendations for NASA’s human spaceflight program.

NASA still plans to launch an unmanned Orion into orbit in 2014 atop a United Launch Alliance Delta 4 rocket to test the capsule’s heat shields and landing systems. The capsule will then be refurbished for a seven-day unmanned mission to lunar space in 2017 followed in 2021 by the first crewed launch, a 10- to 14-day mission out to the Moon and back. Between the 2017 and 2021 Orion-SLS missions, engineers at NASA and Orion prime contractor Lockheed Martin Space Systems, Denver, will shift work on crew support systems into high gear and conduct the launch abort test, Dumbacher told the committee.

No firm date has been set for the so-called Altitude Abort test, which Dumbacher told SpaceNews entails launching an unmanned Orion capsule from Cape Canaveral Air Force Station, Fla., on a converted Peacekeeper missile stage provided by Orbital Sciences Corp. of Dulles, Va. The test will evaluate whether the capsule’s abort system performs as well in midflight as it did in a 2010 pad test at the White Sands Missile Range in New Mexico.

Meanwhile, NASA is moving swiftly to conduct Orion’s first spaceflight by what Dumbacher’s boss —  NASA human spaceflight chief William Gerstenmaier — said last summer was the earliest possible launch date: September 2014.

On Feb. 4, Dumbacher and a United Launch Alliance executive both said NASA is still shooting for a September 2014 Orion debut.

“We’re doing a few mission-unique modifications to the Delta 4, including some wind tunnel testing because the aerodynamics are a little bit different [for Orion], and then we’re planning on launch in September 2014 from Launch Complex 37 at the Cape,” George Sowers, vice president of human launch services for Denver-based United Launch Alliance, said. Orion’s 2014 mission, officially known as Exploration Flight Test-1, is a stress test for the capsule’s heat shield and other critical structural systems. Orion will be sent to a medium Earth orbit, circle the globe twice, then re-enter the atmosphere at about 80 percent of the speed it would pick up on a return from lunar space, splashing down in the Pacific Ocean off the coast of San Diego. Last year, NASA added $375 million to Lockheed’s $6.2 billion Orion prime contract to buy a Delta 4 rocket, conduct the test and provide NASA with the flight data.

Orion, which is now being tested at the Kennedy Space Center in Florida, will have to undergo repairs by Lockheed before it is ready for its space debut in 2014. The capsule’s aft bulkhead cracked during a stress test in November, and Lockheed now needs to fit the capsule with a piece of pressure-distributing hardware called a doubler, Orion program manager Mark Geyer said in January.

Dumbacher told SpaceNews Feb. 4 that the final design for Lockheed’s fix should be ready “in a few weeks.”

Congress ordered NASA to build SLS and finish Orion in response to U.S. President Barack Obama’s 2010 decision to cancel the Constellation Moon-return program, which featured separate space shuttle-derived rockets for crew and cargo missions.

SLS will fly its first two missions in a 70-metric-ton configuration, powered by five-segment solid-fueled boosters that Utah-based ATK was building to serve as the main stage for Constellation’s canceled Ares 1 crew rocket. For its earliest flights, SLS will use surplus space shuttle engines from Pratt & Whitney Rocketdyne of Canoga Park, Calif., and a Delta 4 upper stage.

Later SLS configurations will use an expendable version of the space shuttle main engine, the J-2X upper-stage engine being developed by Pratt & Whitney Rocketdyne, and a new set of competitively procured boosters. The booster competition is expected to begin in 2015.

In the meantime, NASA is spreading $200 million across four companies for a 30-month SLS Advanced Booster Engineering Demonstration and Risk Reduction effort. In October, NASA signed contracts with three of those companies: ATK Launch Systems; Huntsville, Ala.-based Dynetics; and Los Angeles-based Northrop Grumman Corp. The combined value of the awards is $137.3 million.

Aerojet, which proposed work that could lead to a U.S. alternative to the Russian-built, kerosene-fueled RD-180 engine, is the only company with a NASA-selected study concept that does not have a finalized contract. Industry officials said in October this was because NASA and the Air Force, which has already funded some of the work Aerojet wants to carry over for the SLS booster program, had not yet agreed on their respective funding contributions to Aerojet’s engine work.

But Aerojet spokesman Glenn Mahone told SpaceNews Feb. 5 that the Sacramento, Calif., company expects its SLS booster-study contract to be finalized “shortly.”

“Maybe within a week,” Mahone said.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.