The U.S. congressional defense authorization committees slashed funding for the Pentagon’s top two space acquisition efforts in their versions of the 2006 defense spending legislation, but added money for a variety of less costly efforts.

When U.S. President George W. Bush signs the 2006 defense budget, the Space Radar reconnaissance satellites and Transformational Satellite (T-Sat) Communications System are both likely to get far less money than the president requested in January for those programs. However, programs that aim to reduce the cost of space launch and provide warning of laser threats to U.S. satellites may see more funding.

The House of Representatives passed its version of the 2006 Defense Authorization Act on May 25. The Senate had not voted on its version of the bill at press time. After the Senate passes its version, differences will need to be worked out in a conference between members of the House and Senate Armed Services Committees, then sent to Bush for his signature.

The Pentagon’s budget request, which was sent to Capitol Hill in February, contained $18.9 million for aerospace propulsion technologies including hypersonic concepts that could lead to high-speed aircraft that could perform missions including serving as a reusable first stage for launching satellites.

The Senate Armed Services Committee is seeking to bolster that work by adding another $12 million to support a “more aggressive” hypersonic research program and facilitate additional ground tests that would build on the successful flight tests of the X-43A. The House version of the bill did not include the additional money.

The committee indicated in a report accompanying its version of the authorization bill that it is pleased with collaborative work between NASA and the U.S. Air Force on the X-43 program, which included Mach 9.8 flight tests in 2004, and encouraged continued work between the two agencies on the effort.

NASA attempted to discontinue its work in this area last year, but Congress added $25 million to its budget for further X-43 development.

NASA’s 2006 budget request includes no money for hypersonic work. However, Michael Griff in, who was confirmed by the Senate as NASA administrator after the agency sent its 2006 budget request to Capitol Hill, has said he would like to do more work in this area.

The Senate committee also added funding for another new launch concept, called the Radially Segmented Launch Vehicle. The senators added $4 million for the vehicle, which is being developed by KT Engineering of Huntsville, Ala., including engineering development, prototype hardware fabrication and ground testing.

Congress also added $4.7 million for the program in 2004, and $4 million in 2005. However, the Pentagon did not request funding in 2006 for the vehicle, and the House did not add funding for the project.

KT Engineering has worked on its design for the rocket as part of a group of companies that received contracts worth less that $600,000 in 2003 to study new low-cost launchers under the Air Force-Defense Advanced Research Projects Agency Falcon program in 2003. However, KT Engineering’s concept was not among those chosen for continued development under the Falcon effort last year.

David Sisk, president of KT Engineering, declined to comment when asked when the Radially Segmented Launch Vehicle might fly.

Both committees added funding for an experimental payload that could aid the development of electro-optical sensors that could detect laser attacks on U.S. satellites. The House added $2.5 million, and the Senate committee added $5 million, for the Laser Threat Warning Attack Reporting System, which was not funded in the Pentagon’s 2006 budget request.

The Pentagon’s Space Experiments Review Board, which ranks experimental payloads according to priority for rides into space, ranked the Laser Threat Warning Attack Reporting System as its number four priority last fall. U.S. satellites, according to the Senate committee report, “are becoming increasingly vulnerable to deliberate hostile or intrusive attacks from lasers deployed by foreign governments or terrorist groups.”

Budget constraints have kept the Air Force from arranging a launch for the payload, according to a service official. The laser warning payload could potentially be resubmitted for consideration by the review board in November with a potential launch in 2008 or 2009, the official said.

Both committees also added funding to launch the third spacecraft in a series of small satellites than can be directly controlled by military commanders in the field. The Senate committee report described the launch of the TacSat 3 satellite, which also is known as Joint Warfighter 2, as having been included on an Air Force list of priorities that the service could not fit into its 2006 budget request, and added $10 million to handle launch and range cost.

The House added $13.5 million for the TacSat 3 launch, which is expected to take place around 2007. The satellite is planned to include a hyperspectral imaging sensor.