Space Adventures Ltd., which has made a name for itself arranging spaceflights for private citizens aboard Russian Soyuz capsules, has acquired a California-based company that fell on hard times after its contract to develop a partially reusable launcher for the U.S. Department of Defense was canceled.

But details surrounding Space Adventures’ acquisition of Space Launch Corp. are scarce.

In addition to Soyuz rides, Space Adventures of Vienna, Va., arranges commercial flights aboard Russian fighter aircraft and aboard aircraft that provide brief periods of microgravity by flying in a series of parabolic arcs. The company also is taking reservations for tourist flights aboard commercial suborbital rockets, but no such vehicles exist today.

“It is with great anticipation that we join Space Adventures to develop the technologies and business structures required to open the space frontier to all,” Jacob Lopata, Space Launch chief executive officer, said in a May 30 news release.

In interviews, Lopata and Eric Anderson, president and chief executive officer of Space Adventures, said Space Launch’s engineering talent and intellectual property would be useful in developing a space tourism vehicle. But both declined to detail any such plans.

Space Launch will function as a wholly owned subsidiary of Space Adventures, with Lopata retaining his title and duties. Anderson and Lopata both declined to comment on the current size of Space Launch’s staff.

Space Launch’s Web site states under a link titled “management” that the company is putting together “a team with the experience necessary to tackle the specific challenges presented by the space launch industry.” The site notes under a link titled “employment” that the company currently is not hiring, but expects to be doing so “in the near future.”

Anderson and Lopata also declined to discuss the terms of the acquisition or the revenues of either company.

Space Launch has worked on several contracts for the Pentagon, the largest being the Responsive Access, Small Cargo and Affordable Launch (RASCAL) effort. RASCAL was envisioned as a small satellite launcher with a modified U.S. Air Force combat aircraft serving as its first stage that would be capable of placing 150-kilogram payloads into low Earth orbit.

Space Launch was expected to conduct a demonstration launch of the RASCAL vehicle under a Defense Advanced Research Projects Agency contract worth $22 million . But the agency killed the project early last year when it became clear that a custom-designed aircraft would be required, and the estimated cost of the demonstration soared as a result.

The company attempted to revive the RASCAL concept later in 2005, coming up with a design that would use an Air Force F-4 jet as its first stage and launch payloads weighing 10-20 kilograms , but found no takers in the military or elsewhere .

In July 2005, Space Launch announced on its Web site that it had been granted a patent entitled “A System for the Delivery and Maintenance of Microsatellites and Other Space Based Instruments.” The patent covered an air-launched rocket capable of functioning as a satellite platform, the company said.

“This technology will allow the Space Launch Corp. to maintain a long-term competitive advantage in the small satellite market,” the company said.

In January 2006, however, Space Launch announced that it sold its California Rocket Test Center to a company called Protoflight LLC for an undisclosed sum. Lopata said Space Launch purchased that facility from the defunct Rotary Rocket Co. and modified it with the intent of using it for the RASCAL program.

Lopata said Space Launch currently has no other significant testing facilities but has no plans to reacquire the California Rocket Test Center.