WASHINGTON — Two members of the House Appropriations subcommittee that funds NASA, including the chairman, have asked the agency to explain why it is considering giving Space Exploration Technologies Corp. (SpaceX) exclusive use of Launch Complex (LC) 39A — a mothballed space shuttle launch pad NASA no longer wants to pay for.

“[W]e question the seeming desire by NASA to lease LC-39A to a single user for sole use rather than to an entity that would ensure that the pad was re-developed as a multi-user pad,” U.S. Rep. Frank Wolf (R-Va.), chairman of the House Appropriations commerce, justice, science subcommittee, and Rep. Robert Aderholt (R-Ala.) wrote in a July 22 letter to NASA Administrator Charles Bolden. “Before proceeding with any decision regarding the lease of LC-39, we respectfully request a briefing as soon as possible,” says the letter, a copy of which was obtained by SpaceNews.

Since the shuttle program ended in 2011, two launch pads, 39A and 39B, have been vacant at the Kennedy Space Center in Florida. While the heavy-lift Space Launch System (SLS) that NASA is building would use Pad 39B about once every four years beginning in 2017, the agency has no plans for 39A, which cost $1.2 million to maintain in a mothballed state in 2012. NASA is looking to get that $1.2 million off its books by Sept. 30.

NASA was, according to congressional sources, about a week from making a leasing decision on Pad 39A when Aderholt and Wolf weighed in. SpaceX of Hawthorne, Calif., and Blue Origin of Kent, Wash., were the only two respondents to NASA’s May 23 solicitation for potential tenants. 

Blue Origin submitted a multiuser plan, according to these sources, while SpaceX, which would adapt Pad 39A for both its Falcon 9 and planned Falcon Heavy launcher, is open and adamant about its desire for exclusivity. The company is delivering cargo to the international space station and hopes to transport astronauts to and from the outpost starting in 2017.

“SpaceX has a significant book of commercial business which requires the consistent and full use of a launch pad like LC 39A,” SpaceX President and Chief Operating Officer Gwynne Shotwell said via email July 25. “Should SpaceX have the privilege of serving NASA’s need to transport astronauts to and from the International Space Station, LC 39A will be an integral part of ending our nation’s expensive dependency on the Russians for their services.” 

Blue Origin, which is working on a variety of suborbital and orbital space vehicles but has yet to launch anything into orbit, is generally quiet about its plans. But a Blue Origin official said in July that the company is interested in Pad 39A for future orbital operations.

Neither company has revealed the specifics of its proposed pad lease, but Aderholt and Wolf said SpaceX is offering too little money for too long a lease: up to 20 years, according to their July 22 letter to Bolden.

NASA spokesman Trent Perrotto, in a July 26 email, declined comment about NASA’s ongoing evaluation of the two it received for pad 39A. However, he defended NASA’s “open and fair process [which] will ensure the best use of this unique facility, as well as provide the best value to the U.S. taxpayer.

“The agency looks forward to reviewing and evaluating the proposals received and making a selection that will keep this storied launch pad in use for years to come,” Perrotto added.

An aide to Aderholt said the lawmaker was weighing in on behalf of SLS, which is being developed by NASA Marshall Space Flight Center in Huntsville, Ala. Specifically, Aderholt is concerned about having an available backup pad for the heavy lifter — Pad 39A would not be an option if SpaceX gets the lease. 

Meanwhile, Blue Origin’s bid to keep Pad 39A open to multiple users had at least some support from SpaceX competitor United Launch Alliance (ULA) of Denver, which launches most U.S. government satellites.

“ULA has and continues to assess the feasibility of using the national capabilities of LC-39 to improve our service offerings to meet our customer needs most cost effectively,” ULA spokeswoman Jessica Rye wrote in a July 25 email. “We have and will continue to share our technical expertise in launch infrastructure with Blue Origin to enable their leadership to manage the asset for multi-user capability, for which ULA could be one of the users.”

Rye included Pad 39B among the ground assets ULA is eying, although she did not say how the company might use that pad. 

SpaceX wants to crack ULA’s virtual monopoly on U.S. military launches, take away the science launches the Denver-based company does for NASA and the National Oceanic and Atmospheric Administration, and become NASA’s post-shuttle provider of astronaut transportation under the Commercial Crew Program.

The other two companies in the Commercial Crew Program, Boeing Space Exploration of Houston and Sierra Nevada Space Systems of Louisville, Colo., have both proposed launching aboard ULA’s Atlas 5. But neither is planning to use the old shuttle pads as launch sites for possible Commercial Crew missions, according to the Space Act Agreements they signed with NASA in August 2012.

Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...