WASHINGTON — More than a dozen members of the U.S. House of Representatives have asked congressional investigators to scrutinize NASA’s plans to shut down its Constellation program and determine whether or not the U.S. space agency is breaking the law.

In a March 12 letter to the head of the U.S. Government Accountability Office (GAO), 16 House lawmakers assert that legislation passed in December prohibits NASA from terminating or slowing its Constellation program, a 5-year-old effort to build new rockets and spacecraft optimized for lunar missions that President Barack Obama proposed abandoning in his 2011 budget request.

NASA Administrator Charles Bolden said March 16 his agency is complying with the legislation in question — an omnibus spending package approved in December that funds NASA and other federal agencies through this September — which prohibits the agency from ending programs and activities that are part of the Constellation program.

“We’re in full compliance with the intent, well, with the wording of the 2010 authorizations act. We’re not doing any termination activities, we’re not doing any shutdown activities,” Bolden said following remarks at a luncheon organized by the Washington Space Business Roundtable in Oxon Hill, Md. “I think what they’re talking about is just the question that I asked everybody to take a look at what is there in Constellation we can benefit from, what kind of things do you want to retain, and I think that’s prudent.”

But House lawmakers, led by Rep. Robert Aderholt (R-Ala.), are concerned the agency’s planning efforts could delay Constellation development work in 2010 and cause irreparable harm to the program should Congress choose to continue funding all or part of it in 2011.

“We believe that interpretation of this bill language should take into account the fact that these activities are not easily stopped and started but rather are long-term contract plans (as long as 36 months out) involving highly specialized engineering teams both in government and in the private sector,” states the letter, which was spearheaded by Aderholt. Most of the lawmakers who signed the letter — including the two Democrats, Reps. Gene Green of Texas and Suzanne Kosmas from Florida — are from states that play big roles in Constellation.

The letter also asks the GAO to determine whether NASA is abusing the Anti-Deficiency Act when the agency instructs employees to conserve 2010 funds intended for Constellation.

“We believe that this act does not apply to the situation, particularly given the fact that Congress has specifically forbidden the termination not just of the program, but of programs and activities,” the letter states. “Congress, therefore, not NASA, is responsible for contract shutdown costs and will provide them — in [2011], in the event that Congress approves the President’s plan in whole or in part.”

The lawmakers are also asking GAO to determine whether NASA is violating the Impoundment Act by withholding 2010 funds “rather than proceeding with contracts which represent a normal schedule of [2010] activity implied by Congress’s refusal to allow NASA to terminate the Constellation program,” according to the letter.

Finally, the lawmakers contend NASA is using “quite a few employees” to develop new plans for its human space exploration, work that may be “far more extensive than simply discussing options and plans,” according to the letter. “Rather, senior-level program personnel seem to be spending all of their days on the new plans instead of on the Constellation programs, projects and activities, which are their jobs (according to the [2010] bill language).”

Although the letter does not call on GAO to issue a report on its finding, it does ask GAO Comptroller General Gene Dodaro to expedite an investigation of NASA employees tasked with developing new human spaceflight plans. In the letter, the lawmakers assert NASA has failed to provide an answer to congressional staff inquiries submitted Feb. 22 about who is working on the new plans, how much of their workday is consumed by such tasks and from which payroll accounts the employees are being paid.

“This last point is important since it is unlikely that there is substantial payroll funding leftover from previous fiscal years,” the letter states. “If NASA’s actions do indeed comprise the initiation of a new program, and [2010] funds are being used to pay those personnel, NASA is in violation of the bill language and these planning activities must stop immediately.”

The letter instructs Dodaro to respond to the latter question “separate from the other aspects, with the goal of a conclusion in approximately 60 days, as opposed to the typical 100 to 120 days required.”