Few space industry debates have endured longer or aroused more passion than the high cost of launching satellites into orbit, and much of the discussion in recent years has centered on the U.S. Air Force’s Evolved Expendable Launch Vehicle (EELV) program, the government’s primary means of access to space.

The EELV program has come under heavy fire for its high cost, which soared even higher as the retirement of NASA’s space shuttle drove up the cost of propulsion. Another sore spot is the fact that EELV prime contractor United Launch Alliance (ULA), a Boeing-Lockheed Martin joint venture established in 2005, has a virtual monopoly on the U.S. government payload market.

The Air Force’s answer to getting EELV costs down is to commit to buying up to 46 rocket cores from 2013 through 2017, thereby reaping volume discounts and stabilizing the industrial base. The so-called block buy strategy has been decried by Space Exploration Technologies Corp. and Orbital Sciences Corp. — both companies are developing new rockets and are angling for more government business — as well as key members of Congress.

Enter the U.S. Government Accountability Office (GAO) and its top bean counter for space-related procurement issues, Cristina Chaplain. In a report issued last fall, the GAO urged the Air Force to hold off on the block buy until it could get a better handle on costs, arguing that the service might wind up buying more rockets than it needs at unnecessarily high prices.

The Air Force initially indicated that it would nonetheless press ahead with the block buy in the summer of 2012. Lawmakers responded by adding provisions to the Defense Authorization Act of 2012 that cited the GAO report in tightening scrutiny of the EELV program.

In July, the GAO issued a follow-up report indicating that the Air Force had relented, delaying its block buy for at least a year. This should enable the service to satisfy any lingering concerns that ULA’s Atlas 5 and Delta 4 rockets are priced appropriately while giving the newcomers more time to demonstrate that their vehicles can be entrusted with important government payloads.

Chaplain keeps watch over a variety of government space- and missile defense-related procurement activities — she recently led a GAO report criticizing the U.S. Missile Defense Agency for running concurrent production and development programs, for example. The EELV block buy delay is but one tangible measure of her influence.