WASHINGTON — The U.S. Air Force appears to be responding to congressional calls to launch an aging weather satellite sooner rather than later, a development that could provide rocket maker Space Exploration Technologies Corp. another opportunity to win national security business.

Col. Michael Guetlein, commander of the remote sensing systems directorate at Air Force Space and Missile Systems Center in Los Angeles, said the service is now targeting a 2016 launch date for the Defense Meteorological Satellite Program (DMSP) Flight 20 satellite, the last in a series of military weather satellites whose legacy dates back to the 1960s.

DMSP Flight 20 was built in the 1990s and had notionally been scheduled to launch in 2020 on a United Launch Alliance Atlas 5 rocket. The Air Force has also raised the possibility that the satellite, whose twin, DMSP Flight 19, was launched in April and began operations in September, might be destined for a museum rather than orbit.

Key lawmakers are at best ambivalent about funding the satellite’s considerable storage costs, however, and at the same time they want to increase the number of U.S. national security launches that are competitively awarded.

Since 2006, ULA of Denver has effectively been the sole U.S. provider of national security launches, but the Air Force is in the midst of certifying SpaceX’s Falcon 9 rocket to compete in that marketplace. Currently, the service has plans to put just seven launch missions up for bid in the next couple of years, but it has been searching for months for a potential eighth mission, and DMSP 20 has emerged as a top candidate.

In July, the Air Force asked Congress’ permission to reprogram $100 million for fiscal year 2014 to support the eighth competitive launch. That request has been approved by two congressional committees that oversee the Pentagon.

“DMSP 20 is going through the factory now and will be delivered in 2015 with a potential launch date of 2016,” Guetlein said Oct. 3 during a breakfast sponsored by the Marshall Institute, a think tank here.

The service is asking Congress for $39 million next year to begin development of a follow-on weather satellite, but members of the House Armed Services Committee are more interested in DMSP Flight 20. In its version of the National Defense Authorization Act for 2015, the panel recommended denying that request and initiating a competition next year for the launch of the aging satellite.

The fact that launching Flight 20 in 2020 would, according to an Air Force analysis, mean incurring some $425 million in storage costs also has gotten the attention of lawmakers.

In the report accompanying its proposed defense spending bill for 2015, the Senate Appropriations defense subcommittee noted that “only a few of the capabilities provided by this satellite cannot be met by other existing civil and commercial satellites.” The committee urged the Air Force to “pursue a least cost approach for the disposition of this satellite.”

But launching the satellite in 2016 also could prove challenging and costly, particularly if Hawthorne, California-based SpaceX prevails in a competition for the contract. In July, retired Gen. William Shelton, then the commander of Air Force Space Command, said that reconfiguring the satellite to fly on a Falcon 9 rocket would take at least a year and cost tens of millions of dollars.

“The future of DMSP F-20 is not quite clear,” he said.

Many have questioned the need for launching the satellite at all, saying much of the data it is designed to collect is available from other sources.

The Air Force and U.S. National Oceanic and Atmospheric Administration, which operates civilian weather satellites, were expected to complete by this past summer a study on the consequences of not launching Flight 20. The Air Force did not respond by press time to inquiries about the satellite’s launch schedule.