WASHINGTON — The U.S. Air Force announced plans to award space launch contracts later this year for five satellites that include some of the military’s most sensitive big-ticket payloads.

The competition comes less than two years since SpaceX became a legitimate competitor in a market that used to be entirely owned by United Launch Alliance, a partnership of Lockheed Martin and The Boeing Company.

If SpaceX is able to win at least one or two launches in this next round of contracts, it would further cement its standing as a market disruptor and set the stage for the company to win even more military work when the larger Falcon Heavy rocket gets certified to fly government payloads.

The Air Force on Wednesday released a final request for proposals for Evolved Expendable Launch Vehicle (EELV) launch services for two National Reconnaissance Office payloads, the fifth Space-Based Infrared System geosynchronous Earth orbit satellite, an Air Force Space Command mission dubbed AFSPC-44 and a secret surveillance mission code-named SilentBarker.

Proposals are due April 16 and contracts are expected to be awarded in late 2018.

Senior space industry analyst Carolyn Belle, of Northern Sky Research, said the five payloads could create a tough challenge to launch providers because each one is unique. “It’s interesting that they all came out at once,” Belle told SpaceNews.

Previous EELV competitions included satellites like GPS that are critical payloads but part of a large constellation, “which somehow mitigates the risk of any one launch,” Belle said. “Whereas this set of five are more unique payloads.”

The existence of SilentBarker surfaced last year during a House Armed Services Committee strategic forces subcommittee hearing when Gen. John Raymond, commander of Air Force Space Command, explained that the Air Force and the NRO were developing a “space situational awareness architecture” to help improve the protection of satellites from enemy attacks. SilentBarker is the name of the program.

This is the sixth competitive launch service solicitation under the current phase of the EELV program.

The Air Force continues to tweak the process and figure out how to write solicitations to get the best value and lowest price, Bell said. “This is still new. There are still adjustments being made.”

The current field of launch providers includes two companies and three vehicles. ULA can bid the Atlas 5 for the smaller payloads and the Delta 4 for heavier ones, whereas SpaceX so far only has the Falcon 9 and is unable to compete for the largest satellites.

“The Air Force hopes that competition will increase when Falcon Heavy gets its certification,” Belle said. If it succeeds, Falcon Heavy will be a game changer as it could lower the market price of launching big-ticket satellites, she said. “There may be more interest in larger satellites when there’s an availability to actually launch them.”

SpaceX already won an Air Force contract to launch a GPS 3 satellite aboard the Falcon 9 and one to launch a test payload from the Falcon Heavy as the rocket works toward certification. “The government is certainly interested in supporting commercial development as long as they are not particularly sensitive or costly payloads,” Belle said.

The list price for Falcon 9 launches is $62 million but military requirements add expenses. The GPS launch is estimated to run $90 million, still far less than what Atlas 5 would cost.

It could be at least two years before Orbital ATK is ready to join the fray as a third EELV player. The company is developing a next-generation military launch vehicle under an Air Force program.

“Orbital ATK is probably not yet ready for this,” Belle said. “They are only interested in pursuing the next-gen vehicle if they receive additional Air Force funding, which has not yet been secured yet.” There is additional development time that will be needed to finish the vehicle before it begins certification trials.

For this next EELV round, the Air Force will award firm-fixed-price contracts for launch vehicle production, mission integration, and launch operations.

Lt. Gen. John Thompson, commander of Air Force Space and Missile Systems Center said this solicitation “incorporates a tradeoff between past performance, performance and schedule sub-factors, and price to maintain a focus on mission success for these critical payloads.”

SBIRS GEO-5 and AFSPC-44 will be launched from Cape Canaveral Air Force Station or Kennedy Space Center in fiscal year 2021. The NROL-87 would lift off from Vandenberg Air Force Base also in fiscal year 2021. NROL-85 could be launched from the Eastern or Western Range in fiscal year 2021. SilentBarker could take off from Cape Canaveral Air Force Station or Kennedy Space Center in fiscal year 2022.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...