The US Air Force (USAF) is calling for bids from potential suppliers for the Evolved Expendable Launch Vehicle (EELV) Launch Service for the Global Positioning System (GPS) III-3 mission.

United Launch Alliance (ULA) and Space Exploration Technologies (SpaceX) are expected to compete for the contract, according to media sources.

The request for proposal is the second competitive launch service solicitation under the current Phase 1A procurement strategy.

"GPS III focuses on providing improved anti-jamming capabilities, as well as accuracy for precision, navigation, and timing. "
 
Under the previous Phase I strategy, ULA was the only certified launch provider.

However, SpaceX has been qualified to provide EELV launches in May last year, increasing the number of launch service providers to two.

A firm-fixed price contract will be awarded after evaluating proposals through a competitive, best-value source selection process.

Prior to awarding the contract, the contracting officer will ensure that the offeror has a certified launch system.

USAF Space and Missile Systems Center commander lieutenant general Samuel Greaves said: “Launch system certification is a key element (high-technical bar) within this solicitation to provide insight into the technical capabilities and rigorous processes that demonstrate a launch vehicle contractor’s ability to design, develop, manufacture, and launch National Security Space missions and contributes to the overall flight worthiness process.”

Scheduled to launch in 2019, GPS III focuses on providing improved anti-jamming capabilities, as well as accuracy for precision, navigation, and timing.

It will use the common L1C signal that is compatible with the European Space Agency’s Galileo global navigation satellite system.