The U.S. Space Force has decided to delay the planned late February launch of two military satellites aboard a ULA Atlas 5 rocket to “evaluate readiness” of one of the payloads, giving officials a window to move forward the liftoff of an unpiloted test flight of Boeing’s Starliner crew capsule to no earlier than March 25.
The launch of the military’s Space Test Program-3, or STP-3, mission was previously scheduled Feb. 26 on an Atlas 5 rocket from Cape Canaveral Space Force Station. The STP-3 mission will deliver two military spacecraft into a geosynchronous orbit more than 20,000 miles over the equator.
A spokesperson for the Space and Missile Systems Center said the STP-3 launch has been delayed to “evaluate readiness” of one the military satellites, named STPSat6, and “ensure mission success of the primary payload.”
STPSat 6 hosts several payloads and experiments, including the National Nuclear Security Administration’s Space and Atmospheric Burst Reporting System-3 payload, which is designed to detect nuclear detonations from orbit. NASA’s Laser Communications Relay Demonstration experiment and several more payloads are also flying on the STPSat 6 spacecraft.
A smaller satellite named LPDE 1 will ride into orbit with STPSat 6. The LPDE 1 spacecraft is designed to accommodate experimental payloads and small satellites, which could be deployed from the parent satellite in orbit.
The STP-3 mission is also a milestone mission for ULA because it will be the first Atlas 5 launch with U.S.-built payload fairing. The 5.4-meter-diameter (17.7-foot) shroud is identical in size to payload fairings that flew on previous Atlas 5 flights, but those were built by RUAG Space in Switzerland.
But the new fairings are built by RUAG technicians inside ULA’s rocket factory in Decatur, Alabama, using updated manufacturing techniques. The same fairing design is intended to fly on ULA’s next-generation Vulcan Centaur rocket.
The Space Force’s Space and Missile Systems Center said the STP-3 mission does not have a new target launch date.
With the STP-3 mission out of the way, ULA’s first launch of 2021 will carry Boeing’s Starliner spacecraft into orbit on a test flight to the International Space Station.
The unpiloted demonstration mission, named Orbital Flight Test-2, is a repeat of Boeing’s OFT-1 test flight in December 2019. Software problems on the OFT-1 mission prevented the Starliner spacecraft from docking with the space station, forcing a premature landing under parachutes at White Sands Space Harbor, New Mexico.
Boeing said earlier this month that engineers completed “requalification” of the Starliner software code. The software will undergo an end-to-end test next month to check its functionality throughout a simulated Starliner flight from launch through docking, and from undocking through landing.
The Starliner spacecraft is one of two new crew capsules designed to ferry astronauts to and from the space station. SpaceX’s Crew Dragon capsule flew with astronauts for the first time last May, but Boeing’s software problems delayed the Starliner program more than a year.
NASA contracted with Boeing and SpaceX to develop the new crew capsules, ending U.S. reliance on Russian Soyuz spacecraft for astronaut transportation services.
The OFT-2 mission was previously scheduled for liftoff March 29, but NASA and Boeing officials moved the launch date forward to no earlier than March 25 after the STP-3 launch delay.
“The target launch date is enabled by an opening on the Eastern Range, the availability of the United Launch Alliance Atlas 6 rocket, steady progress on hardware and software, and an International Space Station docking opportunity,” NASA said in a statement.
“Boeing recently mated the spacecraft’s reusable crew module on its brand new service module inside the Starliner production factory at Kennedy Space Center in Florida,” NASA said. “Teams are working to complete outfitting of the vehicle’s interior before loading cargo and conducting final spacecraft checkouts.”
Assuming the week-long OFT-2 test flight goes well, Boeing hopes to launch the Starliner’s first Crew Flight Test with a three-person crew as soon as mid-2021. The three astronauts will dock with the space station, where they are expected to spend one-to-two weeks before coming back to Earth.
After the Crew Flight Test, NASA will certify the Starliner to fly on operational crew rotation missions to the space station. Those flights will carry four astronauts and last up to seven months.
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.