The debut launch of Boeing’s Starliner space capsule onboard a United Launch Alliance Atlas 5 rocket has been postponed to Dec. 19, officials announced Tuesday.
The takeoff of the Starliner’s Orbital Flight Test on top of was earlier scheduled for Dec. 17 on a week-long validation mission to the International Space Station. The task is a critical sign for the Starliner’s first flight with astronauts, a goal Boeing officials say is programmed for mid-2020.
“In the course of pre-launch processing of the Atlas 5, there was a problem with the rocket’s purge air supply duct,” ULA said in a statement Tuesday. “Extra time was needed for the Boeing and ULA teams to complete scrutiny of the issue, substitute the duct and complete processing before launch.”
The purge air supply duct is a new element on the Atlas 5 rocket inside the launch vehicle adapter cavity, as stated by ULA. The adapter structure joins the Atlas 5 rocket with the Starliner spacecraft.
The duct is a tube that transmits air from the ground environmental control system into the launch vehicle adapter cavity for pre-launch cooling of avionics and the Starliner service module, as maintained by ULA.
Takeoff time Dec. 19 is planned for roughly 6:59 a.m. EDT (1159 GMT), about 10 minutes before sunrise. The exact launch time will be revealed closer to launch day grounded on the latest tracking of the space station’s orbit.
“We continue to work closely with Boeing to make sure that the Starliner flies the moment the spacecraft and launch vehicle are set,” ULA said.
Boeing is improving the Starliner crew capsule under a $4.2 billion contract granted by NASA in 2014. NASA has employed Boeing and SpaceX to make new human-rated spaceships to end U.S. dependence on Russian Soyuz crew ferry ships to carry astronauts to and from the space station.
ULA has pulled together the Atlas 5 rocket over the last month inside the Vertical Integration Facility just south of pad 41. Technicians first fixed the Atlas first stage on its mobile launch platform inside the VIF, then attached two strap-on solid rocket boosters Nov. 6 and Nov. 7. The Atlas 5’s dual-engine Centaur upper stage was elevated atop the rocket Nov. 8, tailed by a series of checkouts on the launcher before Boeing’s Starliner crew capsule reached for installation on the launch vehicle Nov. 21.
On Wednesday, the Atlas 5 will ride its mobile launch platform for the 1,800-foot journey to pad 41, where ULA has constructed a white room and crew access tower to allow astronauts to enter the Starliner through its side entrance.
Two track mobile railcars will drive the trip on rails from the VIF to the launch mount at pad 41.
Boeing, ULA and NASA teams are getting ready for the Integrated Day-of-Launch Test, or IDOLT, exercise to rehearse launch day procedures before the Starliner’s first space mission.
The Atlas 5 launch team has extended the countdown for Starliner missions to more than 11 hours from its typical duration of early seven hours. The additional time allows a “blue team” of experts — similar to the space shuttle-era closeout crew — to help astronauts in boarding the Starliner spacecraft after the Atlas 5 is powered with cryogenic propellants.
The test “will give us the prospect to deploy the crew access arm and confirm all the arm interfaces and access tower with the spacecraft,” said Caleb Weiss, ULA’s mission supervisor for the Starliner program. “We will completely tank the vehicle, and we will have people out there at the pad that will be modeling day launch operations, just like they will be for an actual launch day.
“So they will be in the white room, they’ll open the hatch of the Starliner,” Weiss said in a previous interview with Spaceflight Now. “They will rehearse going in and out, stocking cargo, configuring Starliner for flight. So it’ll be a really sound end-to-end system checkout of all the launch vehicle and spacecraft systems working in coordination, as well as the people who are implementing the operations.”
As soon as the IDOLT exercise is complete, the rocket will go back to the VIF for further testing and preparation activities before liftoff later this month.