Timer Glitch Means No Space Station Docking for Boeing’s Starliner

Boeing’s uncrewed CST-100 Starliner spacecraft will not be docking to the International Space Station (ISS) tomorrow as planned.  In fact it will not be docking at all.  Although the launch itself went perfectly, an unknown problem with the Mission Elapsed Timer on Starliner caused the spacecraft’s own propulsion system to burn too much propellant achieving orbit.  Not enough remains to rendezvous and dock with ISS.  Tentatively, the automated space capsule will land at White Sands Missile Range, NM Sunday morning.  No one is aboard the spacecraft.

The Boeing Orbital Flight Test (OFT) of its Starliner commercial crew system lifted off on time at 6:36 am ET from Cape Canaveral Air Force Station, FL this morning.  The United Launch Alliance (ULA) Atlas V rocket performed perfectly on this unique trajectory specially designed for crew missions to the ISS.  ULA President and CEO Tory Bruno said at a post-launch press conference that this 81st launch of the Atlas V “hit the bull’s eye” of its intended spot to deliver Starliner.

Atlas V places Starliner in a suborbital trajectory where Starliner’s own Orbital Maneuvering and Attitude Control (OMAC) engines take over for the rest of the trip.

Starliner was operating in a completely autonomous mode and something went wrong with its Mission Elapsed Timer that triggers when the engines fire.  Boeing Vice President for Space and Launch Jim Chilton said they do not yet know what happened or why.

Because of the timer malfunction, the spacecraft apparently thought it already was in orbit and was trying to make orbital corrections, burning propellant.  Flight controllers unsuccessfully tried to send commands from the ground, but the signals did not get through.  Those signals must be transmitted over NASA’s Tracking and Data Relay Satellite System (TDRSS) in geostationary orbit, which provides near-global coverage. NASA Administrator Jim Bridenstine and Boeing’s Chilton said this situation apparently arose at a rare moment when a TDRS satellite could not be accessed, though they are still investigating if that was the problem.  In any case, by the time the link was established, so much propellant had been expended that there is not enough to reach ISS and perform the rendezvous and docking operations.

Flight controllers decided to put Starliner into an orbit where it could return to its landing site in New Mexico within 48 hours.  It is in a stable, if incorrect, orbit at 216 x 186 kilometers.

At the moment the plan is to land at White Sands Sunday morning, but that is tentative.  Boeing needs to understand what went wrong with the timer today and whether it could impact the landing sequence as well.

In the meantime, Boeing and NASA will conduct other tests with the spacecraft while it is in orbit even though it cannot complete its primary task of docking with ISS, remaining for several days, undocking, and then landing.

Bridenstine praised flight controllers for deciding to put the spacecraft into an orbit that protects a landing in 48 hours, “an important test objective in itself.”

Bridenstine emphasized that if a crew had been on board, at no time would their safety have been at risk.  In fact, he and the two NASA astronauts assigned to the first crewed Starliner mission, Crew Flight Test (CFT), insisted that if they had been aboard, they might have been able to remedy the situation.

Nicole Mann and Mike Fincke, who will fly the CFT mission along with Boeing astronaut (and former NASA astronaut) Chris Ferguson, said at the press conference that Starliner crews can override the automated systems and control the engine firings manually.

“In this case we could have stopped the [Reaction Control System] RCS thrusters from firing and then entered the burn ourselves and either had the … computer system execute that burn or we could have flown that burn manually,” Mann said.  “These are the things we spend our time training for,” Fincke added.  Both are military test pilots.

Bridenstine was noncommital about whether another uncrewed flight will be required or if he would approve Starliner docking with ISS without a successful test.  “Certainly I’m not ruling it out. … I’m not saying we’re going to do it, but I’m not ruling it out either.  Remember, when we had space shuttles, every single one of those missions was crewed.  From Day One.  The very first time we launched the space shuttle, it had people on board.  The first time it rendezvoused with an object in space, it had people on board.”  He is focused on understanding what happened today and determining whether or not there is a larger systemic problem.

Bridenstine tried to paint a positive picture, insisting that “today, a lot of things went right. This is, in fact, why we test.”  He said he had already spoken with Vice President Mike Pence, who chairs the White House National Space Council, to bring him up to date.  Pence’s press secretary later issued a statement confirming the briefing and that Pence will continue to receive updates.  “Vice President Pence was assured that NASA will continue to test and improve, in order to return American astronauts to space on American rockets in 2020.”

Boeing’s Starliner is one of two commercial crew systems being developed as public-private partnerships with NASA to restore the ability to launch astronauts to ISS from the United  States.  SpaceX’s Crew Dragon is the other.  NASA has not been able to launch anyone to ISS since the space shuttle program was terminated in 2011.  It pays Russia to ferry crews back and forth.

Both U.S. systems are several years behind schedule, lengthening NASA’s dependency on Russia.  The last seat NASA has on a Russian Soyuz spacecraft is in April 2020.  It is negotiating with its Russian counterpart, Roscosmos, for another seat in the fall of 2020 and possibly in the spring of 2021, but until the Boeing and SpaceX systems are flying, U.S. presence on the ISS will be sharply limited.  Only one American will be on board beginning with that April 2020 Soyuz flight.  Today there are three, as well as one from the European Space Agency and two Russians.

The ISS is a partnership among the United States, Russia, Canada, Japan, and 11 European countries operating through the  European Space Agency.  Crews rotating on roughly 4-6 month schedules have lived aboard ISS continuously for the past 19 years.  The typical ISS crew complement is six.