Boeing’s Starliner crew capsule, making a repeat test flight in a third attempt to reach the International Space Station, finally closed in on the lab complex Friday, executing a series of rendezvous maneuvers while engineers investigated problems with two thrusters and the spacecraft’s cooling system.
Approaching from behind and below, the unpiloted Starliner was expected to home in on the space station using a high-tech robotic vision system, moving in for docking at the lab’s forward port around 7:10 p.m. EDT.
“From Starliner’s cameras, we are seeing ISS,” Rob Hayhurst in mission control at the Johnson Space Center radioed the station crew as the capsule slowly approached.
“Awesome, we’re waving, can you see us?” astronaut Robert Hines joked. “Great news, that’s really good to hear. We’re getting squared away up here and ready to catch her.”
While no astronauts were on board the Starliner, Boeing took advantage of the test flight to send up about 500 pounds of equipment and supplies along with “Rosie the Rocketeer,” an instrumented mannequin collecting data on the cabin environment real astronauts will experience during operational flights.
Launched Thursday from Cape Canaveral atop a United Launch Alliance Atlas 5 rocket, the Starliner reached its planned initial orbit despite the premature shutdown of two thrusters, automatically switching to a backup jet in the same rocket pad to continue the critical maneuver.
At the same time, engineers were monitoring a spacecraft cooling problem that appeared to stabilize after the ship reached orbit. Overnight, however, one of the capsule’s two cooling loops later ran into problems, forcing flight controllers to make manual adjustments.
Without providing details, Boeing said in a statement “the thermal subsystem is maintaining stable temperatures” and a spokesman said the Starliner’s approach to the station could be adjusted as required to maintain proper temperatures if necessary.
Otherwise, Boeing reported the Starliner’s guidance, navigation and control system was working normally, flight software was running smoothly, the ship had good communications through NASA’s Tracking and Data Relay Satellite system and power levels were normal.
In addition, the spacecraft carried out a series of “demo” thruster firings, confirming the ship’s ability to hold position, execute rendezvous abort procedures and adjust its orbit, along with tests of its electronic vision system and its NASA docking mechanism.
Assuming a successful docking and return to Earth, Boeing managers hope to ready a Starliner for launch before the end of the year carrying an astronaut crew to the space station on a piloted test flight. After that, NASA hopes to ferry crews to and from the lab using both SpaceX Crew Dragon and Starliner ferry ships.
The launching Thursday came nearly two-and-a-half years after Boeing first attempted an unpiloted Starliner flight in December 2019.
During that flight, an embarrassing software error prevented the Starliner’s flight computer from loading the correct launch time, throwing off the timing of critical rocket firings. Flight controllers were unable to quickly resolve the problem because of an unrelated communications glitch. As a result, the spacecraft was unable to rendezvous and dock with the space station as planned.
Boeing opted to launch the Starliner on a second unpiloted test flight, at the company’s expense, but corroded valves in its propulsion system, discovered during an August 2021 launch attempt, forced another lengthy delay for troubleshooting and repairs.
Despite the Starliner’s problem-plagued development, NASA is anxious to get the spacecraft certified for astronaut ferry flights. The goal is to provide redundancy and assured access to space in the event either company runs into a problem that might ground their spacecraft.
In 2014, NASA awarded Boeing a $4.2 billion contract to develop the Starliner while SpaceX won a $2.6 billion contract to develop the company’s Crew Dragon.
Despite a smaller contract and vastly less spaceflight experience, SpaceX was able to beat Boeing to the punch, successfully launching an unpiloted Crew Dragon to the space station in 2019 and a piloted test flight with two NASA astronauts in 2020.
Since then, the California rocket builder has launched four operational crew rotation missions to the station for NASA, one commercial flight to the lab and a privately chartered flight to low-Earth orbit.
