Starliner OFT-2 Heading Home on Wednesday

Boeing and NASA confirmed today that the uncrewed Starliner spacecraft will complete the Orbital Flight Test-2 mission on Wednesday. Launched last week, Starliner encountered a few glitches on the way to docking with the International Space Station, but everything appears to have gone well since. Undocking, deorbit burn, and landing in New Mexico are the next big steps to demonstrate Starliner is ready to carry people. The Crew Flight Test could launch by the end of this year. NASA is eager to have this second commercial crew system available to ferry crews to and from the ISS.

Like SpaceX’s Crew Dragon, Starliner was developed through a Public-Private Partnership with NASA where the companies retain ownership of their vehicles. NASA paid for part of development through a fixed price contract and guaranteed to purchase a certain amount of services with the expectation the companies would find other customers as well.

SpaceX has proven that model by launching two Crew Dragons for non-NASA customers already — Inspiration4 and Axiom-1 — with more on the books.

Boeing is years behind, still trying to finish the first step in certifying the vehicle for NASA astronauts — an uncrewed test flight. The first Orbital Flight Test in December 2019 did not go as planned.  OFT-1 was unable to make it to the ISS and almost had a catastrophic ending because of software errors and also had communications problems. It landed safely, but Boeing has been playing catch-up ever since.

The company decided to refly the uncrewed test before putting people onboard. It was ready for the reflight, OFT-2, last August, but 13 stuck propulsion valves scutttled the launch. Because it is a fixed price contract, Boeing must absorb the costs of OFT-2, which was not part of the contract. The company has taken a charge of $595 million in costs against earnings so far.

This mission is the OFT-2 do-over. It did get off the launch pad on May 19 at 6:54 pm ET and docked with the ISS the next day, but there were a few glitches getting there.

The United Launch Alliance Atlas V rocket gets Starliner almost to orbit, but the spacecraft’s own thrusters must get it the rest of the way and perform on-orbit operations like rendezvous with the ISS and the reentry burn.

Starliner has 12 Orbital Maneuvering and Attitude Control (OMAC) thrusters arranged in four groups of three. They are in compartments dubbed “doghouses” because of the shape of the enclosure. Two of the three thrusters in one of the doghouses failed during the orbital insertion burn. The third worked so the mission wasn’t impacted, but the question remains as to what went wrong.

The next day Starliner successfully docked with the ISS, but more than an hour later than scheduled, at 8:28 pm ET instead of 7:10 pm ET.

Two small Reaction Control System (RCS) thrusters, which are separate from the OMAC thrusters, failed during the rendezvous and docking operations. In addition, something went awry with two thermal cooling loops, although temperatures remained stable. The NASA-built docking system had its own problems requiring a reboot by retracting and re-extending the docking ring.

NASA and Boeing officials downplayed the anomalies during a post-docking briefing with reporters. Mark Nappi, the head of Boeing’s commercial crew program, said they may never know the root cause of the OMAC failures since they are in the Service Module, which burns up in the atmosphere during reentry. Only the Crew Module lands.

Starliner did dock successfully, however, and on Saturday ISS crew members opened the hatch and began unloading the 500 pounds of supplies inside.

They are loading Starliner with 600 pounds of equipment for return to Earth including reusable Nitrogen Oxygen Recharge System tanks that will be refurbished and sent back to ISS later.

The ISS crew will close the hatch tomorrow and if all goes according to plan Starliner will undock on Wednesday at 2:36 pm ET and land at its primary landing site, White Sands Space Harbor, part of the White Sands Missile Range in New Mexico, at 6:49 pm ET.

Boeing and NASA are not ready to commit to a launch date for the Crew Flight Test. First they must review the data from OFT-2. The goal is to launch by the end of this year, but NASA’s Aerospace Safety Advisory Panel recently cautioned that there is a “tremendous amount of work” to be done and urged NASA and Boeing not to rush. The schedule is partially dependent on whether Boeing needs to redesign the valves, a decision that was pending prior to this launch.

Once Starliner is certified for operational missions, the plan is for NASA to alternate Boeing and SpaceX missions ferrying crews to the ISS every six months. The point of having two companies develop “dissimilar” systems is to provide redundancy. If one is grounded for any reason, NASA still has the other.

In addition, NASA wanted competition in the pricing of the services. The contracts NASA has with the companies guaranteee six “post-certification missions” each. After that NASA could choose whichever offers the best price, although if Boeing launches only once a year for NASA, its six PCM missions would last pretty much through the end of ISS operations in 2030.

Boeing is partnered with Blue Origin and Sierra Space in the Orbital Reef project to build a commercial space station to succeed ISS. As with the commercial crew systems, NASA’s goal is to be one of many customers for commercial space stations and would purchase services from various providers instead of owning either the space station or the transportation services to get back and forth.