Boeing’s Starliner Spacecraft Successfully Docked with the ISS: A Recap of the Historic Mission

Boeing’s Starliner spacecraft finally made it to the ISS after years of delays. KATE ARKLESS GRAY reports on how the launch went, what the mission will look like and what’s next for Starliner.

Beset by delays, exceeding budgets and technical issues, Boeing finally managed to get its crew flight test of the CST-100 Starliner underway and into space. On Wednesday 5 June 2024, veteran NASA astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams, strapped into the Starliner capsule atop of a ULA Atlas V rocket, and this time they finally got the launch they’d been waiting for.

Starliner finally takes flight

After a smooth ride into orbit, the pair began putting the vehicle through its paces before docking with the International Space Station (ISS) a day after launch. On approach to the ISS, an issue caused software to shut down five of the reaction control system thrusters, and Butch took manual control of the spacecraft while they worked the problem. After individually hot-firing each of the affected thrusters, four of the five were brought back online, and the automated docking was allowed to proceed. A successful docking was achieved in their second docking window, and Butch and Suni received a warm welcome from the seven-strong US and Russian ISS crew when the hatch was opened.

It was the third time in a month that the astronauts had gone through the launch day process, including suit checks, a traditional card game, and a final wave to family before getting on the astro-van to get to the launch pad. The first flight attempt was scrubbed a couple of hours before launch in the very early hours of 7 May, due to an issue with the rocket, and then on 1 June they were less than four minutes away from launch when a call to “hold, hold, hold” was heard on the comms loop. An issue with the ground launch sequencer (the computer that controls the final moments of the count) caused an automatic hold to be added, and since the mission requires an instantaneous launch window to put them on the right track for the ISS, it was another scrub.

With their successful launch, Suni Williams becomes the first woman to pilot an orbital test flight on the new human-rated system, also meanwhile it being her third ever spaceflight. Taking inspiration from Jacques Cousteau’s oceanic research vessel, Suni named their capsule Calypso. Her love of the ocean also inspired the choice of a sequinned soft-toy narwhal as their zero-G indicator, coincidentally also called Calypso by the toy company who produced it.

Following SpaceX’s steps

Starliner is following in the footsteps of SpaceX’s Crew Dragon, which completed its crew flight test almost exactly four years ago. Following their Demo-1 spaceflight, SpaceX has launched eight crews to the ISS on Crew Dragon, as well as four private space missions.

Both Boeing and SpaceX are contracted under NASA’s Commercial Crew Programme to provide human transport to and from the ISS. This approach was developed when the decision to retire the Space Shuttle was taken, and NASA turned to industry to provide a safe, reliable and cost-effective options for both cargo and crew transport.

As well as the issue with thrusters, three new helium leaks (on top of the one identified before launch) have sprung up while in space. NASA and Boeing are monitoring the situation and valves have been manually closed while Starliner is connected to the ISS.

Boeing Starliner Programme Manager, Mark Nappi, played down the issues when speaking to reporters: “Those are pretty small, really, issues to deal with and we’ll figure them out before the next mission.”

A successful crew test flight is required before Starliner can be certified and used to ferry astronauts to the ISS. Boeing is contracted to deliver six flights to the ISS, and once operational, Starliner will enter rotation with SpaceX’s Crew Dragon for missions to the station. With every-other flight being on Starliner, the six contracted Starliner flights would take NASA up to 2030 when the ISS is due to be retired.

This is only the sixth time that the US has launched humans to orbit on a new vehicle (following NASA’s Mercury, Gemini, Apollo, and Space Shuttle and, most recently, on SpaceX’s Crew Dragon), but unlike any previous American orbital crewed space capsule, Starliner will touchdown on land, rather than in the ocean. This makes the recovery operations faster and easier, and avoiding an ocean splashdown means flight hardware does not come into contact with potentially corrosive saltwater. After re-entry, Starliner will jettison its heat shields, deploy its parachutes and inflate airbags before touchdown.

Speaking at a post-launch press conference, NASA Administrator Bill Nelson congratulated Boeing and ULA on a successful launch and commented: “Now Butch and Suni do what they do best. They’re test pilots and they are going to test this thing from izzard to gizzard”.

The mission

There is no mission-critical duration for Butch and Suni’s stay in low-Earth orbit, but it is expected they will stay on the ISS for approximately a week before undocking to begin their return to Earth. Ken Bowersox, associate administrator for NASA’s Space Operations Mission Directorate, explained a lot of conditions have to be just right before they bring Starliner back to Earth. “We’re going to wait until the conditions are right and we’ve accomplished the test objectives, so we may see some additional time elapse before we actually bring them home” he said.

The main objective of this mission is to get Starliner certified as operational so it can go into rotation for crew transport, to complement Crew Dragon, and ensure NASA has a back-up in case anything should happen to either vehicle. While docked to the ISS, Butch and Suni are testing the comfort of Starliner for sleeping, as well as getting the ISS prepared for future Starliner missions.

Unlike the SpaceX Falcon 9, the Atlas V launch rocket is not reusable, but Boeing’s Starliner capsule is designed to be reused up to ten times, with some refurbishment between flights. SpaceX’s Crew Dragon is currently qualified for five flights, and the company is looking to re-qualify Crew Dragon so it can fly 15 missions.

If all goes well with the remainder of the mission and Starliner lands safely, the hope is that Starliner will be certified and the operational Starliner-1 flight, with a crew of four, can be scheduled as soon as possible. As part of their seat-swap agreement, NASA swaps a seat on Crew Dragon for a seat on Russia’s Soyuz to allow for integrated crews. It is unclear what will happen when Starliner is added to the rotation, as it has been suggested that Russia wants to see three operational crewed Starliner flights before putting a cosmonaut aboard the vehicle.

You can keep up to date with the mission and updates on the landing on NASA TV.

Kate Arkless Gray

14 June 2024