One day on the OFT-2 mission, Boeing’s CST-100 Starliner spacecraft landed on the International Space Station for the first time. The docking of the Starliner, which marks a major milestone in Boeing’s exhibition flight for NASA’s commercial crew program, took place at 8:28 EDT (Saturday 00:28 UTC) on Friday night.
The Orbital Test Flight 2 (OFT-2) mission is the second uncrowded test flight of the Boeing CST-100 Starliner capsule, which was required in 2019 due to its failure to complete the original OFT mission. Cape Canaveral on Thursday, on top of a United Launch Alliance (ULA) Atlas V rocket. It began a 24-hour chase that ended in docking with the International Space Station on Friday.
Starliner docking
After an initial phase burn one hour and 15 minutes after launch, Starliner began to fine-tune its approach to the International Space Station (ISS) and with the first of a series of burn to adjust its altitude and change the plane of its orbit to meet. Station. The Second Height Adjustment / Plane Change (NHPC) was burned, followed by a Coelliptic / Plane Change.
Testing of the spacecraft’s systems and docking methods was still ongoing, with a space-to-space commanding test being conducted shortly after the second NHPC burn. After the coliptic burn, Starliner performed another test to demonstrate the capabilities of its vision-based electro-optical sensor assembly (VESTA), which will be used to detect and track ISS, determining the docking distance at the station during the final procedure. .
Subsequently, the Terminal Phase Rendezvous Initiative (TPI) strategy was conducted, placing Starliner on a direct course to intercept the ISS. More VESTA demonstrations took place before Starliner burned its Inbound Flyround Initiation Maneuver 1 (IF1). It was the first of two strategies to align the spacecraft with the docking port, the International Docking Adapter-Forward (IDA-F), the pressurized mating adapter 2 (PMA-2) on the front of the Harmony module.
Then, the second inbound flyround maneuver was performed. The Approach Corridor Initiative (ACI) then ignited, which brought Starliner closer to the ISS. After the ACI, the astronauts on the space station instructed Starliner to maintain a distance of 255 meters in a planned test of the crew’s ability to send instructions to the spacecraft.
After holding for five minutes, Starliner resumed its approach and entered the 200-meter “Keep Out Sphere” around the ISS.
Shortly after clearing it to enter the keep-out sphere, the Starliner docking automatically retreats to the 200-meter mark in another planned demonstration of the security method. Holding the Starliner position, and this time VESTA was tested again.
Starliner Dock with ISS (Credit: Mac Crawford for NSF / L2)
After extending this hold to resolve an inconsistency involving the navigation overlay, the next stage of the Starliner approach brings it to the 10-meter hold point, holding it there to wait for the next docking window due to the previous delay. Holding at 10 meters, starting the final stage of going to the Starliner station, a final VESTA was displayed before the Starliner burned its final approach initiative.
The Starliner docked with the station four minutes later: 25 hours and 34 minutes after the start of the mission from Cape Canaveral.
The Starliner arrived at the space station with 230 kilograms (500 pounds) of cargo, and a special passenger in its commander’s seat: Rosie the Rocketer, an ethnographic test dummy on the back of the Starliner that also flew on the original OFT mission.
During OFT, Rosie carried a suite of sensors to record data that allowed engineers to study the conditions an astronaut in the capsule would experience. For OFT-2, however, he will not be equipped with any sensors or collect any flight data, as all that was needed was collected during the previous flight. Instead, sensors have been installed on and around the seat palette to collect additional data through the data collection system that was previously used in conjunction with Rosie.
During a pre-launch briefing before the launch of the previous OFT-2 launch last year, Boeing Commercial Crew Program Manager John Volmer explained that while Rosie was still in the Starliner, “she’s basically ballasting”, she continued, “We’re measuring, we’re car seats.” And we put sensors in other places, because we saw that we thought it would be more valuable because we got the data from Rosie on the first flight. “