The long-awaited crewed launch of Starliner has gained increased positivity that its latest launch date will remain on target, following numerous slips since the maiden uncrewed flight to the International Space Station (ISS).
While NASA postponed the NET launch date for the Starliner crew flight test (CFT) is now set for April 14, 2024 due to scheduling reasons, NASA Aerospace Safety Advisory Panel (ASAP) – a traditionally conservative body by nature – cited hope that Boeing’s latest issues with the spacecraft are coming to a close for a launch in April. This was followed by the NASA Advisory Council (NAC) citing the specific launch date target.
Starliner completed two uncrewed flight tests, with the first being the infamous mission in December 2019, which revealed numerous software problems and failed to reach the International Space Station (ISS).
The second was Orbital Flight Test-2, which docked to the Station on May 21, 2022, following a launch two days prior from Kennedy.
The spacecraft remained docked to the ISS for four days before successfully landing at the White Sands Missile Range in New Mexico, this time with only more minor problems, such as issues with backup thrusters during the flight.
During a previous meeting in May, the panel had been somewhat critical of Starliner´s progress and warned not to launch too early while bypassing potential safety issues. That was a few days before Boeing and NASA had to admit the flammability issues with some tape used within the capsule and safety concerns about the parachutes.
Now, the ASAP members are far more optimistic about the path to launch following months of work to mitigate the latest issues.
“The ASAP believes it is important to have two crew providers and is pleased to see progress,” said Kent Rominger, a former Shuttle astronaut with five flights under his belt, two as a commander. “Boeing has been responsive; tape removal in the upper dome is complete, while the work in the lower dome should be completed in a few weeks. The parachutes´ soft link joints are being redesigned, and a drop test is upcoming.
“NASA and Boeing are working through the battery redesign plan, and the CFT batteries have been approved for flight. The ASAP was pleased to see the independent reviews.”
This positive review from a figure, as noted by Rominger, bears a lot of value. He was the Head of the Astronaut Office at NASA during the Columbia tragedy in 2003. He belongs to a NASA generation who has the importance of a proper safety culture and the horrible consequences of a lack of such ingrained in their DNA.
The ASAP cited the NET date for CFT is around April 2024, with Boeing still targeting March for having everything checked, verified, approved, and ready on the technical side. Other factors are in play, such as the ISS’ Visiting Vehicle (VV) schedule to find a placeholder for Starliner to dock at the orbital outpost. However, the NAC provided an update with a specific NET 14th of April date.
The clearance of the latest issues includes the P-213 tape referenced in the last update.
The problems with the flammability of the P-213 tape used on Starliner caught Boeing and NASA by surprise. The tape is wrapped around wiring harnesses to protect the wiring from potential abrasions or nicks – and is used a lot in other spacecraft, including on the ISS.
However, it is flammable under specific conditions that might arise after another failure on board happened – a fact found in extensive testing in preparation for the CFT launch.
“This is a tape that’s widely used across the aerospace industry for many applications for protecting wires from abrasion. I would say in the NASA database, the entries were a bit inconsistent relative to the flammability of that tape at various levels of oxygen concentration. And so, it was a bit confusing as to when it could be used and when it couldn’t”, NASA´s Commercial Crew Program manager had said at a press conference in August.
As Rominger stated at the ASAP, removing the tape in the lower part of the spacecraft is still ongoing at KSC but should be completed within the coming weeks. Any remaining tape in some places difficult to access or deemed uncritical will undergo a final evaluation to guarantee an acceptable risk level.
Another issue to be cleared related to the parachutes, with the newly designed drogue and main parachute soft-link joints and stronger main canopy suspension lines will be installed on the CFT spacecraft until the end of the year, with a drop test planned now for the beginning of 2024. Initially, this test had been scheduled for “at the very earliest at the end of November 2023.”
Boeing is also working on a radiator bypass valve issue discovered during ground operations. To prevent this from happening again, the hardware has been modified. Future options to improve the system further are considered, including a system purge to prevent stiction, component upgrades, and changes to the way of operating the system.
Once all these issues have been signed off and cleared for flight, astronauts Butch Wilmore and Suni Williams will be tasked with performing the first crewed mission of the spacecraft.
They continue to train for their mission going through simulations of all phases of flight together with Mission Control at Johnson Space Center (JSC) and other support teams. At the same time, requirements regarding manual crew control of the spacecraft and abort system analysis, which are essential for their safety, have been reached and are soon to be finally closed out.
On the software side, qualification testing of the CFT flight software is completed. Hardware and software integration testing is still ongoing at Boeing.
On the pure hardware side, Starliner´s crew and service module are already mated with normal preflight processing coming up.
The ULA Atlas V rocket is already at Cape Canaveral Space Force Station, and the integration process with the spacecraft should begin soon after a successful drop test.
Lead Photo: Inside Boeing’s Commercial Crew and Cargo Processing Facility at NASA’s Kennedy Space Center in Florida . Photo credit: Boeing/John Grant