After weeks of troubleshooting and testing, NASA and Boeing officials remain uncertain about the return date for the two astronauts aboard the Starliner spacecraft. While engineers have made progress in identifying possible causes for the issues plaguing the vehicle, a definitive return date remains elusive.
During its first crewed test flight, the Starliner experienced several problems, including helium leaks and thruster malfunctions. Extensive ground testing has been conducted to replicate these issues and understand their root causes.
Thruster Concerns:
Engineers fired test engines over 1,000 times to simulate the behavior of the Starliner's thrusters. These tests revealed that heat buildup inside the thrusters might be causing Teflon seals to bulge, restricting the flow of propellant. This finding could explain the unexpected thruster shutdowns during flight.
The testing has provided NASA and Boeing with increased confidence in the spacecraft's ability to safely undock from the International Space Station (ISS). However, the manual maneuvering attempted by the astronauts during the initial trip to the ISS may have placed undue stress on the thrusters, leading to concerns about their long-term reliability.
Helium Leak Investigation:
Analysis of a ground-based Starliner service module, which has been exposed to propellant vapor for three years, suggests that the helium leaks may be caused by degraded seals. The aging of these seals, exposed to the vapor, could have led to their deterioration.
To address this, Boeing is considering using alternative seal materials less susceptible to propellant vapor degradation in future Starliner missions.
Continued Testing:
Additional testing will be conducted this weekend while the Starliner remains docked at the ISS. This will involve firing 27 of the spacecraft's thrusters to further assess the stability of the helium leaks. The findings will be crucial in determining the future of the mission and the astronauts' return.
Return Uncertainty:
Despite the progress made in understanding the Starliner's issues, NASA and Boeing have not definitively confirmed whether the same spacecraft will bring the astronauts home. The agency has contingency plans in place if the Starliner is deemed unsafe for return.
A critical review by the Starliner mission management team will analyze the thruster data and determine the safety of the spacecraft. This review will play a significant role in setting a return date for the astronauts.
Astronauts' Status:
Astronauts Butch Wilmore and Suni Williams arrived at the ISS on June 6th for a planned week-long mission. They have now been in space for about 50 days. While the Starliner can remain in space for a maximum of 90 days, NASA and Boeing are working to ensure a safe and timely return for the astronauts.
The ongoing investigations and testing highlight the complex challenges associated with human spaceflight and the critical importance of thorough analysis and problem-solving. NASA and Boeing are committed to resolving the Starliner's issues and ensuring the safety of the astronauts aboard.
