NASA's ex-engineer warns Boeing Starliner could crash in populated areas as it begins return journey

As NASA prepares to autonomously undock Boeing's Starliner spacecraft from the International Space Station (ISS for its return to Earth, concerns are growing about the safety of the mission. Retired NASA Johnson Space Center engineer Don Nelson has issued a stark warning, suggesting that the spacecraft could lose control during its de-orbit and pose a risk to populated areas.

The Starliner, plagued by technical issues with its propulsion system, was originally meant to return two NASA astronauts, Butch Wilmore and Sunita Williams, to Earth. However, safety concerns led NASA to abandon those plans, with the astronauts now scheduled to return on a SpaceX mission in February 2025. Despite the lack of crew aboard, Nelson fears the spacecraft still presents significant risks.

"There is a high probability that the Boeing Starliner service module's thrusters will exceed their design temperature limits and fail during the deorbit burn," Nelson wrote in an email to NASA’s Commercial Crew Program leadership. He warned that the debris from the spacecraft could impact a populated area, mentioning "downtown Houston" as a potential risk zone.

Nelson argues that the only safe option is to deorbit Starliner into the Pacific Ocean, using a "death dive" trajectory to avoid any risk of impact over land. He criticized NASA’s safety panel for remaining silent on the issue, expressing concern that the current plan could endanger lives.

In an interview with Futurism, Nelson elaborated on his concerns, warning that an imperfect deorbit burn could cause Starliner to break up during reentry. If that happens, debris from the spacecraft could fall over populated areas. He questioned the logic behind deeming Starliner unsafe for a crew return while still planning to bring the vehicle back uncrewed. "If this thing is not safe enough to bring the crew back, why is it safe enough to bring the vehicle back and risk having it impact in a populated area?" he asked.

Nelson, who contributed to numerous NASA missions from Mercury to Apollo and the ISS before retiring in 1999, has a history of raising safety concerns. In his 2017 book *The NASA Letters*, he detailed warnings he made about NASA’s Space Shuttle Columbia before its fatal disintegration in 2003, which killed all seven astronauts aboard.

Starliner’s service module, which houses the malfunctioning thrusters, was designed to burn up during reentry. However, the spacecraft’s crew module is scheduled to land safely in White Sands, New Mexico, using parachutes. NASA has stated it will perform a "breakout burn" to quickly move Starliner away from the ISS in case of control issues during undocking.

Still, Nelson fears that the deorbit burn could cause the seals in Starliner's thrusters to overheat and fail. If the burn is incomplete, he warns, Starliner could remain trapped in orbit, circling the Earth for years before eventually deorbiting unpredictably. He argues that the safest course of action is to lower Starliner into the Pacific Ocean to ensure it doesn't cause damage if it breaks up.

The Starliner mission has been another blow to Boeing, which has struggled with technical setbacks and financial losses in recent years. The spacecraft, which was developed under NASA’s Commercial Crew Program alongside SpaceX’s Crew Dragon, has experienced numerous delays and technical problems. While SpaceX has successfully flown nearly a dozen crewed missions for NASA, Boeing’s first attempt at a crewed flight has been marred by propulsion system failures.

Nelson attributes Starliner's issues to a "buddy-buddy" relationship between NASA and Boeing, as well as inadequate leadership. He emphasized that SpaceX’s Crew Dragon is currently the only viable option for safely returning astronauts from the ISS.

Boeing's challenges extend beyond Starliner. A recent report by NASA's inspector general highlighted significant issues with Boeing’s Space Launch System (SLS), the rocket NASA hopes to use to send astronauts to the Moon. The report cited escalating costs, schedule delays, and concerns over quality management. Nelson called the SLS a "monster disaster waiting to happen" and warned that Congress may eventually cancel the program due to its spiraling costs.

In response to inquiries, NASA did not provide a comment, while Boeing reiterated its commitment to safety. "Boeing continues to focus, first and foremost, on the safety of the crew and spacecraft," the company stated, adding that it is executing the mission as determined by NASA and preparing the spacecraft for a "safe and successful uncrewed return."

As NASA prepares to undock Starliner from the ISS later today, there are growing concerns over the spacecraft’s ability to safely complete its return to Earth. For many involved in the mission, it will be a tense moment as they wait to see whether Boeing’s troubled spacecraft can successfully land without incident.