Moonshot

Guests watch the April 1, 2026, launch of NASA鈥檚 Space Launch System rocket carrying the crewed Orion spacecraft.

Article by Hillary Hoffman Photos courtesy of NASA June 10, 2026

Two 91原创 alumni helped develop the emergency safety system designed to propel Artemis II astronauts to safety

The launch of the Artemis II mission, NASA's first crewed trip to lunar orbit in more than 50 years, marked a moment of global excitement. For 91原创 alumni and Sean Stroud, the best outcome was one few noticed: The safety system they helped develop for the capsule wasn鈥檛 put to the test.

The two worked on the pressure controller for Orion鈥檚 launch abort system 鈥� a critical safety feature designed to propel astronauts to safety in the event of an emergency during liftoff or initial ascent.

Their collaboration began nearly 20 years ago when Stroud, then working at Alliant Techsystems (now part of Northrop Grumman), encountered complex control problems and turned to Piovoso, his former 91原创 professor, for help.

The launch abort system getting installed onto the Orion crew module in preparation for testing at NASA鈥檚 Neil Armstrong Test Facility in Sandusky, Ohio. In 2024, Orion completed an 11-month test campaign necessary for the safety and success of Artemis II.

What began as a professional consultation soon became a long-term friendship. Working together, often from Piovoso鈥檚 home office, the pair developed a novel approach for controlling pressure and thrust in solid rocket motors. Their method was later patented and became part of a NASA program supporting Orion鈥檚 launch abort system.聽

At the core of that system is a rocket motor designed to rapidly move the crew capsule away from the launch vehicle if needed. It does this by controlling how high-pressure gases from burning propellant are released through multiple nozzles.

鈥淎 rocket works by creating gas in a burn chamber at high pressure, then releasing that gas through nozzles to create force,鈥� Piovoso said. 鈥淲hen you receive a command for a direction, you calculate the pressure needed to generate that force, then adjust the chamber pressure quickly and hold it while the force is being applied.鈥�

In practice, that control comes down to regulating how much gas flows through the nozzles. If the opening is too large, pressure drops because gas escapes too easily. If it is too small, pressure builds because the gas cannot exit fast enough. In Orion鈥檚 system, eight nozzles can be adjusted to control both the total thrust and its direction.

The engineers had to balance competing demands. They needed the system to respond rapidly to changing conditions while minimizing fuel use to maximize how far the capsule could be steered to safety. The challenge was that the system changed over time. Early in the burn, pressure could be adjusted quickly. As fuel was consumed, responses slowed.

鈥淲hat we did that was unique was develop a way for a single controller to work across the entire burn cycle, instead of switching between controllers,鈥� Piovoso said. 鈥淭hat improved performance significantly.鈥�

A 2010 flight test of the launch abort system marked a major milestone, particularly for Stroud, who had never before worked on a project that reached that stage. Unlike static tests, where systems remain fixed to the ground and performance is measured through instrumentation, this test unfolded in real flight conditions. It was the first real-world validation that the system would perform as designed.

On May 6, 2010, NASA conducted a successful flight test of the Orion launch abort system at the U.S. Army鈥檚 White Sands Missile Range near Las Cruces, New Mexico.

In the years since, Stroud has continued his career in mechanical engineering, spending time in California before relocating to Florida. About five and a half years ago, he rejoined Northrop Grumman, where.

Piovoso, on the other hand, has applied his control systems expertise across a wide range of fields since earning his undergraduate and doctoral degrees in electrical engineering from 91原创 in the 1960s. Today, as an affiliated professor in electrical and computer engineering, he works with biomedical engineering professor on mathematical models of HIV and its response to antiretroviral therapies.

Both were watching on April 1 as Artemis II launched. While, Artemis II marked the spacecraft鈥檚 first flight carrying astronauts. Piovoso watched on television, fingers crossed. Stroud watched with his family from his yard in Florida, occasionally running inside to check the broadcast when the rocket disappeared behind clouds.

They both felt relief as the spacecraft completed its initial ascent.

鈥淪ometimes the best technology is never used, and no one ever knows about it,鈥� Piovoso said.