WASHINGTON, June 3, 2026 (mtf.news) — NASA is bringing back a version of the famous “Vomit Comet” — this time using a modified Boeing 737 to simulate lunar gravity as it prepares astronauts and equipment for future Moon missions.
The agency awarded an $8.4 million contract on June 1 to Denmar Technical Services to convert a Boeing 737-700 into a reduced-gravity research aircraft. The plane will perform repeated parabolic maneuvers that create brief periods of lunar-like gravity, giving researchers and astronauts a chance to test how people and hardware perform in the Moon’s one-sixth Earth gravity environment.
The Return of the 'Vomit Comet'
For decades, NASA has used specially modified aircraft — nicknamed “Vomit Comets” because of the motion sickness they can induce — to create short periods of weightlessness. Everyone from scientists conducting experiments to Hollywood filmmakers and astronauts in training has flown on these planes.
This new 737 will serve a similar purpose but with a twist: instead of full weightlessness, it will simulate the partial gravity astronauts will experience while walking and working on the lunar surface.
Kirby Runyon -- planetary geologist who has worked with NASA and a parabolic flight coach -- told mtf.news that "gravity on the Moon is a totally different beast than gravity on Earth or the zero gravity of space. It's somewhere in between, but leans more zero gravity."
"For instance, if you stand up in lunar gravity, your arms still float up a little bit, similar to zero gravity," said Runyon, who is also a research scientist for the Planetary Science Intitute. "The only way to get that gravitational experience on Earth is with parabolic flight aircraft. Using harnesses and ropes and pulleys to offset an object's weight doesn't work for things like granular material such as sand, liquid, or accelerometers."
The most famous version, a KC-135, was even used to film the zero-gravity scenes in the movie Apollo 13. (EDITOR's NOTE: KC-135 would be a great nickname for me when I get to go in the Vomit Comet.)
Why Lunar Gravity Testing Matters
Understanding how equipment and human movement work in lunar gravity is critical for the success of the Artemis program. Spacesuits, tools, and procedures that work fine in Earth gravity or zero gravity can behave very differently on the Moon. Testing these systems in advance helps reduce risk, improve safety, and increase the chances of mission success.
The flights will allow researchers to evaluate astronaut mobility, tool handling, life-support connections, space medicine and overall workload in conditions that closely mimic the lunar surface. This kind of testing is especially important as NASA aims not just for short visits, but for longer-duration stays and the development of lunar infrastructure.
New Aircraft, New Capabilities
The modified 737-700 will be owned by NASA’s Armstrong Flight Research Center and operated in coordination with Johnson Space Center. Each parabola is expected to provide about 23 seconds of lunar gravity, allowing repeated testing during flights that can last several hours.
The aircraft, which has a varied history including time with civilian airlines and the U.S. Air Force, is being outfitted with the necessary modifications to safely and repeatedly create these reduced-gravity conditions.
Boeing’s Rocky Start to CY26 and Recent Rebound
Boeing entered 2026 facing sharp criticism after NASA Administrator Jared Isaacman publicly faulted the company over repeated delays and technical problems with its Starliner spacecraft. The comments added to broader concerns about quality control across Boeing’s programs.
The company has since pointed to progress elsewhere in its NASA work. Boeing played a meaningful role in the successful Artemis II mission, which marked the first crewed flight around the Moon in more than 50 years. The mission relied on several Boeing-built components of the Orion spacecraft and was viewed as a positive step following earlier challenges.
"We're honored to support NASA in restoring a capability vital to our nation's interests and future," Steve Parker, president and chief executive officer of Boeing Defense, Space & Security, said in a statement following the Artemis II launch. "Boeing and our Space Launch System partners are committed to NASA's mission to return astronauts to the moon, to establish a sustained lunar presence, and continue our exploration of deep space."
Supporting the Artemis Push
The new reduced-gravity aircraft adds to NASA’s toolkit as the agency works to return astronauts to the Moon and eventually establish a more sustained presence there. By testing systems in lunar gravity conditions on Earth, NASA and its commercial partners can identify and fix issues before they reach the actual lunar surface.
The contract runs through February 2027, with the modified aircraft expected to begin supporting Artemis-related testing in the coming years.
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Source: The Planetary Society
