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The same historic facilities that some 50 years ago prepared NASA's twin Voyager probes for their ongoing interstellar odyssey are helping to ready a towering commercial spacecraft for a journey to the Moon. Launches involve brutal shaking and astonishingly loud noises, and testing in these facilities mimics those conditions to help ensure mission hardware can survive the ordeal. The latest spacecraft to get this treatment are Firefly Aerospace's Blue Ghost Mission 2 vehicles, set to launch to the Moon's far side next year.
The Environmental Test Laboratory at NASA's Jet Propulsion Laboratory in Southern California is where dozens of robotic spacecraft have been subjected to powerful jolts, extended rattling, high-decibel blasts of sound, and frigid and scorching temperatures, among other trials. Constructed in the 1960s and modernized over the years, the facilities have prepared every NASA spacecraft built or assembled at JPL for the rigors of space, from the Ranger spacecraft of the dawning Space Age to the Perseverance Mars rover to Europa Clipper, currently en route to the Jupiter system.
That legacy, and the decades of accumulated experience of the Environmental Test Laboratory team at JPL, is also supporting industry efforts to return to the Moon as part of NASA's CLPS (Commercial Lunar Payload Services) initiative and its Artemis campaign, which will bring astronauts back to the lunar surface.
In recent months, a full-scale model of Firefly's uncrewed Blue Ghost Mission 2 spacecraft was put through its paces by the experts in the lab's vibration and acoustic testing facilities. Lessons learned with this model, called a structural qualification unit, will be applied to upcoming testing of the spacecraft that will fly to the Moon as early as 2026 through NASA's CLPS.
"There's a lot of knowledge gained over the years, passed from one generation of JPL engineers to another, that we bring to bear to support our own missions as well as commercial efforts," said Michel William, a JPL engineer in the Environmental Test Laboratory who led the testing. "The little details that go into getting these tests right - nobody teaches you that in school, and it's such a critical piece of space launch."
Testing just right
The Environmental Test Laboratory team led environmental testing for Firefly's Blue Ghost Mission 1 lander in 2024, and seeing the spacecraft achieve a soft Moon landing in March was a point of pride for them. Firefly's next CLPS delivery debuts a dual-spacecraft configuration and hosts multiple international payloads, with the company's Elytra Dark orbital vehicle stacked below the Blue Ghost lunar lander. Standing 22 feet (6.9 meters) high, the full structure is more than three times as tall as the Mission 1 lander.
This fall, a structural qualification model of the full stack was clamped to a "shaker table" inside a clean room at JPL and repeatedly rattled in three directions while hundreds of sensors monitored the rapid movement. Then, inside a separate acoustic testing chamber, giant horns blared at it from openings built into the room's 16-inch-thick (41-centimeter-thick) concrete walls. The horns use compressed nitrogen gas to pummel spacecraft with up to 153 decibels, noise loud enough to cause permanent hearing loss in a human.
Each type of test involves several increasingly intense iterations. Between rounds, JPL's dynamics environment experts analyze the data to compare what the spacecraft experienced to computer model predictions. Sometimes a discrepancy leads to hardware modifications, sometimes a tweak to the computer model. Engineers and technicians are careful to push the hardware, but not too far.
"You can either under-test or over-test, and both are bad," William said. "If you over-test, you can break your hardware. If you under-test, it can break on the rocket. It's a fine line."
Since the model isn't itself launching to the Moon, Firefly's recent Environmental Test Laboratory visit didn't include several types of trials that are generally completed only for flight hardware. A launchpad-bound spacecraft would undergo electromagnetic testing to ensure that signals from its electronic parts don't interfere with one another. And, in what is probably the most well-known environmental test, flight-bound hardware is baked or chilled at extreme temperatures in a thermal vacuum chamber from which all the air is sucked out. The multiple thermal vacuum chamber facilities at JPL include two large historic "space simulators" built within NASA's first few years of existence: a chamber that's 10 feet in diameter and another that's 25 feet across.
