A team of high school interns in NASA's STEM Enhancement in Earth Science (SEES) program spent summer 2026 modeling when an acoustic propellant sensor can take dependable readings aboard Intuitive Machines' IM-3 lunar lander, according to Mirage News. The MATRIX team, based at the University of Texas Center for Space Research, worked under mentor Dr. Kevin Crosby of Carthage College and the Wisconsin Space Grant Consortium. The lander, named Trinity, is scheduled to set down in the Reiner Gamma region of the Moon in 2027.
The students presented their findings at the SEES Annual Symposium and the Wisconsin Space Grant Consortium Annual Conference, and briefed Intuitive Machines' propulsion engineers on their methods and results.
Why it matters
Measuring how much fuel remains in a spacecraft tank is harder than it sounds. In microgravity, liquid propellant does not pool at the bottom of a tank; it clings to the walls, so conventional float-based or settling methods do not work reliably. Modal Propellant Gauging (MPG), developed by Crosby and colleagues at NASA while he was at Carthage College in Kenosha, Wisconsin, sidesteps that problem by using the acoustic response of a tank to estimate the mass of fuel inside it.
Mirage News reports that MPG has already flown in several spaceflight experiments and is slated for demonstration on IM-3. Knowing when the technique can produce trustworthy readings during a mission is therefore a practical question for mission planners, and the interns' models address it directly.
The work also speaks to a broader goal. Propellant management is a prerequisite for in-space refueling, fuel depots and sustained lunar exploration — capabilities NASA's Artemis campaign is built around.
Rebuilding a flight profile from public records
The MATRIX team worked entirely from open sources, including Intuitive Machines' published mission data. Trajectory records for the IM-1 and IM-2 missions came from NASA's Jet Propulsion Laboratory through its Navigation and Ancillary Information Facility (NAIF).
By comparing IM-2's reconstructed flight path against a model of how the spacecraft would have moved without engine thrust, the students isolated the engine burns and estimated the velocity change each one produced. Because no complete IM-3 trajectory has been released, the team wrote a reconstruction algorithm drawing on the published IM-1 and IM-2 data.
To capture how the liquid would behave inside the tanks, the interns ran computational fluid dynamics simulations of slosh dynamics, then used Monte Carlo simulations to map the range of propellant states the spacecraft might encounter.
Findings and a briefing for engineers
The analysis indicated that MPG can take reliable readings during the mission's two main burns — Lunar Orbit Insertion and Powered Descent — and in some cases during Descent Orbit Insertion as well. The spacecraft's mass at the start of the mission had the largest influence on how long each gauging window stays open, according to the team's results.
The students also identified possible IM-3 launch opportunities in 2027 and produced a landing analysis for Reiner Gamma showing how candidate touchdown sites are distributed around the target.
Their briefing to Intuitive Machines' propulsion group walked the engineers through the methods and results, and demonstrated that a rigorous analysis of an active lunar mission could be assembled from public data alone. The team's paper is titled "Computational Models to Estimate Modal Propellant Gauging (MPG) Windows on the Intuitive Machines IM-3 Mission."
Crosby said the group's grasp of advanced methods in under a month rivaled that of graduate students in the field. He described the work as exceptional and said the presentation to Intuitive Machines engineers impressed everyone with its sophistication and creativity, adding that SEES has long given students room to exceed what is asked of them.
The SEES program places 11th and 12th grade students on small research teams mentored by NASA, academic and industry experts, giving them hands-on exposure to the data, tools and analytical techniques used across aerospace.
The MATRIX team is scheduled to present its research again at the American Geophysical Union Annual Meeting in San Francisco in December 2026. IM-3's Trinity lander remains targeted for a 2027 touchdown at Reiner Gamma.
