A gamma-ray spectrometer developed by a team of scientists and engineers at Lawrence Livermore National Laboratory (LLNL) is on the world's first sample return mission to the Martian sphere.
Led by the Japan Aerospace Exploration Agency (JAXA), the Martian Moons eXploration (MMX) Project launched into orbit on Tuesday, Oct. 20 aboard the H3 rocket from the Tanegashima Space Center in Japan.
The sensor is a key component of the Mars-moon Exploration with GAmma rays and Neutrons (MEGANE) instrument, built in partnership with the Johns Hopkins Applied Physics Laboratory (APL) and NASA. As one of 13 instruments aboard MMX, measurements collected by MEGANE will help reveal the evolutionary history of the Martian moons Phobos and Deimos.
"The primary goal of the mission is to understand the mysterious origins of Phobos and Deimos," said Morgan Burks, LLNL physicist. "There are two competing theories: one is that they are captured asteroids and the other is that they were ejected from Mars."
Based on remote sensing, the moons resemble the carbon-rich material found in the older, outer half of the asteroid belt. However, captured asteroids typically have elliptical orbits instead of the equatorial orbit of the moons, suggesting formation from an impact on Mars, similar to Earth's moon.
"It's fun to think of ourselves as one small piece in this long history of studying the solar system with scientific instrumentation, going all the way back Galileo studying the sky with a crude telescope," said Burks. "We're now sending scientific instruments to the planets and moons directly, and it is pretty exciting."
The MMX spacecraft will arrive in the Martian sphere in less than one year and enter an orbit around Phobos to begin surface observations. LLNL's gamma-ray spectrometer will collect measurements to provide an estimate of elemental composition and guide the mission's landing site selection for acquiring samples from Phobos.
Gamma-ray measurements provide important context for the samples brought back to Earth. In laboratory analysis, researchers will use a wide range of analytical techniques to determine the exact elemental composition with a higher degree of precision.
Designing the sensor for highest resolution while meeting MMX's limited size, mass and power requirements proved to be an immense engineering challenge.
"MEGANE faced tighter resource constraints on MMX than the team's instrument aboard Psyche," said Burks. "This impacted every decision from our choice of a low-mass, low-power cryocooler to radiator design."
Burks led the hardware delivery team at Livermore. Now, as MMX approaches Phobos, he is eagerly anticipating the beginning of the science mission and the role that his team will play in data analysis.
The Laboratory has experts in nuclear spectroscopy, gamma-ray physics and neutron physics. These skills, based in national security applications, will be leveraged by the mission to pursue scientific discovery in planetary science.
