Lunar Trailblazer as a SIMPLEx Mission
Lunar Trailblazer is part of the Small Innovative Missions for Planetary Exploration (SIMPLEx) program. The program was created in 2014 to encourage new ways of doing space science exploration beyond Earth. Its missions so far, like Lunar Trailblazer, are “rideshare missions”. Like how you might have chosen an Uber-pool ride, NASA is taking advantage of large missions that usually launch with extra mass capacity, allowing more spacecraft “seats” on the ride. SIMPLEx missions are required to have a cost and mass that is five to ten times lower than recent traditionally-executed missions, allowing more risk, while still returning the highest possible level of science. Trailblazer may be small, but the team has found many innovative ways to reach that big science goal.
Lunar Trailblazer being moved to the vibration table for testing in January 2024, showing its small size. The Trailblazer satellite itself is about 200 kg. (Credit: Lockheed Martin for Lunar Trailblazer)
One way of maximizing Trailblazer’s scientific impact comes from using partnerships and space-ready technologies to source Trailblazer’s science instruments. Lunar Trailblazer has two instruments: the High Resolution Volatiles and Minerals Moon Mapper (HVM3) and the Lunar Thermal Mapper (LTM). Many of the core technological elements that enabled HVM3 were built and tested under a separate NASA program, one that miniaturized technology from another NASA imaging spectrometer, the Moon Mineralogy Mapper (M3). LTM also has NASA roots, tracing parts of its heritage back to the Diviner radiometer on the Lunar Reconnaissance Orbiter. The United Kingdom Space Agency (UKSA) also funded an Earth-orbiting mission, called TechDemoSat, that flew an instrument similar to LTM. Consequently, LTM is a part of the mission thanks to a collaboration with the University of Oxford and UKSA, who built and funded the instrument to expand Lunar Trailblazer's science. Because of this innovation and collaboration, Lunar Trailblazer is able to keep the cost of the mission low and the science impact high.
Lunar Trailblazer’s instruments; on the left is the Lunar Thermal Mapper (Credit: University of Oxford for Lunar Trailblazer), and on the right is the High Resolution Volatiles and Minerals Moon Mapper (Credit: NASA/JPL-Caltech for Lunar Trailblazer).
Once Lunar Trailblazer launches, the satellite will spend 4 to 7 months in a low-energy transfer trajectory before entering a lunar orbit. This approach follows a path made possible by the gravity of the Earth, the Moon, and the Sun, getting the most out of the fuel Trailblazer can carry in its small volume. Unlike the Apollo missions, Lunar Trailblazer doesn’t have a powerful enough propulsion system to do a few-day direct burn orbital insertion. Instead, since an object in motion stays in motion unless it can slow down, Lunar Trailblazer can fire its engine for short amounts of time at gravitationally favorable points to take a longer but more fuel efficient route. This route goes past the Moon and then arcs back to gravitationally capture into lunar orbit.
Lunar Trailblazer’s fuel tank. (Credit: Lockheed Martin for Lunar Trailblazer)
Once it arrives in lunar orbit, Lunar Trailblazer’s data collection will be laser-focused on answering the mission’s key science questions about lunar water and
geology. One critical element of answering these questions is sending back the data collected. Instead of the data-heavy approach needed to image the whole Moon, Trailblazer will target spots that we know
are the most interesting, thanks to data from prior missions to the Moon.
An aspect of being a low-cost mission is the tradeoff between raising risk and saving money. Lunar Trailblazer implements a single string spacecraft architecture, which means the spacecraft does not have redundancy in computers or other parts
of the flight system. In addition, Lunar Trailblazer also uses commercially available parts and systems instead of custom-designed parts. These parts are tested once they are built into subsystems rather than at component level. Lunar
Trailblazer has completed rigorous environmental, software, and communication testing to make sure all systems are fully operational, but somewhat fewer tests than higher class missions. Though simplified design and reduced testing creates
some risk in the mission, it also greatly lowers costs. This tradeoff enables NASA to fund more small missions that can accomplish high-impact science.
Along with engineering and science innovations, the Trailblazer team is using its affiliations with universities to innovate upon how space missions are staffed. Mission operations– communicating with and commanding the spacecraft, managing
spacecraft resources, and acquiring data– is located at the Caltech Infrared Processing and Analysis Center (IPAC). IPAC has a long heritage of operating science instruments on space telescopes and is expanding its expertise to full
spacecraft. This university-based mission ops will include both students and professionals on console communicating with the spacecraft, helping students from Caltech and Pasadena City College gain experience working on a space mission.
Student interns also provide assistance with ground software, science data processing, and science communications, an innovative approach for space missions. By providing opportunities for the next generation to engage with a cutting-edge
space mission, the Trailblazer team is investing in the future of space exploration.
Though Trailblazer is small in size and budget, the team has carefully designed and built a mission that can make a big impact. The people working on this mission in all capacities have
made Lunar Trailblazer possible, and will continue as the small satellite moves forward into launch and reaches the Moon.
By Isabelle Adamczewski
Isabelle Adamczewski is a Pasadena City College student and an intern at Caltech working on science communication for the Lunar Trailblazer mission.