Lunar Flashlight Research Articles

LONEStar: The Lunar Flashlight Optical Navigation Experiment

This paper documents the results from the highly successful Lunar flashlight Optical Navigation Experiment with a Star tracker (LONEStar). Launched in December 2022, Lunar Flashlight (LF) was a NASA-funded technology demonstration mission. After a propulsion system anomaly prevented capture in lunar orbit, LF was ejected from the Earth-Moon system and into heliocentric space. NASA subsequently transferred ownership of LF to Georgia Tech to conduct an unfunded extended mission to demonstrate further advanced technology objectives, including LONEStar. From August to December 2023, the LONEStar team performed on-orbit calibration of the optical instrument and a number of different OPNAV experiments. This campaign included the processing of nearly 400 images of star fields, Earth and Moon, and four other planets (Mercury, Mars, Jupiter, and Saturn). LONEStar provided the first on-orbit demonstrations of heliocentric navigation using only optical observations of planets. Of special note is the successful in-flight demonstration of (1) instantaneous triangulation with simultaneous sightings of two planets with the LOST algorithm and (2) dynamic triangulation with sequential sightings of multiple planets.

Lunar Flashlight science ground and flight measurements and operations using a multi-band laser reflectometer

The Lunar Flashlight cubesat mission was designed and flown to collect new data on the abundance and distribution of water ice frost in lunar permanently shadowed regions (PSRs) using active laser spectroscopy. Key advantages of active spectroscopy are that it can collect surface reflectance data in locations and conditions where passive spectroscopy cannot operate, specifically nightside locations where no indirect lighting is available, and in the deepest parts of PSRs where indirect lighting may be too faint for passive spectroscopy. Lunar Flashlight launched in 2022 but because of a propulsion system failure, did not make it to the Moon to conduct its science investigation. However, Lunar Flashlight proved to be an extremely successful technology demonstration mission, meeting or exceeding all its technology-focused mission goals, including demonstrating its instrument functionality. This paper describes the extensive ground and test campaigns to characterize the Lunar Flashlight laser reflectometer instrument and its planned utility for science observations, along with recommendations for future instrument design, development, verification, and use.

Lunar Flashlight CubeSat GNC system development

JPL is developing the Lunar Flashlight (LF) CubeSat mission, a 6U 14 kg spacecraft whose objective is to demonstrate new technology and measure potential surface water ice deposits in the permanently shadowed region (PSR) of the moon in preparation of future possible human lunar exploration. This mission will become the first interplanetary CubeSat to orbit the Moon. It uses a new green propulsion system as well as an instrument with spectrally tuned IR laser technology to search for volatiles in a specific region of the moon. The Guidance, Navigation and Control (GNC) system is crucial for delivering the spacecraft from Earth into Lunar orbit and supporting scientific measurements. Due to the challenging lunar orbit insertion and high tip off rate out of launch vehicle's dispenser, the initial design concept using solar sail propulsion accompanied with small commercial-on-the-shelf (COTS) reaction wheels was abandoned mid-course and replaced by a green propulsion system along with larger reaction wheels, both newly developed for LF. However, using thrusters for the small CubeSat created an additional challenge of controlling the spacecraft attitude. The story of the GNC system development, qualifications, technical challenges encountered, and lessons learned are discussed in this paper.

Exploring our solar system with CubeSats and SmallSats: the dawn of a new era

We are on the threshold of a new era in robotic exploration of our solar system, one in which CubeSats and SmallSats will play an important role. As the National Aeronautics and Space Administration (NASA)’s lead center for robotic solar system exploration, JPL has a strategic interest in these new capabilities that enable planetary scientists to expand our knowledge of how our solar system formed, how it works, and even how life originated. In November 2018, JPL’s two Mars Cube One (MarCO) spacecraft, launched with the InSight Discovery mission, made history as they flew past Mars. This first pair of interplanetary CubeSats navigated their way independently to Mars to provide a relay capability for the InSight lander back to Earth. Lunar Flashlight and Near-Earth Asteroid Scout, two CubeSats that are currently under development, will form part of the ‘swarm’ of CubeSats escorted onto a lunar trajectory by NASA’s Artemis-1 mission—the first launch of its new Space Launch System (SLS) rocket. This paper provides an overview of these and other CubeSat and SmallSat mission developments at JPL from the author’s perspective. It is intended to inspire others to follow the trail blazed by these pioneering missions.

The Iris Deep-Space Transponder for the SLS EM-1 Secondary Payloads

The Jet Propulsion Laboratory (JPL) is supporting several deep-space CubeSat missions selected as secondary payloads on the Space Launch System Exploration Mission One (SLS EM-1) launch of the Orion spacecraft. Seven secondary payload CubeSat missions (Lunar Flashlight, Near-Earth Asteroid Scout, BioSentinel, Lunar IceCube, CubeSat for Solar Particles, Lunar Polar Hydrogen Mapper, and ArgoMoon) have baselined the Iris deep space transponder as the main telecommunications and navigation transponder for their missions. Iris, first developed for JPL's interplanetary nanospacecraft pathfinder in relevant environment mission, and further developed for JPL's Mars Cube One mission, is a software-defined radio based on various JPL flight heritage designs. The transponder operates at X-band frequencies (7.2-GHz uplink, 8.4-GHz downlink) for compatibility with NASA's Deep Space Network, but the modular hardware design allows for further expanded capabilities into other frequency bands such as UHF, S-, and Ka-band. The transponder has a maximum power consumption of 35 W at 4-W radio frequency output, with uplink sensitivities down to −150 dBm. Various encoding schemes are available for the user to choose, from traditional convolutional coding with Reed Solomon concatenation to Turbo codes, and support for low-density parity-check coding is in the plan for future support. This paper will discuss the current capabilities and specifications of the Iris deep space transponder, as well as current hardware, firmware, and software implementations, and provide a short overview of future capabilities currently in the works.

Design and Characterization of the Multi-Band SWIR Receiver for the Lunar Flashlight CubeSat Mission

Lunar Flashlight (LF) is an innovative National Aeronautics and Space Administration (NASA) CubeSat mission that is dedicated to quantifying and mapping the water ice that is harbored in the permanently shadowed craters of the lunar South Pole. The primary goal is to understand the lunar resource potential for future human exploration of the Moon. To this end, the LF spacecraft will carry an active multi-band reflectometer, based on an optical receiver aligned with four high-power diode lasers emitting in the 1 to 2-μm shortwave infrared band, to measure the reflectance of the lunar surface from orbit near water ice absorption peaks. We present the detailed optical, mechanical, and thermal design of the receiver, which is required to fabricate this instrument within very demanding CubeSat resource allocations. The receiver has been optimized for solar stray light rejection from outside its field of view, and utilizes a 70 × 70-mm, aluminum, off-axis paraboloidal mirror with a focal length of 70 mm, which collects the reflected light from the Moon surface onto a single-pixel InGaAs detector with a 2-mm diameter, hence providing a 20-mrad field of view. The characterization of the flight receiver is also presented, and the results are in agreement with the expected performance obtained from simulations. Planned to be launched by NASA on the first Space Launch System (SLS) test flight, this highly mass-constrained and volume-constrained instrument payload will demonstrate several firsts, including being one of the first instruments onboard a CubeSat performing science measurements beyond low Earth orbit, and the first planetary mission to use multi-band active reflectometry from orbit.