Tag: Cubesats

On Nov. 28, NASA’s LunaH-Map spacecraft acquired its first star tracker image, showing the constellation Auriga and its two brightest stars, Menkalinan and Mahasim. The LunaH-Map navigation team used these images to test a new type of autonomous optical navigation software that can be run on the spacecraft’s flight computer. On Dec. 2, LunaH-Map also successfully acquired observations of Mars and Uranus and processed them onboard using the autonomous optical navigation software routines. The test was successful and demonstrated that the autonavigation software could autonomously correct raw images onboard, estimate the inertial camera orientation using visible stars, compute the astrometric centers of planetary targets in the field, and compute offsets relative to the spacecraft state. Each of these measurements are critical to performing autonomous navigation with onboard images, without the intervention from operators on Earth. Optical navigation algorithms like the one demonstrated on LunaH-Map will be important for future small spacecraft to perform operations in deep space, given their minimal communications resources.

The mission team also made several attempts to image the Earth and Moon; however, these images resulted in saturation of the star tracker. In the coming weeks, additional imaging opportunities of the Earth and Moon will be evaluated to help further demonstrate these novel autonavigation capabilities.

While a recent telemetry downlink showed an unexpected spacecraft reset, a Deep Space Network (DSN) pass has since indicated that, with the exception of the likely stuck propulsion system valve, the spacecraft is healthy with all subsystems nominal and operating as expected.

NASA’s Jet Propulsion Laboratory and the DSN teams are scheduling a set of tracks for the week of Dec. 5 the team will use to demonstrate a new type of radio ranging technique called Pseudo Noise Differential One Way Ranging (PN DOR). This is a first-time demonstration of PN DOR and will enable better ranging accuracy on future deep space CubeSats as well as larger missions.

The LunaH-Map science team began analysis of the lunar neutron data acquired during the spacecraft’s lunar flyby, including assessing the geometric effects related to the detector, spacecraft and Moon. From the flyby altitudes, the Moon’s epithermal neutron albedo measured by LunaH-Map can be used to derive a bulk hydration of the Moon, which can be compared with previous lunar orbital neutron measurements made by NASA’s Lunar Prospector and Lunar Reconnaissance Orbiter spacecraft. This measurement demonstrated that the instrument can achieve LunaH-Map’s science mission to map ice at the lunar South Pole.

After several whirlwind weeks, the LunaH-Map operations team took the first much-needed break since launch. They are working on a few minor ground system issues and finalizing the procedures and schedules related to the upcoming PN DOR radio ranging test. The team will soon enter an operational cadence with long (multi-day) heating of the propulsion system valve, followed by communications passes to focus on multiple ignition attempts that will, if successful, enable the completion of the LunaH-Map science mission later next year.

After deploying from the Artemis I Space Launch System rocket, NASA’s LunaH-Map spacecraft was powered on and communicating with Earth 5 hours and 33 minutes following launch on Nov. 16. Shortly after deployment, the operations team made first radio contact with the spacecraft and transitioned it out of beacon mode. Over the next 24 hours, the team also successfully commissioned the solar arrays, radio, neutron spectrometer, and various spacecraft bus systems. The neutron spectrometer collected a set of cruise data that indicated the detector is functioning nominally.

On Nov. 17, the team powered on the propulsion system. However, after many ignition attempts, the system was not able to achieve thrust prior to the spacecraft’s planned lunar flyby on Nov. 21. The mission’s original trajectory required that the spacecraft make a propulsive maneuver on Nov. 21 as a step toward its eventual lunar polar orbit. Based on the propulsion data, the team has assessed that the propulsion system valve may be partially stuck.  Heating this valve over many hours may result in freeing it, allowing for ignition. Therefore, the spacecraft has now been instructed to heat the propulsion valve.

If the propulsion system is able to achieve thrust within the next few months, the mission may still recover some or all of LunaH-Map’s original science mission. On the spacecraft’s current path, alternate trajectories are available to achieve lunar orbit – including orbits that could enable low-altitude measurements of the lunar surface. If even more time is needed to heat the valve and ignite the propulsion system, trajectory solutions outside of the Earth-Moon system may exist to fly close to certain asteroids and characterize their hydrogen content.

During the lunar flyby, LunaH-Map’s neutron spectrometer collected neutron data from as close as 810 miles (1,300 kilometers) above the lunar surface. Data from the detector clearly shows neutrons and gamma-rays from the surface of the Moon increasing along the flyby, demonstrating the instrument is operating as expected and could achieve LunaH-Map’s science mission.

After the flyby, LunaH-Map acquired several images of the Moon with its star tracker. In the next few days, the spacecraft will attempt to send these images back to Earth. The mission also plans to conduct an auto-navigation experiment and a radio ranging test with NASA’s Deep Space Network prior to resuming attempts to ignite the propulsion system.

LunaH-Map’s battery charge is functioning well.  The batteries are currently fully charged from the solar arrays.

LunaH-Map is led by Craig Hardgrove at Arizona State University in Tempe. The mission was selected in the first round of NASA’s Small Innovative Missions for Planetary Exploration, or SIMPLEx, program, with a total cost of $13.3 million. SIMPLEx missions provide opportunities for low-cost, high risk science missions that are responsive to requirements for flexibility. These lower cost missions serve as an ideal platform for technical and architecture innovation, contributing to NASA’s science research and technology development objectives. SIMPLEx mission investigations are managed by the Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama as part of the Discovery Program at NASA Headquarters in Washington. NASA provided a ride to deep space aboard the Space Launch System rocket for 10 CubeSats, each of which have separate missions from the agency’s Artemis I flight test.

NASA’s Lunar Polar Hydrogen Mapper (LunaH-Map) CubeSat was launched by the Space Launch System (SLS) rocket for the Artemis I mission on Nov. 17.

LunaH-Map, developed by Arizona State University and sponsored by NASA’s Science Mission Directorate (SMD), will measure the distribution and amount of hydrogen throughout the Moon’s South Pole. If successful, the LunaH-Map spacecraft will produce a high-resolution map of the Moon’s bulk water deposits, unveiling new details about the spatial and depth distribution of potential ice previously identified during a variety of missions. Confirming and mapping these deposits in detail will help NASA understand how the water got there, how much water might be available, and how it could potentially serve as a resource for longer exploration missions on the Moon. The CubeSat’s mission is designed to last around 60 days once science operations begin.