Critical point of the CAPSTONE spacecraft’s deep space route to the Moon

The CAPSTONE mission is scheduled to launch no earlier than May 2022. Rocket Lab’s Photon satellite bus will deliver CAPSTONE on a trajectory to the Moon. Credit: NASA Illustration/Daniel Rutter

Today, November 13, CAPSTONE will reach the Moon and become the first spacecraft to enter a unique elongated orbit that will support

” data-gt-translate-attributes=”[{” attribute=””>NASA’s Artemis missions.

Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) is a microwave oven-sized satellite, weighing just 55 pounds, that will be the first CubeSat to fly to and operate at the Moon. It serves as a pathfinder for Gateway, a Moon-orbiting space station that is part of NASA’s Artemis program. CAPSTONE’s mission will help reduce risk for future spacecraft, including Orion, by validating innovative navigation technologies and verifying the dynamics of a type of halo-shaped orbit that has never been flown before.

The pull of gravity from Earth and the Moon interact in this unique orbit – formally known as a near rectilinear halo orbit (NRHO) –  to allow for a semi-stable orbit. There, physics does most of the work of keeping spacecraft in orbit at the Moon. This reduces the need for spacecraft to use fuel to maintain the NRHO compared to other similar orbits. NASA already has big plans for this special type of orbit. Engineers expect it will allow them to park bigger spacecraft – including Gateway – in orbit at the Moon for at least 15 years. Fuel efficiency is key for such long-duration missions.

In this animation, the predicted trajectory for CAPSTONE’s Near Straight Halo Orbit (NRHO) is shown in red. The NRHO insertion maneuver and two subsequent correction maneuvers ensure that the spacecraft precisely inserts into the NRHO. Without a properly executed insertion maneuver, CAPSTONE will fly past the Moon without putting it into orbit, as shown in blue. Credit: Advanced Space/Matt Bolliger

Over the past four months, CAPSTONE has navigated an unusual but effective deep-space route to the Moon. This route – called ballistic lunar transfer – follows gravitational contours in deep space and allows spacecraft to reach their destination with little energy expenditure. Advanced Space, a small Colorado company that owns and operates CAPSTONE on behalf of NASA, designed this unique trajectory.

CAPSTONE has performed five maneuvers over the past few months to align its orbit insertion trajectory, with the team adapting to unexpected challenges to keep CAPSTONE on track. A final maneuver on October 27 marked the spacecraft’s arrival on the Moon.

“What this CAPSTONE team has overcome to date has been incredible, demonstrating resilience while gaining valuable insights. We are grateful to the exceptional individuals who have gone beyond NASA, Terran Orbital, Stellar Exploration, from NASA’s Deep Space Network and Advanced Space for their tireless work on recovery efforts,” said Bradley Cheetham, CAPSTONE Principal Investigator and Executive Officer of Advanced Space. “Overcoming challenges is the goal of an orientation mission – CAPSTONE capitalizes on this objective.”

CAPSTONE Revealed at Lunar Sunrise: CAPSTONE will fly in cislunar space – the orbital space near and around the Moon. The mission will demonstrate an innovative solution for navigation between spacecraft on the Moon from a nearly rectilinear halo orbit planned for the Artemis Gateway. Credit: NASA Illustration/Daniel Rutter

When CAPSTONE reaches the end of its gravitational trajectory and arrives at the Moon, its approach will be perfectly aligned for the insertion of NRHO – the critical point in its route. Although the timing of previous CAPSTONE maneuvers has been flexible depending on spacecraft performance and other factors, this orbit insertion must occur at exactly the right time to place CAPSTONE in the correct orbit. While traveling at 3,800 miles per hour, it will perform its delicate, timed propulsive maneuver to enter orbit, like a flying trapeze artist who leaps from arc to arc with decisive, acrobatic motion.

The initial orbit insertion maneuver is scheduled for Sunday, November 13 at 7:18 p.m. EST (4:18 p.m. PST). The CAPSTONE team expects it will take at least five days to analyze the data, perform two cleaning maneuvers and confirm the successful insertion into orbit of the near-straight halo.

Beyond that, other goals still await this pioneering CubeSat. Once in lunar orbit, CAPSTONE must fire its thrusters once every six and a half days, if necessary, to remain in its orbit for at least six months, allowing NASA and its partners to understand how to operate in this unique orbit. . Specifically, CAPSTONE will validate the propulsion requirements to maintain its orbit as predicted by the models, thereby reducing logistical uncertainties for future spacecraft.

Additionally, a key software technology – the Cislunar Autonomous Positioning System (CAPS) – will be tested in the coming months. CAPS will demonstrate innovative inter-spacecraft navigation solutions that will allow future spacecraft to determine their location without having to rely exclusively on tracking from Earth. CAPSTONE will do this by communicating directly with NASA’s Lunar Reconnaissance Orbiter – which has orbited the Moon since 2009 – to determine its own position in space. This capability could allow future spacecraft to operate on their own with less ground support and allow ground-based antennas to prioritize valuable science data over more routine operational monitoring.

The CAPSTONE mission will demonstrate several technologies that will lay the foundation for commercial support of future lunar operations. NASA partners are testing cutting-edge tools for mission planning and operations, paving the way and expanding opportunities for more affordable small space and exploration missions to the Moon,

” data-gt-translate-attributes=”[{” attribute=””>Mars, and other destinations throughout the solar system.

CAPSTONE is commercially owned and operated by Advanced Space in Westminster, Colorado. It represents an innovative collaboration between NASA and industry to provide rapid results and feedback to inform future exploration and science missions.  The spacecraft was designed and built by Terran Orbital. Operations are performed jointly by teams at Advanced Space and Terran Orbital.

NASA’s Small Spacecraft Technology program within the agency’s Space Technology Mission Directorate (STMD) funds the demonstration mission. The program is based at NASA’s Ames Research Center in California’s Silicon Valley. The development of CAPSTONE’s navigation technology is supported by NASA’s Small Business Innovation Research and Small Business Technology Transfer (SBIR/STTR) program, also within STMD. The Artemis Campaign Development Division within NASA’s Exploration Systems Development Mission Directorate funded the launch and supports mission operations.