A critical point in the CAPSTONE spacecraft’s deep space path to the Moon

NASA C.APSTONE mission

The CAPSTONE mission is scheduled to launch no later than May 2022. Rocket Lab’s Photon space 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 supports[{” 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 planned trajectory of CAPSTONE’s near-straight coronal orbit (NRHO) is shown in red. The NRHO entry maneuver and two subsequent correction maneuvers ensure that the spacecraft accurately enters the NRHO. Without a properly executed insertion maneuver, CAPSTONE will fly close to the Moon without reaching orbit, shown in blue. Credit: Advanced Space / Matt Bolliger

Over the past four months, CAPSTONE has been navigating an unusual but effective deep space trajectory to the moon. This path – called a ballistic transfer to the Moon – follows the lines of gravity in deep space and allows the spacecraft to reach its destination with little energy. Advanced Space, a small company in Colorado that owns and operates CAPSTONE on behalf of NASA, designed this unique path.

CAPSTONE has performed five maneuvers over the past few months to line up its path to enter orbit, with the team adjusting to unexpected challenges to keep CAPSTONE on track. A final maneuver on October 27 brought the spacecraft to the moon.

“What this CAPSTONE team has overcome so far has been amazing, showing resilience while gaining valuable knowledge. CAPSTONE Principal Investigator and CEO: Advanced Space Officer Bradley Cheetham said overcoming challenges is the purpose of a pilot mission – CAPSTONE benefits from this. Target.”

CAPSTONE has been revealed at sunrise on the moon

CAPSTONE is revealed at sunrise on the moon: CAPSTONE will fly into lunar space – the orbital space near and around the moon. The mission will demonstrate an innovative spacecraft-to-spacecraft navigation solution on the Moon from a semi-rectangular halo orbit scheduled for the Artemis Gateway. Credit: NASA illustration/Daniel Rutter

When CAPSTONE reaches the end of its gravity-driven trajectory and reaches the Moon, its approach will be fully aligned with the entry of NRHO – the critical point for its trajectory. Although the schedule for previous CAPSTONE maneuvers has been flexible based on spacecraft performance and other factors, this in-orbit insertion must occur just in time to put CAPSTONE into the correct orbit. Traveling at 3,800 miles per hour, its precise, precisely timed propulsive maneuver will lead you to enter orbit, like a flying trapeze artist jumping from one arc to another in a decisive acrobatic move.

The initial orbit entry maneuver is planned for Sunday, November 13, at 7:18 p.m. EDT (4:18 p.m. PST). The CAPSTONE team anticipates that it will take at least five days to analyze the data, perform two cleaning maneuvers, and confirm successful insertion into the corona’s near straight-line orbit.

Moreover, there are still other targets awaiting CubeSat. Once in lunar orbit, CAPSTONE is scheduled to launch its thrusters once every six and a half days, if necessary, to stay in orbit for at least six months, allowing NASA and its partners to understand how to operate in this unique. revolves in orbit. Specifically, CAPSTONE will verify thrust requirements to maintain its orbit as predicted by models, reducing logistical uncertainty for future spacecraft.

In addition, a major software technology – the Cislunar Autonomous Positioning System (CAPS) – will be tested in the coming months. CAPS will showcase innovative spacecraft-to-spacecraft navigation solutions that will allow future spacecraft to determine their location without having to rely exclusively on tracking from the ground. CAPSTONE will do this by communicating directly with NASA’s Lunar Reconnaissance Orbiter — which has been orbiting the Moon since 2009 — to determine its position in space. This capability could enable future spacecraft to perform on their own with less ground support and allow terrestrial antennas to prioritize valuable scientific data over more routine operational tracking.

The CAPSTONE mission will showcase several technologies that will lay the foundation for commercial support for future lunar operations. NASA partners are testing advanced mission planning and operations tools, paving the way and expanding opportunities for small, affordable space and exploration missions to the Moon,[{” 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.

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