CAPSTONE Arrives to Orbit at the Moon

The CAPSTONE mission operations team confirmed that NASA’s CAPSTONE spacecraft arrived at its orbit at the Moon Sunday evening. The CubeSat completed an initial orbit insertion maneuver, firing its thrusters to put the spacecraft into orbit, at 7:39 p.m. EST.

CAPSTONE is now in a near-rectilinear halo orbit, or NRHO. This particular NRHO is the same orbit that will be used by Gateway, the Moon-orbiting space station that will support NASA’s Artemis missions. CAPSTONE is the first spacecraft to fly an NRHO, and the first CubeSat to operate at the Moon.

In the next five days, CAPSTONE will perform two additional clean-up maneuvers to refine its orbit. After these maneuvers, the team will review data to confirm that CAPSTONE remains on track in the NRHO.

CAPSTONE Team Stops Spacecraft Spin, Clearing Hurdle to Recovery

CAPSTONE team members successfully executed an operation to stop the spacecraft’s spin on Friday, Oct. 7, clearing a major hurdle in returning the spacecraft to normal operations.

Following a planned trajectory correction maneuver on Sept. 8, CAPSTONE suffered an issue that caused the spacecraft to spin beyond the capacity of the onboard reaction wheels to control and counter. Data from the spacecraft suggests the most likely cause was a valve-related issue in one of the spacecraft’s eight thrusters. The partially open valve meant the thruster produced thrust whenever the propulsion system was pressurized. The mission team extensively reviewed telemetry and simulation data and conducted multiple tests on the spacecraft in order to formulate a plan to stop the spacecraft’s spin despite this issue.

Recovery commands were executed Friday morning. Initial telemetry from CAPSTONE and observation data points to a successful maneuver, indicating the spacecraft has stopped its spin and regained full 3-axis attitude control, meaning CAPSTONE’s position is controlled without unplanned rotation. CAPSTONE now has oriented its solar arrays to the Sun and adjusted the pointing of its antennas to provide a better data connection to Earth.

The risks of this anomaly and recovery process were significant, and the team worked extensively and collaboratively to mitigate these risks. Over the coming days, the team will monitor the spacecraft status and make any needed adjustments to procedures in order to account for and mitigate the effects of the partially open thruster valve. The mission team also will work to design possible fixes for this valve-related issue in order to reduce risk for future maneuvers. CAPSTONE remains on track to insert into its targeted near rectilinear halo orbit at the Moon on Nov. 13.

CAPSTONE – short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment – is owned by Advanced Space on behalf of NASA. The spacecraft was designed and built by Terran Orbital. Operations are performed jointly by teams at Advanced Space and Terran Orbital.

Read the full update from Advanced Space. Additional updates will be provided, as available.

Teams Work Ongoing Recovery Efforts for CAPSTONE 

The CAPSTONE team continues work on recovery efforts. The primary ongoing focus now is to heat the spacecraft’s propulsion system, which dropped below its operational temperature limit following the initial issue that put the spacecraft into safe mode on Sept. 8. Over the past few days, CAPSTONE’s power – though limited by the orientation of the spacecraft in its spin relative to the Sun – appears to be sufficient for heating of the propulsion system. Once the spacecraft propulsion system temperature has been at 41° F (5° C) for at least 12 hours, the team will further evaluate the system for use in the recovery operation. Communications with the spacecraft have also improved, providing mission teams with more data from the spacecraft. Teams are evaluating the data to determine the cause of the issue and design recovery procedures to avoid similar problems during the attempted recovery operation.    

Read the full update from Advanced Space, which owns CAPSTONE on behalf of NASA. Additional updates will be provided as available. 

CAPSTONE Teams Continue Work to Resolve Spacecraft Issue

Following the Sept. 10 update on CAPSTONE, mission owner and operator Advanced Space has provided an update on the mission. Read the full update from Advanced Space.

During or shortly after a planned trajectory correction maneuver on Sept. 8, CAPSTONE suffered an issue that caused the spacecraft to tumble beyond the capacity of the onboard reaction wheels to control and counter. CAPSTONE was attempting to communicate with the ground for approximately 24 hours before any telemetry was recovered. After data was received, mission controllers found that the spacecraft was tumbling, the onboard computer systems were periodically resetting, and the spacecraft was using more power than it was generating from its solar panels.

Using NASA’s Deep Space Network, the combined mission team – including Advanced Space, Terran Orbital, Stellar Exploration, and NASA – re-established contact with CAPSTONE and reconfigured the spacecraft’s systems to stabilize the situation while recovery plans are evaluated. CAPSTONE remains in safe mode and now is power positive, meaning that it is generating more power from the solar panels than the system is using. Navigation data collected after the issue began suggests the Sept. 8 trajectory correction maneuver was completed or nearly complete when the issue occurred. This means the spacecraft remains on the intended trajectory and on course to its near rectilinear halo orbit at the Moon.

While work is ongoing to diagnose the cause of the issue, the team is preparing CAPSTONE to attempt a detumble operation to regain attitude control of the spacecraft.  This detumble operation was successfully demonstrated after separation from the launch upper stage in July. A successful detumble would give CAPSTONE control over its orientation, allowing it to orient the solar panels to the Sun to fully charge the batteries of the power used during the detumble. The spacecraft would then orient to the ground and await further instructions. These recovery operations will be further evaluated over the coming days. Recovery timing will be guided by the data and analysis available to maximize the probability of a successful spacecraft operation.

Updates will be provided as available.

CAPSTONE Spacecraft in Safe Mode, Teams Working to Resolve Issue

The CAPSTONE spacecraft executed a planned trajectory correction maneuver on Thursday evening, Sept. 8, and CAPSTONE mission controllers have since obtained telemetry confirming that an issue put the spacecraft in safe mode near the end of the maneuver. The CAPSTONE mission team has good knowledge of the state and status of the spacecraft. The mission operations team is in contact with the spacecraft and working towards a solution with support from the Deep Space Network. Additional updates will be provided as available.

CAPSTONE – short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment – is owned by Advanced Space on behalf of NASA. The spacecraft was designed and built by Terran Orbital. Operations are performed jointly by teams at Advanced Space and Terran Orbital.

NASA’s CAPSTONE Updates Maneuver Schedule on Journey to Moon

The team for NASA’s Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) is standing down from the trajectory correction maneuver scheduled for July 9 to perform additional analysis on the spacecraft’s performance. The mission team will make a determination whether the maneuver is still needed at this time, and updates will be provided.  

Trajectory correction maneuvers are thruster burns used to clean up expected variation in CAPSTONE’s orbit and more accurately target its path to the Moon. The maneuver scheduled for July 9 was to be part of CAPSTONE’s first series of trajectory corrections. CAPSTONE’s first trajectory correction maneuver on July 7 achieved about 90% of the objectives for this series of maneuvers.  

CAPSTONE remains healthy and on track to arrive to its lunar orbit on Nov. 13. Read more from Advanced Space, which owns and operates CAPSTONE on behalf of NASA. 

NASA’s CAPSTONE Pulls Off First Targeting Maneuver on Journey to the Moon

NASA’s CAPSTONE successfully completed its first trajectory correction maneuver, which started at 11:30 a.m. EDT Thursday. This is the first in a series of thruster burns over the next few months to more accurately target CAPSTONE’s transfer orbit to the Moon. The maneuver lasted just over 11 minutes and changed the spacecraft’s velocity by about 45 miles per hour (about 20 meters per second). CAPSTONE’s next trajectory correction maneuver is targeted for Saturday, July 9.  

CAPSTONE is now about 289,000 miles from Earth, beyond the orbit of the Moon. CAPSTONE will loop back around and arrive to its lunar orbit – called a near rectilinear halo orbit, or NRHO – Nov. 13. CAPSTONE will fly in the NRHO for at least six months to study the dynamics of the orbit, which is the same one intended for Gateway, a lunar space station for science and human exploration under Artemis.  

Two technology demonstrations on CAPSTONE could allow future spacecraft to navigate near the Moon without as much tracking required from Earth. 

Read more from Advanced Space, which owns and operates CAPSTONE on behalf of NASA.  

Mission Team Determines Cause of Communications Issues for NASA’s CAPSTONE

After a thorough review, teams have determined what led to CAPSTONE’s communications issue that began on July 4.  

During commissioning of NASA’s CAPSTONE (short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) spacecraft, the Deep Space Network team noted inconsistent ranging data. While investigating this, the spacecraft operations team attempted to access diagnostic data on the spacecraft’s radio and sent an improperly formatted command that made the radio inoperable. The spacecraft fault detection system should have immediately rebooted the radio but did not because of a fault in the spacecraft flight software. 

CAPSTONE’s autonomous flight software system eventually cleared the fault and brought the spacecraft back into communication with the ground, allowing the team to implement recovery procedures and begin commanding the spacecraft again.  

While CAPSTONE was out of contact with Earth, the spacecraft autonomously maintained its orientation to keep its antenna pointed towards Earth and allow the solar panels to keep its battery charged. CAPSTONE also used its thrusters to perform a standard maneuver to dump excess momentum from its reaction wheels, which are internal wheels that help the spacecraft rotate and point itself.  

The mission operations team conducted CAPSTONE’s first trajectory correction maneuver at approximately 11:30 a.m. EDT today. Teams are currently reviewing the data to ensure the maneuver was successful, and an update will be provided later. This maneuver will more precisely target the spacecraft’s transfer orbit to the Moon. 

Following Communications Recovery, NASA’s CAPSTONE Prepares for First Maneuver

Following communications issues, mission teams for NASA’s Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) have re-established contact with the spacecraft through NASA’s Deep Space Network. Data received from CAPSTONE shows that the spacecraft is in good health and operated safely on its own while it was out of contact with Earth. Teams are preparing to carry out CAPSTONE’s first trajectory correction maneuver – which will more precisely target CAPSTONE’s transfer orbit to the Moon – as early as 11:30 a.m. EDT on July 7. As originally planned, CAPSTONE will arrive to its lunar orbit on Nov. 13.  

The CAPSTONE team is still actively working to fully establish the root cause of the issue. Ground-based testing suggests the issue was triggered during commissioning activities of the communications system. The team will continue to evaluate the data leading up to the communications issue and monitor CAPSTONE’s status. 

A data visualization shows the antenna of the Deep Space Network. CAPSTONE is communicating with one of the Goldstone antenna.
CAPSTONE communicates with Earth via NASA’s Deep Space Network.

The mission team, led by Advanced Space, initially re-established contact with CAPSTONE at 9:26 a.m. EDT on July 6. The signal confirmed that CAPSTONE was in the expected location, as predicted based on data from CAPSTONE’s initial contacts on July 4. The team started recovery procedures and began receiving telemetry data from the spacecraft at 10:18 a.m. EDT.