Capstone does lunar fly-by, takes first lunar pictures, completes main mission

The Moon as seen by Capstone
Click for original image.

The smallsat engineering test lunar orbiter Capstone has now successfully ended its primary mission, completing six months of operation in the near-rectilinear halo orbit that NASA’s Lunar Gateway manned space station intends to fly.

To put a final touch on that main mission, in May mission managers at the private company Advanced Space also completed two additional experiments. On May 3, 2023 they performed a close-fly of the Moon, using the spacecraft’s camera for the first time to take the picture of the Moon to the right.

Then, on May 9 Capstone successfully tested navigation technology in conjunction with NASA’s Lunar Reconnaissance Orbiter (LRO), also in orbit around the Moon.

During the May 9 experiment, CAPSTONE sent a signal to LRO designed to measure the distance and relative velocity between the two spacecraft. LRO then returned the signal to CAPSTONE, where it was converted into a measurement. The test proved the ability to collect measurements that will be utilized by CAPS software to determine the positioning of both spacecraft. This capability could provide autonomous onboard navigation information for future lunar missions.

The mission now enters its extended mission, planned to last at least a year.

Update on lunar orbiter CAPSTONE

Link here. The update comes from Advanced Space, the commercial company tasked by NASA with operating the orbiter, whose main goal its to test operations in the type of orbit around the Moon that NASA plans to put its Lunar Gateway space station, dubbed a Near Rectilinear Halo Orbit (NRHO).

Thus far, since performing the NRHO insertion maneuver on November 13th, 2022, the spacecraft has spent 154 days operating in the NRHO completing 23 NRHO revolutions. During this time, the mission team has maintained knowledge of the spacecraft state well within the mission requirements using ground-based navigation tools and tracking measurements collected by the Deep Space Network including DSS-17 which is an affiliated site at Morehead State University in Kentucky. This navigation information has continued to support the design and execution of required maneuvers to maintain the orbit.

Minimum maneuver size constraints have been sequentially reduced as the combined mission operations teams at Advanced Space, Terran Orbital, and Stellar Exploration continue to mitigate issues with a thruster valve. Since entering the NRHO the spacecraft has executed six Orbit Maintenance Maneuvers (OMM) using approximately 1.8 m/s of fuel. Although the mission plan was originally to do a maneuver every NRHO (approximately once a week), the higher burn threshold has reduced the number of maneuvers performed while also demonstrating the robustness of the stationkeeping strategy utilized by the mission which is the same strategy planned for the Lunar Gateway.

CAPSTONE’s primary mission ends in May, but it will continue on an extended mission for twelve more months.

Though CAPSTONE has provided NASA important orbital data for maintaining Lunar Gateway in lunar orbit, the orbiter’s biggest achievement is its commercial nature. NASA hired Terran Orbital to build it, Rocket Lab to launch it, and Advanced Space to operate it. There was relatively little government participation. Moreover, this privately-run project has demonstrated that an inexpensive smallsat can quickly accomplish the same things that once only big expensive satellites attempted.

Update on CAPSTONE in lunar orbit

Link here. The key takeaway is that this commercial privately built and operated lunar smallsat is doing what it was designed to do, even as its operators continue to overcome periodic technical problems.

For example, beginning January 26th the spacecraft stopped receiving commands from ground controllers. The problem solved itself when on February 6th “an automatic command-loss timer rebooted” the spacecraft. Meanwhile,

CAPSTONE has completed more than 12 orbits in its near-rectilinear halo orbit – the same orbit [that will be used by Lunar] Gateway – surpassing one of the mission’s objectives to achieve at least six orbits. The mission team has performed two orbit maintenance maneuvers in this time. These maneuvers were originally scheduled to happen once per orbit, but the mission team was able to reduce the frequency while maintaining the correct orbit. This reduces risk and complexity for the mission and informs plans for future spacecraft flying in this orbit, like Gateway.

Essentially, mission controllers are figuring out the best and most efficient methods for eventually maintaining Lunar Gateway’s orbit around the Moon, when it gets there.

CAPSTONE enters its planned lunar orbit

After experiencing serious tumbling shortly after launch, engineers have successfully put the technology test smallsat CAPSTONE into its planned lunar orbit (the same to be used by NASA’s Lunar Gateway space station), where it will spend at least six months gathering data.

In addition to studying this unique orbit, CAPSTONE’s mission also includes two technology demonstrations that could be used by future spacecraft. The Cislunar Autonomous Positioning System, or CAPS, is a navigational software developed by Advanced Space that would allow spacecraft operating near the Moon to determine their position in space without relying exclusively on tracking from Earth. CAPSTONE will demonstrate this technology by communicating directly with NASA’s Lunar Reconnaissance Orbiter, which has been in orbit around the Moon since 2009. CAPSTONE will also demonstrate one-way ranging using a chip-scale atomic clock, which could allow spacecraft to determine their position in space without the need for a dedicated downlink to ground stations.

CAPSTONE is also demonstrating a third technology as well as the use of capitalism in space. The third technology is demonstrating the viability of using a tiny inexpensive smallsat for these kinds of interplanetary missions. The capitalism is that CAPSTONE was built by a private company, Terran Orbital, not NASA, and is being operated by another private company, Advanced Space, not NASA. It was also launched by a private company, Rocket Lab, not NASA. All three have proved or are proving that it is faster and cheaper for the government to merely act as the customer to private enterprise, rather than being the builder/operator and boss.

CAPSTONE successfully enters lunar orbit

CAPSTONE successfully entered orbit around the Moon today, putting it into the planned Lunar Gateway halo orbit to test operations in that location.

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.

Mission engineers plan two more engine burns over the next five days to refine the orbit more precisely.

CAPSTONE makes course correction, now on target for lunar orbital insertion on November 13th

Engineers have successfully overcome the valve issue that had caused the CAPSTONE lunar probe to tumble, and have made a subsequent mid-course correction that has put the spacecraft on target for entering lunar orbit on November 13, 2022, as planned.

The CAPSTONE spacecraft successfully completed a trajectory correction maneuver on Thursday, Oct. 27, teeing up the spacecraft’s arrival to lunar orbit on Nov. 13.

CAPSTONE is no longer in safe mode following an issue in early September that caused the spacecraft to spin. The team identified the most likely cause as a valve-related issue in one of the spacecraft’s eight thrusters. The mission team will design future maneuvers to work around the affected valve, including the two remaining trajectory correction maneuvers scheduled before CAPSTONE’s arrival to orbit at the Moon.

Though it appears the CAPSTONE team has figured out how to deal with that malfuncting valve, it is unclear what the long-term ramifications of that valve will be. If it is still leaking it likely means the mission will be shortened because of loss of fuel, as well as the need to use more to compensate.

Engineers regain full control of CAPSTONE

After a month of careful tests and analysis, engineers today successfully regained full control of the CAPSTONE lunar orbiter, on its way to the Moon.

The most likely cause of the anomaly was identified as a valve related issue on one of the spacecraft’s eight (8) thrusters. The partially open valve resulted in thrust from the associated thruster whenever the propulsion system was pressurized. To attempt a recovery from this condition, the mission team conducted multiple tests on the vehicle and evaluated extensive telemetry and simulation data and then formulated a plan for attempting recovery of the vehicle’s full 3-axis control.

This recovery sequence was uploaded to the spacecraft yesterday (Thursday) and was executed early this morning (Friday 10/7). Initial telemetry and observation data after the recovery attempt points to a successful recovery of the system which has now regained 3-axis attitude control. The updated spacecraft attitude has oriented the spacecraft solar arrays to the Sun and implemented an orientation for the downlink antennas which significantly improves data downlink performance as compared to the pre-recovery attitude.

The spacecraft is not out of the woods yet. The engineers still need to figure out how to do future course corrections with “the possible presence of a valve that remains partially open.”

Nonetheless, that they have successfully regained full control means they have a very good handle on the issue, which bodes well for the lunar orbital insertion maneuver on November 13, 2022.

Engineers still struggling to regain full control of CAPSTONE

Though its batteries are now getting charged by the Sun, engineers have still not regained full control of the smallsat lunar orbiter CAPSTONE, presently on its path towards the Moon.

As per the latest update:

The CAPSTONE mission team is continuing to work towards recovery of the spacecraft full three-axis control. This work includes collecting information from the spacecraft, running simulations, and refining recovery plans. The vehicle remains stable and power positive in its current configuration.

In other words, they’ve got the spacecraft oriented so that its solar panels can gather enough sunlight to charge the batteries, but its attitude remains incorrect and they do not yet have CAPSTONE fully under their control.

The spacecraft arrives in lunar orbit on November 13, 2022. At that time however it will have to do an engine burn to enter lunar orbit, and if full control is not regained by then this burn will not be possible because engineers will not be able to point it correctly.

CAPSTONE update: Situation improved but not resolved

Advanced Space, the company operating the CAPSTONE smallsat lunar orbiter that is on the way to the Moon, has issued a hopeful update on the efforts to regain full control of the spacecraft after it began tumbling out-of-control on September 8th.

The communications situation has dramatically improved, the power state of the spacecraft appears to be sufficient for continuous (duty cycled) heating of the propulsion system which dropped below its operational temperature, 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. When the spacecraft propulsion system temps are at +5C for 12+ hours the system will be further evaluated for use in the recovery operation. Information on the cause of the anomaly has been obtained and is being evaluated, and recovery plans that mitigate risk of further anomalous behavior are being developed. We do not have a timeline for a recovery attempt.

It appears they have not yet done the detumble maneuver that the engineers think will bring the spacecraft back to nominal operations. However, the spacecraft appears to also be on its planned course towards the Moon, so all signs suggest a full recovery is likely.

Update on CAPSTONE, still in safe mode

According to a detailed update from Advanced Space, the private company operating CAPSTONE for NASA, engineers have partly recovered control of the spacecraft after an anomaly had caused it to tumble and lose power.

It appears the problem that occurred on September 8th near the end of an mid-course correction engine burn was more serious that NASA initially revealed. CAPSTONE was tumbling out-of-control, its use of power was exceeding the power the solar panels were generating (draining its batteries), and the computer was periodically rebooting.

Since then engineers at Advanced have managed to stabilize the tumbling so that the spacecraft’s batteries were gaining power rather than losing it. Communications were re-established and the computer was also stabilized so that the spacecraft was able to get into a good safe mode. It remains however in a poor orientation that limits communications, power, and prevents proper operations.

While work is ongoing to diagnose the cause of the anomaly, the team is preparing the spacecraft to attempt a detumble operation to regain attitude control of the vehicle. This detumble operation was successfully demonstrated after separation from the launch vehicle in July. A successful detumble will result in the vehicle resuming control of its orientation, orienting the solar panels to the Sun to fully charge the batteries of the power used during the detumble. The spacecraft will then orient to the ground and await further instructions.

When this operation will occur was not stated, but it certainly will take place as soon as possible.

CAPSTONE in safe mode

The lunar orbiter CAPSTONE, presently on its way to the Moon, went into safe mode on September 8th at the end of a mid-course correction engine burn.

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.

Under such conditions engineers almost always recover the spacecraft so that the mission proceeds as normal. No guarantees of course, but it is not unreasonable to expect the same with CAPSTONE.

Rocket Lab considering further targets for in-space Photon upper stage

Capitalism in space: As noted during a speech yesterday by CEO Peter Beck, Rocket Lab is considering further interplanetary targets for its still functioning Photon upper stage, that helped launch NASA’s CAPSTONE mission toward the Moon.

Rocket Lab is continuing to operate Lunar Photon more than a month after it deployed CAPSTONE. The spacecraft is currently about 1.3 million kilometers from Earth, he said, and will swing back to Earth later in the month.

The spacecraft still has 10-15% of its propellant remaining. “As it scoots past Earth,” Beck said, “we’ll have a crack at doing something cool with it and see how far into the solar system we can get with it.”

Rocket Lab hopes to use a future Photon stage to send a probe to Venus, and is using the Photon in space now for engineering tests. It is also selling this technology as a viable cheaper alternative to the typically expensive interplanetary probes.

CAPSTONE completes mid-course correction

Engineers at Advanced Space today successfully completed CAPSTONE’s first mid-course correction, following a quick investigation that determined why communications with the probe was lost for almost a full day.

The communications blackout was apparently due to software issues and human error.

During [in-flight] 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.

All looks good for a November 13, 2022 arrival in lunar orbit.

Having regained communications with CAPSTONE, engineers prepare for first mid-course burn

Engineers are now preparing CAPSTONE for its first first mid-course engine burn, slightly late due to a loss of communications during the past two days.

The spacecraft is in good health and functioning properly.

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.

If all goes well, that engine burn will occur as early as 11:30 am (Eastern) on July 7th.

Engineers lose contact with CAPSTONE on its way to Moon

Shortly after the spacecraft was successfully deployed from its Proton upper stage on yesterday, engineers lost contact with the spacecraft as it headed towards the Moon.

“The spacecraft team currently is working to understand the cause and re-establish contact. The team has good trajectory data for the spacecraft based on the first full and second partial ground station pass with the Deep Space Network,” NASA spokesperson Sarah Frazier wrote in an emailed statement today (July 5).

“If needed, the mission has enough fuel to delay the initial post-separation trajectory correction maneuver for several days,” Frazier added. “Additional updates will be provided as soon as possible.”

The spacecraft will not arrive in lunar orbit until November, but along the way it needs to do a number of course corrections. Thus, there is some time pressure to reestablishing communications. That task now falls with the private company Advanced Space, which won a contract to operate the spacecraft for NASA.

UPDATE: More details are provided by the operators of the spacecraft, Advanced Space press, here. Though they canceled a course correction burn today, they apparently have plenty of time to do it, since the probe is already on a course to reach lunar orbit. The burn was simply intended to increase the accuracy of the trajectory.

Rocket Lab’s Photon completes course corrections, deploys CAPSTONE to Moon

Capitalism in space: Rocket Lab’s Photon upper stage successfully completed its seventh engine burn, putting NASA’s cubesat test lunar orbital on a path toward the Moon.

Following its launch on June 28, CAPSTONE orbited Earth attached to Rocket Lab’s Photon upper stage, which maneuvered CAPSTONE into position for its journey to the Moon. Over the past six days, Photon’s engines fired seven times at key moments to raise the orbit’s highest point to around 810,000 miles from Earth before releasing the CAPSTONE CubeSat on its ballistic lunar transfer trajectory to the Moon. The spacecraft is now being flown by the teams at Advanced Space and Terran Orbital. [emphasis mine]

From here on out CAPSTONE will use its own tiny thrusters to do any course corrections as it heads for an arrival in lunar orbit on November 13, 2022.

The highlighted words in the quote above are significant in and of themselves. The spacecraft is not being operated by NASA. In fact, other than paying for it, NASA has little to do with CAPSTONE. It was designed and built by Terran Orbital. It was launched by Rocket Lab. And it is now being controlled by Advanced Space, a private commercial company focused on providing in-space operations for others.

Rocket Lab’s Photon upper stage completes 3rd of 7 engine firings to get CAPSTONE to Moon

Rocket Lab’s Photon upper stage has now successfully completed the third of seven planned engine burns designed to slowly raise the Earth orbit of NASA’s experimental lunar cubesat CAPSTONE so that it can eventually be sent towards the Moon.

Lunar Photon’s HyperCurie engine will perform a series of orbit raising maneuvers by igniting periodically to increase Photon’s velocity, stretching its orbit into a prominent ellipse around Earth. Six days after launch, HyperCurie will ignite one final time, accelerating Photon Lunar to 24,500 mph (39,500 km/h) and setting it on a ballistic lunar transfer. Within 20 minutes of this final burn, Photon will release CAPSTONE into space for the first leg of the CubeSat’s solo flight. CAPSTONE’s journey to NRHO is expected to take around four months from this point. Assisted by the Sun’s gravity, CAPSTONE will reach a distance of 963,000 miles from Earth – more than three times the distance between Earth and the Moon – before being pulled back towards the Earth-Moon system.

Once in lunar orbit, CAPSTONE will be used to both test operations in that orbit (similar to the one NASA’s Lunar Gateway space station will use) while also demonstrating the use of a cubesat on an interplanetary mission.

CAPSTONE Moon satellite shipped to New Zealand by Terran Orbital

Capitalism in space: Terran Orbital has completed construction of the CAPSTONE Moon smallsat and has now had it shipped to New Zealand for its launch on a Rocket Lab Electron rocket no earlier than May 27th.

Tyvak Nano-Satellite Systems, a Terran Orbital Corporation, built the spacecraft for the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, otherwise known as CAPSTONE. The 12U CubeSat includes a radio tower on top that extends its size from a traditional 12U form factor.

CAPSTONE will not go directly to the Moon but instead, follow a “ballistic lunar transfer” that will take it out as far as 1.5 million kilometers before returning into lunar orbit. That transfer, which will take about four months to complete, is designed to save propellant, making the mission feasible for such a small spacecraft. The CAPSTONE payload and its software are owned and operated by Advanced Space for NASA.

CAPSTONE will use Rocket Lab’s Proton upper stage to get it to the Moon. It will then test maneuvering as well as communicating in the lunar halo orbit that NASA wants to use with its Lunar Gateway space station. It will also be proving out the use of this kind of smallsat for future interplanetary missions.

Rocket Lab gets launch contract for lunar cubesat

Capitalism in space: NASA has awarded Rocket Lab the contract to launch the privately-built, for NASA, lunar orbiting cubesat CAPSTONE, designed to test technologies and the orbital mechanics required to build its Gateway lunar space station.

This quote says it all:

The firm-fixed-price launch contract is valued at $9.95 million. In September, NASA awarded a $13.7 million contract to Advanced Space of Boulder, Colorado, to develop and operate the CubeSat.

Using two different private companies, one to build the satellite and the other to launch it, NASA will get a lunar orbiter for just over $23 million. That total equals the rounding error for almost all NASA-built projects.

The launch is set for early 2021.

Test cubesat to launch to Gateway lunar orbit

NASA has awarded a $13.7 million contract to Advanced Systems to build a cubesat to test placement and operation in the orbit the agency wishes to place its Lunar Gateway space station.

The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) is expected to be the first spacecraft to operate in a near rectilinear halo orbit around the Moon. In this unique orbit, the CubeSat will rotate together with the Moon as it orbits Earth and will pass as close as 1,000 miles and as far as 43,500 miles from the lunar surface.

The pathfinder mission represents a rapid lunar flight demonstration and could launch as early as December 2020. CAPSTONE will demonstrate how to enter into and operate in this orbit as well as test a new navigation capability. This information will help reduce logistical uncertainty for Gateway, as NASA and international partners work to ensure astronauts have safe access to the Moon’s surface. It will also provide a platform for science and technology demonstrations.

While proving the capability of cubesats for these unmanned planetary probes is all to the good, I must once again point out that making this orbit a way station on the way to the Moon actually makes it more difficult to get there. More fuel and equipment is required to transfer to the Moon once you are in Gateway’s planned orbit.

Based on our past experience with NASA boondoggles like this, Gateway will therefore act as a drag on future American lunar exploration. While other nations (China, India) will be landing on the surface, we will repeatedly find that our surface missions are delayed because of the added complexity of going from Earth to Gateway and then to the surface.