Tag: Advanced Composite Solar Sail System

NASA confirms its giant solar sail is tumbling but doing so as planned

9:04 am

NASA today outlined the testing that its engineers are doing with the deployed 860 square foot Advanced Composite Solar Sail System (AC3), including the planned tumbling that an amateur astronomer detected based on the fluctuating brightness of the sail.

Currently orbiting Earth, the spacecraft can be seen with its reflective sails deployed from the ground. As part of the planned deployment sequence, the spacecraft began flying without attitude control just before the deployment of the booms. As a result, it is slowly tumbling as expected. Once the mission team finishes characterizing the booms and sail, they will re-engage the spacecraft’s attitude control system, which will stabilize the spacecraft and stop the tumbling. Engineers will then analyze flight dynamics before initiating maneuvers that will raise and lower the spacecraft’s orbit.

The release adds that NASA has added a feature to its mobile app that will help anyone spot the sail in the night sky.

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Amateur astronomer detects changes in the reflective light coming off of NASA’s orbiting solar sail

10:20 am

Observations by amateur astronomer Marco Langbroek of Delft Technical University in the Netherlands has detected significant changes in the reflective light coming off of the giant orbiting solar sail that NASA engineers recently deployed in orbit.

I observed the Solar Sail again in the evening of September 1, 2024, and this time the brightness of the Solar Sail was quite different. As it rose in the south, it became very bright, reaching magnitude 0 (as bright as the brightest stars in the sky). It then faded again, and next displayed a slow brightness variation with multiple bright maxima and very faint minima.

…The brightness seems to indicate a slow cycle of around half a minute. … The brightness variation could be suggestive of a slow tumble or wobble (a gyration around an axis) that must have been initiated after August 29, when it appeared more steady (apart from a brief bright flare, probably due to a favourable sun-sail-observer geometry).

The sail, dubbed the Advanced Composite Solar Sail System, was launched on April 23rd, and after some initial technical issues it was deployed from its small cubesat on August 30th, expanding to 860 square feet.

The changes Langbroek detected have all occurred after that deployment, and suggest one of two things. Either the NASA engineers are testing the sail’s maneuverability, as planned, and thus the sunlight reflecting off it changes, or there is a problem controlling it that NASA has not yet revealed. We will have to wait to find out.

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NASA solar sail successfully deploys

9:03 am

After experiencing a technical issue that initially delayed deployment, NASA engineers have now successfully deployed the boom of the 860-square-foot solar sail that had been launched in a cubesat only about four feet in size.

NASA’s Advanced Composite Solar Sail System is now fully deployed in space after a successful test of its sail-hoisting boom system. Mission operators confirmed success at 1:33 p.m. EDT (10:33 a.m. PDT) on Thursday, Aug. 29, after receiving data from the spacecraft. Centrally located aboard the spacecraft are four cameras which captured a panoramic view of the reflective sail and supporting composite booms. High-resolution imagery from these cameras will be available on Wednesday, Sept. 4.

The next step will be to test the sail’s ability to maneuver in space, including raising and lowering its orbit using the pressure of sunlight, just like sailboats use the wind.

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