Tag Archives: LightSail

Oumuamua might be artificial lightsail

A new analysis of the velocity and path of the interstellar object Oumuamua suggests it might be an artificial lightsail.

The study, which was posted online earlier this month, suggests that Oumuamua’s strange “excess acceleration” could be artificial in nature, as it has been implied that it is not an active comet. “Considering an artificial origin, one possibility is that ‘Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment,” researchers wrote in the paper.

The paper continues: “Lightsails with similar dimensions have been designed and constructed by our own civilization, including the IKAROS project and the Starshot Initiative. The lightsail technology might be abundantly used for transportation of cargos between planets or between stars.”

They even theorized that Oumuamua “may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization,” though that scenario was called “exotic.”

All of this is speculation. However, that the object is moving faster than expected, based on the initial data of its path, is quite intriguing. The authors of the paper concluded that the excess speed was caused by “solar radiation pressure.” They also calculated that for the light pressure to cause that increase in speed as it moves away requires it to have a large surface area.

The observations are not sufficiently sensitive to provide a resolved image of ‘Oumuamua, and one can only speculate on its possible geometry and nature. Although periodic variations in the apparent magnitude are observed, there are still too many degrees of freedom (e.g., observing angle, non-uniform reflectively, etc.) to definitely constrain the geometry. The geometry should not necessarily be that of a planar sheet, but may acquire other shapes, e.g., involving a curved sheet, a hollow cone or ellipsoidal, etc. Depending on the geometry our estimated value for the mass-to-area ratio will change, but the correction is typically of order unity.

They then speculate the possibility of the object being an interstellar probe.

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LightSail successfully deploys solar sail

Engineers have confirmed that the cubesat prototype LightSail has successfully deployed its solar sails.

This is I think only the second time a solar sail has successfully deployed in space. More significant to me is the fact that it is the first time this kind of complex engineering test has been tried using a cubesat. If cubesats can begin to handle these kinds of tasks, unmanned satellite technology is going to take a gigantic leap forward.

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LightSail deploys its solar sails

Though full confirmation will not come until later tonight, telemetry from LightSail suggests that its solar sails have successfully begun deployment.

Telemetry received on the ground showed motor counts climbing to the halfway point before LightSail traveled out of range. Power levels were consistent with ground-based deployment tests, and the spacecraft’s cameras were on. “All indications are that the solar sail deployment was proceeding nominally,” wrote mission manager David Spencer in an email update.

They will have to wait until the cubesat comes back in range at 2:46 am (Eastern) to see if the deployment completed successfully, as well as download images.

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LightSail back in business?

The Planetary Society’s solar sail engineering test called LightSail has re-established communications with the ground, allowing for the possibility that it can finally achieve its solar sail deployment, the main purpose of the mission.

I had previously reported that the sails had deployed, but a commenter correctly noted that only the panels have deployed, not the sails themselves, which need full battery power. The communications problem has been related to a battery charging problem. They are hoping that the batteries will get charged by mid-day today when they will try to deploy the sails.

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LightSail deploys, then falls silent again

Though it appears that LightSail has successfully deployed its solar sail — the main objective of this engineering flight, the Planetary Society cubesat ceased communications shortly thereafter.

To confirm the success of the mission they need to re-establish communications, which they hope will happen when the spacecraft’s orbit exposes it to more sunlight and the battery gets charged.

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LightSail deployment scheduled for Tuesday

Assuming all goes well with the orbital preparations today, LightSail will perform its test deployment on Tuesday at 11:44 am.

If successful, this deployment will achieve several significant engineering firsts, the most important of which will be to have demonstrated that a cubesat can be used for such a task. Proving that fact will increase their commercial usefulness for future space endeavors.

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LightSail reboots and restores communications

The Planetary Society’s solar sail engineering cubesat test LightSail has rebooted its computers and re-established communications with Earth.

The mission’s primary mission is to test the engineering design of the deployment of the solar sail. They will now be able to proceed with this deployment.

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Solar sail experiment stymied by software crash

The Planetary Society’s LightSail solar sail test mission, launched as a secondary payload on last week’s Atlas 5 X-37B launch, has fallen silent because of a software problem.

The communications problem occurred before the mission could achieve its main engineering goal of testing the deployment of the solar sail. They still hope to regain communications, but time is limited as the cubesat is in a low orbit that will decade relatively quickly.

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LightSail to launch on a Falcon Heavy

The Planetary Society announced today that its solar sail experiment, LightSail, will be launched in 2016 on a Falcon Heavy.

It will be a secondary payload on what might be one of Falcon Heavy’s early demo flights. They also say the launch date is scheduled for April 2016, but since the rocket has not yet been tested I wouldn’t take that date too seriously.

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