Live Coverage: LightSail 2 Sail Deployment

The Planetary Society's LightSail 2 mission team has successfully deployed the spacecraft’s solar sail. Re-watch live video from mission control here:

Update: Wednesday, 24 July 2019

Flight controllers successfully downloaded partial imagery from LightSail 2 this morning that confirm the solar sail is fully deployed. Upon completion of image downlink during subsequent ground station passes, The Planetary Society will issue a full story.

New data points from LightSail 2 telemetry show the solar sail was in its expected orientation during ground station overflights. Once the mission team has completed imagery downlink, they will move on to stored telemetry files, which will allow them to more thoroughly evaluate the sail’s performance.

Updates: Tuesday, 23 July 2019

The fourth and final LightSail 2 ground station pass of the day is complete. The spacecraft spent 1 orbit in solar sailing mode, and all of its major systems were reporting nominally. A preliminary look at attitude control system data showed the solar sail was angled to within 30 degrees of its expected orientation—a promising early sign the spacecraft is tracking the Sun properly. 

Only the Cal Poly ground station was in range during this pass. LightSail 2 did not rise far above the horizon, and communications performance with the spacecraft was lower than previous passes, possibly due to the orientation of the spacecraft during the pass and the presence of the newly deployed solar sail. The team was not able to download image thumbnails and will try again tomorrow. 

The third LightSail 2 ground station pass of the day is complete. Flight controllers successfully commanded the spacecraft into solar sailing mode, and the momentum wheel, which is responsible for turning the spacecraft into and away from the Sun's rays each orbit, spun up as expected. 

All indications are that LightSail 2's solar sail has deployed successfully. Flight controllers sent the deployment command at approximately 11:45 PDT (18:45 UTC). Telemetry showed the motor count increasing as expected, and the motor appeared to halt at the correct time. LightSail 2's cameras also appeared to capture imagery as planned.

The mission team will now confirm successful deployment by downloading imagery during subsuquent ground station passes today. The next Cal Poly pass begins at about 13:25 PDT (20:25 UTC).

Ground station pass 1 of the day is complete. All critical pre-sail deployment tasks were successful, including the upload of final positioning data to the spacecraft that will allow it to track where it is in orbit during solar sailing. LightSail 2 is currently go for solar sail deployment during the next pass, which begins at about 11:40 PDT (18:40 PDT).

The LightSail 2 team is on console this morning at the Cal Poly CubeSat lab in San Luis Obispo, California. Live coverage of sail deployment begins at 11:20 PDT, and the primary sail deployment pass begins at 11:40 PDT.

Update: Monday, 22 July 2019

LightSail 2 is still on track for solar sail deployment tomorrow. The latest orbital predictions for tomorrow's Cal Poly ground station passes are:

• Pass 1, 09:56 PDT / 16:56 UTC: Status checks and preparation for sail deployment
• Pass 2, 11:40 PDT / 18:40 UTC: Sail deployment primary pass
• Pass 3, 13:25 PDT / 20:25 UTC: Sail deployment status checks, backup sail deployment
• Pass 4, 15:11 PDT / 22:11 UTC: Telemetry downlink

Update: Friday, 19 July 2019

Mission officials today cleared the spacecraft for a possible sail deployment attempt on Tuesday, 23 July 2019, during a Cal Poly ground station pass that begins around 11:22 PDT (18:22 UTC). A backup pass is available the following orbit starting at 13:07 PDT (20:07 UTC). These times may change slightly as new orbit predictions become available.

Prior to the deployment attempt, LightSail 2 will fly within range of its ground station at Kauai Community College, which will give flight controllers a chance to assess the spacecraft’s status one final time.

See our latest blog update for more details.

Live video and audio from mission control, located at Cal Poly San Luis Obispo in California, will be available during ground station passes. Watch this page and The Planetary Society’s social media accounts for live updates.

During our webcast, you will see and/or hear various LightSail 2 team members. Our mission control is located in a working engineering lab on the campus of Cal Poly San Luis Obispo—the birthplace of CubeSats—so you may also notice students passing by.