Planetary Society Says LightSail 2 Demonstrated Flight by Light

LightSail with its solar sail deployed. (Credit: The Planetary Society)

The Planetary Society says that its LightSail 2 satellite has demonstrated the ability to change its orbit by the power of light.

Since unfurling the spacecraft’s silver solar sail last week, mission managers have been optimizing the way the spacecraft orients itself during solar sailing. After a few tweaks, LightSail 2 began raising its orbit around the Earth. In the past 4 days, the spacecraft has raised its orbital high point, or apogee, by about 2 kilometers. The mission team has confirmed the apogee increase can only be attributed to solar sailing, meaning LightSail 2 has successfully completed its primary goal of demonstrating flight by light for CubeSats.

“We’re thrilled to announce mission success for LightSail 2,” said LightSail program manager and Planetary Society chief scientist Bruce Betts. “Our criteria was to demonstrate controlled solar sailing in a CubeSat by changing the spacecraft’s orbit using only the light pressure of the Sun, something that’s never been done before. I’m enormously proud of this team. It’s been a long road and we did it.”

The milestone makes LightSail 2 the first spacecraft to use solar sailing for propulsion in Earth orbit, the first small spacecraft to demonstrate solar sailing, and just the second-ever solar sail spacecraft to successfully fly, following Japan’s IKAROS, which launched in 2010. LightSail 2 is also the first crowdfunded spacecraft to successfully demonstrate a new form of propulsion.

“For The Planetary Society, this moment has been decades in the making,” said Planetary Society CEO Bill Nye. “Carl Sagan talked about solar sailing when I was in his class in 1977. But the idea goes back at least to 1607, when Johannes Kepler noticed that comet tails must be created by energy from the Sun. The LightSail 2 mission is a game-changer for spaceflight and advancing space exploration.”

Picture and Animations of LightSail 2 Deployed

LightSail with its solar sail deployed. (Credit: The Planetary Society)

This image was taken during the LightSail 2 sail deployment sequence on 23 July 2019 at 11:48 PDT (18:48 UTC). Baja California and Mexico are visible in the background. LightSail 2’s dual 185-degree fisheye camera lenses can each capture more than half of the sail. This image has been de-distorted and color corrected.

LightSail 2 Sail Deployment From Camera 1
Credit: The Planetary Society

View of the deployment of half of LightSail 2’s square sail from Camera 1, which happened on 23 July 2019 at 18:47 UTC. The animation runs at about 100 times actual speed.

LightSail 2 Sail Deployment From Camera 2
Credit: The Planetary Society

View of the deployment of half of LightSail 2’s square sail from Camera 2, which happened on 23 July 2019 at 18:47 UTC. The animation runs at about 100 times actual speed.

LightSail 2 Deploys Solar Sail

Artist’s concept of LightSail 2 above Earth. (Credit: Josh Spradling / The Planetary Society)

Update: Wednesday, 24 July 2019

10:00 PDT

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.

Planetary Society to Deploy LightSail 2 on Tuesday

Artist’s concept of LightSail 2 above Earth. (Credit: Josh Spradling / The Planetary Society)

LightSail 2 Mission Update
The Planetary Society

The Planetary Society’s LightSail 2 spacecraft is almost ready to go solar sailing. 

Mission officials today cleared the spacecraft for a possible sail deployment attempt on Tuesday, 23 July 2019, during a ground station pass that starts at roughly 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. 

Live sail deployment coverage will be available at planetary.org/live. A video and audio stream from mission control, located at Cal Poly San Luis Obispo in California, will be available during ground station passes. Rolling updates will also be posted on the page for context.

LightSail 2 Phones Home to Mission Control

Artist’s concept of LightSail 2 above Earth. (Credit: Josh Spradling / The Planetary Society)

LightSail 2 Mission Update
July 2, 2019

The Planetary Society’s LightSail 2 spacecraft sprang loose from its Prox-1 carrier vehicle as planned today, and sent its first signals back to mission control at Cal Poly San Luis Obispo in California.

The CubeSat, about the size of a loaf of bread, was scheduled to leave Prox-1 precisely 7 days after both spacecraft successfully flew to orbit aboard a SpaceX Falcon Heavy rocket.

Following deployment from its spring-loaded enclosure known as a P-POD, LightSail 2 deployed its radio antenna and began transmitting health and status data, as well as a morse code beacon indicating its call sign. The mission team received LightSail 2’s first signals on 2 July at 01:34 PDT (08:34 UTC), as the spacecraft passed over Cal Poly.

“The Georgia Tech Prox-1 spacecraft did its job perfectly, delivering LightSail 2 to the desired orbit for solar sailing,” said LightSail 2 project manager Dave Spencer. “Receiving the initial radio signal from LightSail 2 is an important milestone, and the flight team is excited to begin mission operations.”

“We’re all very happy—after years of preparation, we are flying an operational spacecraft!” added Bruce Betts, LightSail program manager and Planetary Society chief scientist.











NIAC Phase II Award: Diffractive Lightsails

Diffractive lightsails (Credit: Grover Swartzlander)

NASA Innovative Advanced Concepts (NIAC) Program
Phase II Award: Up to $500,000 for 2 Years

Diffractive Lightsails
Grover Swartzlander
Rochester Institute of Technology

Solar sails are propelled by the free and abundant momentum afforded by sunlight. Propulsion and navigation are achieved by directing reflected or transmitted light away from the natural direction of sunlight. The magnitude and direction of this radiation pressure force depends on factors such as the light deflection angle, the angle of the sail with respect to the sun, and the distance from the sun. Sail areas spanning hundreds of square meters have been envisioned for nearly 100 years for a wide range of space missions that are not practical for chemical rockets.

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Secondary Payloads Increasingly Take Center Stage

CubeSats (Credit: ESA/Medialab)

by Douglas Messier
Managing Editor

On most launches, the small secondary satellites that ride along with the primary payloads garner little attention.

That has begun to change in recent years as CubeSats have become increasingly capable. The importance of these small satellites could be seen in the recent launch of an Indian PSLV rocket, which carried a CartoSat Earth observation satellite and 30 secondary spacecraft from India, Canada, Finland, France, Republic of Korea, UK and the United States.

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ULA to Launch X-37B, LightSail on Wednesday

X-37B after landing at Vandenberg Air Force Base on June 16, 2012. (Credit: Boeing/USAF)
X-37B after landing at Vandenberg Air Force Base on June 16, 2012. (Credit: Boeing/USAF)

The U.S. Air Force’s mysterious X-37B spacecraft and The Planetary Society’s LightSail prototype will share a ride into space from Cape Canaveral on Wednesday aboard an United Launch Alliance (ULA) Atlas V booster. NASA will also conduct a materials sciences experiment aboard the X-37B.

The launch window opens at 10:45 a.m. EDT and runs until 2:45 p.m. EDT. ULA will webcast the launch at http://www.ulalaunch.com.

The weather forecast shows a 60 percent chance of favorable weather conditions for launch.

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Planetary Society’s LightSail Spacecraft to Launch Aboard Falcon Heavy in 2016

The Planetary Society's LightSail-1 solar sailing spacecraft is scheduled to ride a SpaceX Falcon Heavy rocket to orbit in 2016 with its parent satellite, Prox-1. (Credit: Josh Spradling / The Planetary Society)
The Planetary Society’s LightSail-1 solar sailing spacecraft is scheduled to ride a SpaceX Falcon Heavy rocket to orbit in 2016 with its parent satellite, Prox-1. (Credit: Josh Spradling / The Planetary Society)

PASADENA, Calif. (Planetary Society PR) — The Planetary Society, the world’s largest and most influential space interest group, announces that its LightSail solar sail spacecraft will reach space on a SpaceX Falcon Heavy launch in 2016. The announcement was made during a live webcast on July 9th.

“It’s fantastic that at last we have a launch date for this pioneering mission,” said Planetary Society CEO Bill Nye The Science Guy. “When I was in engineering school, I read the book about solar sailing by my predecessor, Society co-founder Louis Friedman. But the dream of sailing on light alone goes back much further.”

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