LightSail 2 Just Deployed Its Sails in Space, and It”s a Glorious Moment for Science

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August 12, 2019 | Originally published by Date Line: August 12 on

LightSail 2 has successfully deployed its solar sails. Shortly after 12:00 pm PST (19:00 UTC) The Planetary Society tweeted that the sails were deployed, and that the spacecraft was sailing with sunlight.

We can all enjoy their success and start to wonder how solar sails will fit into humanity”s plans for space exploration.

This is a dramatic moment for LightSail 2 and for The Planetary Society, the world”s largest non-profit space organization.

LightSail 2 is the third spacecraft in their LightSail program. It was launched on June 25, and has been in orbit since then, preparing for sail deployment and sending us some sweet pictures of Earth.

A series of tweets from The Planetary Society told the tale throughout the morning.

LightSail 2”s sail is actually a system of four smaller triangular sails that make one large square when deployed. Once deployed, the sail measures 32 sq. meters, or 340 sq. ft. Once it”s deployed, it can be used to raise the spacecraft”s orbit, demonstrating the power and usefulness of solar sails.

Related Links

LightSail – Flight by Light for CubeSats, Planetary Society – LightSail® is a crowdfunded solar sail project from The Planetary Society. Our LightSail 2 spacecraft, launched 25 June 2019, is the first spacecraft in Earth orbit propelled solely by sunlight. On 31 July 2019, we announced we had officially raised LightSail 2’s orbit by a measurable amount, showing that solar sailing is a viable means of propulsion for CubeSats—small, standardized spacecraft that are part of a global effort to lower the cost of space exploration.

The Planetary Society has championed solar sailing for decades. In 2005 we launched the world’s first solar sailing spacecraft, Cosmos 1, which was lost due to a rocket failure. Ten years later in 2015, our LightSail 1 spacecraft successfully completed a test flight. LightSail 2 launched on 25 June 2019 and deployed its solar sail on 23 July 2019.

Breakthrough Initiatives

Circling one star among hundreds of billions, in one galaxy among a hundred billion more, in a Universe that is vast and expanding ever faster – perhaps toward infinity. In the granular details of daily life, it’s easy to forget that we live in a place of astonishing grandeur and mystery.  The Breakthrough Initiatives are a program of scientific and technological exploration, probing the big questions of life in the Universe: Are we alone? Are there habitable worlds in our galactic neighborhood? Can we make the great leap to the stars? And can we think and act together – as one world in the cosmos?  Breakthrough Initiatives were founded in 2015 by Yuri and Julia Milner to explore the Universe, seek scientific evidence of life beyond Earth, and encourage public debate from a planetary perspective.

Breakthrough initiatives include:

Breakthought Listen – a $100 million program of astronomical observations in search of evidence of intelligent life beyond Earth. It is by far the most comprehensive, intensive and sensitive search ever undertaken for artificial radio and optical signals. A complete survey of the 1,000,000 nearest stars, the plane and center of our galaxy, and the 100 nearest galaxies. All data will be open to the public.
Breakthrough Message – a $1 million competition to design a message representing Earth, life and humanity that could potentially be understood by another civilization. The aim is to encourage humanity to think together as one world, and to spark public debate about the ethics of sending messages beyond Earth.
Breakthrough Watch – a multi-million dollar astronomical program to develop Earth- and space-based technologies that can find Earth-like planets in our cosmic neighborhood – and try to establish whether they host life.
Breakthrough Starshot – a $100 million research and engineering program aiming to demonstrate proof of concept for a new technology, enabling ultra-light unmanned space flight at 20{1f71c8e63fc312dbb7e68cbee9f84746085cdcbce567c037f7e85e4e98c84910} of the speed of light; and to lay the foundations for a flyby mission to Alpha Centauri within a generation. Along the way, the project could generate important supplementary benefits to astronomy, including solar system exploration and detection of Earth-crossing asteroids. A number of hard engineering challenges remain to be solved before these missions can become a reality and are listed in the May 24th Breakthrough Starshot RFP and bidders briefings for consideration by experts and public alike, as part of the initiative’s commitment to full transparency and open access.