Focus on LightSail-A

by Paul Gilster on July 9, 2014

As Cosmos 1 demonstrated, launching solar sails isn’t always easy. The Planetary Society’s sail perished thanks to a malfunctioning Volna booster not long after launch in 2005. When NASA attempted to launch its NanoSail-D in 2008, a problem aboard the Falcon 1 booster destroyed the craft. And when the agency launched the backup, NanoSail-D2, in December of 2010, the CubeSat-based sail failed to eject from the FASTSAT satellite it was aboard. Just when all seemed lost, NanoSail-D2 ejected on its own on January 17, 2011 and deployed its sail soon after.

Now we’re looking at a new Planetary Society venture called LightSail-A, which grows out of the NanoSail-D project and, according to news that should be firmed up tonight, should be ready for launch in the near future. As with Cosmos 1, the funding for LightSail-A was raised from private sources and Planetary Society membership dues, with the spacecraft itself being built by Stellar Exploration Inc. out of San Luis Obispo, CA. With mylar sails 4.5 microns thick, the sail will extend upon deployment to cover 32 square meters. Three CubeSat spacecraft form a ‘bus’ about the size of a shoebox that weighs in at no more than 4.5 kilograms.

LightSailEarth

Image: The Planetary Society’s LightSail-1 will test out solar sail technologies in Earth orbit as a prelude for later missions including solar storm monitoring at L1. Credit: The Planetary Society/Rick Sternbach.

Back in June, the Planetary Society’s Jason Davis described recent LightSail-A activity:

During the past two years, LightSail has come of age. The solar sail itself demonstrated a full deployment back in 2011, but the guts of the spacecraft were far from mature. Project manager Doug Stetson and his team have been shaking out bugs and overhauling LightSail’s electronics, attitude control, software and communications systems. Next up is a full “day in the life” flight system test on Wednesday, June 4 that includes another sail deployment and full operation of the spacecraft as if it were in orbit. I’ll be on hand at Cal Poly San Luis Obispo to observe and report.

The test in question had to be delayed because of problems involving the TRAC (Triangular Rollable and Collapsible) boom system so crucial in proper deployment of the sail. A breakdown of the three deployment problems the team uncovered is here. Later testing on June 24 showed that fixes for the power anomalies, spacecraft processor overload and other boom deployment issues seem to have worked. Davis has made a video of the June 24 deployment test available; he’s also offering regular updates explaining technical features of the diminutive spacecraft.

The LightSail project involves three craft, the goal of the first being to test deployment and basic operations at an altitude of 800 kilometers. A second mission, LightSail-B, will collect scientific data and demonstrate controlled solar sailing, while a third has the ambitious goal of reaching the L1 Lagrangian point, a useful position from which to detect solar activity producing geomagnetic storms.

At this point it’s always a good idea to distinguish between the phenomenon LightSail-A will be exploiting — the momentum imparted by solar photons — and that other means of ‘sailing’ through space, the solar wind. The sailing metaphor is what can make this confusing. The solar wind consists of particles streaming out from the Sun, moving much slower than the speed of light and offering a push to spacecraft designed to exploit them. So-called ‘magsails’ are under study that could use the solar wind for fast interplanetary transport, but the force from the solar wind is a thousand times less than the photon force a solar sail can draw on in its operations. By ‘solar sailing,’ then, I refer to drawing on the momentum imparted by massless photons.

We’ll know more about LightSail-A’s shakedown cruise this evening, when The Planetary Society hosts a live webcast from 2200-2330 EDT (0200-0330 UTC), billed as the venue for “a major announcement about our solar sail spacecraft.” Expect a tour inside the cubesat and presentations by the engineers behind it, as well as an announcement about its launch. Confusingly, The Planetary Society is referring to its sail as both LightSail-A and LightSail-1, but I suspect that by the time the evening is over, we’ll have the basic nomenclature set.

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{ 7 comments… read them below or add one }

ljk July 9, 2014 at 11:31

Cosmos 1 contained a CD with messages and historical articles and stories on solar sailing, most of which are online here:

http://planetary.s3.amazonaws.com/solarsailcd/index.htm

Does anyone know if LightSail 1 will be carrying a copy of this CD or a revised version?

jamesmessig July 9, 2014 at 13:15

Hope LightSail 1, 2 and 3 work. Space travel technology as it is playing out in hardware is becoming lots of fun again.

As is the case with Paul Gilster, I have a special interest in light sails. I am sure many of my fellow spaceheads who view and/or comment here at TZ-CD have likewise.

Alex Tolley July 9, 2014 at 22:24

Launch in 2016 on a Falcon Heavy. I assume it must be very cheap to wait for this launch.

More details here

Alex Tolley July 9, 2014 at 22:38

I assume it must be very cheap to wait for this launch.
Free!

I like the Prox-1 satellite that will observe Lightsail’s deployment as part of it’s own flight. Very cool if this all comes off.

Antonio July 10, 2014 at 8:19

“Confusingly, The Planetary Society is referring to its sail as both LightSail-A and LightSail-1, but I suspect that by the time the evening is over, we’ll have the basic nomenclature set.”

They explain it here: http://www.planetary.org/blogs/jason-davis/2014/lightsail-update-launch.html

“As I’ve previously discussed, LightSail-1 is the design designation for two nearly identical solar sailing CubeSats named LightSail-A and LightSail-B. In May 2015, LightSail-A may join a group of other ride-sharing spacecraft aboard an Air Force Atlas V flight as part of NASA’s Educational Launch of Nanosatellites (ELaNa) program. ELaNa helps CubeSat operators find rides to orbit.

The decision on whether or not to fly LightSail-A will be based largely on systems tests that still lie ahead. If LightSail-A goes to space, it won’t reach a high enough altitude for the momentum it gains from solar sailing to overcome atmospheric drag. The spacecraft will deploy its sails, capture images, and communicate with the ground, giving engineers a chance to work through any problems en route to a full-fledged solar sailing flight.

LightSail-B is the big show. The CubeSat will be embedded inside another small satellite called Prox-1. Together, Prox-1 and LightSail-B will ride into space aboard SpaceX’s Falcon Heavy launch vehicle. The mission is currently scheduled for April 2016.”

ljk July 10, 2014 at 9:25

LightSail update: Launch dates

Posted by Jason Davis

2014/07/10 02:00 UTC

Topics: Lightsail and Cosmos-1, events and announcements, solar sailing

I’m excited to report some big news on The Planetary Society’s LightSail project: actual launch dates on actual launch vehicles!

In April 2016, LightSail-1 and its parent satellite, Prox-1, are scheduled to hitch a ride to orbit aboard SpaceX’s new Falcon Heavy rocket. LightSail-1 will be released into space, unfurl its silver sails and attempt to become the first CubeSat to demonstrate controlled solar sailing—flight by light.

Full article and videos here:

http://www.planetary.org/blogs/jason-davis/2014/lightsail-update-launch.html

To quote:

As I’ve previously discussed, LightSail-1 is the design designation for two nearly identical solar sailing CubeSats named LightSail-A and LightSail-B. In May 2015, LightSail-A may join a group of other ride-sharing spacecraft aboard an Air Force Atlas V flight as part of NASA’s Educational Launch of Nanosatellites (ELaNa) program. ELaNa helps CubeSat operators find rides to orbit.

The decision on whether or not to fly LightSail-A will be based largely on systems tests that still lie ahead. If LightSail-A goes to space, it won’t reach a high enough altitude for the momentum it gains from solar sailing to overcome atmospheric drag. The spacecraft will deploy its sails, capture images, and communicate with the ground, giving engineers a chance to work through any problems en route to a full-fledged solar sailing flight.

LightSail-B is the big show. The CubeSat will be embedded inside another small satellite called Prox-1. Together, Prox-1 and LightSail-B will ride into space aboard SpaceX’s Falcon Heavy launch vehicle. The mission is currently scheduled for April 2016.

I see there is a CD on LightSail at least in this image:

http://planetary.s3.amazonaws.com/assets/images/spacecraft/2014/20140709_LightSail1_Build03.jpg

Could it be a copy of this:

http://planetary.s3.amazonaws.com/solarsailcd/index.htm

Michael July 10, 2014 at 14:49

To me,

Photonic sail = Specific photons? i.e. laser, microwave etc..
Light sail = Sun light photons?

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