Images confirm LightSail-2 deployment success
Click for full resolution image.
Capitalism in space: The LightSail-2 engineering team has now confirmed, based on images from the cubesat, that its light sail has successfully deployed.
Flight controllers at Cal Poly San Luis Obispo in California commanded the spacecraft to deploy its solar sails yesterday at about 11:47 PDT (18:47 UTC). Images captured during the deployment sequence and downloaded today show the 32-square-meter sail, which is about the size of a boxing ring, deploying as the spacecraft flew south of the continental United States.
Image caption: 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.
To the right is a reduced version of this image. As they note, the sail is distorted because of the fisheye nature of the camera lens. Nonetheless, it looks like the sail is deployed, and will be able to do its job, testing how one maneuvers in space using only sunlight.
UPDATE: Rex Ridenoure from Ecliptic Enterprises emailed me to explain that the distortion is only seen in the image above, that the image at the link has been corrected for this (as noted in the caption above). If you compare the two, you will see that the Earth is round in the corrected image.
Since the sail is much closer to the lens, I remain unsure how much of what we see of its shape is real, or a function of the fisheye lens. Later thumbnails show the sail more flat and tightly stretched, suggesting that this image was taken during deployment.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for full resolution image.
Capitalism in space: The LightSail-2 engineering team has now confirmed, based on images from the cubesat, that its light sail has successfully deployed.
Flight controllers at Cal Poly San Luis Obispo in California commanded the spacecraft to deploy its solar sails yesterday at about 11:47 PDT (18:47 UTC). Images captured during the deployment sequence and downloaded today show the 32-square-meter sail, which is about the size of a boxing ring, deploying as the spacecraft flew south of the continental United States.
Image caption: 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.
To the right is a reduced version of this image. As they note, the sail is distorted because of the fisheye nature of the camera lens. Nonetheless, it looks like the sail is deployed, and will be able to do its job, testing how one maneuvers in space using only sunlight.
UPDATE: Rex Ridenoure from Ecliptic Enterprises emailed me to explain that the distortion is only seen in the image above, that the image at the link has been corrected for this (as noted in the caption above). If you compare the two, you will see that the Earth is round in the corrected image.
Since the sail is much closer to the lens, I remain unsure how much of what we see of its shape is real, or a function of the fisheye lens. Later thumbnails show the sail more flat and tightly stretched, suggesting that this image was taken during deployment.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I am disappointed to see that the material is shiny on both sides. A radiometer is driven from light on a black surface. It would been interesting to see which side creates more thrust even though it’s in a vacuum.
Hopefully it is high enough and will not be compromised by Earth’s atmosphere which is a significant drag on low Earth orbit satellites.
Max wrote: “I am disappointed to see that the material is shiny on both sides.”
It does not matter that the back side is shiny, as only the side toward the light source (the sun) will do the propulsive work. A solar sail is very different from a radiometer. An advantage to having two shiny sides is that it does not matter which side is toward the sun and doing the propulsion, which may give the controllers more options and freedom.
Making the “other” side not shiny would make the sail heavier, reducing its performance.
One scientist’s recommendations for what to do if you find a meteorite.
http://meteorites.wustl.edu/what_to_do.htm?mod=article_inline
Pay particular attention to the rude admonishments, because in all likelihood:
“I’m sorry, but you have not found a meteorite.”
Amazingly: “most things that fall from the sky are not meteorites.“
Sorry, wrong post.
I was rather amazed at the amount of pressure the Sun exerts. From Wikipedia: “A typical spacecraft going to Mars, for example, will be displaced thousands of kilometers by solar pressure”
The answer my friends is blown in the wind … or was it blowing …?
or some such.
Sail needs Solar Winds, and good Solar activity.
Sunspots ON ! Flares, STANDBY !
Fair winds and following Seas LightSail-2 !!
If they had placed it into a polar orbit it would have lasted longer in orbit.
As it is, as one side of its orbit moves away from the Earth the other side of the orbit moves closer until it hits atmosphere.
pzatchok wrote: “If they had placed it into a polar orbit it would have lasted longer in orbit.”
And if unicorns had wings we’d all be saints. The Planetary Society purchased the satellite and the launch vehicle it could afford. In the past few decades it has been hard enough to get anything like this even into orbit. To nitpick them because they are doing this technology test in Earth orbit is quite unseemly. It does not do you credit.
If they were in a polar orbit would they be able to face the sun for the whole orbit?
If so could they use the solar thrust, light pressure to slowly break orbit? Or at least raise their orbit.
I fully understand their budgetary concerns.
pzatchok: I can’t answer your specific question. However, I do know the Japanese in 2010 did put a solar sail in a solar orbit, called Ikaros, and used sunlight to adjust its orbit. Unfortunately their website never provided much additional information. See the links here.
pzatchok asked: “If they were in a polar orbit would they be able to face the sun for the whole orbit? If so could they use the solar thrust, light pressure to slowly break orbit?”
The object of this exercise is to learn how to use and control a solar sail. Ikaros gave an excellent proof of concept, as it showed that it changed its velocity due to light pressure. The orbit that LightSail 2 is in gives the flight controllers plenty of opportunity to turn the sail “with the wind” and “into the wind.”* My expectation is that something will go wrong, they will lose the sail, and they will learn an important lesson about the hazards to sailing with photons. If nothing goes wrong, then they will have to wait for another sail before learning that lesson.
In the case of a polar orbit, one in which the sail is always in sunlight, then the acceleration would always be away from the sun, perpendicular to its orbital plane around the Earth, and not in a direction that changes the apogee or perigee. Counterintuitively, its orbit would not change as dramatically in such a polar orbit. Most likely the plane of the orbit would change by a few feet, or less, away from the Earth’s center of mass, where the direction of gravity would keep the plane from moving any farther (sine of the gravity vector balances the solar force on the sail).
* Everyone, please note that solar sails use the momentum of photons, not the particles of the solar wind.