A US-based nonprofit organization led by science educator Bill Nye is poised to launch a space-based crowd-funding mission that, if successful, will launch an awning for maneuvering an Earth orbit satellite for the first time.
Awnings have long been a darling of science fiction. But only in recent years have scientists taken serious steps to make them workable.
Driven by large, lightweight mirrors, they bounce off incident photons – just like a normal mirror. You see your image as you look inside.
However, these are not designed for reflection, but to exploit the fact that photons, though they are massless, have an impulse. That is, when they bounce off a suitable surface like countless tiny billiard balls, they press very gently on it.
The shot of a single photon is tiny. However, if you direct enough light at a sufficiently large surface, the effect will add up. It's not as if the wind is hitting a yacht sail, but it's not as different as it sounds.
"The interesting thing is that it works like a sailboat," says Nye.
There have been a number of attempts to demonstrate the feasibility of solar sails, from a project called Cosmos 1
However, the new project called LightSail 2 will be the first attempt to use an awning to maneuver in Earth orbit.
Built by The Planetary Society a nonprofit organization dedicated to the advancement of space exploration and research night of June 24, Florida, as part of the payload of a Falcon Heavy rocket currently the largest rocket built by the private company Space Exploration Technologies ( SpaceX ).
Millions project was 100% funded by individuals – people passionate about space and ready to leave their own dollars behind [it]"says Jennifer Vaughn of the Planetary Society.
In total, more than 40,000 people contributed, from $ 5 million to over $ 1 million.
The spacecraft itself, explains Bruce Betts, chief scientist and LightSail program manager of the organization, is a "three-unit cube satellite". "It's the size of a loaf of bread," he says.
It weighs only five kilograms, lowers the initial cost and makes it possible to share space with other projects.
Once in orbit, four cobalt alloy outriggers are deployed, unfolding 32 square meters of glossy Mylar film – the sail itself.
"That's about the size of a boxing ring," says Betts, adding that "one of the big challenges was figuring out how to stuff all this stuff into a tiny spaceship."
To navigate, the spacecraft uses a solar-powered flywheel to change the angle of the entire vehicle, including the light sail, according to Mission Spokesman David Spencer.
This allows it to be controlled by changing the angle at which sunlight falls on the sail. When the spaceship needs a push, it turns so that the sail faces the sun. When such a jolt hits it in the wrong direction, it turns so that the sail faces the sun.
Even when the sail is fully exposed to the sun, pressure will be very small – similar to the weight of a housefly sitting on your forearm, says Betts.
Spencer adds, "It's always there and you can use it." but the sail, Spencer says, should allow him to increase that by about 500 feet each day.
"If we achieve a measurable increase per day, that's a win," he says.
Not that the mission is without risks. Spencer believes that the biggest flaw lies in the sun sensors and magnetometers that allow the spaceship to detect the direction it points into.
"These things must work properly for the spacecraft to control itself."
Faulty cosmic rays or other radiation can also cause problems with software and hardware damage.
Meanwhile, the LightSail 2 mission is also of great interest to NASA scientists who want to launch their own light-propelled mission NEA Scout in 2020 to explore a small near-Earth asteroid (NEA ) with the designation 1991VG.
This spacecraft weighs 13 kilograms, uses the launch space of six cube saddles and has a light sail measuring 82 square meters.
However, even such a large surface provides only a very small acceleration – about 0.07 millimeters of speed per second per second, explains Les Johnson from NASA's Marshall Spaceflight Center in Alabama, USA, and principal investigator Mission.
But that's enough to get four to five kilometers per second faster in the two years and then slowly meet with the asteroid.
The mission costs only $ 28 million – a fraction of the cost of traditional asteroid rendezvous missions.
"What's really cool about a sail?" He adds. "If everything still works, we can make a loop and come back. It will take a few months, but if we need more data, we will return. "
His team and the LightSail 2 team, he adds, have been in touch for a long time.
"We are all solar sailors who want to achieve the same goals, so we talk to each other," he says.
What is interesting from a technological point of view, He adds, that neither the light sail of NASA nor that of the Planetary Society uses exotic new materials.
"These booms and sail materials have been around for a long time," he explains.
"What made this possible was the miniaturization of spacecraft. As everything began to shrink, the sails we could build suddenly started to get useful acceleration. So the whole field could start. "
Meanwhile, the LightSail 2 maneuvers should be visible from across much of America and Australia – basically by anyone within 42 degrees of the equator, says Betts.
How bright it will be depends on the angle of the light sail at a particular time, but if you catch it at the right time, Betts says, "It will be unbelievably bright – much brighter than the brightest Star. "
Nye adds that there will be a place on the Planetary Society website where you can enter your latitude and longitude and get directions.
"It's very likely that people who live not too far from the equator will get more than a glimpse of it," he says.