Space Station Laser Link Blasts Broadband Data from Orbit
A new laser link with the International Space Station could do what optical fiber has done for internet access on Earth -- by turning orbital communications from painfully slow dial-up to blazing-fast broadband. Continue reading
A new laser link with the International Space Station could do what optical fiber has done for internet access on Earth - by turning orbital communications from painfully slow dial-up to blazing-fast broadband.
In recent tests of the Optical Payload for Lasercomm Science (OPALS) instrument, which is attached to the space station's exterior, NASA scientists and engineers have demonstrated that laser communications, as opposed to traditional radio transmissions, could revolutionize how we communicate with space-based assets.
"OPALS has shown that space-to-ground laser communications transmissions are practical and repeatable," said Matthew Abrahamson, OPALS mission manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "As a bonus, OPALS has collected an enormous amount of data to advance the science of sending lasers through the atmosphere. We look forward to continuing our testing of this technology, which sends information to and from space faster than with radio signals."
OPALS was delivered to the ISS in April by a SpaceX Dragon cargo vehicle and it has since completed the first 4 months of its prime mission. In an effort to minimize the impact of atmospheric turbulence on data loss, OPALS uses 4 individual lasers and average out the data received by the Optical Communications Telescope Laboratory's ground station at JPL's Table Mountain Observatory in Wrightwood, Calif. The next big step for system development is the use of adaptive optics to dynamically compensate for this turbulence.
"Four lasers from the ground station travel through the sky toward the space station. Under clear, dark background conditions, it's very easy for the payload to acquire the ground beacon. Daylight conditions have proven more challenging, but we are working on increasing capabilities during the day as well, through software enhancements," said Abrahamson.
According to a JPL news release, some of the landmark transmissions included:
A night pass over Table Mountain on June 5 that lasted 148 seconds. A video, with the message "Hello, World!" was beamed from the space station every 3.5 seconds. Normally the 175-megabit video would take 10 minutes to transmit over traditional radio comms.
Also in June, Lewis Carroll's "Alice's Adventures in Wonderland" was transmitted multiple times.
To commemorate the 1969 Apollo moon landing, in July, OPALS beamed a high-definition video of the landing in just under 7 seconds. Using existing radio-based infrastructure, it took 12 Between 200-300 megabytes of engineering data was downlinked, taking only 20 seconds. Normally, it would take 3 hours. The data was completely reconstructed after being received, which highlighted OPALS' low bit error rate.
All in all, OPALS is proving laser communications between the Earth and orbit could transform how we transmit data into space, but the biggest challenge to this method is, of course, the weather.
"We're finding that differing weather patterns and geometry variations are proving to be challenging," added Abrahamson. "We've had a half dozen or so pass attempts with varying levels of success, and we are looking to continuing these collaborations in the future."
As the technology matures, there will inevitably be some very obvious spin-offs that we could see enriching our everyday lives. Instead of using lossy radio communications, laser communications with satellites could significantly boost the bandwidth into low-Earth orbit and geostationary altitudes. Needless to say, this would be a significant boost for commercial high-definition video. Also, the scientific gains could be mind-blowing; imagine a high-definition laser link with rovers on Mars and other solar system destinations.
"OPALS is going to change the way we communicate with and build spacecraft in the future," said Abrahamson.
This artist's rendition shows OPALS operating from the International Space Station.
In recent weeks, the crew on board the International Space Station have been treated to some awesome views of space weather in action. The sun, which has been spluttering out some small to mid-sized flares and coronal mass ejections recently, frequently injects charged particles into our planet's magnetosphere. After being channeled toward high latitudes by Earth's magnetic field, this solar plasma impacts our atmosphere, erupting into a stunning auroral display.
This view from the space station was captured by one of the crew and shows the multicolored streamers of an aurora over the Southern Hemisphere -- known as the Aurora Australis. The different colors correspond to different gases in the atmosphere becoming energized by the solar plasma impacting the atmosphere at high altitudes.
Russian cosmonaut Oleg Artemyev
of a diffuse aurora over Earth out of one of the space station's windows. The orbiting outpost's solar panels can be seen to the left.
With the space station's robotic Canadarm 2 folded outside the space station, NASA astronaut Reid Wiseman
A bright green aurora snakes over the atmosphere below the space station. Green aurorae are caused by lower altitude oxygen atoms in our atmosphere being energized by solar wind electrons.
A burst of beautiful green and red aurorae were spotted on Aug. 19 and NASA astronaut Reid Wiseman
: "Never in my wildest dreams did I imagine this."
The nighttime hemisphere of the Earth is almost dark apart from the ghostly glow of a green aurora.
Often resembling a curtain swaying in the wind, aurorae are strikingly dynamic. They morph into a variety of shapes depending on the quantity of solar plasma hitting the atmosphere and the orientation of the magnetic field.
on Aug. 27, a stunning, curved aurora cuts across the limb of the Earth.
Looking down at Earth during a solar storm, ESA astronaut Alexander Gerst
, "This is what we see looking down while being inside an aurora."
The moon sets into an "glowing ocean of green",
. Two Soyuz spacecraft can be seen in the foreground docked to the space station.