adaptable and cost-efficient, they say. Boeing’s Laser Communications program, known as Lasercom, has given itself two years to get a product ready—a quest potentially so rewarding and historically relevant that other countries and companies have joined in the competition, according to Jamal Madni, Lasercom business development lead and engineer. “It’s a race to the laser,” Madni said. What the Lasercom process entails is this: Information packets are beamed from space into fiber-optic communications networks on the ground, which, when fully developed, have the ability to bring far faster data rates than signals currently transmitted from space on federally controlled radio frequencies. Plus, lasers offer nearly unlimited data capacity, as opposed to existing bandwidth-limited radiofrequency systems now stretched to their boundaries, according to the program. Simply put, although radio waves travel at the speed of light, their capacity is limited. On the other hand, huge amounts of data can be transmitted in much less time using a light beam, or laser, Madni said. In some cases, he added, a laser can send 100 million times more data (in bits) than radio waves over the same amount of time. “When we’re talking about gigabits and terabits of information, such as images and video, we are talking about getting information months faster from deep space, for instance,” Madni explained. Added Chris Johnson, director of Global Sales and Marketing, Boeing Government Space Systems: “It’s like going from dial-up at a few kilobits per second to the broadband we have today with tens-of-gigabits-persecond capability.” In a trial run in June, an Optical Payload for Lasercom Science instrument, built by NASA and the Jet Propulsion Laboratory, sent a beam from the International Space Station to an optical bench—a series of lenses and mirrors that stand upright on a platform—connected to a telescope at Table Mountain Observatory near Wrightwood, Calif. An adaptive optics system, created by Boeing Internal Research and Development and linked to the Table Mountain receiver, corrected for atmospheric disruptions (such as weather), allowing for highrate data transfer. Everyone involved came away encouraged by the system’s performance, Johnson explained. “It demonstrated that laser communication from the space station to a ground site aided performance by our adaptive optics system, paving the way for what space and satellite capabilities can be in the future,” Johnson said. A fundamental challenge now is to refine the technology so Lasercom can correct itself in the presence of a variety of atmospheric interferences, according to Johnson and Madni. Bad weather, for example, can make it difficult to secure a good connection. Peter Chu, Advanced Technologies manager and optics expert with the Boeing program, said Lasercom will need to create cost-effective optical assemblies, which will fit on satellites or aircraft or ground stations, to steer data in different directions, including from the ground to space. Different shaped mirrors and power adjustments help guide the intricate transmissions. “Because the LEO-to-ground link is only in view of a ground station for a fraction of its orbit, we need a very fast system,” Chu explained, referring to low Earth orbit. “We need to acquire quickly, maintain contact throughout the entire pass and get the data into the fiber optic terrestrial network. A lot of people thought it couldn’t be done.” The need for more sophisticated communications touches nearly every aspect of society, from commercial and financial needs to general aviation, military and space sectors, Madni said. Military transmissions, using narrow Lasercom beams, would have a much lower probability of being detected and intercepted, better protecting troops, said Ron Burch, director of Advanced Military Satellite Communications. “It’s very difficult to jam light,” Burch said. “We’re using infrared light, which is invisible to the human eye.” Military jets, such as the EA-18G Growler, could leverage the system to communicate with other aircraft and not put its electronic warfare missions at risk, according to Burch and others on the program. Boeing passenger jets Photos: (Clockwise from top left) Lasercom testing took place in June at Table Mountain Observatory near Wrightwood, Calif.; the telescope, connected to an optical bench, received a large amount of data transmitted from the International Space Station; optical lenses and mirrors are part of the Lasercom technology. PAUL PINNER | BOEING 14 BOEING FRONTIERS
Frontiers December 2015 - January 2016 Issue
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