SINCE the dawn of the space age, Nasa has been relying on radio communications technology to send and receive data to and from spacecraft. Although it has developed higher data-rate radio frequency systems, data-compression, and other techniques to boost the amount of data that its current RF systems can handle, they cant keep pace with the projected data needs of advanced instruments and further human exploration. To break this bottleneck, Nasa is turning to optical communications technology that would use lasers to increase data rates over existing systems by anywhere from 10 to 100 times. Nasas current legacy radio-based network includes a fleet of tracking and data relay satellites and a network of ground stations. At the current limit of 6 Mbps for the Mars Reconnaissance Orbiter (MRO), Nasa says it currently takes 90 minutes to transmit a single HiRISE high-resolution image from Mars back to Earth. However, the new optical communications system would reduce the transmission time down to just five minutes and even allow streaming of high definition video from distances beyond the Moon. The Laser Communications Relay Demonstration (LCRD) is designed to enable Nasa, other governmental agencies and the commercial space industry to undertake future, complex missions by providing significantly higher data rates for approximately the same mass, power, and volume as a comparable RF system. Nasa says laser-based space communications will enable missions to use bandwidth-hungry instruments, such as hyperspectral imagers, synthetic aperture radar (SAR), and other instruments with high definition in spectral, spatial, or temporal modes. Laser communication will also make it possible to establish a virtual presence at a remote planet or other solar system body. Gizmag