1. (2006).Space probe breaks laser record: a spacecraft has sent a laser signal to Earth from 24 million km (15 million miles) away in interplanetary space.BBC News 6 January.http://news.bbc.co.uk/2/hi/science/nature/4587580.stm
2. Edwards C. Jr. Stelzried C. Deutsch L.et al. (1998).NASA's deep space telecommunications roadmap.