SOFIA

A 2.5-metre (98-inch) telescope mounted in a Boeing 747 aircraft, due to begin operations in 2001. SOFIA is an acronym for "Stratospheric Observatory for Infrared Astronomy". It is the successor to the Kuiper Airborne Observatory (KAO). Flying at between 41,000 and 45,000 feet, SOFIA will operate above 85 per cent of the Earth's atmosphere and above 99 per cent of the atmospheric water vapour, which interferes with infrared astronomy. Its capability will encompass the visible, infrared, sub-millimetre and microwave regions of the spectrum.