Skylon is a series of designs for a single-stage-to-orbitspaceplane by the British company Reaction Engines Limited (REL), using SABRE, a combined-cycle, air-breathingrocket propulsion system. The vehicle design is for a hydrogen-fuelled aircraft that would take off from a purpose-built runway, and accelerate to Mach 5.4 at 26 kilometres (85,000 ft) altitude (compared to typical airliners' 9–13 kilometres or 30,000–40,000 feet) using the atmosphere's oxygen before switching the engines to use the internal liquid oxygen (LOX) supply to take it into orbit. It could carry 17 tonnes (37,000 lb) of cargo to an equatorial low Earth orbit (LEO); up to 11 tonnes (24,000 lb) to the International Space Station, almost 45% more than the capacity of the European Space Agency's Automated Transfer Vehicle; or 7.3 tonnes; 7,300 kilograms (16,000 lb) to Geosynchronous Transfer Orbit (GTO), over 24% more than SpaceXFalcon 9 launch vehicle in reusable mode (As of 2018[update].) The relatively light vehicle would then re-enter the atmosphere and land on a runway, being protected from the conditions of re-entry by a ceramic composite skin. When on the ground, it would undergo inspection and necessary maintenance, with a turnaround time of approximately two days, and be able to complete at least 200 orbital flights per vehicle.
Deeply involved in the investigation of the 1967 Apollo 1 fire, Shea suffered a nervous breakdown as a result of the stress that he suffered. He was removed from his position and left NASA shortly afterwards. From 1968 until 1990 he worked as a senior manager at RaytheoninLexington, Massachusetts, and thereafter became an adjunct professor of aeronautics and astronauticsatMIT. While Shea served as a consultant for NASA on the redesign of the International Space Station in 1993, he was forced to resign from the position due to health issues.
AtransitofEarth by the Moon, as photographed by the Deep Space Climate Observatory from the Sun-Earth L1Lagrangian point. This animation was compiled from a set of 60 frames—20 distinct images, each compiled from monochrome images taken in red, green and blue filters—taken over the course of five hours on July 16, 2015. Each monochrome frame was taken every 30 seconds. Due to the speed of the Moon's motion, this results in a slight green shift in some frames of the animation.
