Fig. 15. One of the ten identical energy-exchanger/binary-cycle power units in the Lockheed Power Satellite. The three p-v plots are qualitatively, but not necessarily quantitatively, correct. Source: Adapted from Ref. 21. combinations are clearly possible. Of these four, the Lockheed system has been described in the most detail (see Ref. 21) and is reviewed in the next section. 6. THE LOCKHEED LASER SPS This description is based on Ref. 21. The Lockheed system, illustrated in Fig. 14, consists of the three components shown in Fig. 13, namely, a power satellite, a laser beam plus relay satellite(s), and a ground station where the beam is converted into electrical power. A total system would, of course, consist of many power satellites and their respective beams, relays, and conversion stations. The Lockheed power satellite is deployed in a sun-synchronous, low Earth orbit (LEO) at an altitude of 900 km or more. Relay satellites are located both in geosynchronous equatorial orbit (GEO) at 35,800 km altitude (above sea level) and in LEO, with one GEO relay and one or fewer LEO relays per power satellite. At the power satellite, sunlight is reflected from a large (2.8 km diameter) mirror through a concave window 13 m in diameter and into a solar cavity. Within the cavity, the focused sunlight vaporizes liquid potassium and heats the vapor to 3400 K. Before entering the cavity, the liquid potassium flows through capillaries in the cavity walls. This flow serves to keep those walls cool relative to 3400 K. The liquid potassium then enters the cavity through jets in the window support structure, after having cooled that structure and the window. The 3400 K potassium vapor flows from the cavity to 10 identical energy- exchanger/binary-cycle power units (see Fig. 15). The binary cycle consists of loops
RkJQdWJsaXNoZXIy MTU5NjU0Mg==