GaAs solar array from Northrop Grumman lets MESSENGER orbit Mercury at high temperatures
Redondo Beach, CA--The solar array from Northrop Grumman Corporation (NYSE:NOC) on NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft features advanced triple-junction gallium arsenide (GaAs) solar cells and an electrical harness developed and qualified for this mission that gives the first spacecraft to orbit Mercury a power system that works to its maximum in the searing heat that surrounds the planet closest to the sun. The company also perfected a fully robotic welding process to assemble the photovoltaic (PV) cells before they were bonded to the solar array panel. The work was done under the pressure of meeting a launch window that was so tight that missing it would have meant a year-long wait until the next launch opportunity.
Solar array performance is critical—if it fails, so does the mission. Two single-sided solar panels are MESSENGER's main source of electrical power. They are two-thirds mirrors and one-third solar cells. The mirrors reflect the sun's energy and keep the panels cooler. The panels also rotate away from the sun to get the required power and maintain an operating temperature of about 300 degrees F.
Since its launch, MESSENGER has completed one swing past Earth, two Venus flybys, and three Mercury flybys. By using the gravity of each planet to gain speed and alter its trajectory, MESSENGER was able to conserve the fuel it will need during its mission orbiting a planet that is only 29 million miles from the sun, about two thirds closer to the sun than Earth. At Mercury's equator, surface temperatures become hot enough to melt lead. The spacecraft's fast, elliptical orbit allows it to approach Mercury, gather data and swing out far into space to cool down.
SOURCE: Northrop Grumman; www.irconnect.com/noc/press/pages/news_releases.html?d=224024
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Gail Overton | Senior Editor (2004-2020)
Gail has more than 30 years of engineering, marketing, product management, and editorial experience in the photonics and optical communications industry. Before joining the staff at Laser Focus World in 2004, she held many product management and product marketing roles in the fiber-optics industry, most notably at Hughes (El Segundo, CA), GTE Labs (Waltham, MA), Corning (Corning, NY), Photon Kinetics (Beaverton, OR), and Newport Corporation (Irvine, CA). During her marketing career, Gail published articles in WDM Solutions and Sensors magazine and traveled internationally to conduct product and sales training. Gail received her BS degree in physics, with an emphasis in optics, from San Diego State University in San Diego, CA in May 1986.