MAY 2016 | 11 A half-century ago, development began on a lunar probe that helped BY MICHAEL LOMBARDI Surveying the future hen Neil Armstrong made his first step on the surface of the moon, he famously called it “a giant leap for mankind.” But getting there required many small and purposeful steps. And some of the most important were taken by lunar probes named Surveyor, made by a Boeing heritage company. There was little solid data about the lunar surface in 1961, when President Kennedy challenged America to land men on the moon before the end of the decade. What was the lunar soil made of? How much weight could the surface bear? Enough to hold a spacecraft with two astronauts on board? What about the magnetic and thermal properties on the lunar surface? It was all critical information that would be needed in designing a lunar lander—for astronauts. Early attempts to gather data about the moon, beginning in 1961 with Project Ranger, were unsuccessful. The first six spacecraft failed. In July 1964, Ranger 7 became the first U.S. probe to return close-up photos of the moon, but by then NASA had started other programs to gather data for the Apollo manned missions that were planned. NASA had approved a pair of unmanned exploration programs, which included five Lunar Orbiters that were tasked with photographing the moon’s surface to aid in selection of suitable landing sites for the Apollo missions, as well as to collect data on the moon’s gravitational field, levels of radiation and the density of micrometeorites in the vicinity of the moon. The second program was known as Surveyor, with the primary mission to validate the technology for soft landings on the moon. Surveyor would also provide data to determine whether the Apollo lunar lander design was compatible with the actual conditions HISTORICAL PERSPECT I V E that would be encountered on the lunar surface and, in general, to add to the scientific knowledge about the moon. Hughes Space and Communications, North American Aviation and McDonnell Aircraft competed for the Surveyor project. All are now Boeing heritage companies. In January 1961, NASA accepted the design proposed by Hughes. Hughes was contracted to build seven Surveyors, and on May 1966— 50 years ago this month—Surveyor 1 was launched to the moon. Unfortunately, it would not be the first soft landing on the moon. Four months earlier, the Soviet Union achieved that objective with Luna 9. But for six weeks, including a two-week-long shutdown for the lunar night, Surveyor 1 transmitted 11,237 high-resolution pictures back to Earth. Surveyor 2 was lost because an engine failed to fire; Surveyor 3 bounced twice before coming to rest 103 feet (31 meters) from the initial landing site. But it still managed to send back 6,300 pictures—many were of its mechanical scoop used to dig 7 inches (18 centimeters) into the lunar soil. Surveyor 4 was lost; Surveyor 5 irradiated the lunar soil so that its composition could be analyzed. Surveyor 6 engines were fired for 2.5 seconds and the spacecraft moved 8 feet (2.4 meters) away from its landing site to get a stereoscopic view of the lunar surface and a viewing of the area disturbed by the original landing. With the successful conclusion of the Surveyor 6 mission, the program had accomplished all of its goals for the Apollo program. Unlike the previous Surveyor missions that landed in the barren maria, or dark and flat regions, of the moon, Surveyor 7 was sent to the rim of the crater Tycho in the lunar highlands, where it examined an area filled with debris created by the formation of the crater and obtained very different types of lunar samples than the previous Surveyors. All seven spacecraft are still on the moon. In 1969, Apollo 12 landed within a quarter-mile (402 meters) of Surveyor 3 and astronauts Pete Conrad and Alan Bean retrieved parts of it, including the camera, to determine the effects of long exposure to the lunar environment. The camera is on display at the Smithsonian National Air and Space Museum in Washington, D.C. • MICHAEL.J.LOMBARDI@BOEING.COM astronauts walk on the moon W
Frontiers May 2016 Issue
To see the actual publication please follow the link above