— Ch. 1 · Program Genesis And Goals —
Surveyor program.
~4 min read · Ch. 1 of 6
In 1960, NASA's Jet Propulsion Laboratory began work on a new robotic program to prepare for human lunar landings. The agency selected Hughes Aircraft Company the following year to build the spacecraft systems. This initiative aimed to prove that soft landings on the Moon were possible before sending astronauts. The total cost of the Surveyor program reached $469 million by its conclusion in January 1968. Seven robotic probes traveled directly to the Moon without entering orbit around it. Each craft carried instruments to test soil mechanics and evaluate landing site safety for future Apollo missions. Before this effort, scientists did not know how deep the lunar dust layer extended. If the dust proved too thick, no astronaut could safely descend. The program demonstrated that landers could survive the journey and operate on the surface.
Engineering Architecture And Design
Hughes Aircraft designed each probe as a single unmanned unit launched atop an Atlas-Centaur rocket. The vehicle traveled from Earth to the Moon in approximately 63 to 65 hours. Upon arrival, it decelerated from 2.6 kilometers per second relative to the Moon over just three minutes. A main solid fuel retrorocket fired for 40 seconds starting at 75.3 kilometers above the surface. This stage jettisoned along with the radar unit when the craft reached 11 kilometers altitude. Smaller doppler radar units and three vernier engines handled the final descent using liquid fuels fed by pressurized helium. The last 3.4 meters were completed in free fall after the vernier engines shut off. This approach avoided surface contamination from rocket blast during touchdown. Surveyor 1 weighed between 952 kilograms and 1,020 kilograms at launch depending on configuration.