Free Astronomy Magazine May-June 2019

17 MAY-JUNE 2019 ASTRONAUTICS of a spaceship. With this program completed, JPL began developing spacecraft for deep space missions. From May 1960, JPL also embarked on a much bolder project to de- velop two similar spacecraft, one to be placed in lunar orbit for map- ping and the other designed for landing. Unfortunately, the devel- opment of the powerful Centaur stage that had to launch the two new probes towards the Moon was delayed. By accepting Kennedy’s After inspecting two sites in the sea, NASA left the Ranger 9 mission to scientists who, for the final im- pact in March 1965, chose Alphon- sus, a crater 119 km in diameter, with a central peak and a flat floor covered with interesting “cob- webs” and small craters with dark halos that seemed to be volcanoes. The Ranger Program answered the most urgent question about the na- ture of the lunar surface: it seemed that it would support the weight