28 ASTRONOMY • APRIL 2020
A near-tragedy in space challenged the crew
of Apollo 13. They missed walking on the
Moon, but in the end, triumphed.
BY DAVID J. EICHER AND BRIAN MAY
The Saturn V stack and its mobile launch tower stand
atop the huge crawler-transporter that carried the
Saturn V rockets from the Vehicle Assembly Building
to launch pad 39A. At the time, these tractors were the
largest self-powered land vehicles, reaching speeds of
only 1 mph (1.6 km/h). ALL IMAGES: NASA/JSC