By Julie Cooper

Each month in “Slice of History” we feature a historical photo from the JPL Archives. See more historical photos and explore the JPL Archives at https://beacon.jpl.nasa.gov/.

Granite Oil Slip Table — Photograph Number P-2784Ac

In 1963, spacecraft vibration tests were conducted in the Environmental Laboratory at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. A slab of granite, coated in oil, provided a smooth and stable base for the magnesium slip plate, test fixture and Ranger 6 spacecraft mounted on it. There were vibration exciters (shakers) on each end, capable of more than 25,000 pounds of force. The horizontal fixture at left was used for low frequency vibration testing, and the equipment was capable of testing along all three spacecraft axes.

During the 1960s, Ranger, Surveyor and Mariner spacecraft were developed, built and tested at JPL. Because of the heavy use, a similar but smaller test fixture was used for vibration tests on spacecraft components and assemblies. Building 144 still contains test facilities, but this equipment was removed and the room now contains an acoustic chamber.

This post was written for “Historical Photo of the Month,” a blog by Julie Cooper of JPL’s Library and Archives Group.

By Julie Cooper

Each month in “Slice of History” we’ll be featuring a historical photo from the JPL Archives. See more historical photos and explore the JPL Archives at https://beacon.jpl.nasa.gov/.

Ranger Midcourse Motor — Photograph Number 384-5117B

Engineer Ted Metz proudly showed off the Ranger midcourse correction motor in a photo similar to this one that appeared in the May 1965 issue of Lab-Oratory, the JPL employee newsletter. “Since few Lab employees have seen the Ranger and Mariner midcourse propulsion unit, we show here the rocket motor portion of the system held by Propulsion project engineer, Ted Metz. This 50-pound thrust motor utilizes hydrazine fuel and has successfully corrected the trajectories of the Mariner R, Mariner IV and Rangers VI through IX spacecrafts.”

From 1961 to 1965, there were six Ranger flights that failed for various reasons and three very successful ones (Rangers 7, 8, and 9). Mariner R (based on the Ranger spacecraft, also called Mariner 2) had flown by Venus, and Mariner 4 was on the way to Mars.

This post was written for “Historical Photo of the Month,” a blog by Julie Cooper of JPL’s Library and Archives Group.