What was Surveyor Model 2?

This was another test flight for NASA’s Surveyor lunar lander spacecraft. A malfunction with the rocket left the payload tumbling in the wrong orbit. The payload reentered Earth’s atmosphere May 5, 1966.

Nation	United States of America (USA)
Objective(s)	Highly Elliptical Orbit
Spacecraft	SD-3
Spacecraft Mass	1,728 pounds (784 kilograms)
Mission Design and Management	NASA / JPL
Launch Vehicle	Atlas Centaur (AC-8 / Atlas no. 184D / Centaur D)
Launch Date and Time	April 8, 1966 / 01:00:02 UT
Launch Site	Cape Canaveral, Fla. / Launch Complex 36B
Scientific Instruments	None

Key Dates

April 8, 1966: Launch

May 5, 1966: Spacecraft reentered Earth’s atmosphere

In Depth: Surveyor Model 2

This was a NASA test to launch a dummy Surveyor lunar lander spacecraft into a barycentric orbit towards a simulated Moon.

Unlike the two previous Surveyor mass model tests, this flight was supposed to demonstrate a restart capability for the Centaur upper stage. The Centaur-Surveyor combination successfully achieved parking orbit around Earth with a first firing, but when it came time for the second firing, the Centaur RL-10 engines fired for only a few seconds instead of the planned 107 seconds.

A thrust imbalance left the payload tumbling and in an incorrect orbit of 113 × 208 miles (182 × 335 kilometers) at a 30.7-degree inclination. The problem was later traced to a hydrogen peroxide leak in the ullage motors of the Centaur stage.

With no hope of reaching its ultimate orbit (planned for 104 × 236,000 miles or 167 × 380,000 kilometers), the payload reentered Earth’s atmosphere May 5, 1966.

Key Source

Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.