Camera, Lunar Lander, Surveyor, Variable Focal Length and Iris Assembly

Object Details

Manufacturer

Hughes Aircraft Co.

Summary

This variable focal length and iris camera assembly was mounted on the Surveyor spacecraft. The iris could be operated in an automatic mode, which was controlled by integrating the scene luminance through a photocell in the lens.

In 1970, the Hughes Aircraft Co. donated the camera to the Smithsonian Institution.

Long Description

This is the variable focal length and iris assembly, which was mounted in the cylinderical lens support structure under the mirror elevation drive assembly in the Survey TV camera on the Surveyor spacecraft. It was responsible for the optical formation of the image on the underlying vidicon faceplate. The lens could vary its focus from 1.23 m to infinity by means of a rotating focus cell. Although the lens was a zoom type, it was calibrated to operate only at 25- or 100-mm focal lengths. These positions correspond to a wide-angle field of view of 25.2 x 25.2 degrees and a narrow-angle field of view of 6.4 x 6.4 degrees, respectively. In the narrow angle mode, the angular resolution of the camera was >0.5 mrad at 15% relative response, which allowed investigators to discriminate objects <1 mm in diameter near the spacecraft footpads (1.6 m from the camera). The iris could be operated by ground commands to give 11 positions for calibration, resulting in the capability of changing the aperture area by a factor of 1.414 to the values of f/4, f/4.8, f/5.6, f/6.7, f/8, f/9.5, f/11, f/13, f/16, f/19, and f/22. The iris could also be operated in an automatic mode, which was controlled by integrating the scene luminance through a photocell in the lens. Potentiometers geared to the iris, focal length, and focus elements allowed readouts of these functions.

Credit Line

Donated by Hughes Aircraft Co.

Inventory Number

A19700116000

Restrictions & Rights

Usage conditions apply

Type

SPACECRAFT-Uncrewed-Instruments & Payloads

Materials

Lens with housing and motors.

Dimensions

Overall: 5 in. tall x 3 1/4 in. wide x 5 1/4 in. deep, 1 lb. (12.7 x 8.3 x 13.3cm, 0.5kg)

Country of Origin

United States of America

See more items in

National Air and Space Museum Collection

Location

Steven F. Udvar-Hazy Center in Chantilly, VA

Exhibit Station

Space Science

National Air and Space Museum

Record ID

nasm_A19700116000

Metadata Usage (text)

Not determined

GUID (Link to Original Record)

http://n2t.net/ark:/65665/nv99f3c3dd4-bc2b-415c-ab01-984e7c6586f6