The Apollo Scientific Instrument Module (SIM) Cameras

Please note some of the photographs contained in this paper are quite large.

Last update: 2017-02-17

Overview

One of the key goals for Apollo was to provide high quality photographic imagery of the lunar surface from orbit.

The early Apollo lunar orbiting missions carried out photo-geological surveys of much of the lunar surface adjacent to their orbital ground track. For the initial flights (Apollo's 8 to 14) the ground tracks were limited to the equatorial region of the Moon, as the choice of the initial Apollo landing sites was in the Apollo zone along this equatorial band (see map below).

Click on above image to enlarge. The low orbital inclination limited the amount of orbital progression, as the Moon rotated beneath the orbiting Command and Service Module (CSM). The majority of the photography of the lunar surface for these initial Apollo missions was taken with hand held Hasselblad cameras using a variety of film and lens combinations. On Apollos 13 & 14, in addition to the Hasselblad camera, a Hycon terrain mapping camera was also carried to obtain high resolution 127-mm photography of proposed sites landing sites for Apollo 16. This camera was mounted on one of the Command Module's (CM) windows, and operated semi-automatically. The imagery acquired was very limited due to the Apollo 13 abort, and also hardware failures during the Apollo 14 mission.

The need to produce highly accurate topographic maps of the lunar surface was identified as a prime goal of the later Apollo flights to aid in the interpretation of the photo-geological studies using imagery from Apollo, earlier orbiting spacecraft and Earth based telescopes. These objectives were defined at the Falmouth Conference of Lunar Science and Exploration in 1965.

The objectives set were:

To establish a selenodetic coordinate system.
To derive a lunar reference figure with respect to a point that represents the lunar centre of mass.
To establish a three dimension geodetic control point system on the lunar surface in terms of latitude, longitude, and height above the reference surface datum.
To provide data for a comprehensive series of medium scale (1:250,000) topographic and geological maps.
To provide data for large scale (1:20,000) topographic and geological maps of potential landing sites and other sites of interest.
To describe in detail the gravitational field of the Moon.

The orbital imagery returned by the initial Apollo lunar missions was of limited use for topographic mapping of the Moon. Plans were therefore put in place to develop a metric lunar mapping camera and a optical bar panoramic camera to be carried on the three 'J' missions.

During the summer of 1964, as the Apollo Block II Service Module design was being defined, North American in Downey, California, under guidance from MSC in Houston, modified the proposed design to provide an empty bay to hold future scientific experiments. Detailed planning of the orbital experiments to be carried in the Service Module began in May 1968, with the formal go ahead being given by Associate Administrator for Manned Spaceflight, George Muller in early May 1969. The space available in the spare bay in the Service Module was reduced by the need to install a third liquid oxygen tank, following the review of the cause of the Apollo 13 mishap. The new tank was installed on a shelf in the forward quarter of the spare bay.

The plan called for the space rating of existing airborne photo-reconnaissance cameras. The photo lab at the Manned Spacecraft Center (MSC) identified the 5-inch aerial reconnaissance camera produced by Fairchild Space and Defense Systems of Long Island, New York as the most suitable hardware for the mapping camera. They also identified the 24-inch-focal-length optical bar panoramic camera produced by the Itek Optical Systems Division of Lexington, Massachusetts.

The Apollo Orbital Science Photographic Team was headed by Frederick J. Doyle of the U.S. Geological Survey at McLean, Virginia.

The orbital coverage of the Lunar Mapping Camera is shown below.

The orbital coverage of the Panoramic Camera is shown below.

Red = Apollo 15

Yellow = Apollo 16

Blue = Apollo 17

The Lunar Mapping and Panoramic Cameras were mounted in the forward portion of the Apollo Scientific Instrument Module (SIM) in bay 1 of the Service Module on Apollo 'J' missions 15 to 17. The following figure shows the layout of the SIM bay carried on Apollo 15 & 16.

Click on above image to enlarge.

Shown below is an alternative illustration of the Apollo 15 & 16 SIM bay configuration.

Click on above image to enlarge.

The compliment of experiments in the SIM bay was changed for Apollo 17. See the figure below.

Click on above image to enlarge.

The image below shows the SIM bay in the Apollo 15 SM during pre-flight processing.

Click on above image to enlarge.

The above diagram shows the separation on the SIM bay door during the translunar coast, and shows how the trans-Earth EVA was performed.

Control panel 230 was added to the CM to enable control of the new SIM bay experiments, which included the Lunar Mapping Camera to activate/deactivate camera heaters and functions, compensate for image motion and extend/retract the camera on its deployment rails. For the Panoramic Camera the panel was used to activate/deactivate camera heaters, supply/remove primary camera power, select operate/standby operation modes, supply film roller torque to prevent slack in film during launch and maneuvers, activate a five-frame film advance cycle if the camera was not operated in a 24-hour period, increase/decrease the width of the exposure slit, and select the stereo or monoscopic mode of operation. This panel was primarily operated by the Command Module Pilot (CMP). Also included on this panel was a power switch to activate the scientific data system information collection and processing equipment. Another switch on this panel activates the remote checkout of the scientific data system frequency generating equipment by the ground.

The exposed film was retrieved from the SIM bay during the early portion of the trans-Earth coast.

In A, the astronaut (CMP) is shown egressing through the CM hatch. During the EVA, all three astronauts are exposed to the vacuum of space and hence all must wear their spacesuits. In B, the CMP has moved to the vicinity of the SIM bay and is preparing to remove the film cassettes from the Lunar Mapping and Panoramic Camera's. He anchors himself to the spacecraft by inserting his feet into special foot restraints, termed Â‘golden slipperÂ’, because they were formerly gold coloured. In C, the EVA astronaut is seen removing the film from the mapping and stellar cameraÂ’s in one cassette. Another astronaut (usually the LMP) remains Â‘standingÂ’ in the Command Module main hatch, from where he documents the film retrieval procedure with photographs and verbal descriptions. From here he also assists the EVA astronaut during his transfers to the SIM bay and passing the retrieved film cassettes to the third astronaut (usually the CDR) who has remained within the Command Module. The film cassettes are safely stowed within the CM for their return to Earth.

Below is a training photograph of Apollo 17 CMP Ron Evans passing a Panoramic Camera film cassette to LMP Harrison H. Schmitt.

Click on above image to enlarge.

The images above shows Apollo 17 CMP, Ron Evans, retrieving a film cassette from the SIM bay during his trans-Earth EVA.

Click here to view a 61-second MPEG of Ron Evans during the early part of his trans-Earth EVA.

Sources

On the Moon with Apollo 16, Gene Simmons - NASA EP-95, 1972

On the Moon with Apollo 17, Gene Simmons - NASA EP-101, 1972

Apollo over the Moon, Harold Masursky, G. W. Colton, Farouk El-Baz - NASA SP-362, 1978

North American Rockwell - Space Division, Fact Sheet SP-29, 1972

Chariots for Apollo: A History of Manned Lunar Spacecraft. C. G. Brooks, J. M. Grimwood, L. S. Swenson jnr - NASA SP-4205, 1979

Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions. William Crompton - NASA SP-4214, 1989

National Space Science Data Center


Return to SIM Bay Cameras	The Fairchild Lunar Mapping Camera