Julie Cooper is a certified archivist who identifies and processes collections for the JPL Archives, and helps researchers find information about the history of JPL.
In 1979, this test fixture was used to study how much damage would occur when a solar panel was hit with hail measuring 1/2 inch to 5 inches in diameter. The white tube is the hailgun barrel. Interchangeable barrels of various sizes matched the diameter of the “hail” or ice ball being tested. The solar panel was mounted on the ceiling of the test facility, and an air compressor provided the force to project hailstones upward at about the same velocity as a storm. In this photo, Lee Albers and Bill Peer of the Test and Mechanical Support Section at NASA's Jet Propulsion Laboratory load an ice ball into the barrel.
Some of the same equipment was originally used to test possible hail damage in Deep Space Network antenna panels. In summer 1962, after similar tests were done at the South Africa Deep Space Station, a hailstorm simulation facility was developed at JPL to continue the study. The equipment included heated molds to form ice balls of various sizes and a chest freezer to keep them at 18 degrees Fahrenheit.
December 24, 2013, marked 50 years since the official beginning of the Deep Space Network. On that date in 1963, JPL Director William Pickering sent out a memo announcing that the Deep Space Instrumentation Facility, or DSIF, Interstation Communications, and the mission-independent portion of the Space Flight Operations Facility would be combined and renamed the Deep Space Network, or DSN. At that time, the DSIF already included five large antennas in California, Australia, and South Africa, to provide complete communications coverage as the Earth rotates.
The DSIF began with mobile tracking stations that were used to track the Explorer spacecraft, and in 1958 the first 85-foot (26 meter) antenna was built in the Mojave desert, at the Goldstone Tracking Station. As new communications technology developed, new antennas have been added to the DSN sites and existing antennas enlarged or modified to increase their capabilities. This photo shows a Cassegrain cone 100-kw transmitter developed for the 85-foot antenna at the Goldstone Venus site (DSS-13) in Goldstone, Calif. It was placed on a cone test elevator in the high-voltage power supply building at Goldstone and raised up high enough that the radiating feed horn on top of the cone was above the roof line of the building during tests. Development and testing was completed in time for it to be used in communicating with the Mariner 4 spacecraft that went to Mars.
In August 1964, this test fixture was used by the Spacecraft Design Section at NASA's Jet Propulsion Laboratory in Pasadena, Calif., to study spin stabilization of spacecraft - in this case, Rangers 8 and 9 (part of the Ranger Block 3 design). Many spacecraft had used spin stability for attitude control during acceleration or thrust, and it was found that a slower spin provided better stability for the coasting phase.
One method of decreasing the spin of a spacecraft, or de-spinning, was the deployment of yo-yo devices. Weights were attached to rigid or stretch cords, then released while the fixture was spinning. The cords would unwind, like the arms of a figure skater extending to slow a spin, and then the cords were released. In this photo, the cables and weights can be seen, attached to the outside of the white circle. The test fixture is surrounded by what appear to be bales of paper and trash to absorb the impact of the weights when they were released from the spinning test fixture.
This photo was taken in November 1960 to show the lightweight balsa wood impact limiter that was to be used in the NASA Jet Propulsion Laboratory's Ranger Block II spacecraft design (Rangers 3, 4, and 5). The woman holding the sphere is Systems Design secretary Pat McKibben. The sphere was 65 cm in diameter, and it surrounded a transmitter and a seismometer instrument that was designed by the Caltech Seismological Laboratory. The sphere would separate from the spacecraft shortly before impact and survive the rough landing on the moon. The capsule was also vacuum-filled with a protective fluid to reduce movement during impact. After landing, the instrument was to float to an upright position, then the fluid would be drained out so it could settle and switch on.
Due to a series of malfunctions in 1962, these three Ranger spacecraft either crashed without returning data or missed the moon. In July 1964, the first successful Ranger spacecraft, Ranger 7, reached the moon and transmitted more than 4,000 images to Earth.
Because the data return rate from Mariner 4 was very low, the Mariner 4 Television Experiment Team spent hours waiting for each new image to appear. In this photo they are waiting for the first picture from Mars. Mariner eventually returned 22 images. From left to right: Robert Nathan (NASA's Jet Propulsion Laboratory), Bruce Murray (associate professor of planetary science), Robert Sharp (Caltech), Robert Leighton (principal investigator), and Clayton La Baw (JPL).
Murray had been a member of the Caltech faculty for about five years when this photo was taken in July 1965. He went on to replace William Pickering as Director of JPL in 1976, retired from that position in 1982, and returned to Caltech.
In 1961, mathematicians from NASA's Jet Propulsion Laboratory and Caltech worked together to construct a Hadamard Matrix containing 92 rows and columns, with combinations of positive and negative signs. In a Hadamard Matrix, if you placed all the potential rows or columns next to each other, half of the adjacent cells would be the same sign, and half would be the opposite sign. This mathematical problem had been studied since about 1893, but the solution to the 92 by 92 matrix was unproven until 1961 because it required extensive computation.
From left to right, holding a framed representation of the matrix, are Solomon Golomb, assistant chief of the Communications Systems Research Section; Leonard Baumert, a postdoc student at Caltech; and Marshall Hall, Jr., a Caltech mathematics professor. In a JPL press release, Sol Golomb pointed out the possible significance of the discovery in creating codes for communicating with spacecraft.
The team used JPL’s IBM 7090 computer, programmed by Baumert, to perform the computations.
The Seasat project was a feasibility demonstration of the use of orbital remote sensing for global observation. It was launched on June 26, 1978 and carried five sensors:
-- The Radar Altimeter (ALT) measured wave height at the subsatellite point and the altitude between the spacecraft and the ocean surface. The altitude measurement was precise to within ±10 cm (4 in.). The altitude measurement, when combined with accurate orbit determination information, produced an accurate image of the sea surface topography.
-- The Seasat (Fan-Beam) Scatterometer System (SASS) measured sea surface wind speeds and directions at close intervals from which vector wind fields could be derived on a global basis.
-- The Scanning Multichannel Microwave Radiometer (SMRR) measured wind speed, sea surface temperature to an accuracy of ±2°C, and atmospheric water vapor and liquid water content.
-- The Synthetic Aperture Radar (SAR) was an imaging radar that provided images of the ocean surface from which could be determined ocean wave patterns, water and land interaction data in coastal regions, and radar imagery of sea and fresh water ice and snow cover.
-- The Visual and Infrared Radiometer (VIRR) objective was to provide low-resolution images of visual and infrared radiation emissions from ocean, coastal and atmospheric features in support of the microwave sensors. Clear air temperatures were also measured.
This 1978 illustration was based on a painting, probably by artist Ken Hodges. He created artwork for many different Jet Propulsion Laboratory missions in the 1970s and 1980s, before computer aided animation was used for mission presentations and outreach.
In 1991, Diatek Corporation of San Diego put a new infrared thermometer - Model 7000 - on the market. Early electronic thermometers had been used by some hospitals and doctors' offices for several years before that time, but this Diatek model was a pioneering effort to modify space-based infrared sensors for a medical infrared thermometer. The underlying technology was developed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., for missions including the Infrared Astronomical Satellite, or IRAS. IRAS measured the temperature of stars and planets by reading the infrared radiation emitted from them, while the thermometer almost instantly determined body temperature by measuring the energy emitted from the eardrum - quite an advancement in medical technology. Diatek was part of the JPL Technology Affiliates Program, or TAP, in the late 1980s and received help from JPL personnel in adapting infrared sensor technology to this new product.
An intense magnetic field facility was completed in 1964 by the Physics Section of the Space Sciences Division at NASA's Jet Propulsion Laboratory. It was intended for use in studying superconductors, spectroscopy and new materials, and in other experiments where a wider range of measurements was possible because of the high magnetic field. This photo shows the magnet at center. The system also included a control room, cooling tower, pumps and a heat exchanger. The generator was located in a separate room because of the noise. Water was pumped through the magnet at about 440 gallons per minute, to regulate the temperature of the large copper coil in the center of the magnet. The closed loop system contained distilled water with sodium nitrite for corrosion control.
According to a technical report about the facility, the magnetic field of the magnet and bus bars penetrated nearby rooms to a depth of about 30 feet. Any iron that could be attracted to the magnet had to be removed from the area.
In 1952, the majority of the 1,000 employees at NASA's Jet Propulsion Laboratory were men, and most of the women working on lab were in clerical positions. There were some exceptions, such as the women of the Computing Section, and three women who had technical positions in the Analytical Chemistry Laboratory. In addition to chemist Lois Taylor, seen in this photo, Julia Shedlesky also worked as a chemist and Luz Trent was a lab technician. Taylor began working at JPL in 1946. The Chemistry Section was involved in the development of new solid and liquid propellants, propellant evaluations and general studies on combustion processes in motors.