Caltech's Jet Research Articles

From the historian-designing the United States' initial 'deep-space networks': choices for the Pioneer lunar-probe attempts of 1958-9

To support the series of early Pioneer lunar-probe attempts by the US Air Force and US Army, Ramo-Wooldridge's Space Technology Laboratories (STL) and Caltech's Jet Propulsion Laboratory (JPL) designed two separate networks of ground stations in 1958-9. Since the probes were means of restoring international prestige to the US, and thus were scheduled to be launched within a year of authorization, both networks had to be installed on a crash basis. The differences between the two initial networks in terms of antenna design, operating frequency, and location are described, and it is shown how the extra months afforded to JPL due to the later launches of the Army probes allowed its engineers to design and install the first elements of a system that evolved within a few years into NASA's Deep Space Network.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Magellan Venus data “continues to amaze”

Images of Venusian “pancakes,” “ticks,” and “coronae” were presented by Magellan scientists with their assessments of the underlying processes at work on the planet at the AGU Spring Meeting. According to project scientist Steve Saunders of Caltech's Jet Propulsion Laboratory, “we are just getting started” on analyzing the Magellan data. “The results are overwhelming, spectacular. They continue to amaze everyone.”The Magellan data have so far revealed a landscape that exhibits little evidence of crater degradation, few examples of highly eroded terrain, plains regions that are highly fractured, and evidence of widespread, localized volcanism, Saunders said.

The Research and Development of Silicon-Germanium Thermoelements for Power Generation

ABSTRACTOn the 25th of August 1989, radio signals from the unmanned Voyager II spacecraft produced high resolution radio displays of the planet Neptune and its moon, Triton, on the monitors of Caltech's Jet Propulsion Laboratory. Thus ended the 12-year NASA Voyager I and II missions to the giant outer planets of our solar systems. Somewhat overlooked in the excitement over the impressive scientific findings from Voyager's epic planetary encounters was the power system aboard the spacecraft for data collection and signal transmission. This was the multi-hundred watt, radioisotope fueled thermoelectric generator using thermocouple modules made of Si-Ge alloys. The first section of this paper presents a historical review of the research program at the RCA Laboratories in Princeton, N.J. during the 4-year period required for the conception and development of Si-Ge thermoelements for power generation. This includes RCA's strategy in thermoelectric materials research from the viewpoint of device principles and requirements, scientific issues relating to the growth and thermoelectric characterization of Si-Ce alloys, and device feasibility studies. The performance of Si-Ge thermoelements in the power source of several space missions is also discussed. Finally, a perspective is presented on the research management of this remarkably successful program. The second section of the paper describes the results of more recent research on the thermoelectric properties of hot-pressed, sintered Si-Ge alloys and, in particular, the effects of grain size and additions of GaP. In the final section, consideration is given to future areas of research based, in part, on the results of the earlier studies of Si-Ge technology for thermoelectric power generation.

Analysis Of Multiple Imagery At Jet Propulsion Laboratory's Image Processing Laboratory

Computer image processing at Caltech's Jet Propulsion Laboratory (JPL) began over a decade ago with digital processing of single images of the lunar surface returned by the Ranger and Surveyor spacecraft. During the past decade, advanced techniques have been developed at JPL for processing large volumes of imagery returned by the more recent planetary spacecraft, including the Mariner 6, 7, and 9 missions to Mars, the Mariner 10 mission to Venus and Mercury, the Viking Orbiter and Lander Mars missions, and the current Voyager mission to Jupiter and Saturn. In addition, the Image Processing Laboratory (I PL) has become involved in processing of earth resources imagery acquired by the Landsat earth orbital satellite and a variety of other sensors flown on aircraft and spacecraft. The trend within the facility has been toward development of technology capable of processing increasingly larger image data bases. A variety of applications in both the planetary and earth observations areas involve merging and/or processing of more than one image and often require correlation of data acquired by a variety of sensors. This paper describes the evolution that has occurred, and the use of multiple imagery is illustrated through a variety of applications.

Deep space network equipment available for radio astronomy

Cal Tech's Jet Propulsion Laboratory has announced that some of the equipment in its Deep Space Network (DSN) is available free for limited use by qualified radio scientists. DSN equipment includes a 210‐foot paraboloid and an 85‐foot paraboloid at Goldstone, California and 85‐foot paraboloids overseas.

Space Work

Caltech's Jet Propulsion Laboratory has awarded a $4‐million contract to Consolidated Vacuum Corporation, a subsidiary of Bell & Howell/Consolidated Electrodynamics Corp. of Rochester, N.Y., for the design and construction of a space‐environmental facility capable of simulating solar radiation as well as the atmospheric conditions of outer space. The simulator is described as a stainless steel tower 80 feet high and 27 feet in diameter, with a vacuum chamber in the lower portion large enough to accommodate full‐scale space vehicles. The upper portion of the tower will house the solar‐simulation unit.