Long Duration Exposure Facility (LDEF) low temperature Heat Pipe Experiment Package (HEPP) flight results

The Low Temperature Heat Pipe Flight Experiment (HEPP) is a fairly complicated thermal control experiment that was designed to evaluate the performance of two different low temperature ethane heat pipes and a low-temperature (182 K) phase change material. A total of 390 days of continuous operation with an axially grooved aluminum fixed conductance heat pipe and an axially grooved stainless steel heat pipe diode was demonstrated before the data acquisition system's batteries lost power. Each heat pipe had approximately 1 watt applied throughout this period. The HEPP was not able to cool below 188.6 K during the mission. As a result, the preprogrammed transport test sequence which initiates when the PCM temperature drops below 180 K was never exercised, and transport tests with both pipes and the diode reverse mode test could not be run in flight. Also, because the melt temperature of the n-heptane PCM is 182 K, its freeze/thaw behavior could not be tested. Post-flight thermal vacuum tests and thermal analyses have indicated that there was an apparent error in the original thermal analyses that led to this unfortunate result. Post-flight tests have demonstrated that the performance of both heat pipes and the PCM has not changed since being fabricated more than 14 years ago. A summary of HEPP's flight data and post-flight test results are presented

Plasma-tail activity and the interplanetary medium at Halley's Comet during Armada Week: 6-14 March 1986

The encounters of five spacecraft with Halley's Comet during 6-14 March 1986 offered a unique opportunity to calibrate the solar-wind interaction with cometary plasmas as recorded by remote wide-field and narrow-field/narrowband imaging. Perhaps not generally recognized in the comet community is the additional opportunity offered by the Halley Armada to study the structure of the solar-wind and interplanetary magnetic field (IMF) in three dimensions using five sets of data obtained over similar time intervals and heliocentric distances, but at somewhat different heliolatitudes. In fact, the two problems, i.e., comet physics and the structure of the interplanetary medium, are coupled if one wants to understand what conditions pertained at the comet between the encounters. This relationship is discussed

NASA Standard GAS Can Satellite

This paper describes a new direction in small low cost spacecraft. This 150 pound satellite provides access to conduct experiments in space on an economical and short term basis. It can be used by commercial as well as scientific institutions. Currently called the XSAT, it was developed by NASA in cooperation with Defense Systems Inc. (DSI) of McLean, Virginia. XSAT provides for experimental payloads up to 50 pounds, 50 watt hours per day, one megabyte data storage, three day command memory and packetized protocol. Structural and thermal designs can handle worst case loads of the STS manned launch vehicle. XSAT can be operated by an experimenter using a personal computer from a ground-based station either locally or over normal telephone lines. An Attitude Control System (ACS) and/or propulsion system is added to XSAT on a mission peculiar basis in order to accommodate the requirements of each specific payload

Addressing Barriers to Breast Cancer Screening: Where to Intervene to Increase Mammogram Completion Rates

Methods: Study sought to determine if an intervention would aid in increasing mammogram screening rates in the Jefferson Family Medicine Associates practice.https://jdc.jefferson.edu/patientsafetyposters/1061/thumbnail.jp