Aerospace & Aviation

Reliability estimates of system undergoing development testing

Transition metal complexes of 8-aminoquinoline

Minimum weight proton shield synthesis for space vehicles

Bromine trifluoride method for oxygen in liquid alkali metals

High energy molecular beam facility

View factor in radiant heat transfer calculations

Crystal structure influence on friction and wear characteristics of binary tungsten-cobalt and molybdenum-cobalt alloy systems in vacuum

Apparatus for measuring temperature drop across bolted interface

Photographic study of nucleate boiling of methanol and water from discrete-bubble to multibubble regime

Performance of 84 deg flat plate helical inducer compared with 78 deg and 80.6 deg inducers

Radiation processes related to oxygen-hydrogen combustion at high pressures

A large volume of data were generated both during the development program and the flight lifetime of the Explorer XIII Micrometeoroid Satellite. These data, in the form of payload telemeter signals, were recorded on magnetic tape. To facilitate the reduction of these data, the development of an automatic data read out system, suited both to the special characteristics of the data signals and to the requirements of high-speed digital computing equipment, was initiated at the start of the satellite development program. As indicated earlier in this report, the telemeter signal is a nonsynchronous time-division multiplex containing information coded in three independent forms: Duration of subcarrier oscillation bursts, frequency of the oscillations, and the time (spacing) between the bursts. The data readout system decommutates and digitizes this information and records the digitized data on magnetic tape in computer format. The readout of data coded in all three forms is simultaneous and is done at a rate of up to 25 channels per second. A major design criterion of the data readout system was that the performance should be satisfactory when there was a significant amount of noise in the telemeter signal. The design concept of the data readout system included the shared use of digital formatting and tape recording equipment that was a part of other data readout systems in existence at the NASA Langley Research Center.

An essential phase of the Explorer XIII development was a thermal study and design to provide an acceptable temperature environment for the electronics components and external surfaces of the satellite during ascent and in orbit. It was necessary to establish by preflight analysis and tests that tolerable temperatures could be maintained in three regimes of flight. In the first regime (from launch until release of the heat shield) the satellite was subjected to radiative and conductive heat from the shield. In the second regime, after release of the shield at 350,000 feet, the satellite was heated by free molecular flow. In the third regime - the orbit phase - it was necessary that temperatures within limits for a 1-year lifetime be established. In addition to these three regimes, a study was made to investigate the effect of elevated rocket-motor temperatures during launch and after burnout. This chapter will deal with some pertinent preflight estimates and correlation of these estimates with flight data.

Vibrational relaxation and concentration effects on induction period of hydrogen-oxygen reaction

Oxidation kinetics of nickel sheet in flowing air and gas mixtures