Engineering topics

Murphy, J.

Publications and source records attributed to Murphy, J..

21 records · Page 2

NASA NTRS1982

The Magsat mission

The cesium-vapor scalar and fluxgate vector magnetometers aboard the Magsat spacecraft, which has a twilight, sun-synchronous orbit with a 96.76-deg inclination, have together measured the earth's magnetic field magnitude to accuracies better than 2 nT, and the magnitude of each field component to better than 6 nT. The magnetometers are located at the end of a boom to isolate them from the effects of spacecraft fields, and an optical system was used to measure the attitude of the vector magnetometer and sun sensor at the boom relative to the two star cameras of the main spacecraft structure. The data gathered is available from the National Space Science Data Center in several formats and is currently undergoing analysis. Scalar and vector error budget values are given for the spacecraft's five error sources, which include the instrument, position and time errors, digitization noise, attitude errors, and spacecraft fields.

Langel, R.↗

NASA NTRS1977

NASA Goddard Space Flight Center

The contribution of the Goddard Space Flight Center to the National Geodetic Satellite Program is reported. All of the major types of tracking systems, including those employing optical, electronic, range-and-range-rate, and laser technologies, which were developed and operated by Goddard, are described. The MINITRACK data were used to derive geodetic results. The methods used for the analysis of these data are presented.

Berbert, J. H.↗

NASA NTRS1972

Mascon distribution on the moon

Results concerning the distribution of mascons on the moon have been obtained from an analysis of Apollo 8, 10, 11, and 12 lunar orbit missions. It was concluded that the tugging and pulling by the moon on the orbit plane of the Apollo spacecraft yields qualitative information concerning the distribution of the mascons.

Murphy, J.↗