Engineering topics

Mclaughlin, W. I.

Publications and source records attributed to Mclaughlin, W. I..

24 records · Page 2

NASA NTRS1979

Mission design for the infrared astronomical satellite /IRAS/

IRAS, a joint United States, Netherlands, United Kingdom astronomical satellite, is scheduled to be launched early in 1981 with the purpose of completing an all-sky survey in the infrared wavelengths from 8 to 120 microns and to observe objects of special interest. The mission design is driven by thermal constraints primarily determined by the Sun and Earth; the orbit and survey strategy must be chosen so as to satisfy the mission requirements before the cryogenic system is depleted of its liquid helium. Computer graphics help the designer choose valid survey strategies and evaluate resulting sky coverage.

Lundy, S. A.↗

NASA NTRS1978

Infrared astronomical satellite

Design and mission characteristics of the Infrared Astronomical Satellite (IRAS) are reviewed with attention to the satellite/telescope configuration. The IRAS will be launched into a 900 km near-polar orbit (inclination 99 deg), with a cryogenically cooled 60 cm telescope capable of collecting 700 million bits of data per day. The telescope is expected to add from 6000 to one million new IR sources to the astronomical catalogs. Objects for study include stars, extended sources, asteroids, zodiacal light, artificial satellites, high energy protons, and dust.

Mclaughlin, W. I.↗

NASA NTRS1978

Simulation of the infrared sky

The paper describes the simulation of the infrared sky, including both astrophysical and nuisance objects, carried out in order to quantitatively study the impact of the various categories of expected events on the design of the telescope and data analysis system. Analysis of sources is outlined, and implementation of a sky model is covered.

Aumann, H. H.↗

NASA NTRS1977

On the timing of an interstellar communication

By considering prominent events that are observable from both earth and nearby stellar systems it is possible to establish common clocks that may be useful in estimating arrival times for signals of intelligent extraterrestrial origin. The geometry and statistics of a timing strategy are developed together with quantitative estimates of its effectiveness and limits on its application. Effectiveness is measured by comparing the timing strategy with one randomized in time. Limitations arise from inaccuracies inherent in the determination of stellar parallaxes and result in standard deviations of the order of weeks to months for time estimates. The problem can be alleviated by choosing clocks close to Sender in angular distance. Signal opportunities for several nearby sun-like stars are calculated using the bright Nova Cygni 1975 as a clock.

Mclaughlin, W. I.↗

NASA NTRS1977

On the mass of Saturn's rings

This paper presents a statistical estimate of the mass of Saturn's rings, determined to be (6.2 plus or minus 2.4) x 10 to the -6th masses of Saturn. This value was obtained by fitting a gravitational model of the Saturn system which included rings, satellites, and the planet to the observed secular apsidal and nodal rates of the inner satellites. The apsidal commensurability of particles in the rings of Titan was shown to produce no significant effect on the structure of the rings.

Mclaughlin, W. I.↗

NASA NTRS1977

Mission design for SEASAT-A, an oceanographic satellite

SEASAT-A is a NASA earth satellite for measuring global ocean dynamics from space. Launch is planned for May 1978. The instruments on the spacecraft will provide data on wave height and direction, surface wind speed and direction, ice fields, ocean surface topography and weather. This paper is concerned with the mission design for SEASAT-A. A primary topic here is the selection of the orbit which best satisfies the measurement objectives of the various instruments. The maintenance of this orbit under drag and other perturbations is discussed. The design of the mission profile is outlined. Finally precision orbit determination for SEASAT-A is discussed since it is required to maximize ocean topography accuracy.

Cutting, E.↗