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| The LES-1 Communications Satellite (including booster) |
Part One - An Experimental Satellite
On
02.11.65, an experimental satellite, designed and built in a laboratory
created by the Massachusetts Institute of Technology, working closely
with the United States Air Force and the Department of Defense, was
launched from Cape Canaveral in Florida. Only two yeddars later, this very same satellite would be abandoned and unceremoniously take its' place in the skies above Earth as just another piece of orbiting space junk.
Forty six years later, an amateur radio operator in Great Britain, carefully rotating the dials of his ham radio receiver, heard what he thought was a faint but distinct radio transmission, rhythmically emanating from somewhere above the earth. Detailed research into the signal's origin made it clear the transmission was coming from a satellite which had been launched into space on 02.11.65; it was the very same satellite which had been given up for dead in 1967. The communications satellite, LES-1, it turns out, had never stopped calling out with a signal, although, it seems, no one had been listening for many, many years.
Lincoln Laboratory and LES-1
LES-1 is an acronym which stands for Lincoln
Experimental Satellite 1. It was the first of nine experimental
communications satellites built for the United States government by
the Lincoln Laboratory, an organization created in 1951 by the
Massachusetts Institute of Technology (better known to many as MIT) at
the urging of the United States Air Force. The Lincoln Laboratory is an
organization that exists to this day and since its inception, it has
been directly involved in work that is vital to US national security,
pioneering technologies and systems which allow us to both communicate
more efficiently with each other while also continuously monitoring
developing conditions around the globe.
Since
the beginning, one of the main interests of the Lincoln Laboratory has
been long range data communications systems, many of which have been designed
specifically for the military. One of its' first major success stories
was Project West Ford, begun in 1961 and sponsored by the Air Force, in
which thousands of tiny metallic needles were launched into space. Once
deployed, the needles gradually dispersed and formed a ring around the
globe. Ground station operators were then able to bounce radio signals
off the needles (also known as "dipoles") within this ring in order to
communicate with other ground stations.
By
1963, Lincoln Laboratory found itself directing efforts away from
passive communications satellites, as exemplified by the metallic
dipoles of Project West Ford, to creating and testing active
communications satellites, equipment which could play a much more dynamic role in how it interacted with the radio signals it received. This
included both space bound satellites as well as the ground based
systems that would be communicating with them. The overarching goal was
to evaluate the effectiveness of these systems insofar as they could be
used to effect efficient military command and control. The Lincoln Experimental Satellites were the first such venture into this new world.
The
Lincoln Experimental Satellites would, as the name implied, allow for
experimentation with and testing of different technologies which had the
potential of being used in future communications satellites. This
included:
- The generation of X-band power using all solid-state devices;
- The incorporation of this power source into a small all solid-state communications transponder;
- A switched high gain antenna pointing system at X-band frequencies;
- The highly sophisticated logic to drive the antenna switch;
- Earth and sun sensors operating at visible wavelengths to provide input to the switching logic:
- A magnetic torqueing system to align the satellite spin axis for thermal control;
- A follow-on magnetic torqueing system for aligning the satellite spin axis normal to the orbit plane.
- The demonstration of micropower logic in a space radiation environment
LES-1 Goes Into Space
Lincoln
Experimental Satellite 1 was successfully launched from its pad at
Launch Center 20 (LC-20) at Cape Canaveral on February 11th, 1965.
The
rocket which carried LES-1 into space was a Titan IIIA, which at that
time was also something of an experiment, as it was a prototype design
of an expendable launch vehicle being developed by the Martin Marietta
Corporation.
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| Launch of the Titan IIIA rocket with satellite Lincoln Experimental Satellite (Pubic Domain image courtesy of Wikipedia) |
After
lifting off the ground, the powerful twin Aerojet LR87
liquid-propellant rocket engines quickly gained speed and thrust the
three stage Titan rocket and her satellite payload to the prearranged location, a 32 degree inclined 1,500 n.m. circular orbit above Earth. Next would be the release of LES-1 into orbit.
Once
in position, the third stage of the Titan rocket was shot out and away
from the two lower stages and LES-1 was released into space. Before
commencing operations as a communications satellite, LES-1 would need
to maneuver herself out of the initial release orbit and into the
correct final orbit around earth, a 32 degree inclined, 1500 n. m. by 8000 n. m. elliptical orbit. This would be achieved with the help of a solid propellant booster rocket attached to the base of the satellite.
(To Be Continued...)
References
Print Publications
- H. Sherman, D. C. MacLellan. R. M. Lerner and P. Waldron - The Lincoln Experimental Satellite Program (LES-1, 2, 3, 4) A Progress Report (AIAA Paper No. 66-271)
- Goddard Space Flight Center - NASA Compendium Of Satellite Communications Programs - June, 1973
Online
- https://en.wikipedia.org/wiki/Project_West_Ford
- https://en.m.wikipedia.org/wiki/MIT_Lincoln_Laboratory
- https://en.wikipedia.org/wiki/LR-87
- https://www.hq.nasa.gov/pao/History/SP-4217/ch8.htm
- https://en.wikipedia.org/wiki/Titan_IIIA
- https://en.m.wikipedia.org/wiki/LES-1
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