Observation Satellite (TIROS) was the first platform for space-based weather observation, both in visible and
infrared wavelengths. All modern satellites have attitude and orbit correcting capabilities via gas jets, but
there is only a limited supply of gas available so the lifetime of a satellite is limited as well. Scientists who
monitored the performance of TIROS I noticed that the Earth's magnetic field affected the satellite's attitude as
it orbited. They reasoned that attitude control coils could be installed and energized on TIROS II using
electrical power from its solar panels rather than the onboard fuel supply. This article from a 1961 edition of
Popular Electronics describes the effort.
[Table of Contents]People old and young enjoy waxing nostalgic about
and learning some of the history of early electronics. Popular Electronics was published from October 1954 through April
1985. As time permits, I will be glad to scan articles for you. All copyrights (if any) are hereby acknowledged.
See all articles from
Tilting TIROS II
tilts space satellite
The nation's latest "weather-eye" satellite, "Tiros II," has achieved a major "first" in space. By means of a remote-control
system, ground observers can tilt the satellite in space for improved TV coverage of clouds above the earth.
Spherical "cage" designed to produce magnetic fields resembling those of the earth was used in pre-launching tests
of Tiros II. Here, Warren P. Manger, of the RCA Astro-Electronics Division, takes reading of magnetic effect within
the wired "cage," preparatory to rotating the satellite on its mount for study of the orientation system.
Magnetic orientation system being tested at RCA's Space Center in Princeton, NJ. Lights above and around the satellite
are used to check operation of solar cells which surround satellite.
Developed by the Radio Corporation of America, the new orientation technique uses the effect of the earth's magnetic
field to alter the "attitude" of the satellite upon command - without the need for special propulsion devices. This
technique was the outcome of studies by RCA and government scientists of an unexpected gradual shift in the attitude
of the first Tiros satellite under the influence of the magnetic field surrounding the earth.
In the first
Tiros, which returned nearly 23,000 useful TV cloud pictures to earth following its launching last April, these magnetic
forces caused the satellite to tilt gradually away from the predicted position of its axis in space. In Tiros II,
the forces are being harnessed by a controllable magnetic field generated around the satellite itself by wire coils
on the lower sides of the vehicle. Interacting with the earth's magnetic field, this controllable field gives ground
observers an invisible "hand" to tilt the satellite on command, in order to obtain a more advantageous angle.
Equipped with the orientation-control system and with newly developed infrared instruments to measure the emission
and reflection of solar heat by the earth and its atmosphere, Tiros II represents the second step in the experimental
weather satellite program being conducted by the National Aeronautics and Space Administration to study the feasibility
of regular satellite weather operations.
Among the major features common to both the Tiros I and II satellites
are electronic clocks that control the timing of cameras, tape recorders, and infrared systems during each orbit;
more than 9000 solar cells on the top and sides of the satellite to convert electrical energy for operation of the
electronic systems; "yo-yo" weights which slow the satellite's spin from 120 rpm to 12 rpm as it enters orbit; and
five pairs of solid-fuel spin-up rockets to restore spin momentum.
Wide-angled television camera on Tiros II is checked by
and Ralph Jordan at the RCA Space
Center. Tiros II, mounted on its side in this photo, is
identical in external
appearance to Tiros I.