* NEWS RELEASE NATIONAL AND SPACE ADMINISTRATION a A 40 0 MARYLAND AVENUE, SW, WASHINGTON 25, D C. TELEPHONES WORTH 2-4155 - WORTH 3- 1110 F O R RELEASE: Sunday Release No. 62-194 September 16, 1962 SIXTH TIROS SCHEDULED FOR LAUNCH Th e sixth TIROS meteorological satellite is scheduled to be launched by th e National Aeronautics an d Space Administration no t earlier than September 18, 1962, at th e Atlantic Missile Range, Cape Canaveral, Florida. If th e launching is successful, it will mark the sixth time in as many attempts that a U. S. meteorological satellite ha s been placed in orbit, establishing a record unmatched by an y other NASA spacecraft system. Similarly, it will se t a n e w reliability record fo r th e Delta booster vehicle which will have orbited 11 satellites in a ro w -- an unprecedented record U. S. rocketry. Launching of th e TIROS is timed to permit maximum coverage by th e satellite's tw o T V cameras of tropical storm areas i~n the Atlantic an d Pacific Oceans during th e last half of th e 1962 hurri- cane season. It is expected to operate through December. TIROS V, launched on June 19, this year, has provided coverage over hurricane an d typhoon areas in the Atlantic an d Pacific Oceans during th e first portion of th e 1962 season. Th e useful lifetime of a TIROS satellite averages about four months. Although th e wide-angle T V camera in TIROS V continues to oper- ate, th e medium-angle Tegea lens ha s no t functioned since July 6t h because of a random electrical failure in the camera's system. In view of th e importance of th e TIROS' cloud cover photographs during th e time of greatest hurricane an d typhoon activity (June through November), a backup TIROS wa s scheduled in order that coverage would no t be interrupted. Therefore, although originally forecast fo r launching in November, th e sixth TIROS wa s moved up to September. Because of this change, th e TIROS will no t be equipped to conduct in - frared experiments. Future TIROS satellites ar e programmed to carry
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infrared equipment and will continue radiated and reflected energy
studies similar to those conducted by earlier TIROS spacecraft.
A September launching date was selected in order that the TIROS
TV photographic data could also support the Mercury-Atlas 8 launch-
ing, now scheduled for later in September.
During the first two weeks of its anticipated four-month life-
time, the TIROS cameras will be pointed at the Northern Hemisphere.
After this 14-day period, the cameras will scan the Southern Hemi-sphere for about 30 days before returning to coverage of the North-ern Hemisphere once again.
The new TIROS will weigh 281 pounds. Compensating weight has
been included to make up for the infra-red equipment. Like TIROS V,it will be launched into a circular orbit -- about 402 miles (350nautical miles) above the earth -- with an angle of inclination of58 degrees to the equator. It will orbit the earth once every hour
and 37 minutes.
The TIROS program has met with unprecedented success since its
inception in April 1960 with the launching of TIROS I. To date theTIROS system has:
1. Demonstrated that the meteorological satellite conceptis practical from an engineering standpoint.
2. Provided cloud cover photographs on a "real-time" basisfor immediate use in daily weather forecasts, opening anew era in weather forecasting.
3. Identified hurricanes and typhoons, located them with
respect to land masses and followed their movement.
4. Distinguished itself as a vehicle for ice study and ice
reconnaissance.
5. Provided data leading to the eventual development of anautomated cloud pattern identification system, based onthe shape and brightness of clouds.
6. Obtained data for the measurement Of solar radiation ofthe earth's atmosphere.
NASA's Goddard Space Flight Center, Greenbelt, Maryland, is re-
sponsible for overall technical direction of the TIROS program, in-cluding tracking and data acquisition. The National Weather Satellite
Center of the U. S. Weather Bureau is responsible for the operational
use of the photographic data and for related research.
sensor mounted on the rim of the satellite to determine when thesatellite's field of view crosses the earth's horizon. This infor-mation is relayed to ground stations by a tracking beacon and aidsin determining the satellite's position in space relative to theearth.
The second control system is the north indicator consisting ofnine solar cells equally spaced around the sides of the satellite.These cells are designed to measure the position of the satellite
with respect to the sun. This information is telemetered to groundstations where computers process the data and compute on the 'sun-angle" which enables technicians to determine the north directionin each photograph.
The third system is the magnetic attitude control which con-sists of a wire coil around the outside lower portion of the space-craft. This generates a controllable magnetic field around thesatellite which interacts with that of the earth. Thus, the mag-netic coil provides a means for gradually tilting the satellite oncommand from a ground station to obtain the most advantageous anglefor picture taking and to position solar cells for recharging the
batteries.
The final system consists of mechanisms which control the spinrate and stability of the satellite. Within ten minutes after thepayload is separated from the third stage of the booster vehicle, atimer releases two weights attached to cables wound around thespacecraft. As these weights unwind, they lower the spin rate fromabout 126 RPM to about 12 RPM. When completely unwound, they dropoff automatically,
In order for the TIROS to remain stable in orbit, it must main-tain a spin rate of at least eight RPM. When this minimum is ap-
proached, a pair of small solid fuel rockets is fired on radio com-mand from the ground. They increase the spin rate by about threeRPM. There are five pairs of spin-up rockets, each of which can befired once. Finally, the satellite has an internal arrangement ofsliding weights or "precession dampers" mounted on curved trackswhich are Aepigned to cancel any wobbling motion that may occur.
TIROS GROUND STATIONS
Two primary ground stations are maintained in conjunction withthe TIROS program. Both are operated by the Radio Corporation ofAmerica under a Goddard contract. one is located at NASA's Wallops
Station, Wallops Island, Virginia, and the other is at the PacificMissile Range, California-. A backup station is.available at RCA'sSpace Centers Princeton, New Jersey.
These stations send signals commanding the satellite to trans-.i; hotographs either from the tape recorders or by direct read-
olt Then it is within a radius of 1,500 miles. Upon receipt of the'cormmand" signal, photograph transmission takes place. At the sta-t:lons, photographs are displayed on kinescopes to be photographed
Ai 35 mm cameras. Ile6eorological teams at both stations analyze
the photographic data which is relayed to the Weather Bureau's::ational Weather Satellite Center, Suitland, Maryland, for use inpreparation of weather forecasts.
THE DELTA LAUNCH VEHICLE
The launch vehicle for TIROS is the NASA-developed Delta, athree stage rocket which has performed flawlessly in the last tenof its 11 launch attempts. Delta is nine stories high and weiguis
57 tons.
The vehicle's first stage is a 60-foot modification of theAir Force-developed Thor (SM-75) and generates 150,000 pounds ofthrust during the two and two-thirds minutes its 50 tons of pro-pellant burn.
The second stage is 17 feet tall and weighs a little more thantwo and one-half tons. It is powered by an AeroJet-General liquidengine which develops 7,500 pounds of thrust and burns slightlyless than two minutes.
Delta's one-half ton, solid propellant third stage is fivefeet high and uses an Allegany Ballistics Laboratory ABL 248 en-
gine with a thrust rating of 3,000 pounds. Its burning time is 410
seconds.
For a minute and a half after lift-off, Delta is guided by its
Thor auto-pilot. After burn-out of the Thor booster, a Dell Tele-phone Laboratories
radio guidance system makes refined velocity andsteering corrections as needed. Shortly after first stage burn-uutseparation, and after ignition of the second stage, the fairing --covering the third stage and the TTOS' ayload -- is jettisoned.
Second stage burning ends about four and one-half minutes af-ter lift-off. The vehicle, with second and third stages stillattached is now at an altitude of about 125 miles. At this pointa six-minutc coasting period occurs. During this period, guidanceis provided by a 42-pound flight control system contained in thesecond stage. The satellite and the third stage are spin stabilizedby small rockets mounted on a "spin table" between the second andthird stages. At the end of the coast period -- about ter minutesafter launch -- the second stage separates, and third stage igni-tion occurs. Soon the required orbital velocity of 17,000 milesper hour is reached and the satellite, trailed by the third stage,is injected into orbit.
Program Manager for the Delta is T. 3. !forris, of NASA Headquar-ters. The Goddard Delta vehicle manager is William R. Schindler.
Robert H. Gray heads the Goddard Field Projects Branch at Cape Cana-
veral.
THE TIROS RECORD
TIROS I; The TIROS I spacecraft was launched at the Atlantic Missile
Range on April 1, 1960, by a Thor-Able rocket. (Delta boosters have
been used to launch all remaining TIROS spacecraft). During its 78
days of operation, until June 17, 1960, TIROS I transmitted almost23,000 cloud cover photographs of which more than 19,000 were useablefo r weather analysis purposes. As the pioneer spacecraft in the
meteorological satellite program, TIROS I opened a new era in weather
observation by providing data covering vast areas of the earth Which
were available to weathermen and weather research programs.
TIROS II; TIROS II was placed into orbit November 23, 1960, and pro-
vided more than 23,000 useable photographs of cloud cover. Its oper-ational lifetime far exceeded initial estimates and photographs from
the spacecraft's rat cameras were received through November 1961.
Photographs of ice pack conditions in the Gulf of St. Lawrence proved
that weather satellites could locate ice boundaries in relation toopen seas. In addition, data provided by the satellite wlas used by
forecasters for the suborbital flight of Alan B. Shepard, Jr., in. aar
1960, and the launching of RangerI two months later.
TIROS III; The TIROS III spacecraft, launched July 12, 1961, added
further milestones to the TIROS record, particularly in the detection
of tropical storms. All six of the hurricanes of the 1961 seasonwere observed by TIROS III. HurricaneEsther was detected by the
satellite two days before it was observed by conventional methods.
TIROS III provided information which resulted in 70 storm advisories
being issued. These aere sent to weathermen in the Far East, Latin
America., the Indian Ocean and the Continental U. S. In addition, itsdata led to adjustments in 76 lnational Weather Satellite Center anal-
yses.
TIROS III photographs were used to support Project Mercury,
Ranger, the Air Force's Discoverer satellite series, the firing of
Long Tom meteorological rockets in Australia and the iNavy's 1961
Antarctic resupply mission. Use of TIROS III data was discontinued
in the Fall of 1961 because of loss of contrast in its photographs.
During its lifetime, TIROS III transmitted more than 24,000 useable
cloud cover photographs.
TIROS IV; The TIROS IV spacecraft was launched on February 8, thisyear, primarily to continue earth cloud cover photo coverage and to
confirm its capability as an ice reconnaissance vehicle. Under Pro-