tiros vi press kit

8/8/2019 Tiros Vi Press Kit

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* NEWS RELEASE

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

a A 400 MARYLAND AVENUE, SW, WASHINGTON 25, D C.

TELEPHONES WORTH 2-4155 - WORTH 3- 1110

FOR RELEASE: Sunday

Release No. 62-194 September 16, 1962

SIXTH TIROS SCHEDULED FOR LAUNCH

The sixth TIROS meteorological satellite is scheduled to be

launched by the National Aeronautics and Space Administration not

earlier than September 18, 1962, at the Atlantic Missile Range,

Cape Canaveral, Florida.

If the launching is successful, it will mark the sixth time

in as many attempts that a U. S. meteorological satellite has been

placed in orbit, establishing a record unmatched by any other NASA

spacecraft system. Similarly, it will set a new reliability record

for the Delta booster vehicle which will have orbited 11 satellites

in a row -- an unprecedented record for U. S. rocketry.

Launching of the TIROS is timed to permit maximum coverage bythe satellite's two TV cameras of tropical storm areas i~n the

Atlantic and Pacific Oceans during the last half of the 1962 hurri-

cane season. It is expected to operate through December. TIROS V,

launched on June 19, this year, has provided coverage over hurricaneand typhoon areas in the Atlantic and Pacific Oceans during the first

portion of the 1962 season. The useful lifetime of a TIROS satellite

averages about four months.

Although the wide-angle TV camera in TIROS V continues to oper-

ate, the medium-angle Tegea lens has not functioned since July 6th

because of a random electrical failure in the camera's system. In

view of the importance of the TIROS' cloud cover photographs during

the time of greatest hurricane and typhoon activity (June through

November), a backup TIROS was scheduled in order that coverage would

not be interrupted. Therefore, although originally forecast for

launching in November, the sixth TIROS was moved up to September.Because of this change, the TIROS will not be equipped to conduct in-

frared experiments. Future TIROS satellites are programmed to carry



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.

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THE TIROS SPACECRAFT

The TIROS spacecraft is shaped like an 18-sided bass drum. It

is 22 inches high and 42 inches in diameter. The sides and top of

the spacecraft have 9,120 solar cells which provide electrical

power for 63 nickel-cadrium batteries. Over one-quarter of its 281

pounds is structural weight. Protruding from the top of the space-

craft is an 18-inch receiving antenna, At the bottom, are four 22-

inch transmitting antennas spaced at 90 degree intervals.

Except for the omission of the infrared equipment, the space-

craft is the same as TIROS V. Its basic weather-observing instru-

ments include recording television cameras and their transmitters,

receivers and control circuitry.

The term TIROS means Television InfraRed Observation Satellite.

TV CAMERA SYSTEM

The heart of the TIROS system consists of two independent tele-

vision camera systems. One uses a wide-angle (104 degrees) Elgeetlens capable of photographing an area in excess of 600,000 square

miles, or a square area of about 750 miles on each side. The sec-

ond system uses a medium-angle (76 degrees) Tegea lens which covers

an area of approximately 232,000 square miles, or about 450 miles

on each side. Both cameras use one-half inch Vidicon tubes which

were especially developed for the TIROS spacecraft and which retain

still photographs temporarily on the tube. An electron beam con-

verts the "stored" photographs into a TV-type signal which can be

transmitted directly to the ground stations or recorded on magnetic

tape for read-out when the spacecraft is within the required 1,500

mile radio range of the ground stations.

Each tape recorder with its 400-foot-long tape can record up

to 32 pictures during an orbit. The two TV camera systems can be

operated separately or simultaneously. Operation of the cameras

is based on commands sent from ground stations which set timers

similar to ordinary alarm clocks in the spacecraft. These settings

trigger the cameras when the satellite passes over an area from

which photographs are desired. Then, when it is within range of

the ground stations, read-out occurs. Complete ground station

read-out of the tapes from each camera takes about three minutes.

The process automatically erases the tapes, which are then rewound

and ready for the next orbit.

Control Systems

Four basic control systems are integrated into the TIROS space-

craft. The first is the horizon scanner which uses an infrared

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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.

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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.

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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-

ject TIREC - TIROS Ice Reconnaissance - a joint NASA-U.S. Weather

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.3lreau-U.S. Navy-Canadian government project, aircraft took photographs

,Ahile flying the predicted path of the TIROS. These photographs were

compared with those taken by the TIROS and it was concluded t1-.at the

photography provided by TIROS was a better means of ice study over large

areas than the conventional aircraft reconnaissance method.

TIROS IV was also used for a joint NASA-Air Force project called

Bright Cloud to develop a cloud identification system based on shape and

brightness by using TIROS photographs.

During its operational, lifetime which lasted until June 12, the

fourth TLROS sat llite transmitted 23,300 useable cloud cover photo-

graphs. Information it provided resulted in issuing 102 storm advis-

ories. 'Seventy-nine adjustments in National Weather Satellite Center

analyses were also made based on TIROS data.

TIROS v; The fifth TIROS was launched Yune 19, this year, in conjunc-

tion with the 1962 hurricane season, Although its medium-angle camera

malfunctioned on July 6, to date TIROS V has observed all tropical

storms -- both hurricanes and typhoons -- which have occurred. It gave

first warning on half of the world's ten most serious storms in August,

As of Septeiriber tenth, more than 20J000 useable photographs have beentransmitteed bv the TIROS V.

'HE TIROS TEAI1

The National Aeronautics and SDace Administration is responsible

for the TIROS project. Development and operational phases of the

project are directed by NASA's Goddard Space Flight Center, Greenbelt,

Maryland. Goddard is also responsible for preparing the command pro-,

gramming infformation which is relayed to the satellite by the ground

stations. The programming information is based on data from the

Goddard Tracking and Data System Division and recommendations made by

the U. S. Weather Bureauts Office of National Weather Center, Suitland,Maryland.

Design and construction of the TIROS spacecraft was accomplished

by the Radio Corporation of Americats Astro-Electronics Division,

Princetorn, New Jersey, under the technical direction of Goddard. RCA

is also responsible for the special equipment used at the TIROS ground

stations.

Prime contractor for the Delta vehicle is the Douglas Aircraft

Clompany, Santa Monica, California, which also is responsible for pre-

launch and launch operations. Logistic support is provided by the

Air Force Missile Test Center which operates the Atlantic Missile Range.

Meteorological analysis ana interpretation of the TIROS IV pic-

tures is accomplished by the U. S. Weather Bureau's National Weather

Satellite Center, in cooperation with the U. S. Navy Photographic

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Interpretation Center, the Air Force Cambridge Research Laboratories,

the Air Force and Navy Weather Services, and a number of university

research groups.

Key officials responsible for the TIROS project are:

Dr. Morris Tepper, Director of Meteorological Systems,

NASA Headquarters.

Dr. William K. Widger, Chief of Operational Meteoro-.

logical Systems, NASA Headquarters.

Mr. William G. Stroud, Chief of the Aeronomy and

Meteorology Division, Goddard Space Flight Center.

Mr. Herbert I. Butler, Associate Chief for Projects,

Aeronomy and Meteorology Division, Goddard Space Flight

Center.

Mr. Robert M. Rados, TIROS Project Manager, Coddard

Space Flight Center.

Mr. Abraham Schnapf, TIROS Program Manager, for RCA's

Astro-Electronics Division.

Dr. S. Fred Singer, Director of the U. S. Weather

Bureau's Meteorological Satellite Activities.

Mr. Dave Johnson, Deputy Director of the U. S. Weather

Bureau's National Weather Satellite Center.

END

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