nasa facts tiros

8/7/2019 NASA Facts TIROS

1/8

(B-2-64)

NASA FACTSAn Educational Services Publication of the

National Aeronautics and Space Administration

Page 1

TIROS25013&JA 32

RECEIVING ANTENNA

BATTERIES

WIDE-ANGLETV CAMERA #1

TAPETRANSPORT

The TlROS weather satellite.

Carla ... Donna . .. Esther .. . Flora .. .These were destructive hurricanes which took

thousands of lives an d caused millions of dollarsin damage.

Future counterparts, with other feminine names,will surely be as severe, but their destructive re-sults will be minimized because people will be

-------------------

forewarned through information gathered bymeteorological satellites in space, taking picturesof the earth's surface and cloud cover. Suchwarnings have enabled people in the hurricanebelt to prepare themselves for high winds andwater, and thus to spare lives and property. Suchwas the case with Carla

- - - - - - - -------------------------------- -


2/8

The NASA weather satellite program whichn detect hurricanes in their formative stages,

a great deal of other informationto meteorologists is carried out with TIROS.

satellite name is an acronym for TelevisionSatellite.

Kites, balloon, airplanes and sounding rocketsused to gather weather data from

distances above the earth's surface, withthat were effective-sometimes even star-But TIROS can go higher, stay aloft muchand perform tasks never before possible

f accomplishment. TIROS orbits at about 450above the earth, takes its pictures with

(TV) apparatus and transmits the m tofor interpretation by meteorologists. In

TIROS has equipment fo r detecting andinfrared radiation reflected by the

atmosphere.

DEFINITIONS

(Quoted from th e NASA publicationSP- l , Short Glossary of Space Terms)

ACQUISITION - t h e process of locating the orbit of asatellite or trajectory of a space probe so that trackingor telemetry data can be gathered. Also, the processof pointing an antenna or telescope so that it is properly oriented to allow gathering of tracking or telemetrydata from a satellite or space probe .APOGEE-in an orbit about the earth, the point atwhich th e satellite is farthest from the earth; the highest altitude reached by a sounding rocket.AXIS-a straight line about which a body rotates, oraround which a plane figure may rotate to produce asolid; a line of symmetry . Also, on e of a se t of reference lines for certain systems of coordinates.COMMANO-a signal which initiates or triggers anaction in the device which receives the signal.ELECTRON - t h e subatomic particle that possesses thesmallest known electric charge.INFRARED -Infrared radiation; electromagnetic radiation in the wavelength interval from the red en d of thevisible spectrum on the lower limit to microwa"es usedin radar on the upper limit.PERIGEE-that orbital point nearest the earth when theearth is the center of attraction.READOUT - t h e action of a radio transmitter transmitting data either instantaneously with the acquisition ofthe data or by play of a magnetic tape upon which thedata have been recorded .TELEMETRY- t h e science of measuring a quantity orquantities, transmitting the measured value to a distantstation, an d there interpreting, indicating, or recordingthe quantities measured .

(NASA FACTS 8-2-64)TIROS I was launched at Cape Canaveral

(now Cape Kennedy) on April 1, 1960, by aThor-Able launch vehicle. Successor TIROSsatellites have followed: TlROS " through VIII.Others are scheduled.

Operating in a near-circular orbit more than400 miles above the earth (apogee, 461 miles,perigee, 436 miles) TIROS I made meteorologicalhistory by giving meteorologists an unprecedentedopportunity to study the earth's claud patternsand relate them to the weather. Among the striking patterns seen fo r the first time in their entirety

TI ROS has various sensors, or sensing elements, which" sense" information and convert it into signals whichcan be measured. These include two TV cameras tophotograph cloud cover; a multi-channel scanning radiometer to observe water vapor, night clouds, reflectedsunshine, emitted heat and loud resolution cloud mapping; an d non-scanning radiometers to measure totalradiation an d thermal radiation


3/8

(NASA FACTS 8-2-64) . .were large-scale cyclones with spiral bands sometimes covering areas a thousand miles across.

Photographs transmitted by the satellite's twotelevision cameras also indicated the presence ofjet streams (currents of ai r blowing at speeds of200 miles an hour or more, at high altitudes) regions of moist and dry air, thunderstorms, weatherfronts , and many types of cloud patterns.

TIROS I stopped transmitting about midnightof June 29, 1960, after 1,302 orbits of the earth,when its power supply failed. It had transmitted22,592 pictures .

HURRICANE DETECTIONWhat daes early detection of a hurricane mean

in terms of saving lives?

PageInformation from TIROS III in September o

1961 gave warning of Hurricane Carla in timeto make possible the largest mass evacuation eveto take place in the United States. More than350,000 people fled from the path of the stormand a relatively small number of deaths waattributable to Carla as it swept across thcountry.

President Lyndon B. Johnson, when he waVice President and chairman of the National Aeronautics and Space Council, estimated the following national cost savings, based on the accuratpredictions of weather only five days in advancinclude:

$2.5 billion a year to agriculture.$45 million to the lumber industry.$100 million to surface transportation.$75 million to retail marketing.$4 billion in water resources management.

TIROS III HURRICANE DATAANNA BETSY

CARLA DEBBIE ESTHER

Pictures of hurr icanes token by TIROS.

.._________________________________________ --==-__________ - -----


4/8

4THE TIROS SYSTEM

The TIROS satellite is a cylindrical, 300-pound,polygon resembling a bass drum or anhat box. It stands 22 inches high and42 inches in diameter. Its sides and

p are covered with more than 9,000 solar cellswhen exposed to the sun's rays, produce

power to recharge the satellite's 63batteries.

A diagram of a standard TIROS configuration .

Protruding from the top of the satellite is anreceiving antenna through which it re

commands from ground stations. At thefour 22-inch transmitting whip antennas

at 90-degree intervals. Throughantennas the satellite's transmitters relay

pictures, infrared data and telemetry inforspacecraft temperature,

battery charge levels, spin rate and so

(NASA FACTS 8-2-64)TV CAMERAS .Two independent television camera systems,

capable of separate or simultaneous operation,make up the heart of the TIROS sate llite. Thesecameras are aligned parallel to the satellite's spinaxis and extend several inches below the baseplate. Each camera system consists of a vidicontube and a focal plane shutter which permitspictuIes to be stored temporarily on the tube faceplate for a brief period.

Florida during the time of Gordon Cooper's flight inFaith 7 .

The Great Lakes region as seen by TlROS .


5/8

(NASA FACTS B-2-64)An electron tube beam converts a stored pic

ture into a TV-type electronic signal which istransmitted to a ground station or processed ona magnetic tape recorder from which it is sent toearth at a later time, when the satellite is withina 1,500 mile radius of a Command and DataAcquisition station.

Up to 64 pictures-32 on each tape-can berecorded and stored by TlROS during each orbit..Read-out," or sending, which takes about threeminutes, is accomplished at a ground station byradio command. This process automaticallyerases the tapes which are then rewound andready fo r use as the satellite begins another orbitaround the world.

Operation of the cameras, by direct read-outor magnetic tape storage techniques, is basedon radio commands relayed from a ground sta-

Page 5tion. These commands set timers in the satellitewhich activate the camera system when the satellite passes over on area from which cloud coverpictures are desired.

COMMAND AND DATA ACQUISITIONSTATIONSThree Command Data Acquisition Stations, the

NASA Wallops Island Station, Wallops Island,Virginia, the Pacific Missile Range Station, onSon Nicolas Island, California and the AlaskaStation at Fairbanks, Alaska, support the TIROSproject. TV pictures from the satellite are flashedon special screens and photographed by 35 mm.cameras at these ground stations. Meteorologists analyze the photographic data almostimmediately.

MOSIAC OF TIROS PHOTOGRAPHS

WEATHER MAP, MAY 20, 1960, WITH TIROS CLOUD DATAA mosaic of cloud pictures, and a weather map based upon it.


6/8

Poge 6

Th is antenna at Wallops Island, Virgin ia, receives sig-nals from TlROS .

CONTROL CENTERThe TIROS Technical Control Center at the

Goddard Space Flight Center, Greenbelt, Maryland, monitors operations of the satellite onceorbit has been achieved. This Center directsthe TIROS command and data acquisition network an d monitors the spacecraft and the performance of the three TIROS Command and DataAcquisition Stations.

EXPERIMENTSIn addition to television observations of cloud

cover, TIROS obtains measurements of infraredradiation. This is invisible heat radiation, orradiant heat, comprised of rays similar to visiblel ight, but below the red band of the visible lightspectrum. Instruments for making infraredmeasurements are called radiometers .

(NASA FACTS B-2-64)atmosphere. The equipment records data ontiny tape recorders fo r playback on command bya ground station.

Since the amount of infrared radiation received by the earth from the sun is fairly wellknown, the measurements by TIROS of energyreflected and radiated back into space enablescientists to estimate the amount retained toproduce or affect weather.

The infrared observations are transmitted asdata-not pictures-and must be reduced, analyzed, an d plotted on maps to be interpreted.Hence, they are not useful fo r o p ~ r a t i o n a l weather observation in the same manner as theTV pictures. But they are of great significancefo r scientific studies. Also, the infrared experiments are part of a continuing program to develop techniques for data collection for use inpreparation of infrared nighttime cloud covermaps to supplement the daytime TV picture data.

DATA UTILIZATIONEach of the three TIROS ground stations has

meteorologists on site as an integral part of thestation team, responsible for making rapid analyses of the TIROS TV picture.

These analyses are transferred to a mapchart (nephanalysis) in the form of graphic identifications of the cloud elements observed, andtransmitted to the National Weather SatelliteCenter via the Goddard Space Flight Center.

The nephanalyses are checked fo r quality,then are redrawn and transmitted tt.0ut 600recipients in the U.S. They are re an(mittedfrom points on the west, east, an i southwestU.S. coasts, to th e Far East, Europe and SouthAmerica.

WHEEL CONFIGURATIONSpeeding through space i" a circular orbit,

with an inclination angle of 58 degrees to theThe infrared detectors carried by TIROS take equator, TIROS is able to take cloud cover pic-

readings to provide information on how the sun's tures of not more than 25 percent of each orbit.ne,gy is absa,bed and ,efleeted _ _ _ this coverage, the National Aero-


7/8

--(NASA FACTS 8-2-64)nautics an d Space Administration plans to modifythe original TIROS satellite into a "wheel confIguration," an d change the orbit into a sun-synchronous orbit.

Under this concept, two TV cameras aremounted 180 degrees apart on the side ratherthan on the bottom of the satellite.

The modified TIROS will be launched into anominal 450-mile near-polar orbit. Once inorbit, the satellite is turned around so it will spinon its sides like a wheel. Since the side of thespinning satellite is pointed toward the earth atal l times, such a system, turning at 12 revolutions per minute, can provide a maximum of oneTV cloud-cover picture every three seconds.

Complete earth coverage can be obtainedevery three days by the "wheel configuration"TIROS.

Coverage by " wheel " type TlROS.

AUTOMATIC PICTURE TRANSMISSION (APT)A new "automatic picture transmission" sys-

tem (APT) is being successfully tested on TIROSVIII.

Unlike the transmission system carried in theearly TIROS satellites which displayed each TV

Page 7line on a tube, built a picture on a screen, andthen photographed the screen, the APT systemtransmits pictures by a process similar to thaused to send radio photographs. These pictureswill appear on facsimile machines as they arereceived.

When this photo system becomes operationait will provide cloud-cover pictures at relativelylow-cost to ground stations anywhere in theworld, whenever a satellite is within radio range.

Cost of a typical ground station equipment fo rthe APT system, which consists simply of a receiving antenna and amplifier, an FM receiver and thefacsimile recording equipment, is about $30,000.

The antenna fo r the new Automatic Picture Transmissionsystem .

TIROS LIFETIMEOriginal useful life expectancy of TIROS satel-

lites was about three to four months. However,al l but the first TlROS have exceeded this lifespan, providing research and development knowledge fo r NASA and cloud-cover photos fo r useby the U.S. Weather Bureau in daily operations.TlROS I operated 21/2 months, TlROS II, 10months, TIROS ' " and IV, 4 V2 months, TIROS V,10 1/2 months, TIROS VI, 13 months. TIROS VII,launched June 19, 1963, and TIROS VIII, Decem-ber 21, 1963, were still operating when this waswritten.


8/8

Page 8TIROS satellites took approximately 300,000

photos during the first three years of operation.

DELTA LAUNCH VEHICLETIROS is launched by the 90-foot, 57-ton,three-stage Delta booster. The nation's most

reliable space booster, Delta scored 21 straightlaunch successes from 1960 to 1963.The Delta first stage is the DM-21 Thor, a 57-

foot, liquid-fueled rocket which generates approximately 170,000 pounds of thrust during itsburning time of two minutes and twenty-fiveseconds.

The liquid-fueled second stage produces about7,500 pounds of thrust for 160 seconds. TheTIROS mission calls for Delta to coast fo r aboutsix minutes following second stage burnout .

The Delta third stage is a solid fuel, 3,000pound thrust engine, which burns about 40seconds.

HURRICANES

Any intense storm originating in the tropicswhich ha s winds of 74 miles per hour or strongeris considered a hurricane . If the strongest windsare less than 74 miles per hour, it is called atropical storm.

Although meteorologists don't know just howa hurricane is formed it is believed that largebodies of warm, moist ai r are the breedinggrounds for hurricane development . Tropicaloceans near the equator which have these characteristics are the Atlantic near the Cape Verde

NASA FACTS fo rmat is designed fo r bul let in-board displayuncu t, or for 8 x lO Y. l oose leaf n o tebook inser t ion whencu t along dot ted lines and folded along solid lines. Fornotebook ring insertion, punch at solid dots in th e margins.

(NASA FACTS 8-2-64)Islands, just off the westernmost tip of Africa,the Caribbean Sea and the Gulf of Mexico.

Most of the hurricanes which affect NorthAmerica occur during the months of August,September and October.

The highest wind speed observed du ring ahurricane was 186 miles per hour recorded inNew England in 1938. However, wind damageindicates that speed in excess of 200 miles pe rhour have occurred. Winds of 90 and 100miles per hour are fairly common in welldeveloped hurricanes.

A Delta launch vehicle at l ift off with TlROS .

NASA FACTS is an educational publication of NASA's Divisionof Educational Programs and Services. It will be mailed toaddressees who request it from: NASA, Educational Publicat ions Distribution Center, AFEE-l , Washington , D.C. , 20546.

u.s. GOVER NMENT PRINTING OFFICE ; 196 4 O F" -717-829Fo r sa le b y th e Super intendent of Do cume nts , U.S. Gove rnme nt Pr in tin g Office

Wash ington , D.C. , 20402 - Pr ice 15 ce nts per copy

nasa facts tiros

Documents