atmosphere explorer-b press kit

8/8/2019 Atmosphere Explorer-B Press Kit

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,NA11NAL AM-)NAUTIIS AND SPACE ADMINISTRATION WI) i-IP,WASHINGTON D C A20546 WO w-'.97?*I NFOR RELEASE: THURSDAY P.M." ~MAY 5., 1966 i

RELEASE NO: 66-96 M ,

K PROJECT: ATMOSPHERE EXPLORER-B(To be launched no earlierthan May 11)CONTENTS

GENERAL RELEASE ----------------------------------1-4AE-B SCIENTIFIC OBJECTIVES------------------------5-6THE SPACECRAFT-----------------------------------6-8SCIENTIFIC EXPERIMENTS----------------------------9Ion Mass Spectrometer--------------------------9-10Neutral-Particle Mass Spectrometer------------10-11Density Gages---------------------------------12Electrostatic Probes---------------------------13-14OPTICAL ASPECT SYSTEM----------------------------14Daylight Aspect Sensors------------------------14-15Night Sensors----------------------------------15Day-Night Switching Detectors------------------16SPACECRAFT POWER SUPPLY---------------------------16-17INTERNAL PRESSURE RELIEF--------------------------17-18TELEMETRY AND DATA RECORDING SYSTEM---------------18-19SPIN-AXIS AND SPIN-RATE CONTROL SYSTEM------------19-20T ELTA LAUNCH VEHICLE------------------------------21-23ATMOSPHERE EXPLORER-B FACT SHEET------------------23-25COMMUNICATIONS AND DATA-HANDLING SYSTEM-----------25TRACKING, TELEMETRY AND COMMAND STATIONS----------25-26


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PARTICIPANTS IN AE-B-------------------------------26-28

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AERONAUTICS AND SPACE ADMINISTRATION WO 2-4155N E W SWASHINGTON, .C. 20546 TELS. WO 3-6925FOR RELEASE: THURSDAY P. M.

RELEASE NO: 66-96

NASA TO LAUNCHATMOSPHERE

EXPLORER

The National Aeronauti-.is and Space Administration will Ilaunch a 495-pound spacecraft into a 750 by 170 mile orbitaboard a Delta launch vehicle from Cape Kennedy, Fla. noearlier than May 11.

Called Atmosphere Explorer-B, the aeronomy spacecraft jwill carry eight experiments to measure temperatures, com-position, densities and pressures in the upper atmosphere, ona global basis. 4

If successfully placed in orbit, AE-B will be named jExplorer XXXII; at the same time, it will give the three-stageDelta launch vehicle a record of 35 spacecraft orbited in 38launches.

This will be the first use by the Delta of a new third-stage motor (the FW-4 solid propellant unit) although FW-4stages have been used on three Scout launch vehicle flights.

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Primary scientific goal of the AE-B experimenters isto collect accurate data which will provide a better under-

standing of how and why changes occur in the upper atmosphere.

A secondary objective is to study the effects of short-term disturbances in the atmosphere caused by radiation fromsolar storms. These storms now occur more frequently becauseof an increasing level of solar activity. One vitallyimportant effect of such storms is disruption of short-waveradio communications which use the ionosphere as a reflectorin bouncing signals around the globe.

Solar activity varies over an 11-year period. Duringthis cycle, the activity of the Sun slowly tapers off from ahigh point for about the first nine years and then rapidlyrises back to the high phase during the remaining two years.

Since the last high point was in 1957, the Sun is justentering its period of maximum change. By launching the AI'-Bat this time, the experimenters have the opportunity to covermuch of this period of maximum change during the spacecrafttsexpected lifetime of about a year.

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-3-The AE-B will be the second aeronomy spacecraft launched

by NASA. The first, Explorer XVII (AE-A), was launched April 3,1963. Designed for a lifetime of three months, this battery-powered spacecraft lasted 100 days. It provided the firstworldwide measurements of upper atmospheric constituents andparameters which have already revised man's thinking about thephysics of the atmosphere.

The AE-B is similar to Explorer XVII, but weighs 55 poundsmore than its predecessor. It is a 35-inch-diameter stainlesssteel, hermetically-sealed sphere. This houses the necessaryelectrical and mechanical instrumentation.

The only appendages on the spacecraft are a cantedturnstile antenna and two electrostatic probes which protrude18 inches on each side of the spacecraft's equator. The re-mainder of the scientific instruments are mounted in vacuum-sealed holes on the spacecraft surface. A total of 2064 solarcells are bonded directly to the spacecraft shell to provideelectric power to recharge the batteries, thus extending itslifetime to about a year.

Other changes are expected to improve data collection andrecording capabilities. These Include a tape recorder to storescientific data picked up over areas where there are no groundstations and a spin-axis orientation system to help keep thespacecraft oriented properly for maximum use of scientificinstrumentation. -more-


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-4-Some pressure will be built up inside the sealed space-

craft during its lifetime due to the hydrogen and possiblysome oxygen generated by the batteries. Pressure will berelieved by three fuel cells. These cells produce an electro-chemical reaction upon contact with hydrogen or oxygen, tochange the gases into water, and store the water.

Pressure relief beyond the lifetime of these cells willbe attained by a motor-driven vacuum valve. This unit willpermit the battery gases to leak out of the spacecraft on Xcommand at a rate of about three pounds a day.

The Atmosphere Explorer program is directed by the Physicsand Astronomy Programs Division of the Office of Space Scienceand Applications at NASA Headquarters. Project management isunder the direction of Goddard Space Flight Centers Greenbelt,

rlMd., which also is responsible for tracking and data ac-quisition and the Delta launch vehicle. In addition, allexperiments on board are the responsibility of OSFO scientists.

TeheoAEgy was designed and built by Goddard's SpacecraftTecnolgyDivision and the Aeronomy Branch. Prime contractor

forthethree-stage Delta launch vehicle is the Douglas Air..craft Company, Inc,0 Santa Monica, Calif. The NW-4 motor is

U

developed by United Technology Corp,s Sunnyvale, Calif.(END OF GENERAL RELEASE; BACKGROUND INFORMATION FOLLOWS)

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-5-AE-B SCIENTIFIC OBJECTIVES

The Atmosphere Explorer-B (AE-B) is the second aeronomyspacecraft of a series which began with the launch of ExplorerXVII in April, 1963.

The primary scientific goal of the AE-B investigators isto obtain sufficiently accurate measurements of the upperatmosphere around the globe and its variations With time of day,season and year. Such data will permit identification of theunderlying processes of this region of the atmosphere and anevaluation of their relative importance.

The experiments and orbital parameters of the AE-B havebeen selected to provide, with simultaneous operation, thebasis for the study of physical processes as opposed to, forexample, studies which are primarily mapping, descriptive,or of a survey nature.

A second objective of the AE-B project is to study theeffects of short term perturbations of the atmosphere whichare induced by the direct and delayed effects of solar storms.These effects will be primarily evident in the auroral regionsand in the area of the South Atlantic magnetic anomaly.

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EARTH ASPECTSENSOR \,--X-- nni / PURGINGiPRESSURIZATION - ECONPORT &TEMP. PROBE

-X AXIS AE+X AXISSOLAR & *I I I11E 18.437LUNAR Iv\\hlSASPECT \\ \PLT T7SENSORS SN

S9.375/DIA RF ANTENNA (4)

AE-B SPACECRAFTFRONT VIEW


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-6-Scheduling of the spacecraft's operations therefore will

include extensive coverage of these regions as well as exten-sive global and temporal coverage.

THE SPACECRAFT

The basic spacecraft structure of the AtmosphereExplorer-B consists of a spherically-shaped, 35-inch diametershell. The hermetically sealed shell is made of stainlesssteel, 25/1000ths of an inch thick.. Access to the internalcomponents of the spacecraft is through a bolted lid section.

A total of 2064 solar cells are affixed directly to thespacecraft shell. Five trapezoidal-shaped patches of thesecells are located on the top of the spacecraft and seven on thebottom. Each patch consists of 43 modules of cells connectedin series with each module containing four solar cells con-nected in parallel.

The only appendages on the spacecraft include a cantedturnstile antenna which projects from the bottom. Additionally,there are two electrostatic probe experiments, one projectingfrom each side of the spacecraft. These probes are 18.4 incheslong.

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-7-The AE-B is designed to be vacuum tight, thus preventing

the spacecraft from measuring its own gaseous dischargesas it orbits the Earth. The integrity of the spacecraft'sinternal pressure is maintained by copper shear gaskets locatedat the various joints.

Stainless steel was used for the spacecraft shell becauseof the excellent vacuum properties of this metal. Stainlesssteel does not outgas extensively in the vacuum of outer space.That is, it does not release electrons extensively which couldbe picked up by spacecraft sensors.

The AE-B is spin-stabilized, employing a yo-yo de-spinmechanism to attain the proper spin rate of 30 revolutions perminute. This mechanism consists of two long wires with weightsat their ends which automatically unlatch in orbit. The wiresunwind from around the spacecraft's equator due to the cen-trifugal force of the weights.

As the weights swing out, the spinning spacecraft providesthe kinetic energy (energy of motion) to speed the weights intheir ever-widening circles. The spacecraft provides thisenergy only at the expense of its own spinning motion, andthus begins to slow its spin, When they reach the full lengthof the wires, the weights are released. At this point, thespacecraft is spinning at the desired rate.

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Since the AE-B is spin stabilized, the experiments are llocated on the spacecraft in such a manner as to take advantage iof the favorable aspect of the spinning motion. The experimentsensors are located on the spacecraft as follows:

-- Nearly equally spaced around the spacecraft equator:One neutral-particle mass spectrometerOne ion-mass spectrometerTwo magnetron density gagesTwo electrostatic probes

-- degrees off the spacecraft equator toward the top:One magnetron density gage

-- On the top at the spin axis:One neutral-particle mass spectrometer

In the primary mode of operation, the AE-B will generallyspin through space to make certain that its sensors detectinformation in the direction of the spacecraft's orbital path.Thus, the gas-sampling sensors located around the spacecraft'sequator are arranged so as to be cyclicly oriented first in thedirection of the spacecraft motion, and then in the directionopposite to the forward motion after the spacecraft rotates J180 degrees.

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--ELECTRICAL CHECKOUT& FLIGHT TURN-ON- + \ \PLUGSEPARATION PLUGPLANE

AE-B SPACECRAFTSIDE VIEW

* -. * -.. -. -- - _


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SCIENTIFIC EXPERIMENTS

The selection of the eight experiments for the AE-Bwas based on the results of the Explorer XVII spacecraftand upon the needs of the resulting data studies. In par-ticular, these experiments will make high-resolution directmeasurements of neutral and charged particle constituents ;and other parameters of the Earth's upper atmosphere. Inparticular, these experiments are designed to collect datafor analyzing the distributions and concentrations of theparticles and their energies.

All of the experiments onboard the AE-B were provided bythe Goddard Space Flight Center.

A description of the AE-B experiments follows: c

Ion Mass Spectrometer

The AE-B carries one ion mass spectrometer to measure theconcentration and scale height of the ionic constituents ofthe atmosphere. This instrument is located on the spacecraft'sequator. It is designed to collect data on the followingatmospheric ions: hydrogen, helium, atomic nitrogen and atomicoxygen.

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Ions enter the spectrometer through an orifice in thespacecraft's skin and are accelerated along the axis of theinstrument. This is accomplished by means of an electricfield created within a series of parallel grids in thespectrometer. The acceleration potential of this field isvaried such that only the selected ions (hydrogen, helium, etc.)reach the resonant velocity of the instrument. These arecollected and measured as an ion current which is then con-verted to ambient ion density. The particles of interest canbe identified by the potential required to accelerate them toresonant velocity.

Neutral-Particle Mass Spectrometer

Two such spectrometers are carried on the AE-B to helpdetermine the concentration and temperature of the neutralconstituents of the atmosphere. One of these units is locatedon the spacecraft's equator while the other unit is locatedon the top at the spacecraft's spin-axis. These spectrometersare nearly identical to those employed on the Explorer XVII,except for several relatively minor but significant changeswhich allow for more precise measurements. The neutral particlemass spectrometers are designed to measure the concentration ofthe following neutral atmospheric constituents: atomic hydrogen,helium, and both molecular and atomic nitrogen and oxygen.

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A neutral-particle mass spectrometer counts electricallyneutral particles in space by breaking such particles intopositive ions and negative electrons. The resulting ionsare made to move through electric and magnetic fields ofknown strength which deflect the particles. The extent ofthis deflection depends largely on the mass of the particles;particles of the same mass will be deflected along the samepath.

A sensing device in the spectrometer is located such thatit intercepts the stream of particles so they can be counted.Since the field strength and location of the sensor is specificfor certain masses of particles, and since the mass of the ionis specific for each component that is ionized, selected com-ponents of the atmosphere can be identified.

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Density Gages

Three magnetron density gages are included in the AR-B'sscientific payload to help determine the total netural par-tidle density and scale height in the atmosphere.

Two of the gages are located on the spacecraft's surfaceat the equator. The third gage ia located 55 degrees off theequator towards the top of the AE-B. All of the gages arevacuum-sealed into openings on the spacecraft surface. Theseorifices give the gages an unimpeded view fromahorizon tohorizon.

A magnetron gage employs a cold-cathode to produce elec-trons. These are trapped in the gage's magnetic and electricfields which have lines of force perpendicular to each other.

Because the electrons are trapped in the fields, theyhave long paths of movement, thus making it more likely thatthey will collide with any neutral gases entering the gag .Such collisions produce ions. The number of ions generatedis measured as a current which is proportional to the particledensity in the gage. This gage density is, in turn, propor-tional to the atmospheric density.

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ETP ELECTRONICS& PRESSURE GAGE | BREAK-OFF MECHANISMPOWER SUPPLIES GCA PRESSURE GAGE(ABOVE BATTERY BOX) MISCELLANEOUSBREAK-OFF ELECTRONICS PACKAGEMECHAISM\ & l / BATTERY BOXNRC PRESSURE GAGETYPICAL OF 6.. PRESSUR MAGNETIC CONTROL RODSTELEETRY(ATTITUDE CONTROL)

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EXPLOSIVE -YO-YO EXPLOSIVESWITCHES RELEASE MECHANISMM.S. EMISSION REGU LATORS& BATTERY CHARGER YO-YO DESPIN(ABOVE BATTERY BOX) WEIGHT

ION MASS ISPECTROMETER -X AXIS ELECTRONMASS SPECTROMETER TEMPERATURE PROBEELECTRONICSINTERIOR VIEWCENTER SECTIONAE-B SPACECRAFT


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Electrostatic Probes

The AE-B carries two electrostatic probes to determinethe concentration and temperature of thermal electrons in theupper atmosphere. These probes are cylindrical electrodeswhich protrude about 18 inches out from either side of thespacecraft at the equator. Two probes are used to insurethat one of them always will be ahead of the spacecraft andthereby free from the plasma wake behind the orbiting AR-B.

In the launch configuration, these spring-mounted probesare held down close to the spacecraft by the nose fairing of'the launch vehicle. Once the nose fairing has been ejectedduring flight, however, the two probes spring straight out intheir orbit configuration.

When a voltage is applied to an electrostatic probe im-mersed in a plasma, such as the AE-B will be in orbit, anelbctron current is collected as a function of the appliedvoltage. Proper interpretation of this current gives thedensity and temperature of the ambient electrons in the im-mediate vicinity of the spacecraft.

The AE-B electrostatic probes are similar to those flownpreviously on Explorers XVII, XXII, XXVII, XXXI, Tiros VII andAlouette II and numerous sounding rockets.

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Thus, all of the data collected with these spacecraftcan be correlated with the data from the AE-B probe.

OPTICAL ASPECT SYSTEM

The function of the Optical Aspect System on the AK-B isto permit the spacecraft's orientation to be determined at anytime with respect to the Earth, Sun or Moon. This Informationis necessary for the correct interpretation of the scientificdata collected by the spacecraft's experiments.

The Optical Aspect System consists of four sets of sen-sors for collecting aspect data regardless of whether thespacecraft is experiencing day or night. It also has a switch-ing system for turning off those aspect sensors not in use atany given time.

Daylight Aspect Sensors

1. Digital Sun Sensor and Sun Slit: This sensor givesa seven-bit indication of the angle between the spin axis ofthe spacecraft and the SiUn.

The digital Sun sensor employs seven photocells placed ashort distance behind a light mask with seven different pat-terns of rectangular openings. Light entering the openingsat a particular aspect angle illuminates none, any, or anycombination of the seven photocells.

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As many as 128 separate possible sun angles can bemeasured in this manner.

The Sun slit part of this sensor, which has a 140-degreefield of view, provides an additional pulse at the instantwhen the aspect sensor sweeps across the Sun.

2. Visible Earth Horizon Sensors: There are two suchsensors on the AE-B. They are narrow pencil-beam detectorswhich are sensitive to Earth shine in the visible part of theenergy spectrum. These sensors are mounted at 68 degrees and112 degrees, respectively, with respect to the spacecraft'sspin axis.

Night Sensors

1. Infrared Earth-Horizon Sensors: These sensors areidentical to the visible Earth-horizon sensors with the ex-ception that they are sensitive only to the seven-to-15-micronregion of the ultraviolet portion of the energy spectrum.

2. Moon Slit Detector: This detector provides an out-put pulse whenever its aspect sensor sweeps across the Moon.It is turned on only at night.

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Day-Night Switching Detectors

There are two types of day-night switch detectors whichare actually identified as Sun switch detectors. The firstsenses whether the Sun is shining on the spacecraft. If itis, the infrared horizon sensors and the Moon slit detectorsare turned off. Otherwise, these aspect sensors are left on.The second type of Sun switch detector blanks the output ofthe Earth-horizon detectors whenever they sweep across the Sun.

SPACECRAFT POWER SUPPLY

The basic power supply of the AE-B consists of about 178pounds of silver-zinc batteries with a total capacity of 10,500watt hours. This is the same type of power supply employed onthe Explorer XVII which had sufficient power for 100 days ofoperation. If the batteries on the AE-B are utilized on thesame five turn-on per day basis as the Explorer XVII, the AR-Bcould be expected to have battery power enough for six monthsoperation. The additional battery lifetime is made possibleby improvements in shelf life, better battery pack balancingand reduced power demands.

Unlike the Explorer XVII, the AE-B has been equipped witha modest solar cell system which is expected to provide 10watts of power on the average when commande-'.

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This system gives the AE-B project personnel the capa-bility of extending the useful lifetime of the spacecraft be-yond the six month, period as well as increasing the turn-onrate if desired.

The solar cells are bonded directly to the spacecraft'sstainless steel shell, thus avoiding the use of paddles. Thiswill minimize outgassing to such an extent that the particleflow will not be detectable by the experiment sensors.

INTERNAL PRESSURE RELIEFSince the AE-B is a hermetically sealed spacecraft with

an extended lifetime, some pressure will be built up internallydue to the hydrogen normally generated by its batteries. Asmall amount of oxygen also might be produced.

As a means of preventing a large pressure built up, theAE-B is equipped with three Gas Combination Cells which havethe job of minimizing execessive pressure for about ninemonths after launch. These devices each contain an exposedgas electrode on which hydrogen or oxygen is absorbed. Whenhydrogen is absorbed, it reacts electrochemically with an oxi-dizer (copper oxide) stored inside the device to produce water.

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If oxygen also is present, the two gases react catalyti-cally on the exposed electrode surface, also forming water.All of the water produced in this fashion remains within thecombination cells.

Release of excessive pressure beyond'the lifetime of theGas Combination Cells is attained by a motor-driven vacuumvalve. This valving permits the evolved gases to leak out ofthe spacecraft on command at the rate of about three and ahalf pounds per square inch a day until the pressure is ade-quately reduced. The valve is then commanded to close untilneeded again.

TELEMETRY AND DATA RECORDING SYSTEM

Telemetry: Two identical telemetry systems are used onthe AE-B. Each of these redundant systems are solid state as-semblies which supply an output power of 500 milliwatts each.These pulse code modulated (PCM) systems are capable of hand-ling 8640 bits/second.

The turnstile antennas on the AE-B provide an approximateomni-directional pattern with lows expected to be less thanabout four decibels. These antennas are used with the commandreceiver, tracking transmitter, and the telemetry system.

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Data Recording: As a means of permitting greater geo-graphical coverage than was possible with the Explorer XVII,the AE-B has been equipped with a single-speed, continuous-loop tape recorder. This unit, controllable with an onboardtimer, timer-clock system, can be commanded to record scien-tific sensor data over any geographical area where there isno ground station. To minimize its complexity, this recorderhas a capacity adequate for accommodating only a single turn-on (four minutes of operation at 8640 bits/second) of thespacecraft.

The onboard timer can be preset and initiated upon com-mand to turn the recorder on through the spacecraft electricalcontrol system. The time base for the timer is driven by atuning fork (plus or minus 0.1 percent accurate) and provid'sone-minute tux -on resolution referenced to command time.

The accuracy of the system can be verified by a commancreadout of the clock up to 128 minutes after initiation ofthe delay timer.

SPIN-AXIS AND SPIN-RATE CONTROL SYSTEM,

Spin Axis Control: The spin axis of the spin-stabilitedAE-B generally will be naintained normal to the orbit plane-with magnetic spin-axis orientation device.

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In this manner, the spacecraft's experiment will gainoptimum orientation for collecting data. Generally, the mag-netic device provides control of the spacecraft's residualmagnetic field upon command and thereby affords control ofthe spin axis.

The spin-axis orientation device on the AE-B achievesspin-axis orientation by generating a magnetic dipole momentwithin the spacecraft along the spin (X) axis. This momentwill react with the Earth's magnetic field to produce spin-axis precession. At 30 rpm, the precession rate will be nomi-nally l/4 degree per minute, enough to cancel out any deviationof the spin axis from the orbital plane.

Explorer XVII, in which no control was employed, exper-ienced a precession of about 10 degrees a day and only infre-quently achieved an optimum orientation.

Spin Rate Control: Spin rate control of the AE-B isachieved by means of a magnetic dipole moment generated in thespacecraft's Y-Z plane and properly phased with respect to theEarth's magnetic field. This moment will produce a torque toincrease or decrease spin rate. The sense of the torque maybe selected by command. This systemnwill be able to 3hangethe spin rate 15 rpm per 24 hours of system operation. Lessthan one watt of power is required when the spin rate systemis on. -more-


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DELTA LAUNCH VEHICLE

Delta program management is under the direction of theOffice of Space Science and Applications' Launch Vehicle andPropulsion Programs. Project management is the responsibilityof Goddard Space Flight Center. Prime contractor for theDelta launch vehicle is the Douglas Aircraft Company, SantaMonica, Calif.

Successful orbiting of the AE-B onboard the Delta willgive this vehicle a record of 35 spacecraft orbited out of 38launches.

The Delta vehicle has the following characteristics:Overall length: 90 feetMaximum diameter: 8 feetNominal liftoff weight: 114,000 pounds

First stage: Douglas Aircraft Co. Thor Missile.Burning time: About two minutesand 25 secondsThrust: 172,000 poundsFuel: Kerosene/liquid oxygenWeight: Over 50 tons

Second stage: Aerojet-Gencral Corp., AJ-10-118A pro-pulsion system.Burning time: About two minutesand 40 seconds

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Thrust: 7550 poundsFuel: Liquid UDMIVRedFuming Nitric AcidWeight: Two and one-half tons

Third stage: United Technology Corp.,, FW-4.Burning time: 31 secondsThrust: 5450 pounds-Fuel: Solid propellantWeight: About 660 poundsLength: About 62 inchesDiameter: 19.6 inches

The flight sequence for the Delta is as follows: Afterburnout, the first stage falls away and the second stage ignitesimmediately. Thirty seconds after second stage ignition, thenose fairing is Jettisoned. It is this fairing which protectsthe AE-B, the third-stage rocket and the third-stage instru-mentation from aerodynamic heating during flight through theatmosphere. After second-stage burnout, the vehicle begins acoast period of approximately seven minutes. Near the end ofthis period, small rockets mounted on a table between the secondand third stage ignite and spin the table up to 90 revolutionsper minute. The second stage separates and the third stageignites and burns to achieve orbital velocity of about 17,000miles an hour.

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Third stage separation then takes place and the payloadis pushed into orbit, after which it is de-spun to the de-sired spin rate of 30 revolutions per minute.

ATMOSPHERE EXPLORER-B FACT SHEETSPACECRAFT

Weight: About 495 pounds total: Experiments 50 lbs.Structure 92 "Batteries 178Other 17 5Structure: A 35 inch diameter stainless steel spher-

ical shell with appropriate internalstructure. Structure surface fitted with2064 solar cells.

Appendages: A canted turnstile antenna consisting offour 3/8th of an inch diameter rods meas-uring 20-1/8 inches long protruding fromthe bottom of the spacecraft. There alsoare two 18.4 inch long electrostatic probesprotruding from either side of the space-craft at the equator.

Lifetime: Designed for six months useful lifetimewithout recharge. This can be extendedto nine months or a year with recharge.

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LAUNCH PHASESite: Complex 17B, Cape Kennedy, Eastern Test

Range.Vehicle: Three-stage Delta.

Launch Azimuth: 45 degrees.Orbital plan: Apogee: 750 miles (1200 kilometers)

Perigee: 170 miles (250 kilometers)Period: About 100 minutesInclination: 64 degrees

POWER SYSTEMPower supply: Multiple silver-zinc battery packs with

a total capacity of 10,500 watt-hours.The solar cells feed an average of tenwatts of power on command during thespacecraft's lifetime.

Voltage: Voltage requirements vary from 3.1 to 21volts.

Pressurerelief: The battery evolved gases inside thehermetically sealed spacecraft are com-bined as water by three gas combinationcells to minimize the pressure. Pressurerelief beyond the life of these cells isattained by a motorgdriven vacuum valve.

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This valve permits the gases to leak outof the sealed spacecraft at the rate ofabout three pounds a day on command.

COMMUNICATIONS AND DATA-HANDLING SYSTEMTelemetry: Pulse code modulation (PcM) 8640 bits/

second.Transmitter: Requires about one-half watt output.Encoder: 45 channels at 20 nine-bit samples/second.Taperecorder: An endless loop unit with more than two

million bit capacity (2.1 x 106) perreadout.

TRACKINGj TELEMETRY AND COMMAND STATIONSAll tracking and telemetry stations are part of the

Goddard Space Flight Center's Space Tracking and Data Acqui-sition Network (STADAN). Primary stations: Rosman, NorthCarolina, and Fairbanks, Alaska. These stations will be usedto acquire te?.emetry data from the spacecraft.and relay it inreal time to the AE-B control center at Goddard by way of micro-wave communications facilities. Commands for the spacecraft,originating in the control center, will be sent by the samemicrowave system to the primary stations for subsequent trans-mission to the spacecraft. Secondary stations: These stations,listed below, will be used as scheduled by project requirementsfor command and telemetry functions whenever the spacecraft isnot in view of the primary stations.

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Blossom Point, Maryland; College, Alaska; Fort Myers,Florida; East Grand Forks, Minnesota; Joharnesburg, Republicof South Africa; Kano, Nigeria; Lima, Peru; Goldstone Lake,California; St. Johns, Newfoundland; Canberra, Australia;Quito, Ecuador; Santiago, Chile; Winkfield, England.

PARTICIPANTS IN AE-B

NASA HEADQUARTERS

Dr. Homer E. Newell Associate Administrator fo rSpace Science & ApplicationsJesse L. Mitchell Acting Director, Physics &Astronomy Programs Div., OSSAFrank Gaetano AE-B Program ManagerR. Horowitz AF-B Program ScientistVincent L. Johnson Director, Launch Vehicle &Propulsion ProgramsT. B. Norris Delta Program Manager

GODDARD SPACE FLIGHT CENTERDr. John F. Clark Acting DirectorDr. John W. Townsend, Jr. Deputy DirectorDr. George F. Pieper Assistant Director for Space

SciencesNelson W. Spencer Chief, Laboratory for Atmos-pheric and Biological Sciences

& AE-B Project ManagerLarry Brace AE-B Project ScientistPeter L. Luppino Tracking & .Data SystemsManager

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William R. Schlinder Delta Project ManagerRobert H. Gray Assistant Director, UnmannedLaunch Operations

DOUGLAS AIRCRAFT COMPANYMarcus F. Cooper Director, Florida Test Cen.-ter, Cape KennedyJ. Kline Delta Systems Engineer

EXPERIMENTERSH. Taylor Ion Mass Spectrometer (1)C. Reber Neutral Particle MassSpectrometer (2)L. Brace Electrostatic Probes (2)G. Newton Pressure Gages (3)All experimenters are members of the Aeronomy Branch of

the Laboratory for Atmospheric and Biological Sciences at theGoddard Space Flight Center.

PRINCIPLE CONTRACTORS

Aero Geo Astro Corp. Ion SpectronaterCollege Park, Md.Applied Physics Lab. Spin-axis OrientationHoward County, Md.The Budd Company Spacecraft shellPhiladelphia,Consolidated Systems Corp. Two Mass SpectrometersMonrovia, Calif.GCA Corp. Two Density GagesBedford, Mass.National Research Corp. One Density GageEquipment, Corp.Newton Highlands, Mass.

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Yardley Electric Co. Silver-zinc batteriesNew York CityUNIVERSITY PARTICIPANT

University of Michigan Two electrostatic probesSpace Physics ResearchLab.

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atmosphere explorer-b press kit

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