NASA Technical Memorandum 88820
ACTS Experiments Program
(M&SA-TH-88820V &C3S EXPEBIUEN1S PBOGHAB H86-3162512 P CSCL 17B
Unclas63/17 a3525
Ronald J. SchertlerLewis Research CenterCleveland, Ohio
Prepared for theGlobecom '86sponsored by the Institute of Electrical and Electronics EngineersHouston, Texas, December 1-4, 1986
NASA
https://ntrs.nasa.gov/search.jsp?R=19860022153 2020-04-03T08:06:58+00:00Z
ACTS EXPERIMENTS PROGRAM
Ronald J. Schertler
National Aeronautics and Space AdministrationLewis Research CenterCleveland, Ohio 44135
ABSTRACT
This paper presents an overview of theACTS Experiments Program. ACTS is beingdeveloped and will flight test the advancedtechnologies associated with: a Ka-bandmultibeam antenna, onboard signal processingand switching as well as .laser communications.A nominal 3 yr experiments program is plan-ned. Through the experiments program, the.capabilities of the ACTS system will be madeavailable to U.S. industry, university andgovernment experimenters to test, prove thefeasibility and evaluate the key ACTS systemtechnologies. Communication modes of oper-ation using the baseband processor and micro-wave switch matrix are presented, along withthe antenna coverage pattern. Potentialexperiment categories are also presented andbriefly discussed. An overall schedule ofactivities associated with the experimentsprogram is outlined. Results of the ACTSExperiments Program will provide informationvital to successful industry implementationof ACTS technology in future operationalsystems.
ACTS PROGRAMThe ACTS is a key element in the goal of
NASA's Advanced Communications Program todevelop high-risk, advanced communications'technology usable in multiple frequency bandsto support our nation's future communicationsneeds. Realization of this goal will enablegrowth in capacity and effective utilizationof the frequency spectrum and maintainUnited States preeminence in satellitecommunications.
To accommodate the projected increasesin telecommunications demand for the 1990's,technology innovations which permit moreeffective frequency spectrum use and cost-effective customer premises satellite earthterminals and networks are needed.
Using multiple spot beams and advancedonboard switching and processing systems,'ACTS will pioneer new vistas in communication
satellite technology. These antenna andswitching systems technologies, which aregeneric for existing (Ku) as well as new (Ka)frequency bands, require flight experimenta-tion as an essential part of this technologydevelopment process.
The NASA ACTS program sponsors the devel-opment and flight test of high-risk, advancedcommunications satellite technology. Keytechnologies to be validated.as part of theACTS program include: MULTIBEAM ANTENNA - arapidly reconfigurable hopping beam antennato serve users with optimum efficiency; BASE-BAND PROCESSOR - a high-speed digital switch-board in the sky for efficient use of timeand transponder capacity via individual mes-sage routing; MICROWAVE SWITCH MATRIX -dynamic reconfigurable switch to handle high-volume traffic via point-to-point communica-tions; RAIN FADE COMPENSATION - techniquessuch as forward error correction, power con-trol and use of diversity ground terminalsto automatically adjust to uplink and down-link fades; KA-BAND COMPONENTS - developmentof both flight and ground terminal hardwareat 20 and 30 GHz; and LASERCQM COMMUNICATIONSdevelopment of laser communications technol-ogy for intersatellite link applications.
NASA Lewis Research Center in Cleveland,Ohio, has been assigned overall projectmanagement responsibility for the ACTS Pro-ject. ACTS is being developed for launchfrom the shuttle.
RCA's Astro-Electronics Group, Princeton,New Jersey, leads the contractor teamdeveloping ACTS. Major members of this teamunder RCA are TRW Electronics Group, SpaceCommunications Division, Redondo Beach,California; Communications Satellite Corpor-ation (COMSAT), Washington, DC; and MotorolaInc., Aerospace Electronics Office,Scottsdale, Arizona.
ACTS EXPERIMENTS PROGRAMA major goal- of the NASA ACTS program is
to obtain the widest possible involvement ofall United States institutions and the tele-communications user community in the evalua-tion and testing of this advanced technology.This goal will be accomplished through theACTS Experiments Program. The ACTS Experi-ments Program will make available the cap-abilities of the ACTS system (flight andground segments) for experimentation to thepublic and private sectors of the UnitedStates (industry, universities and govern-ment). This will allow experimenters totest, prove the feasibility and evaluate thekey ACTS system technologies. The flightand ground segments are being developed topermit the required experiments and dataanalysis to be conducted.
A nominal 3-yr period of experimentationis planned after launch and a subsequentperiod of on-orbit checkout.
ACTS SYSTEM OVERVIEWThe ACTS system (Fig. 1) is made up of a
flight segment and a ground segment. Theflight segment consists of a Multibeam Com-munications Package (MCP) and the spacecraftbus. The ACTS flight' segment is shown inFig. 2. ACTS will be located in geosynchro-nous orbit at 100° west longitude. In orbitACTS will weigh approximately 2860 Ib andwill measure 46.5 ft from tip to tip alongthe solar arrays and 30 ft from one antennato another.
Separate Ka-band (30/20 GHz) antennas,each with horizontal and vertical polariza-tion feed systems, are provided for transmitand receive signals. The offset Cassegrainantenna system provides hopping spot beamsfor independent and simultaneous coverage ofan east and west scan sector (see Fig. 1),with additional spotrbeams for isolated loca-tion coverage outside of each sector and .three fixed spot beams. Within the beams,access will be by demand assigned multipleaccess (DAMA) utilizing Time DivisionMultiple Access (TDMA). The MCP providesthe means for receiving, processing, switch-ing, amplifying and transmitting signalscarrying high-speed digital communicationstraffic.
A major feature of the ACTS system is theuse of dynamic rain fade compensation. TheACTS flight system will incorporate threebeacons for real time fade measurements; twoin the downlink frequency band and one in the
uplink frequency band. Signals from allthree beacons will be transmitted via a full
CONUS coverage antenna. The downlink fre-quency beacons at 20.185 GHz (verticalpolarization) and 20.195 GHz (horizontalpolarization) will be used for telemetry,ranging and power monitoring (fade control)as well as for propagation studies. Theuplink frequency beacon at 27.505 GHz (verti-cal polarization) will be used for powermonitoring for the ACTS communication systemand for propagation studies.
In addition to the rf communicationspackage, ACTS will include a laser opticalcommunication package provided by the AirForce. The laser communications package isbeing developed for the Air Force by MITLincoln Laboratory. NASA's Goddard SpaceFlight Center (GSFC) will also provide hard-ward for integration by Lincoln Laboratoriesinto this laser communications package. Thelaser communications experiments will involvea series of tests intended to verify theengineering parameters, operational perform-ance and technical maturity of both hetero-dyne (MIT/LL) and direct detection (NASAGSFC) high-rate data transmission experiments.Tests of these optical communications con-cepts will be a major step in developingcrosslink systems to operate betweensatellites.
Initial testing with the ACTS laser com-munication system will be performed using aspecial purpose ground station as a substitutefor another satellite. Although atmosphericeffects on an optical signal propagatingbetween a ground station and the ACTS degradelink performance below that which would beexpected in a space-to-space optical communi-cation link, the ground sites permit asimpler and less expensive initial verifica-tion of intersatellite optical communicationtechnology. The ground station for the het-erodyne optical communication experimentswill use technology similar to that whichcould be used in a second crosslink package.The ground stations for the direct detectionexperiments will be special optical sitesoperated by NASA GSFC. Follow-up demonstra-tions of a complete heterodyne optical inter-satellite communication crosslink could usethe ACTS experiment package in combinationwith a heterodyne receiver and transmitteraboard a low-earth-orbit (LEO) spacecraft.Similarly, a direct detection package aboarda LEO spacecraft could be used to demonstratea direct detection crosslink to the ACTSoptical communication package.
The ACTS ground segment comprises theNASA Ground Station and Master ControlStation (MCS) co-located at Lewis inCleveland. Additional ground stations willbe provided by ACTS experimenters.
The MCS will provide spacecraft control,network control, experiment management anddata recording. All traffic requests willbe processed and set up by the MCS. Trafficchannel assignments are made on a demandbasis under central control of the MCS usinginband orderwire channels via the satellite.
RF MODES OF OPERATIONACTS has two basic rf modes of operation:
a Baseband Processor (BBP) mode and a Micro-wave Switch Matrix (MSM) mode. Both modesoperate in a TDMA format with a one milli-second time frame. The BBP mode operateswith two simultaneous and independent hoppingbeams to provide flexible, demand-accesscommunication between small earth stationslocated directly on customer's premises.Single-hop interconnectivity in a mesh net-work is provided between all ground terminalswithin the two hopping scan beams under thecontrol of the MCS. The channel frequencyassignment for the two beams are identical(frequency reuse). Bandwidth efficientSerial Minimum Shift Key (SMSK) modulation isused. Uplink bursts are organized in an FDM/TDMA format, while downlinks bursts are TimeDivision Multiplexed (TDM). The BBP provideson board demodulation, data storage, decoding(if appropriate), routing, encoding (ifappropriate), modulation and downlink trans-mission to the designated area in synchroni-zation with the hopping spot beam dwells.
The BBP routing is switchable on a word-by-word basis, where a word is equivalent tothe capacity of a 64 KBPS channel. Fadecontrol is provided by a combination of for-ward error correction, burst rate reductionand data rate reduction.
The MSM mode employs three active fixedspot beams operating at the same frequency.Dynamic interconnectivity of high volume com-munications traffic among three fixed beamsis accomplished by the switch matrix on aTDMA basis. A 900 MHz (nonlinear) channel isprovided whereby the uplink signal is down-converted to IF, routed and upconverted tothe downlink frequency on a burst-by-burstbasis. Switch configurations are program-mable and can be changed by the MCS to opti-mize traffic flow. Demand assignment isprovided by two-way, inband, orderwire chan-nels between the MCS and the traffic termi- 'nals. Fade compensation is provided byoutput power control independently on boththe uplink and downlink as well as employingground station diversity.
Although the normal MSM mode is SS-TDMA,the switch and the multibeam antenna providethe flexibility to freeze the switch to
provide three wideband, spot-to-spot Ka-bandcommunications channels in a "bent pipe" con-figuration for lower-rate carriers as well asa limited number of multiple carriers pertransponder.
ACTS MULTIBEAM ANTENNA COVERAGECoverage of the ACTS multibeam antenna
for the Continental United States is shown inFig. 3. For the BBP mode of operation, twoindependent orthogonally polarized hoppingbeams provide simultaneous coverage for boththe uplinks and downlinks. The hopping .beams(designated East and West) each providecoverage to: (1) a contiguous area in theNortheast (different for each beam) and (2) aseries of isolated spot regions each with abeamwidth of approximately 0.3°. A total of13 spot regions is divided between the twobeams. In addition, ACTS will also contain aseparate lower gain, 1 m diameter, steerableantenna capable of being pointed anywherewithin the hemisphere of ACTS's field ofview. This steerable antenna has a beamwidthof approximately 1° at 20 GHz. It will func-tion as one of the isolated spot beams asso-ciated with the West beam. This steerableantenna will provide coverage for Alaska andHawaii as well as for tracking the shuttleor a spacecraft in low-earth orbit.
In the MSM mode, three active, independ-ent beams are employed. ACTS has three fixed
beam spots pointed at Cleveland, Atlanta andTampa regions. In this mode of operation, itis also possible to "stop" either or both theEast and West hopping beams at any locationwithin their respective beam coverage pat-terns and use these stopped beams in placeof either or both Atlanta and Tampa beams.
The ground coverage patterns provided bythe ACTS Multibeam and steerable antennasprovide a large measure of flexibility foraccommodating and interconnecting experi-menters in various network configurations.
ACTS GROUND TERMINALSTable I highlights the characteristics
of typical ACTS ground terminals capable ofoperating in the BBP or MSM modes. Experi-menters will be able to interchange compon-ents or subsystems, choosing antenna sizeand uplink power to match their needs. Rainfade compensation can be implemented eithermanually or automatically.
In the BBP mode, the clear weather uplinkburst rates will be either 27.5 and 110 MSPS,where as in the case of rain degradation theburst rates will be coded and reduced to 13.75and 55 MSPS respectively. The 27.5 MSPSburst rate channels will occupy the same
spectral bandwidth as the 11C MSPS channel ,and will be frequency division multiplexedon the uplink. The 1-msec TDMA frame can ..dynamically accommodate various combinations,of both uncoded and coded 27.5 and 110 MSPSburst rates in different time slots withinthe frame. The downlink beams use single-carrier Time Division Multiplex (TDM) trans-mission at an uncoded burst rate of 110 MSPSand a coded burst rate of 55 MSPS. The BBPthroughput capacity is planned in multiplesof incremental standard data rate of 64 KBPS,called an Equivalent Voice Circuit (EVC).Different voice, video and data traffictransmission rates can be accommodated byaggregating these basic 64 KBPS channels.
It should be noted that currently, verysmall aperture terminals (VSAT) using non-processing satellites are gaining greatacceptance as a cost-effective solution forbursty two-way data, while bypassing theterrestrial network. However, VSAT networksare not competitive for toll-grade voice net-
working or T-l capacity that is needed in manybusiness applications. The ACTS technologyachieves this toll-grade network voice andT-l capacity, as well as bursty data, whilestill employing VSAT type 1.8-m stations(MICRO-1).
In the MSM Dynamic mode, a ground termi-nal with a 220 MSPS capacity is being plannedfor Satellite Switched-TDMA operation. Inthe MSM Static mode, the 900 MHz widebandchannels can support lower-rate carriers ina bent-pipe mode.
The versatility of the ACTS ground ter-minals in both physical size, rf power andtraffic capacity should meet the experi-menters' needs without undue complexity orexpense.
EXPERIMENT CATEGORIESIn order to meet the goals of the ACTS
Experiments Program, experiments are neededto: (1) verify the on-orbit performance ofthe advanced technology components of theACTS flight system, including both rf andoptical; (2) verify the feasibility of thesystem concepts which provide spectrum con-servative communications services; (3) demonrstrate and evaluate the system networkingaspects of the switching and processing tech-nology; (4) characterize the transmissionmedium, along with techniques to combat'fadeattenuation; (5) evaluate the basic capabil-ities and performance of various types oflow and high data rate TDMA ground terminals;(6) demonstrate the commercial viability andmarket acceptability of both existing and newtelecommunications, voice, video and dataservices.
A number of representative experimentsubcategories have been identified for theACTS Experiment Program. These experimentsubcategories and their relationship to thetechnology to be developed within the ACTSprogram are briefly described in the follow-ing section. It should be noted that thisexperiments subcategory list is not meant tobe exhaustive. Experiments within the scopeof the ACTS program but not identified inthis subcategory listing are certainlyinvited.
Flight System Technology ExperimentsExperiments to evaluate the performance
and reliability of the specific multibeamcommunications subsystems which are includedon board the ACTS flight system, such as themultiple beam antennas, the baseband proces-sor, matrix switch, low noise receivers andtraveling wave tube transmitters.
Ground System Technology ExperimentsExperiments that evaluate the performance
of the ground stations.
Network ControlExperiments to evaluate the performance
and efficiency of a Time Division MultipleAccess (TDMA) and Demand Assigned MultipleAccess (DAMA) System and to evaluate networkaccess and control as a function of signalquality and time. Experiments to evaluatethe performance of various communicationsprotocols.
Acquisition, Tracking, and SynchronizationExperiments that evaluate acquisition,
tracking and Time Division Multiple Access(TDMA) synchronization and timing consideringACTS flight station-keeping accuracy andantenna-pointing accuracy.
Transmission ImpairmentsExperiments that evaluate system impair-
ments, particularly interference as a func-tion of beam separation.
Enhancement of Link Availability/RainCompensation Techniques.
Experiments to evaluate 30/20 GHz avail-ability and performance improvements withsuch techniques as earth stations withspatial diversity, adaptive power control
and forward error correction.
Propagation ExperimentsExperiments to develop propagation sta-
tistics to characterize propagation impair-ments such as fading, scintillation anddepolarization for all CONUS rain zones.
Experiments to evaluate quantitatively theimpact of such propagation impairments onthe ACTS system performance.
End-to-End System ExperimentsExperiments to develop voice, video and
data applications for use with advanced com-munications satellite systems.
Lasercom ExperimentsOptical experiments to demonstrate the
performance of both heterodyne and directdetection laser high-rate data transmissionlinks between synchronous orbit and opticalterminals located either on earth, in low-earth orbit or at other longitudes insynchronous orbit.
NASA recognizes that it may be ofinterest to some organizations experimentingwith ACTS to keep certain information regard-ing the conduct of their experiment or itsanalyzed results proprietary. Public dis-closure of an ACTS experiment and itsanalyzed results is certainly encouraged.Legal, cooperative agreements protectingproprietary information, however, can beentered between NASA and those organizationsso desiring, on an individual basis. Suchan agreement will protect the proprietaryaspects of an experiment from public dis-semination, while still providing NASA withan evaluation and verification of the per-formance of the ACTS spacecraft.
EXPERIMENT APPROACHThe schedule of activities for the ACTS
Experiments Program is shown Fig. 4. ANotice of Intent for Experiments (NOI) wasissued by NASA Headquarters in March 1983 to:(1) identify those organizations interestedin experimenting with the Advanced Communica-tions Technology Satellite and (2) to deter-mine insofar as possible what the experimentcharacteristics and requirements would be.The NOI solicited an expression of intent toconduct an experiment and a preliminarydescription of the proposed experiment. NASAwill strive to accommodate all United Statesexperiments that are technically and scien-tifically relevant to the basic objectivesof the ACTS program.
To facilitate the timely development ofthe multibeam antenna, it was necessary tospecify the antenna beam locations inmid-1985. Selected antenna ground coveragelocations were based, among other considera-tions, on the initial experimenter responsesto the NOI.
A more formal commitment to the experi-ments program will be solicited through an
Experiments Opportunity Notice (EON) plannedfor issue in 1987.
Experimenters are expected to includepersonnel from Lewis, other NASA centers,United States industries,' universities andother government agencies.
Responsibilities of both NASA and theexperimenters are outlined in Table II.NASA will furnish the ACTS spacecraft, theNASA Ground Station (NGS) arid Master ControlStation (MCS) and access to the ACTS space-craft at no cost to the experimenter duringthe planned 3-yr experiments period. Experi-menter access to and use of the NGS will alsobe accommodated on a noninterference basis.NASA will manage the planning, schedulingand operations of all experiments. Data forcomponent performance evaluation for theadvanced technology hardware on board thespacecraft, along with pertinent spacecraft/MCS auxiliary correlating data necessary forthe various technology and system experimentswill be collected and archived in the MCS anddistributed to the appropriate investigators.
The experimenters will be responsible forproviding the resources required to plan,coordinate, conduct their proposed experi-ments and to report the analyzed results.
An important element in the developmentof the experiments program will be the forma-tion of an Experiments Working Group. Thisgroup will be composed of all experimentersand will define plans and coordinate ACTSNetwork/Experiment compatibility. Key activ-ities of this group will be to promotedialogue between experimenters as well asfoster the formation of experiment teamswhere individual experimenters could pooltheir 'resources to maximize their experimentcapability. This group will also assistNASA in determining experiment networks andthe allocation of the various ACTS systemresources to and for the various phases of -.the experiments program.
A NASA Ground Terminal Development teamhas been formed at Lewis to assist in theprocurement of suitable ground terminals forexperiments. NASA, in coordination withexperimenters, will develop overall groundterminal requirements and system specifica-tions. Designs will stress component modu-,larity to allow experimenters flexibility inconfiguring their own terminals. This teamwill act as a procurement agent for govern-ment agencies and other interested organiza-tions in an attempt to lower terminal costsby aggregating individual procurements intoa group buy. Procurements will be structured
to minimize cost as well as to encourage themaximum number of equipment/terminal manu-factures to participate. Ground terminaldesigns and specification will also be madeavailable to interested experimenters. Thisteam will also assist experimenters withtraining, site selection, installation,checkout and maintenance of their groundterminals.
After launch and a subsequent period foron-orbit checkout, a nominal 3 yr period ofexperimentation is planned. It should benoted that a launch date has not been estab-lished at this time due to Shuttle manifestuncertainty. The earliest1launch date wouldbe May 1990. Figure 5 provides an overviewof the major activities and interactionbetween the NGS/MCS, the ACTS spacecraft andthe experimenters ground terminals duringthis experiments operation period. The MCSwill provide Mission, Network and ExperimentOperations functions.
EXPERIMENTER RESPONSESA summary of the experimenter responses
to date to the NOI for ACTS Experiments ispresented in Table III. Eighty-five (85)organizations have responded, representing abroad cross section of the United States
telecommunication industry, universities andgovernment agencies. From these responses,some 122 experiments have been proposed anddistributed throughout the various experimentcategories presented in Section 7.
SUMMARYAs the ACTS project completes its prelim-
inary design phase, the designs of all majorflight and ground segment system and sub-system are nearing completion. Key sub-systems are already being implemented inhardware. As the characteristic of thesemajor system elements take shape, moredetailed experiment planning is beinginitiated by NASA.
The ACTS project objectives will be metonly when the ACTS system is deployed, testedand evaluated by a broad cross section ofUnited States experimenters. When completedin the 1990s, the ACTS program will havedeveloped a mature, space-qualified base oftechnology from which industry can draw newcommunications satellite capabilities.Implementation of this technology in theoperational systems of the 1990's and beyondwill help ensure continued growth of theU.S. communications satellite industry andenhance its position as a leader in advancedcommunications satellite technology.
TABLE I. - TYPICAL ACTS GROUND TERMINALS
Satelliterouting mode
Type Antennadiameter,
M
Trans-mitterpower ,W
Capacity Uplinkburstrate,MSPS
Downlinkburstrate,MSPS
Access
EVC - 64 KBPS Equivalent voice circuit
Basebandprocessor viatwo hopping
beams
Micro-1
LBR-2
LBR-1
1.8
3.0
5.0
10
15
15
1 to 24 EVC
1 to 48 EVC
1 to 96 EVC
13.75
27.5
110
55
110
110
TDMA
TDMA
TDMA
MSM - Microwave Switch Matrix
MSM static(bent pipe)via three
stationary beams
MSM Dynamicvia three
stationarybeams
Micro-2
HBR
0.3-1
5.0
1
480
56 - 512 KBPS
220 MBPS
N/A
220
N/A
220
FDMA
TDMA
TABLE II. - EXPERIMENTS PROGRAM RESPONSIBILITIES
NASA provides:
Spacecraft time during nominal 3-yr experiment periodMaster control station operationsExperiment program managementNASA ground station for experimenter useData measurements aboard spacecraft and at master control station
NASA will assist experimenters in:
Experiments planningPurchasing and/or leasing terminalsUtilizing NASA ground station or other organizations' ground terminals
Experimenter provides:
Experiment planResources to conduct experimentExperimenter working group supportExperiment operationsAnalysis of experiment results
TABLE III. - SUMMARY OF NOTICE OF INTENT RESPONSES(AS OF JULY 1986)
85 Organizations responded:
122 Experiments
18 Equipment manufacturers7 Carriers
17 Educational institutions5 Health organizations9 Federal government7 NASA centers1 State and local government3 State telecommunications systems6 Nonprofit public service organizations4 Telecommunications consultingcompanies
8 Other corporate firms
JJ3TOGINAL PAGE- iSPOOR QUALITY
FLIGHT SYSTEMMULTIBEAU
COMMUNICATIONSPACKAGE
RECEIVE 2.2 METERMULTIBtAM ANTENNA,
JOGHi
ACTS GROUND SEGMENT
NASA GROUND SEGMENT
C-BANO TT&CSTATION
CARPCNTERSVILLE. NJ
SATELLITE CONTROLCENTER
E.WINDSOR, NJ
MASTER CONTROLSTATION
NASA GROUNDSTATION
EXPERIMENTERNETWORK
PROPAGATION
FIGURE 1.- FUNCTIONAL OVERVIEW OF ACTS SYSTEM.
FIGURE 2.- ADVANCED COMMUNICATIONS TECHNOLOGY SATELLITE.
SEATTLE/PORTLAND
/ r- DENVERv KANSAS CITY/ \
CLEVELAND
SAN FRANCISCOX̂
LOS ANGELES/SAN
PHOENIX/SCOT7SDALE —WHITE SANDS —'
DALLAS/FT.WORTH
— NASHVILLE/HUNTSVILLE
-f— ATLANTA
— MEMPHIS
TAMPA/ORLANDO
-MIAMI
HOUSTON J L NEW ORLEANS
0 SPOT BEAMF FIXED BEANf POLARIZATION
ACTS AT 0° LATITUDE. 100° WSTEERABLE ANTENNA WILL COVER ALL OF U.S. INCLUDING ALASKA & HAWAII
FIGURE 3.- ACTS ANTENNA COVERAGE.
1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993
1 1 1
NOI BEAM^ LOCATIONS
FIXED
1 1 1 1 1 1 1 1
EON LAUNCHV
EXPERIMENTER WORKING GROUP
EXPERIMENTER G/T DEVELOPMENT
EXPERIMENT OPERATIONS
NOI - NOTICE OF INTENTEON - EXPERIMENT OPPORTUNITY NOTICE
NOTE: LAUNCH DATE HAS NOT BEEN ESTABLISHED AT THIS TIME DUE TO A SHUTTLE MANIFEST UNCERTAINTY. EARLIEST LAUNCH DATE WOULDMAY, 1990.
FIGURE 4.- ACTS EXPERIMENTS PROGRAM SCHEDULE.
NASAPRIMARYSTATION
MASTER CONTROL STATION
(REQUEST.DATA.
REPORT)
MASTERCO NT MO I.STATION
EXPERIMENT TECHNICALOPERATIONS
• SCHEDULE AND DATAREQUEST PROCESSING
• DATA DISSEMINATION
• REAL-TIME EXPERIMENTCONTROL INTERFACE
• REPORT GENERATION
(SCHEDULE REQUEST.REAL-TIME REQUESTI
(SCHEDULE. STATUSDATA. REQUESTRESPONSE. AND
PERFORMANCE DATA)
(DATA REQUEST)
NETWORK/MISSIONOPERATIONS
NETWORKCONTROL
MISSIONCONTROL
DATA
(EXPERIMENT ANDSYSTEM DATA)
DATA HANDLING ANDMANAGEMENT SYSTEM
(DATA COLLECTION.PROCESSING. ANALYSIS.
RECORDING. ANDARCHIVING!
FIGURE 5.- ACTS EXPERIMENT OPERATIONS OVERVIEW.
1. Report No.
NASA TM-888202. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle
ACTS Experiments Program
5. Report Date
6. Performing Organization Code
679-507. Authors)
Ronald J. Schertler
8. Performing Organization Report No.
E-3182
10. WorK Unit No.
9. Performing Organization Name and Address
National Aeronautics and Space AdministrationLewis Research CenterCleveland, Ohio 44135
11. Contract or Grant No.
12. Sponsoring Agency Name and Address
National Aeronautics and Space AdministrationWashington, O.C. 20546
13. Type of Report and Period Covered
Technical Memorandum
14. Sponsoring Agency Code
15. Supplementary Notes
Prepared for the Globecom '86, sponsored by the Institute of Electrical andElectronics Engineers, Houston, Texas, December 1-4, 1986.
16. Abstract
This paper presents an overview of the ACTS Experiments Program. ACTS 1s beingdeveloped and will flight test the advanced technologies associated with: aKa-band multlbeam antenna, onboard signal processing and switching as well aslaser communications. A nominal 3 yr experiments program 1s planned. Throughthe experiments program, the capabilities of the ACTS system will be made avail-able to U.S. Industry, university and government experimenters to test, provethe feasibility and evaluate the key ACTS system technologies. Communicationmodes of operation using the baseband processor and microwave switch matrix arepresented, along with the antenna coverage pattern. Potential experiment cate-gories are also presented and briefly discussed. An overall schedule of activ-ities associated with the experiments program 1s outlined. Results of the ACTSExperiments Program will provide Information vital to successful Industry Imple-mentation of ACTS technology 1n future operational system.
17. Key Words (Suggested by Authors))
Satellite communicationsCommunication networksCommunication systems
19. Security Classif. (of this report)
Unclassified
18. Distribution Statement
UnclassifiedSTAR Category
20. Security Classif. (of this page)
Unclassified
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