Manned Space Flight Network

The Manned Space Flight Tracking Network for Apollo 9, consisting of 14 ground stations, four instrumented ships and six Instrumented aircraft, is participating in its third manned flight. It is the global extension of the monitoring and control capability of the Mission Control Center in Houston. The network, developed by NASA through the Mercury and Gemini programs, now represents an investment of some $500 million and, during flight operations, has 4,000 persons on duty. In addition to NASA facilities, the network includes facilities of the Department of Defense and the Australian Department of Supply.

The network was developed by the Goddard Space Flight Center (GSFC) under the direction of NASA1s Office of Tracking and Data Acquisition.

Basically, manned flight stations provide one or more of the following functions for flight control:

1. Telemetry

2. Tracking

3. Command and

4. Voice communications with the spacecraft

Apollo missions require the network to obtain information — instantly recognize it, decode it, and arrange it for computer processing and display in the Mission Control Center.

Apollo generates much more Information than either Projects Mercury or Gemini; therefore, very high speed data processing and display capability are needed. Apollo also requires network support at both Earth orbital and lunar distances. The Apollo Unified S-Band System (USB) provides this capability.

Network Configuration for Apollo 9 Unified S-Band Sites

NASA 30-Ft. Antenna Sites NASA 85-Ft. Antenna Sites

Antigua (ANG) Honeysuckle Creek (HSK),

Ascension Island (ACN) Australia (Prime)

Bermuda (BDA) Goldstone (GDS), Calif.

Canary Island (CYI) (Prime)

Carnarvon (CRO), Australia Madrid (MAD), Spain (Prime)

Grand Bahama Island (GBM) ■«Canberra (DSS-42-Apollo Wing)

Guaymas (GYM), Mexico *Goldstone (DSS-ll-Apollo Wing)

Merritt Island (MIL), Fla. *Madrid (DSS-6l-Apollo Wing)

Texas (TEX), Corpus Christ! (Backup)

Tananarive (TAN), Malagasy Republic (STADAN station in support role only.)

* Wings have been added to JPL Deep Space Network site operations buildings. These wings contain additional Unified S-Band equipment as backup to the Prime sites to allow for the use, if necessary, of the Deep Space 85-ft. antennas.

Network Testing

The MSFN began its Network Readiness Testing for Apollo 9 on Jan. 20 and continued through Feb. 5 when the network went on mission status. Through established computer techniques Goddard1s Real-Time Computer Center (RTCC) conducted system-by-system, station-by-station tests of all tracking/data acquisition and communications systems until all support criteria were met and the MSFN pronounced ready to participate in the mission.

Spacecraft Communications

All Manned Space Flight Network stations are prepared to communicate with the Apollo 9 spacecraft in two different modes, S-Band and VHF.

When a station acquires the spacecraft, those sites having Unified S-Band and VHF air-to-ground capability will select the besht quality and pass it to the Mission Control Center. All stations will monitor air-to-ground conversations for a possible crew request to switch the spacecraft communications.

NASA Communications Network - Goddard

This network consists of several systems of diversely routed communications channels leased on communications satellies, common carrier systems and high frequency radio facilities where necessary to provide the access links.

The system consists of both narrow and wide-band channels and some TV channels. Included are a variety of telegraph, voice and data systems (digital and analog) with a wide range of digital data rates. Alternate routes or redundancy are provided for added reliability.

A primary switching center and intermediate switching and control points are established to provide centralized facility and technical control under direct NASA control. The primary switching center is at Goddard, and intermediate switching centers are located at Canberra, Australia; Madrid, Spain; London, England; Honolulu, - Hawaii; Guam and Cape Kennedy, Pla.

Cape Kennedy 13 connected directly to the Mission Control Center by the communication network1s Apollo Launch Data System (ALDS), a combination of data gathering and transmission systems designed to handle launch data exclusively.

After launch all network and tracking data are directed to the Mission Control Center through Goddard. A high-speed data line connects Cape Kennedy to Goddard, where the transmission rate is increased from there to Mission Control Center Upon orbital insertion, tracking responsibility is transferred between the various stations as the spacecraft circles the Earth.

Two Intelsat communications satellites will be used for Apollo 9, one positioned over the Atlantic Ocean at about 60 degrees W. longitude in a near equatorial synchronous orbit varying about six degrees N. and S. in latitude. The Atlantic satellite will service the Ascension Island USB station, the Atlantic Ocean ship and the Canary Island site.

Only two of these three stations will be transmitting information back to Goddard at any one time, but all three stations can receive at all times.

The second Apollo Intelsat communications satellite is located about 170 degrees E. longitude over the mid-Pacific near the Equator at the international dateline. It will service the Carnarvon, Australian USB site and the Pacific Ocean ships. All these statioia^Sill be able to transmit simultaneously through the satellites to the Mission Control Center via Jamesburg, Calif., and the Goddard Space Plight Center.

Sltes with "Dual" Capability

Certain stations of the Manned Space Plight Network can provide tracking, voice and data acquisition for two Apollo spacecraft simultaneously, provided they are within the beam-width of the single Unified S-Band antenna. Two sets of frequencies separated by approximately five megahertz are used for this purpose. In addition to this primary mode of communications, the Unified S-Band system has the capability of receiving data on two other frequencies; primarily used for downlink data from the CSM*

For Apollo 9, this capability will be utilized when the LM and CSM have separated. Effective "dual" acquisition displacement distance between CSM and LM is one-hundred miles at a relative angle of forty-five degrees.

The "Dual" sites; 85 Ft. Antenna Systems

Honeysuckle Creek, Australia

Madrid, Spain

Goldstone, Calif.

30 Ft. Antihna Systems

Carnarvon, Australia Ascension Island Merritt Island, Fla. Guam Island, Pacific

Spacecraft; Television

Television transmissions will be received, recorded and converted to commercial (home) format for release to the public by the Merritt Island, Fla., and Goldstone, Calif., Manned Space Flight Network stations.

Prime Site

Wing Site (backup)

Prime Site

Wing Site (backup)

Prime Site

Wing Site (backup)

Kauai, Hawaii

Bermuda (Uplink only)

Antigua (Uplink only)

0 0

Post a comment