Accession Number:

AD0683093

Title:

SYSTEM OF COMMUNICATION WITH INTERPLANETARY SPACE VEHICLES,

Descriptive Note:

Corporate Author:

FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s):

Report Date:

1968-08-19

Pagination or Media Count:

6.0

Abstract:

A communications system used during deep-space probes Zond, Mars, and Venera is described. The equipment in the Deep-Space Communications Center usually one point provides communications for all deep-space probes. Communication is periodic and scheduled. When the interval between communication-exchange sequences is long enough 15 days, receiver tuning problems arise because of the Doppler frequency shift and signal delay. To avoid these problems, deep-space communications systems in the USSR have a programmed control for correcting the ground-based transmitter and receiver heterodyne frequencies. This control uses the real-time parameters from the space-flight trajectory and velocity. The control system determines the difference between measured and predicted system frequency and signal-delay time. The accuracy of the frequency control is about 0.25 Hz with a phase shift of 1--2 degrees, and the accuracy of signal-delay time is 1--2 msec. A noncoherent detector is used in the space receiver because the ground transmitter imparts about 100 kw of power to the antenna. The ground receiver has a coherent receiver, and the message from space is modulated by a code-FM-PM or code PM-PM system. Practical use of the communication system described shows that it provides communication without additional receiver-frequency adjustment and is recommended for use in deep-space communications. Author

Subject Categories:

  • Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE