Communications from a Mars Entry Probe

Abstract

A low risk experiment to determine the principal properties (density, pressure, temperature) of the Martian atmosphere has been studied. A. slender conical capsule is ejected from the Mars fly-by or orbiting spacecraft and enters the planet’s atmosphere. Theoretical and experimental data support the concept of continuous communication between the sharp cone capsule entering the Martian atmosphere and the spacecraft. The communications system basically consists of a 25 watt transmitter phase modulating a 100 mc carrier on the entry capsule and a wideband receiver on the spacecraft. Transmitting power and spacecraft data storage considerations resulted in a data transmission rate of 147 bits per second in a pulse code modulated format.