The system design of atmospheric probes is dominated by the atmospheric entry and descent/drift through the atmosphere, even if surface operations are possible (e.g. Venera 7, 8, Pioneer Venus Day Probe, Huygens). Common experiment types for such probes include entry accelerometry, radio science for tracking the probe's motion, sensors for atmospheric temperature, pressure and humidity, mass spectrometry, aerosol analysis, (spectro-) photometry and nephelometry.

First Soviet Venera and Mars entry probes

This section covers early (1961–65) Soviet entry probes to Venus and Mars designed and built by Korolev's OKB-1 design bureau (now RKK Energia), all of which failed during launch or cruise. In 1965 further development of the deep space and lunar probes was handed over to NPO Lavochkin's Babakin Space Centre (then called OKB-301). Very few published details exist concerning the entry probes.

1VA entry probes

The first launches of atmospheric entry probes were those of Venera 1, lost en route, and its ‘twin’ that failed to leave Earth orbit. The Venera 1 entry capsule was not designed to transmit a signal from the Venusian atmosphere. One could thus argue that these 1VA entry probes should be classed as ‘destructive entry probes’ rather than an atmospheric entry probe in the modern sense of the phrase. The carrier spacecraft part of the 1VA probes were somewhat similar to those of the two Mars 1M craft, which were lost in launch failures in October 1960 (Figure 16.1).