The Soviet probe Venera 4 successfully sent a descent capsule into the Venusian atmosphere in October 1967, collecting and transmitting data on temperature and pressure. In the same month, the American Mariner 5 spacecraft flew within 4,000 km of Venus and measured the surface temperature at 267°C during its flyby, gathering additional atmospheric data without landing. An earlier Soviet attempt, Cosmos 167 in June 1967, failed to achieve the proper orbit to carry it to Venus after separating from its rocket, but still provided some planetary information.

1. October 18, 1967
The Soviet probe Venera 4 sent a
descent capsule into the Venusian
atmosphere.
While getting close to Venus it collected
data and sends it back to Earth.
When Venera 4 arrived at Venus it
dropped several instruments, including a
thermometer and a barometer, into the
atmosphere.

2. October 19, 1967
Mariner 5 flew within 4,000 kilometers
(2,400 miles) of the Venusian cloud tops.
During its flyby, the spacecraft measured
a surface temperature of 267°C.
The Mariner 5 did not land on Venus but
it did collect data by flying by Venus.
June 17, 1967
Cosmos 167 the final stage of the rocket
carrying the spacecraft into orbit.
It failed but it also gave us some
information about Venus.

3. It was unable to achieve the necessary
trajectory to carry it on to Venus.