Venera 4
Venera 4 — the first probe to send back data from inside the atmosphere of another planet (18 October 1967). For 93 minutes on its parachute it measured the air of Venus — 90–95% carbon dioxide — until it fell silent about 25 km up, at 22 bar and 277 °C. The deep atmosphere proved far hotter and denser than it was built for.
Key facts
Mission & specifications
Mission
- Operator
- Lavochkin (USSR)
- Launched
- June 12, 1967
- Status
- Completed
Trajectory
- Distance from the Sun
- 0.726 AU
- Computed from the cached position
- Distance from Earth
- 0.335 AU
- Computed from cached positions
- Distance from Venus
- 13,150,559 km
- Computed from cached positions
Mission
Venera 4 was the first probe to send back measurements from inside the atmosphere of another planet. It was launched on 12 June 1967 with a 383 kg descent probe: a sphere about a metre across, protected by a heat shield, with thermometers, a barometer, a radio altimeter, a density gauge and eleven gas analysers. Before arrival it was chilled to −10 °C. On 18 October 1967 at 04:34 UT the probe entered the night-side atmosphere of Venus. After braking behind its heat shield it opened its parachutes, and its instruments ran for 93 minutes, returning 23 sets of readings as it sank. The atmosphere was denser than expected, so it drifted down more slowly than planned. It fell silent about 25 km above the surface, at 22 bar and 277 °C, either because its batteries ran out or because the heat and pressure overcame it. It found the air 90–95% carbon dioxide; the carrier craft detected no magnetic field. At first it was believed to have reached the ground, and these to be surface readings. The probes that followed showed that the surface was even hotter and the pressure even higher.
- 1967Launch toward VenusLaunch
An atmospheric probe sets out, chilled for the heat to come.
The probe enters the night side at 04:34 UT and opens its parachutes.
- 1967First data from another planet's atmosphereMilestone
93 minutes of readings: 90–95% carbon dioxide, until silence about 25 km up at 22 bar and 277 °C.
Images
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