Mariner 5

Mariner 5

Spacecraft· NASA / JPLcompleted

Mariner 5 — NASA/JPL's Venus flyby of 19 October 1967, rebuilt from Mariner 4's flight spare. Carrying no camera, it swept about 4,000 km past Venus and used radio occultation and field/particle instruments to probe the crushing CO₂ atmosphere, find a hydrogen corona, and show Venus has essentially no magnetic field yet still deflects the solar wind.

Open in 3D viewSee Mariner 5 in the live, interactive 3D map

Key facts

Distance from Sun
0.728 AU
Status
Completed
Launched
1967

Mission & specifications

Mission

Operator
NASA / JPL
Launched
June 14, 1967
Status
Completed

Trajectory

Distance from the Sun
0.728 AU
Distance from Earth
0.597 AU
Distance from Venus
713,082 km

Mission

Mariner 5 was a mission of thrift and ingenuity — built from the spare parts of an earlier flight and turned to an entirely new target. Originally a backup for Mariner 4's 1964 Mars flyby, the leftover spacecraft was rebuilt to study Venus instead, its heat shielding reworked for a mission toward the Sun rather than away from it. Launched on 14 June 1967, it swept about four thousand kilometres past Venus on 19 October. It carried no camera; this was a mission of invisible senses. As the spacecraft passed behind the planet, engineers watched its radio signal bend and fade through the atmosphere, and from that occultation — with its ultraviolet and particle instruments — Mariner 5 measured the crushing density of Venus's carbon-dioxide air, detected a tenuous hydrogen corona, and showed that Venus has essentially no magnetic field of its own yet still carves a bow shock in the solar wind. It sharpened the emerging, forbidding portrait of Venus as a world utterly unlike Earth.

  1. 1967Rebuilt for VenusLaunch

    Mariner 4's flight spare, reworked from a Mars to a Venus mission, launches on an Atlas-Agena.

  2. 1967Venus flybyFlyby

    Carrying no camera, it uses radio occultation and field instruments to probe the CO₂ atmosphere and confirm Venus lacks a magnetic field.

  3. 1968Contact endedMission end

    After a brief re-acquisition in October 1968, contact attempts are formally ended.

Images

Mariner 5, a refurbished Mariner-4-class craft that flew past Venus in 1967 — it carried no camera
NASA / JPL (public domain) · Wikimedia Commons

Images from open archives · credit shown per image