National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Mars 4
 By Target   By Name   By Decade 
Search all Missions Between:      and      Search
1950-1959 1960-1969 1970-1979 1980-1989 1990-1999 2000-2009 2010-2019 2020+
Mars 4
Mars 4 Mission to Mars

Goals: Mars 4 was to orbit Mars (along with Mars 5), taking pictures and conducting remote-sensing experiments on the atmosphere and surface, and to serve as a communications relay for the Mars 6 and 7 landers.

Accomplishments: Faulty transistors disabled the spacecraft's ability to slow down and enter an orbit around Mars, so Mars 4 became a flyby mission. It transmitted the results of one imaging session and some radio occultation data which constituted the first detection of the nightside ionosphere on Mars. Following the flyby, Mars 4 returned data about the interplanetary environment.

Key Dates
21 Jul 1973:  Launch
10 Feb 1974:  Mars Flyby
Status: Unsuccessful
Fast Facts
Mars 4 Facts This was part of a planned Soviet fleet intended to preempt America's 1976 Viking missions.

A transistor failure prevented the planned orbit insertion. The spacecraft flew past Mars instead.

The spacecraft did transmit interplanetary data after the flyby.
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 30 Nov 2010