Orbiter

Explorer 33

Unknown

Milestones

Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016 (NASA SP-2018-4041)Table 1, no. 70 (launch)
WikidataQ1384557 (identifiers, Wikipedia links)
Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016 (NASA SP-2018-4041)Table 1, no. 70: code P, partial success (outcome: sources disagree)
Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016 (NASA SP-2018-4041)no. 70, Results: "The mission was declared a success by 1 January 1967, although the spacecraft continued to return useful data until 15 September 1971" (outcome: sources disagree)
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes, 1958–2000 (NASA SP-2002-4524)Master Table p. 184, Explorer 33: code P, partial success (outcome: sources disagree)
NSSDCA Master Catalog and lunar mission pages1966-058A: "failed to achieve lunar orbit but did achieve mission objectives" (outcome: sources disagree)

Checked on 2026-10-04