Apollo Program · Uncrewed test flight

Apollo 6

Uncrewed test

Launch: 1968-04-04 12:00 UTC
Return: 1968-04-04 21:57 UTC
Duration: 09:57:20

Mission summary

Apollo 6 was the second and final uncrewed Saturn V flight, intended to repeat Apollo 4's full-profile test before the rocket was committed to a crewed flight. The mission suffered severe pogo oscillations during first-stage burn, two S-II engine cutouts, and a failed S-IVB restart. Despite these anomalies, ground controllers improvised a CSM-engine workaround and the heat-shield re-entry test succeeded. NASA accepted the results as sufficient and committed the next Saturn V to a crewed flight (Apollo 8) without further uncrewed testing.

Launch vehicle

Saturn V SA-502 (second Saturn V)

Objectives

Second flight test of the Saturn V.
Verify Saturn V performance under simulated lunar-mission profile.
Repeat CSM heat-shield test at simulated lunar-return velocity.

Milestones

When	Event
1968-04-04 12:00 UTC	Launched from LC-39A. https://www.nasa.gov/mission_pages/apollo/missions/apollo6.html
1968-04-04	Severe pogo oscillations during S-IC first-stage flight; two J-2 engines on the S-II second stage shut down prematurely. https://history.nasa.gov/SP-4029/Apollo_06a_Summary.htm
1968-04-04	S-IVB failed to restart for the trans-lunar injection-simulating burn; ground controllers used the SPS engine on the CSM as a workaround. https://history.nasa.gov/SP-4029/Apollo_06a_Summary.htm
1968-04-04 21:57 UTC	CSM splashed down in the Pacific; recovered by USS Okinawa. https://history.nasa.gov/SP-4029/Apollo_06a_Summary.htm

Primary sources

Last updated 2026-05-09 15:17 UTC.