Apollo 6 Launches

apollo 6 soaring through the skyApollo 6 soaring through the sky - Image credit: NASA

Apollo 6 was launched on 4 April 1968.

It was the final unmanned Apollo mission, so a lot of things had to go right to be clear to make the next mission a success.

Expectations were very high for the mission:

  1. demonstrate trans-lunar injection capability of the Saturn V
  2. repeat demonstration of the Command Module's (CM) heat shield capability to withstand a lunar re-entry

Shortly after launch it was already clear that things weren't going to go as planned.

Rocketdyne J-2 Engine Failure

A phenomenon called pogo oscillation ruptured the internal fuel lines to the some of the Rocketdyne J-2 engines of the Saturn V rocket. That caused the second and thrid stages to shut down early.

This led to a different parking orbit than what was planned. The third stage engine also failed to restart for the trans-lunar injection.

apollo 6 interstage falling

The interstage falling - Image credit: NASA

Command and Service Module Re-entry

The second objective was to perform a high speed re-entry of the Command and Service module, in case a mission had to be aborted.

This re-entry was successful and the CSM landed 80 kilometers from the planned touchdown, in the North Pacific Ocean, north of Hawaii.

apollo 6 command moduleThe Apollo 6 Command Module is hoisted aboard the U.S.S. Okinawa - Image credit: NASA

Despite a failure of one of the objectives, officials felt confident enough to go ahead and perform a manned mission, using the Saturn IB rocket for  the Apollo 7

Leave a comment

Please note, comments must be approved before they are published