Apollo 6

[catdlr]

Apollo 6 Mission 1968 NASA; Saturn V & Apollo Spacecraft Earth Orbit Test

Jeff Quitney
Published on Jan 7, 2018


An unmanned test of the Saturn V launch vehicle; the final unmanned Apollo test mission. The sound on this film was missing.

Apollo 6 (also known as AS-502), launched on April 4, 1968, was the second A type mission of the United States Apollo program, an unmanned test of the Saturn V launch vehicle. It was also the final unmanned Apollo test mission.

The objectives of the flight test were to demonstrate trans-lunar injection capability of the Saturn V with a simulated payload equal to about 80% of a full Apollo spacecraft and to repeat demonstration of the Command Module's (CM) heat shield capability to withstand a lunar re-entry. The flight plan called for following trans-lunar injection with a direct return abort using the Command/Service Module's (CSM) main engine, with a total flight time of about 10 hours.

A phenomenon known as pogo oscillation damaged some of the Rocketdyne J-2 engines in the second and third stages by rupturing internal fuel lines, causing two second-stage engines to shut down early. The vehicle's onboard guidance system was able to compensate by burning the second and third stages longer, though the resulting parking orbit was more elliptical than planned. The damaged third stage engine also failed to restart for trans-lunar injection. Flight controllers elected to repeat the flight profile of the previous Apollo 4 test, achieving a high orbit and high-speed return using the Service Module (SM) engine. Despite the engine failures, the flight provided NASA with enough confidence to use the Saturn V for manned launches. Since Apollo 4 had already demonstrated S-IVB restart and tested the heat shield at full lunar re-entry velocity, a potential third unmanned flight was canceled.

Objectives

Apollo 6 was intended to send a Command and Service Module (CSM) plus a Lunar Module Test Article (LTA), a simulated Lunar Module (LM) with mounted structural vibration sensors, into a translunar trajectory. However, the Moon would not be in position for a translunar flight, and the Service Module engine would be fired about five minutes later to slow the craft, dropping its apogee to 11,989 nautical miles (22,204 km) and causing the CSM to return to Earth, simulating a "direct-return" abort. On the return leg, the engine would fire once more to accelerate the craft to simulate the nominal lunar return trajectory with a re-entry angle of -6.5 degrees and velocity of 36,500 feet per second (11,100 m/s). The entire mission would last about 10 hours.

This would test the Saturn V launch vehicle's ability to send the entire Apollo craft to the Moon, and in particular test the stresses on the Lunar Module and the vibration modes of the entire Saturn V with near-full loads. A full lunar mission spacecraft weight was not quite simulated because the LTA-2R weighed 26,000 pounds (12,000 kg), only about 80% of a nominal LM (32,000 pounds (15,000 kg)). Also, the CSM was only fueled to a weight of 55,420 pounds (25,140 kg) instead of the nominal lunar mission weight of 63,500 pounds (28,800 kg).

It was the first mission to use High Bay 3 in the Vertical Assembly Building (VAB), Mobile Launcher 2, and Firing Room 2.

Unlike the virtually perfect flight of Apollo 4, Apollo 6 experienced problems right from the start. Two minutes into the flight, the rocket experienced severe pogo oscillations for about 30 seconds.

After the first stage was jettisoned, the S-II second stage began to experience its own problems. Engine number two had performance problems from 225 seconds after liftoff, which abruptly worsened at T+319 seconds, and then at T+412 seconds the Instrument Unit shut it down altogether. Then two seconds later, engine number three shut down as well. The Instrument Unit was able to compensate, and the remaining three engines burned for 58 seconds longer than normal. The S-IVB third stage also had to burn for 29 seconds longer than usual. The S-IVB also experienced a slight performance loss.
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Originally a public domain film, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

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Update: Jeff Quitney YT account that was suspended.  No alternate video has been located
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https://youtube.com/watch?v=6nLQ1EeU6lo

[MATTBLAK]

Thank you so, SO much for putting this Apollo 6 film up!! I've waited many years to see virtually any footage from this troubled, but very important mission. You are literally 'doing God's work' for Space Geeks like me!!

[brihath]

Awesome video...thanks for sharing!  I love the Beethoven soundtrack to the film.  One German phrase is particularly appropriate: "Such ihn uber'm Sternenzelt" which means Seek Him beyond the Stars".

The back story regarding how NASA overcame the issues that plagued this flight to allow for a manned launch of the Saturn V only a year later must be a fascinating one.  I am not sure if it has been detailed in a publication, but it would make for a great read.  All of this occurred concurrent with NASA's effort to recertify the Apollo Command module for flight following the Apollo 1 fire.

[HDTVGuy]

"Apollo: A Race to the Moon' by Murray and Cox has a good description of the work done to rectify the problems encountered on this flight.

I've always liked Apollo 6, as the CM is in a local museum here in Atlanta.

[catdlr]

Thank you so, SO much for putting this Apollo 6 film up!! I've waited many years to see virtually any footage from this troubled, but very important mission. You are literally 'doing God's work' for Space Geeks like me!!

MATTBLAK, Thanks for the kind words.  You lifted my heart with your comment.  I was too surprised that there was nothing on NSF for Apollo 6.  I'm happy to contribute.

[kking]

After reading GO FLIGHT, I'd love to find a audio tape of flight control loops in mission control during the launch.

[Sam Ho]

The Mission Report is here:  In addition to the J-2 failures, there was also a structural failure in the SLA.
http://hdl.handle.net/2060/19700025117

[the_other_Doug]

The Mission Report is here:  In addition to the J-2 failures, there was also a structural failure in the SLA.
http://hdl.handle.net/2060/19700025117

Which had nothing to do with the first stage POGO issues, as many people assume.  The SLA panel failures had to do with rainwater getting into the honeycomb structure of the panels, expanding as the stack reached low external pressures (as well as moving destructively within the panels during max-Q), and breaking a couple of the hold-downs.  That caused one whole panel and a portion of another to rip off.

Amazing, that the stack stayed together with one of the four SLA panels completely off the bird.  I think pre-flight analyses had predicted that you needed all four SLA panels in place to maintain structural integrity at the CSM separation plane.  The fact that the stack survived three different situations that, pre-flight, were thought to have been non-survivable just goes to show how sturdy those Saturn stages were, overall...

[Lars-J]

I'm sorry, but that could have been better - IMO. I expected some informative narration, not some 2001 inspired music montage. Interesting footage, but the music. Ugh.

[catdlr]

I'm sorry, but that could have been better - IMO. I expected some informative narration, not some 2001 inspired music montage. Interesting footage, but the music. Ugh.

Gee, your hard.  It's a 1960's NASA film.  Frome what I reviewed (and I've seen alot), it's about par for them (as well as for some other vendors that I've posted).

[Lars-J]

I'm sorry, but that could have been better - IMO. I expected some informative narration, not some 2001 inspired music montage. Interesting footage, but the music. Ugh.

Gee, your hard.  It's a 1960's NASA film.  Frome what I reviewed (and I've seen alot), it's about par for them (as well as for some other vendors that I've posted).

I'm only comparing to the great video in the "Saturn Base Heating" thread: http://forum.nasaspaceflight.com/index.php?topic=44635.0 - but perhaps it spoiled me.

[catdlr]

I'm sorry, but that could have been better - IMO. I expected some informative narration, not some 2001 inspired music montage. Interesting footage, but the music. Ugh.

Gee, your hard.  It's a 1960's NASA film.  Frome what I reviewed (and I've seen alot), it's about par for them (as well as for some other vendors that I've posted).

I'm only comparing to the great video in the "Saturn Base Heating" thread: http://forum.nasaspaceflight.com/index.php?topic=44635.0 - but perhaps it spoiled me.

Lar-J,  I understand.  We're lucky any of these historic videos are being found and uploaded to YouTube.  Who knows how many many testing/development videos are in homes of retired engineers waiting to be discovered.

[4throck]

I'm certain the Apollo 6 video originally had sound. Perhaps a copy with sound will surface latter.

Sure, some of these are not spectacular in any way (editing, narration, etc).
But as mentioned, we are fortunate to have these videos available.

They are very useful because without them, even if you have raw footage, you can't identify were it belongs.
Also, by piecing together documentaries covering the same flight, you can reassemble the original sequences.

 

[HDTVGuy]

I'm very grateful catdlr digs these out and posts them for us.

Better is the evil of good.

[catdlr]

Kennedy Space Center: "Bridge to Space" 1968 NASA; Apollo 6 Saturn V Launch

Jeff Quitney
Published on Jan 26, 2018


A tour of NASA's Kennedy Space Center (KSC, NASA Kennedy) culminates in an unmanned test of the Saturn V launch vehicle (Apollo 6); the final unmanned Apollo test mission. This film was shot in Panavision anamorphic 70mm by director Robert Gaffney.

Apollo 6 (also known as AS-502), launched on April 4, 1968, was the second A type mission of the United States Apollo program, an unmanned test of the Saturn V launch vehicle. It was also the final unmanned Apollo test mission.

The objectives of the flight test were to demonstrate trans-lunar injection capability of the Saturn V with a simulated payload equal to about 80% of a full Apollo spacecraft and to repeat demonstration of the Command Module's (CM) heat shield capability to withstand a lunar re-entry. The flight plan called for following trans-lunar injection with a direct return abort using the Command/Service Module's (CSM) main engine, with a total flight time of about 10 hours.

A phenomenon known as pogo oscillation damaged some of the Rocketdyne J-2 engines in the second and third stages by rupturing internal fuel lines, causing two second-stage engines to shut down early. The vehicle's onboard guidance system was able to compensate by burning the second and third stages longer, though the resulting parking orbit was more elliptical than planned. The damaged third stage engine also failed to restart for trans-lunar injection. Flight controllers elected to repeat the flight profile of the previous Apollo 4 test, achieving a high orbit and high-speed return using the Service Module (SM) engine. Despite the engine failures, the flight provided NASA with enough confidence to use the Saturn V for manned launches. Since Apollo 4 had already demonstrated S-IVB restart and tested the heat shield at full lunar re-entry velocity, a potential third unmanned flight was cancelled.

Objectives

Apollo 6 was intended to send a Command and Service Module (CSM) plus a Lunar Module Test Article (LTA), a simulated Lunar Module (LM) with mounted structural vibration sensors, into a translunar trajectory. However, the Moon would not be in position for a translunar flight, and the Service Module engine would be fired about five minutes later to slow the craft, dropping its apogee to 11,989 nautical miles (22,204 km) and causing the CSM to return to Earth, simulating a "direct-return" abort. On the return leg, the engine would fire once more to accelerate the craft to simulate the nominal lunar return trajectory with a re-entry angle of -6.5 degrees and velocity of 36,500 feet per second (11,100 m/s). The entire mission would last about 10 hours.

This would test the Saturn V launch vehicle's ability to send the entire Apollo craft to the Moon, and in particular test the stresses on the Lunar Module and the vibration modes of the entire Saturn V with near-full loads. A full lunar mission spacecraft weight was not quite simulated because the LTA-2R weighed 26,000 pounds (12,000 kg), only about 80% of a nominal LM (32,000 pounds (15,000 kg)). Also, the CSM was only fueled to a weight of 55,420 pounds (25,140 kg) instead of the nominal lunar mission weight of 63,500 pounds (28,800 kg).

It was the first mission to use High Bay 3 in the Vertical Assembly Building (VAB), Mobile Launcher 2, and Firing Room 2.

Unlike the virtually perfect flight of Apollo 4, Apollo 6 experienced problems right from the start. Two minutes into the flight, the rocket experienced severe pogo oscillations for about 30 seconds.

After the first stage was jettisoned, the S-II second stage began to experience its own problems. Engine number two had performance problems from 225 seconds after liftoff, which abruptly worsened at T+319 seconds, and then at T+412 seconds the Instrument Unit shut it down altogether. Then two seconds later, engine number three shut down as well. The Instrument Unit was able to compensate, and the remaining three engines burned for 58 seconds longer than normal. The S-IVB third stage also had to burn for 29 seconds longer than usual. The S-IVB also experienced a slight performance loss.
-------------------------------------------------------
Originally a public domain film from the US National Archives slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

===================================
Update: Alternate video source to replace Jeff Quitney former YT account that was suspended.
===================================

[MATTBLAK]

Thank you for that. Though I see that the flat earth retards have already started commenting on the film

EDIT: Thanks for removing their idiotic comments.

[FlokiViking]

I really enjoyed that Bridge video.  Interesting mix of mid-60's life on the bus tour, nature scenes, and music, along with the historic technical achievements of the time.
Definitely one to add to my Apollo playlist collection.
Thanks for the reference!

[catdlr]

Apollo 6 Launch - Multi View

Sep 10, 2024
Apollo 6 Launch - Multi View
17 different views of Apollo 6 from the launch through to orbit - April 4th 1968

[dandy_don]

Amazing that NASA allowed Apollo 8 to fly after the previous Saturn V had first stage problems that caused fuel line ruptures and engine shutdowns in the second stage.   

Today's NASA wouldn't let astronauts return in a Starliner with some thruster issues despite Boeing saying everything was okay.   FWIS, Boeing was correct on that call.   

[laszlo]

Amazing that NASA allowed Apollo 8 to fly after the previous Saturn V had first stage problems that caused fuel line ruptures and engine shutdowns in the second stage.   

Today's NASA wouldn't let astronauts return in a Starliner with some thruster issues despite Boeing saying everything was okay.   FWIS, Boeing was correct on that call.

The big difference is that the Saturn V's problems were diagnosed, understood, remedied and tested before the astronauts climbed into Apollo 8.