This is an image of a Saturn on the launch pad on July 20th 1973

enter image description here

It appears to be resting on an elevated platform that raises it significantly off the ground.

Why was this done? It seems like a lot of effort and risk to raise the rocket so much, and the benefits seem minimal.

  • 3
    $\begingroup$ Here's another photo showing the elevated platform. The dark image in the question makes it hard to see the milk stool, IMHO. $\endgroup$
    – DarkDust
    Mar 12 '17 at 8:43
  • 33
    $\begingroup$ A careful examination of history shows that this launch took place just month's before the 1973 oil crisis. Keen NASA administration officials with tremendous foresight decided to place the rocket closer to space, thereby requiring less petroleum-based propellant. See for example here and here. These were difficult times for space agencies. $\endgroup$
    – uhoh
    Mar 12 '17 at 9:04
  • 17
    $\begingroup$ The image is NOT of a Saturn V. $\endgroup$ Mar 12 '17 at 13:22
  • 3
    $\begingroup$ A KSP player would tell you it's for the tiny bit of added delta V. $\endgroup$
    – Joshua
    Mar 12 '17 at 18:59
  • 9
    $\begingroup$ It brings the moon a bit closer. $\endgroup$
    – Wossname
    Mar 13 '17 at 11:49

Your picture is not of a Saturn V, it's of a Saturn IB. The purpose of the elevated platform (known as the "milkstool") is to lift the rocket up so that it can be launched from Pad 39B using the same connections to the launch tower that the much taller Saturn V used.

The early Saturn IB launches used the shorter Pad 34 and Pad 37, but by 1973, those launch pads had been decommissioned, leaving only Pad 39.

  • 2
    $\begingroup$ I wonder how they got it up there on the milkstool. Did they lift it straight up with a crane on the launch tower? $\endgroup$
    – LocalFluff
    Mar 12 '17 at 12:34
  • 12
    $\begingroup$ They built up the stack in the VAB: first the milkstool, then the first stage, etc. $\endgroup$ Mar 12 '17 at 13:18
  • $\begingroup$ Were these not also used for missions to the Soyuz space station in the day? And were those Saturns not merely modified V's to leverage the rockets already built for the program, but mothballed with the operational cuts to the moon program killed further actual moon landings... $\endgroup$
    – David W
    Mar 14 '17 at 16:54
  • 1
    $\begingroup$ @DavidW, in addition to testing flight hardware for the Apollo program, the Saturn IB was used for the three crew flights to Skylab and for the Apollo-Soyuz Test Project. No Apollo ever visited a Soviet Salyut space station. $\endgroup$
    – Mark
    Mar 14 '17 at 19:59
  • $\begingroup$ @mark My apologies - I was confusing the single Apollo-Soyuz joint "goodwill" mission in 1975 where the two ships docked in a scientifically worthless but cold-war significant "detente" show. Thanks for helping me clear the confusion. $\endgroup$
    – David W
    Mar 14 '17 at 20:37

Offered as a supplement, since no one has posted a direct size comparison:

enter image description here

The height difference in the Saturn V and Saturn 1-B is clear in this image.

Edit: SA-1 through -9 are Saturn 1s, SA-201 through -205 are 1-Bs, the last 2 are Vs.

The mission payloads, from left to right:

  • SA-1, development flight with dummy second stage and payload
  • SA-4, more realistic dummy second stage and engine-out test
  • SA-5, complete launcher, dummy payload
  • SA-6/AS-101, "boilerplate" dummy Apollo CSM payload
  • SA-9/AS-103, "boilerplate" dummy Apollo CSM payload + Pegasus satellite
  • SA-201, unmanned Block 1 Apollo CSM
  • SA-203, no payload, restart test of S-IVB upper stage
  • SA-204, Apollo 5, unmanned Apollo LM test
  • SA-205, Apollo 7, first manned Apollo CSM flight
  • SA-501, Apollo 4, unmanned Apollo CSM + dummy LM
  • SA-513, Skylab 1, unmanned space station launch

All of Apollo 8 through Apollo 17 were similar to SA-501; the Skylab crew flights were CSM on Saturn 1B and were similar to SA-205.


  • 14
    $\begingroup$ Which one is the 1-B? $\endgroup$ Mar 12 '17 at 17:32
  • $\begingroup$ That's a great comment, thanks. Editing answer to show that. $\endgroup$ Mar 12 '17 at 18:01
  • $\begingroup$ I keep wanting to describe the differing payloads of each launcher in this diagram; would you mind if I added that information to this answer? $\endgroup$ Mar 13 '17 at 0:14
  • 2
    $\begingroup$ I understand. There is some upper stage and payload commonality. And, never discount the effects of politics. "It's just an upgrade to an existing rocket!" $\endgroup$ Mar 13 '17 at 14:49
  • 1
    $\begingroup$ The original Saturn concept would use a lot of stage commonality across a large range of rockets. The Kennedy challenge timeframe and the post-Apollo-landing withdrawal of funds curtailed the plan, but it should be noted that the I and IB had almost identical first stages, and the IB and V had almost identical uppermost stages. $\endgroup$ Mar 14 '17 at 3:27

A little digging into KSC Launch Complex 39's Wikipedia page and I found this.

A total of thirteen Saturn Vs were launched for Apollo, and the unmanned launch of the Skylab space station in 1973. The mobile launchers were then modified for the shorter Saturn IB rockets, by adding a "milk-stool" extension platform to the launch pedestal, so that the S-IVB upper stage and Apollo spacecraft swing arms would reach. These were used for three manned Skylab flights and the Apollo-Soyuz Test Project, since the Saturn IB pads 34 and 37 at Cape Canaveral AFB had been decommissioned.

While the unmanned launch of Skylab used a Saturn V, the launch vehicle for crewed missions was the smaller Saturn IB. Skylab 1&2

This deliberate double exposure illustrates the comparative sizes and configurations of the Skylab 1 and 2 Space Vehicles at Launch Complex 39 at the Kennedy Space Center, as they sat on the launch pads in 1973. The double exposure creates an illusion that the rockets are side by side, although actually, they are 1 1/2 miles apart.


This photo of Skylab-1 and Skylab-2 vehicles clarifies that the extension platform were in fact used for crewed mission So, the picture is from manned skylab mission launch aboard Saturn IB vehicle.

  • 1
    $\begingroup$ It seems the crew may indeed launch here. I can't tell for sure based on the wording in the caption. $\endgroup$
    – uhoh
    Mar 12 '17 at 8:21
  • 1
    $\begingroup$ Found [this image of Skylab 1 and 2 launch side by side] (nasa.gov/mission_pages/skylab/SkylabImagesCol_archive_1.html) . So, the crewed missions were the ones with the 'milk-stool' supports for launch. $\endgroup$ Mar 12 '17 at 8:38
  • 1
    $\begingroup$ I'm just editing the answer. Couldn't hyperlink. Its a substantial proof. I'll include it in the answer. $\endgroup$ Mar 12 '17 at 8:42
  • 3
    $\begingroup$ I've never seen SA-513 referred to as "Saturn V 2" outside of that Astronautix page. The mission reports refer to the launcher simply as Saturn V. It's also occasionally referred to as a Saturn INT-21, which was a proposed production version of the 2-stage Saturn V, but SA-513 was a plain old Saturn V built for the Apollo program. $\endgroup$ Mar 12 '17 at 20:08
  • 2
    $\begingroup$ The double exposure is an excellent comparison of the two rockets and a good visual explanation of the milkstool configuration, but the answer as written is primarily about the Saturn V, so it just reinforces the misunderstanding in the original post. $\endgroup$ Mar 13 '17 at 0:12

That upper platform was the crawler used for the transport of the fully assembled Saturn V from the assembly building to the launch pad. The lower platform was necessary for the exhaust of the rocket engines. There should be enough space for the flames to escape to the side and not to damage the bottom of the rocket.

  • 6
    $\begingroup$ Look more closely: the Saturn stands on an additional structure. It's called the "milk stool". $\endgroup$
    – DarkDust
    Mar 12 '17 at 8:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.