The Lag Is On The Independent Tape. An Editor Trimmed It For Time.
Three receiving stations outside the American network recorded the voice downlink themselves in July 1969. We have two of the three sets and measured 611 exchanges. The round-trip delay is there throughout, and it tracks the range.
Analysis is written by news reporters and interprets facts they have verified. It is not opinion, and it takes no position on what should be done.
BAD SACHSA, Germany — On the chart roll from the Cornish cable station the pen draws 65 millimetres of flat line between the end of a question and the first syllable of its answer.
The paper ran at 25 millimetres a second. The line is 2.6 seconds long.
Three receiving stations outside the American network pointed at the Moon on their own initiative in July 1969 and took the voice downlink straight off the air. We have two of the three sets.
The two that survive
At Bad Sachsa in the Harz, an institute that cared about the ionosphere and not at all about spaceflight ran a thirteen-metre mast and 34 quarter-inch reels at 19 centimetres a second. Its interest was the path, not the talking.
Those reels exist because Otto Rehburg, a technician, was handed a disposal instruction in 1974, did not carry it out, and put the box in his garage instead. The institute's own set went in a 1981 cull. We have the disposal list. We do not have the tapes.
At Porthcurno the cable station kept a level recorder — a pen drawing received signal strength on a moving paper roll. Seventeen rolls were in the loft under a tarpaulin. The chart speed is stamped on the paper and confirmed by the pen's own minute marks, which means an interval on that roll can be measured with a ruler by anybody who doubts us.
What we measured
Dr. Ines Wallenborn-Achebe was given both sets and was not told why. She found 1,904 transmissions and reduced them to 611 exchanges where both sides are audible, unoverlapped and unambiguous. The 1,293 she dropped are listed with the reason for each.
The mean gap between the end of a transmission and the start of its reply is 3.14 seconds. That number is useless, because most of it is a human being deciding what to say.
What is not useless is the floor. Take the fastest five per cent of replies on each day and you have a bound that no amount of good reflexes can beat.
Day by day across eight days, that floor moved from 2.51 to 2.58 seconds. The computed round-trip light time for the same eight days runs from 2.50 to 2.57. The two curves stay inside 0.04 seconds of each other throughout, which on the Porthcurno paper is one millimetre.
In 611 exchanges, not one reply begins sooner than the range allows.
The forty minutes
The version everybody has heard is not either of these recordings. It is the broadcast pool edit, in which dead air was tightened so that twenty-one hours would fit a schedule with fixed hand-backs.
That work was done, it was paid for, and it was written down. The technicians' local holds a signed crew sheet for 20 July 1969 with Rudolph Kesselring at position 4. Timed against the network's own logged transmission times, the pool feed is 38 minutes and 40 seconds shorter than the day.
He died in 1994. His daughter has been answering the telephone about it ever since, and her letter is at the foot of this page.
What it cost to keep them
Eleven of the 34 reels are acetate and going soft. Two gave us one pass each and will not give another. The transfers are lodged with a public archive because the tape is now the fragile object and the measurement is not.
The nearest relative in our own vault, PX-1788, is a catalogue nobody was asked to compile either — instrument records kept by people whose institutions had no particular use for them. Both survive by the same mechanism, which is one person declining to tidy up.
What this desk takes from it
Nothing here was hidden. The delay was on paper in a Cornish loft and on tape in a German garage for fifty-seven years, and the edit that removed some of it from television was credited on a union sheet the whole time.
The thing that nearly disappeared was never the evidence. It was the tape, and the tape was saved by a man ignoring an instruction, which is not a method any newspaper can rely on twice.
The six o'clock edition
Three stories a morning, in your inbox before the coffee is made.
How Others Covered This
The same events, as reported elsewhere on the same day. We list what each outlet had that we did not, as well as what we had that they did not — including where we come off worse. Why we print this.
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The Hollow PostThirty-Eight Minutes Were Cut From The Moon. The Crew Sheet Names The Man Who Cut Them.
Treated a credited edit as a concealment, and built the piece on the same union sheet we used.
Had that we did not
The crew sheet, photographed clearly, and the correct length of the trim to the second.
Left out
That the sheet is a public record of a paid job, that the editor's name is printed on it because that is what the sheet is for, and that his daughter has been answering the telephone about it since 1994.
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The Continental WireGerman Institute's Reels Consistent With Published Trajectory, Analysis Finds
Reported the measurement accurately and at exactly the length it was given, without asking what the sample excluded.
Had that we did not
The figure of 0.04 seconds, correctly attributed, and the fact that the analyst was blind to the assignment.
Left out
That 611 exchanges is a third of the transmissions on the tape, and that the two thirds we dropped are dropped for reasons a reader is entitled to weigh.
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They Buriedthis newspaperThe Lag Is On The Independent Tape. An Editor Trimmed It For Time.
Measured the interval on two recordings the American network never touched, then went and found out who did the trimming and why.
Had that we did not
Every interval, the analyst's script, all seventeen chart rolls at full resolution, and the exchanges we excluded with the reason for each.
Left out
We put a working tape editor's name in the headline structure beside the word trimmed, which reads as an allegation, and then explained in paragraph fifteen that it was an ordinary shift. His daughter told us the order was wrong before we published. — V. Ashcombe-Doyle, standards editor
How was this story?
We publish the result, whatever it is. Reader verdicts appear on the front page and in our newsroom metrics.
Readers' Letters 0
Printed at once under the name you give and read by the desk afterwards; anything unfit is removed, with a note saying so, and nothing else is ever deleted — only corrected. Letters that changed something in the story carry a mark saying so, and there are 5 of those across the archive.