Apollo 13 interviews


1.) Bill Wood on the LM / IU frequency clash.
2.) Bruce Window on getting Parkes up.


1.) On the LM / IU frequency clash

Bill Wood

Bill Wood at Goldstone talks about the problems caused by having the Lunar Module and the Instrument Unit on the SIVB on the same frequency. At the time of the explosion, Bill was USB team leader at the Goldstone Wing site, DSS11 (Pioneer).

audio. 2.2MB mp3 file runs for 9 minutes.

(The photo shows Bill, at left, at Goldstone MSFN station during Apollo 10.)

Bill also writes:

“A little background about how the Apollo S-band transponders worked. When the transponders are not locked to an uplink from the MSFN, the downlink goes back to a rest frequency that is close to the center of its range. To acquire the transponder the uplinking station sweeps its transmit frequency until it captures the transponder receiver. Then the MSFN exciter operator decays the sweep and locks the uplink frequency to the required exciter frequency synthesizer for normal tracking. (Page 262 of SP-87 [18MB PDF file] has a detailed description of the two-way lock process.)

However, both GDS Prime and GDS Wing were both uplinking at the same time while both the S-IVB IU and the LM transponders were locked together. When the GDS Wing station uplink to the IU was turned off, both transponders stayed locked to the GDS Prime uplink.

The only way the two transponders could be separated was to have the LM turn off its S-band transponder. Once that was done the station assigned to track the S-IVB IU could drag it off to one side before the LM transponder was powered up. Then the station assigned to track the LM could reacquire the LM and keep it away from the IU transponder. This process was completed over HSK after the handover from GDS.”

(Recorded 08 April 2010. With thanks to Bill Wood.)

2.) On getting Parkes up

Bruce Window

Bruce Window in the control room at Parkes, shortly after arriving from Tidbinbilla.

Bruce writes:

I am leaning over the intercom writing something. You can see my suit coat folded up on top of the intercom. We just got into the dish and were flat out trying to make it all happen.

Dr John Bolton (CSIRO) is at left near the door, Jack Dickinson (Tidbinbilla RF Senior Tech.) is near me and facing me, and Peter Stewart (RF/Comms Technician, Tidbinbilla) is seated at SDDS with head in hand.The CSIRO dish driver [Neil ‘Fox’ Mason] is at left foreground.”

Bruce adds (January 2011):

“I know now, on reflection, that with the first pass of Apollo 13 at Parkes, the cable that I had in my hand that I couldn’t connect to Honeysuckle was a Telemetry data cable, because I now remember feeding the Downlink Audio into an ordinary phone line that the CSIRO had set up.”

Photo © CSIRO / ATNF, used with thanks.

audio. 2.1MB mp3 file runs for 8 minutes.

(Excerpted from a longer interview recorded March 2010.
With thanks to Bruce Window.)