Explanatory Preamble
 |
Bryan Sullivan |
|
The recording commences just at the completion of the
SRT (Station Readiness Test) for the tracking period for Apollo 16 where the CSM and the LM were both in lunar orbit number four. The spacecraft
were separated and the LM had just completed the Descent Orbit Insertion
(DOI) manouvre which was carried out behind the moon during the previous
orbit.
Moon rise over HSK was about an hour and a half away
and the station was entering the H-70 (Horizon minus 70 minutes) countdown
to be followed by the H-30 countdown to the AOS (Acquisition of Signal/Spacecraft)
or in this case local moon rise. The station was about to commence a period
of intensive interface testing with the Goddard Spaceflight Centre (GSFC)
and Mission Control Centre at Houston (MCC-H)
Previous activities had included a three hour in-house
SRT, conducted in three different phases which had been in progress for
approximately two hours.
Phase 1 tested the station intercom(munication)
system where all operator positions were manned and a roll-call was conducted
by the COMMS supervisor to test each operator’s headset/microphone.
This activity effectively ‘pulled together’
the operations team and gave the station operations console supervisors,
OPS 1 and OPS 2, confirmation that all of the forty-odd operator positions
were manned.
The station had eight internal voice communication
channels referred to as ALPHA loop, BRAVO loop through HOTEL loops. ALPHA was the station’s primary operations coordination loop
between the operations console and mainly the section supervisors. BRAVO
was an engineering coordination loop for lengthy conversations regarding
equipment problems. CHARLIE loop was mainly for the OPS 2, Telemetry
and Computer supervisors to coordinate data flow operations. The other loops
were for local communications within each section. [See
these pages from the HOD relating to Phase 1.]
There were three external channels or ‘nets’
referred to as NET1, NET2 and NET3. The NET1 was for the astronauts
to converse exclusively with the CAPCOM (Capsule Communicator) flight controller
at MCC-H. The NET2 was for the operations coordination between the
tracking station(s) and the other MCC-H flight controllers. NET3 was for coordination of pre-tracking testing as well as facilitating ‘out-of-conference’
or ‘off-net’ conversations with individual stations.
The SRT Phase 2 tested all of the individual
stand-alone subsystems of each section – Unified ‘S’ Band
(USB), Ranging, Timing, Telemetry, Recorders, Video, Computers and Communications.
These activities involved diagnostic testing, alignment and calibration
checking of all units within each subsystem.
Phase 3 SRT involved the testing of integrated
subsystems to verify the many hardware interconnections with the a vast
array of peripheral units such as the decommutators, up-data buffers, pulse
amplitude modulation (PAM) processors, analog multiplexer quantizers (AMQ)
and the station timing system for GMT signals as well as consoles, printers
and teletype (TTY) machines.
The next major activity was the CADFISS (Computation
And Data Flow of Integrated Sub-Systems) testing where the real-time CADFISS
computers at the GSFC tested each tracking station in turn prior to handing
them over to the Mission Control Center. Specific tracking, ranging, telemetry
and command data was exchanged and compared with known or predefined values.
This part of the SRT was conducted under the GSFC Network Operations Manager
(NOM) in a sequence as per the mission tracking support schedule.When the
NOM was satisfied that all CADFISS testing was ‘GO’, the station
was configured into the MCC-H Real Time Computer Complex (RTCC) via the
world wide NASA Communications System (NASCOM).
The station then moved into the H-70 interface
testing countdown, with MCC-H conducting a further series of data flow tests
which were more aligned with the upcoming events or phase of the mission
timeline. Specific telemetry data and biomed formats, spacecraft commands
and tracking data that were more closely tailored to give the flight controllers
confidence that the stations were correctly configured and ready to support
the upcoming events in the mission flight plan.
The time from the commencement of the SRT Phase 3 through
the H-70 testing and up to the start of the H-30 countdown was one of the
busiest and most activity intensive periods of the Apollo tracking day.
Personnel heard on this tape (in order of appearance): |
| OPS1 |
Bernard Smith |
| VIDEO |
? |
| SIM |
Neil Sandford |
| OPS2 |
Bryan Sullivan |
| SB1 |
Frank Campbell |
| SB2 |
Neil McVicar (at HSKX, Tidbinbilla) |
| CADFISS TRACK |
? |
| GWM |
? |
| 1218 (Computers) |
Don Loughead |
| DATA |
Bill Perrin |
| GODDARD OPS |
? |
| COMMS |
Keith Hiscock |
| CRO |
Paul Oats |
| APOLLO CONTROL |
? |
| GOLDSTONE |
? |
| TIC |
? |
| GODDARD OPS |
? |
| VOICE CONTROL |
? |
| HAWAII |
? |
| NETWORK |
? |
| MIL |
? |
| CADFISS TM |
? |
| RTC |
? |
| BDA |
? |
| COMM MGR |
? |
|
Start of Tape Track # 1
Times in red are from the start of the audio file.
00:00. At the start
of this audio recording we hear OPS1 concluding video testing where simulated
TV signals from the station’s simulation (SIM) console are processed
by the video processing system.
00:14. OPS2 announces
the end of SRT Phase 3 testing and advises the USB supervisors, SB1 and
SB2, of the required configuration for start of the H-70 testing.
00:50. OPS2 requests
changes in the Univac 1218 computers from SRT to mission support configuration.
01:16. OPS2 authorises
an in-house test of the CADFISS analog magnetic tape with the telemetry
decomutators (DECOMS) and the computers prior to the H-70 start.
01:33. OPS2 requests
the COMM supervisor to configure all of the station’s external data
lines for interface testing.
01:50. OPS2 initiates
an end-of-file (EOF) mark on the command history tape while the computer
operator visually verifies the tape movement. Also the computer operator
verifies a dump of the command activity log file (LOG DUMP) to magnetic
tape.
02:20. OPS2 requests
a LOS/ROS (loss of signal/return of signal) file mark on the telemetry log
tape, however the decommutators were not inhibited from the computers as
the TLM supervisor was still testing the CADFISS tape.
02:40. OPS2 verifies
that both of the up-data buffers (UDBs) are in ‘safe’ mode in
order to prevent spurious command data being sent to the USB power amplifiers
(PAs or transmitters).
02:47. The simulation
console operator (SIM) advises OPS2 that all of the SRT patches are removed
from the mission support equipment and that all radio frequency (RF) signal
sources (test oscillators and signal generators) are turned off.
03:00. The COMMS
supervisor configures Net 1 to normal, thereby enabling HSK to hear the
conversations between the astronauts and the MCC-H CAPCOM (CAPsule COMmunicator)
as well as the periodical mission summaries from ‘Apollo Control’
public relations.
[Conversations between Carnarvon and Goddard, and
Goldstone and Goddard are also heard, as well as Public Affairs commentary in the background.]
04:26. GODDARD OPS
calls HSK ‘off-a-net-3’ meaning a direct connection with HSK without
any other stations hearing, i.e. Net 3 is now ‘out of conference’.
GODDARD OPS checks the HSK status for the start of the H-70 testing.
04:41. OPS1 advises
that ‘we are GO for interface’ and that the status for tracking
(CADFISS) is: (HSK or ‘prime’ site) SYS-1: CSM, SYS-2: LM and
(HSKX or ‘wing’ site [Tidbinbilla]), SYS-3: CSM, SYS-4: LM.
05:02. OPS2 announces
that the command interface test has started. Command data is now being received
from the CADSFISS computers by the HSK Univac command computer.
05:30. The CADFISS
Real Time Command (RTC) operator is testing the ‘uplink’ path
through the UDBs to the PAs (radiating into dummy load), through to the
verification receivers, back to the telemetry computer and back to the CADFISS
computers.
Telemetry testing commences with specific data formats
for engineering and biomed that will be required for the upcoming mission
support period.
06:23. CADFISS TM
(Telemetry) requests HSK to change the biomed telemetry format.
07:00. CADFISS RTC
requests access to the ‘wing’ site (HSKX [Tidbinbilla]) after
completion of the ‘prime’ site command testing.
08:18. NETWORK hears
that Bermuda (BDA), Hawaii (HAW) and Mila (MIL, Merrit Is.) have configured
their teletype (TTY) circuits back to normal following their support of
the DOI data playback (Descent Orbit Insertion) manouvre of the LM.
COMM MGR requests Hawaii to send a ‘number comp’
(number comparison test) on their bravo channel to verify that their TTY
configuration is correct.
Each station had two teletype circuits, one for sending
low speed tracking data and the other for receiving low speed command data,
referred to as the alpha and bravo channels.
08:53. RTC advises
HSK that command interface is GO whereby OPS2 sends a history transmission
of all the commands processed during the test via the high speed data line,
he then writes an end-of-file on the command history magnetic tape and initiates
a dump of the activity file to the log magnetic tape.
09:36. OPS2 advises
COMPUTERS that the UDBs are in ‘safe’ mode where they will remain
until they are switched back to ‘operate’ mode during the H-30
countdown.
With the completion of the command interface testing
both HSK and HSKX USB sections prepare for their tracking CADFISS tests
including boresight alignment, predefined antenna movement (tracking) and
ranging equipment. These tests are usually coordinated between OPS1, SB1
and SB2.
09:58. OPS2 requests
COMMS to reconfigure the RO (receive only) teletype to normal from its support
of the low speed CADFISS tracking data test.
10:26. GODDARD OPS
prepares to start telemetry testing predefined formats of spacecraft engineering
parameters and astronaut biomed data from the CADFISS magnetic tape through
the Univac telemetry computer and out via the Data Transmission Units (DTU),
modems and the high speed lines back to GSFC.
10:43. COMMS supervisor
reports the arrival of a teletype cue, where OPS2 requests the DATA supervisor
to ‘roll the (CADFISS telemetry) tape’.
11:12. CADFISS TM
queries the patching of the telemetry formats after which DATA supervisor
tells OPS2 that the analog magnetic tape recorder was running at the wrong
speed.
12:44. The DATA
supervisor is discussing the track 11 SM4/6 CSM hi-bit rate and FM biomed
thru the AMQ (Analog Multiplexer Quantizer) processor. Here
he is referring to data from the scientific experiments within the SIM bay
on the CSM service module of the spacecraft. This
telemetry was downlinked along with biomed data on a frequency modulated
(FM) subcarrier and processed thru the AMQ and then by the Univac telemetry
computer.
Regarding the ‘inquisition’ into the operator
error with the CADFISS tape, maybe OPS2 was wondering to whom the
Fickle Finger of Fate should point.
14:00. SB2 advised
OPS1 that the wing site ranging computer has locked onto the CADFISS test
data.
14:18. OPS2 advises
the DATA supervisor of a successful test of the CADFISS biomed data formats.
Note the sounds of the teletype printers clattering
away with hard-copy of the various test results.
End of audio tape part 1.
Go to Part 2.
Notes by Bryan Sullivan. Times, Colin Mackellar.
Listen to the audio of Part 1 of the tape – 14 min 32 s – 1.8MB mp3 file.