ARIA stories from Stan Anderson:
Stan writes: Doc (Weaver) was the Officer in Charge of the Aircraft Operations Control Center (ARIA Control) and I was his Non-Commissioned Officer In Charge.
Fried Chicken Fixes
The stories that came back from some of the ARIA missions are the stuff of legend; talk about bailing wire, gum and paper clips!!!
One such example. During one of the Apollo missions, every time the antenna operator took the antenna out of the “stow” position it would blow a circuit breaker so that there was no control over the antenna. After going through every spare circuit breaker on the plane, in desperation, the antenna operator went to his in-flight lunch (fried chicken wrapped in aluminum foil), took some of the aluminum foil and wrapped it around a pencil and jammed it into the circuit breaker slot. Problem solved.
High speed maintenance
Another example: On the first manned Apollo mission, Apollo 7 an orbital mission, we had two ARIA flying out of Perth. One of the aircraft, scheduled to cover Revs 134 and 135, called that he was unable to take off because the generator drive shaft on his #4 engine sheared. Normally it would have been a simple task to replace the drive shaft as the generator was gimbal mounted held by three pins. But one of the pins was corroded so it required a maintenance man to climb in through the back of the engine and pull the drive shaft and replace it with a new one. Normally this would have taken three people 5 hours (15 man hours) to do this, according to our Maintenance Control at Patrick, but two men did the job in 1 1/2 hours (three man hours). The plane took off and although unable to cover Rev 134 they did cover Rev 135. My job as Aircraft Status monitor at ARIA Control at Patrick (thanks to Doc, I will forever be known as “Stanley Status”) was to report the aircraft status to Houston. So I did: “ARIA 4 is Red Can Not Support due to #4 generator drive shaft sheared.” Apparently the Houston Controller (an Air Force Major named Mike) didn’t understand what I was telling him and called Doc, our ARIA Controller, for clarification to which Doc replied, “His motor’s broke, Mike.” Other than the humor of Doc’s response, what I am pointing out, however, is the work of the Maintenance team at Perth, with their commitment and sense of urgency to get the mission done that they could work at the speed they did to fix the problem.
Stu Roosa’s message to ARIA Control
For each Apollo mission, we would make up mission badges for the ARIA Control team and an extra three badges for the Apollo Crew would be sent to the Cape through internal mail. We were never sure if they received them except in the case of Apollo 11 when I had a chance to give them to Mike Collins personally. He had parked his aircraft right outside our building at Patrick AFB after a proficiency flight and the astronauts were in and out of our building all the time.
In ARIA Control we had two sets of consoles: the back console where the ARIA Controllers and “higher-ups” sat was raised about 8 inches while the front “support” console was lower. My console position was at the right end of the lower console next to the message window so I could pass messages back and forth. Next to my position was the DOD Rep’s console. Our DOD reps were civilian contractors (PANAM, I think but they could have been RCA) who filled several functions, including sim team and also serving as the ARIA Rep at MCC Houston; most had been in space biz since the Mercury days.
On Apollo 14, the DOD Rep was Jim Plaisted, a retired USAF major. During a lull in one of the Apollo 14 sims, Jim and I were chatting when we noted that the Apollo 14 crew consisted of Navy RADM Alan Shepard, Navy Captain Ed Mitchell and Air Force Lt Col Stu Roosa. Interservice rivalry being what it is, not only was Col Roosa “outmanned” by two Navy types, he was also the junior ranking man on the crew. So we decided to send him a “morale booster” to keep his spirits up on the mission when I sent the mission badges; but not knowing if the crew would ever receive our badges, we decided to keep things quiet.
So Apollo 14 takes off and shortly after TLI between Carnarvon LOS and Guam AOS, Houston made contact through one of our ARIA aircraft. As noted elsewhere, ARIA was critical at filling the Carnarvon–Guam gap because voice relay and telemetry recording were critical during and after the TLI burn. CAPCOM radios, “Apollo 14 this is Houston through ARIA”. The response come back (from Command Module Pilot, Roosa), “Ah roger, Houston. And would you tell the folks at ARIA Control I received their message and it is taped to the panel in front of me.” That took everybody in ARIA Control (and elsewhere) completely by surprise, except for Jim Plaisted and me who collapsed in gales of laughter and high fives. Within 15 seconds, we had calls on three different circuits (MCC Houston, Houston ARIA and I think Dominic was the third one) all asking “What’s he talking about? What message?” Of course, from Jim and my reactions, Lt Col Larry Brown, who had replaced Doc as ARIA Controller, looked over his console and says, “Okay you two, what did you do?” So we told him. When I sent the mission badges up to the Cape, the “morale booster” we sent along to Col Roosa as a 4" x 6" Air Force flag. When Col Brown passed it on to USAF Major Mike Monkvic at MCC Houston, his response was “Way to go, guys. Way to go.”
So while there was always a lot of stress during the Apollo missions, there were lighter moments too.
ARIA saves the day for Apollo 5
In the early days through at least Apollo 11, ARIA used S-Band downlink for telemetry and voice, uplink for voice. Contact with Houston was through HF SSB both upper and lower sideband. Sometime around Apollo 12, I can’t remember before or after, we started working with the military Tactical Satellite (TACSAT). By Apollo 14, we were using TACSAT communications to drive the biomed computers at Houston. I seem to remember that the data loss was something on the order of 1 bit in 1 billion. Pretty pure. Without GPS, the exact location of and ARIA was never precise enough to relay ground track positioning data. I don’t remember where the TACSAT signal was brought to ground and fed to Houston.
Acquiring the Apollo spacecraft was probably quite a bit easier for ARIA than the ground stations. As I remember it, the ground station antennas had a 1/2 degree S-Band beam width. The ARIA had a 1 degree beam width but we also had an additional distinct advantage. With only a 7 1/2 ft antenna, we could sweep the horizon over a 80 degree horizontal arc (40 degrees either side of center) for the signal.
In addition to the S-Band antenna our dish had four VHF antennas, one in each quadrant, used for signal acquisition. When the antenna was initially unstowed for tracking, the antenna operator would control it manually to acquire the spacecraft. As soon as a VHF signal was acquired the dish would automatically seek to equalize the signal strength from each of the VHF antennas thereby “homing in” on the S-Band signal (either 2272.5 or 2287.5 MHz). The antenna operator would put the antenna in AutoTrack Mode starting the gyroscopes that would allow the antenna to continuously track the spacecraft even if there were momentary signal losses due to aircraft motion, atmospheric interference or other causes.
The antenna with the 40 degree VHF beam width sweeping capability was put to good use a couple of times allowing us to obtain telemetry data that we might not have otherwise been able to receive.
Each aircraft had the equivalent of a small telephone book of computer generated “look angles”, i.e., antenna azimuth and elevation at 10-second intervals, for each orbital pass it was supposed to cover based on a nominal flight plan (a neat trick given the ground tracks and altitudes of the aircraft and spacecraft at a given point in time over a specific lat/long on the globe.) They had to have the nominal look angles on board the aircraft in the event they had no contact with ARIA Control given the vagaries of HF communications.
Under normal circumstances we, in ARIA Control, would start receiving a real-time Look Angle update from the Houston tracking computers for a specific ARIA at H-46 (H- “Horizon Time”, AOS (Acquisition of Signal) – remember that VHF and S-Band are both line-of-sight). We would have the message complete by H-42 minutes, then it would be reviewed by ARIA Control support staff and put on the 100 word/min teletype to the ARIA by H-36. The reason I remember the times so well is that in addition to monitoring ARIA status I was also responsible to for maintaining a checklist for each aircraft for each pass to insure that their pre-pass checklist was complete prior to turning them over to NASA (the term we used was “Go Remote”) and the MSFN for the duration of the pass – at 30,000 feet, generally 10 minutes.
As a matter of interest, my checklist for each ARIA had about twelve items beginning at H-50 (when we requested the look angles from NASA) to H+14 when the aircraft, after LOS, would give us a “Quick Look” as to their estimate of the quality of the telemetry data received during the pass; 64 minutes of a 90 minute orbit. Now imagine maintaining individual checklists on four, five or six or more aircraft spaced 5, 8, 10, 15 or 30 minutes apart around the globe – all at the same time – particularly when more than one aircraft would be supporting two successive orbits. To be politically incorrect, a one-armed paper hanger had nothing on me. It took a lot of concentration and a lot of focus. That is why we would spend about 100 hours of sim time between each mission.
An example of ARIA’s VHF sweep capability saving the day, and NASA’s butt in the process, occurred on Apollo 5 –
The mission profile called for the LM to fire the Descent Propulsion engine over Carnarvon on Rev 3. Well, the engine didn’t fire. So all of the pre-planned look angles for tracking the LM over the Atlantic Ocean went to hell in a handbasket.
We had two aircraft, ARIA 4 flying from Dakar, Senegal and ARIA 5 flying out of Johannesburg, South Africa over the South Atlantic. So the immediate focus was to get whatever telemetry they could from the LM on Rev 4. But where to point the antenna? The last position data to the tracking computers had come from Carnarvon. Because of the 1/2 degree beam width on the NASA ground antennas, they never saw the LM again.
Finally, Stan Davis, our ARIA Liaison at Houston for the mission called ARIA Control and gave us some “best guestimate” coordinates for a possible ground track. It required ARIA 4 flying easterly off the West Coast of Africa to do a 135 degree turn and fly to the Northwest. Even then he would be almost 1,000 miles off the ground track (instead of the normal 100 mi.). But, thanks to the VHF acquisition, he still managed to obtain about 6 minutes of S-Band telemetry. Coupled with the 10 minutes of data from ARIA 5 downrange, NASA had 16 minutes of LM telemetry to figure out what went wrong. Interestingly, ARIA 5, being at the most southerly portion of the orbit, had almost no course corrections to make to acquire the LM.
Ironically, almost prophetically, we had simulated almost the identical scenario with “ARIA 4” prior to the mission, and the ARIA 4 crew was in the back of ARIA Control watching the sim at the time! So rather that simply following blind directions, they could actually visualize what the situation was and knew exactly how to respond.
Arguably, without the 16 minutes of ARIA data, the LM descent propulsion system test would have either had to be flown again (jeopardizing the timeline for all future launches) or crammed into a later mission. So, yes, ARIA’s VHF sweep capability proved to be worth more than its weight in gold.
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