A Few Recollections
I was a ground communications technician in Hawaii (WAFB) and on Eniwetok from 1966 through 1970 and was the principal ARIA comm operator during the Apollo missions of that time. WAFB was the Pacific comm hub for the Western Test Range in those days. Eniwetok was one of the down range sites and a HF communications point for ARIA missions.
At one point (early 1967?) several of us from around the world spent a week or so at PAFB training on the ARIA systems and working out procedures for establishing and maintaining HF communications during missions. During that week we flew a mission for a missile launch from a sub. As I recall it was the first or one of the first Polaris launches from a British sub. I was able to watch over the shoulder of the ALOTS (Airborne Light Optical Tracking System) operator as he locked onto the missile when it popped out of the water and followed it for several minutes. I well remember that trip because I flew the old Northwest Airlines charter DC6 from Hawaii to Kwajalane to Eniwetok, spent a couple of weeks learning the equipment, flew back to Hawaii and on to Florida for the week of training, then all the way back to Eniwetok. I had been married about two months at the time and did manage one overnight stop in Hawaii with my bride during that odyssey.
During one of the early Apollo missions (might have been 10) I flew aboard one of the ARIA for training/orientation between my shifts on the console at Wheeler Range Communications Control Center (WRCCC). I recall being seated in the back by the crew chief who warned me the aircraft was heavy and the takeoff roll would be long. So I timed it at 102 seconds. It was a bit disconcerting because I knew Kehee Lagoon was at the end of the runway and the Aloha Tower not far beyond. But we got off successfully and I stood behind the HF operator for most of the mission. Quite useful to see the action from the other end of the circuit. That experience allowed me to modify some procedures to improve our HF link quality on future missions. It also gave me great respect for the guys who crewed the aircraft.
While on Eniwetok I worked with my counterparts at WRCC to develop a technique for quieting the HF radio circuits. Prior to that the AF guys at Patrick complained because the voice circuits through Eniwetok were noisy. Unlike the other sites around the world (except perhaps Mahe) the links to Eniwetok were HF radio, not cable or satellite. So we ended up with a double HF hop (ARIA to Eniwetok, Eniwetok to Hawaii) when Eniwetok was in use. The method we worked out was to put a low level tone on the opposite sideband of the link transmitter. At the receive end we cross-patched the AGC circuit so the gain control voltage from the sideband with the tone suppressed the noise on the voice side when no one was talking. This was quite successful and was used for the remainder of the Apollo missions. It made Eniwetok an effective site for ARIA comm relay. We extended that technique to the aircraft quit soon after and were able to greatly improve the utility of the ARIA voice circuits for the remainder of the APOLLO missions.
During one of the first Apollo missions supported by ARIA we had an aircraft over the far west Pacific or perhaps the Indian Ocean. Communications with the capcom was from Houston through Goddard to WRCCC via microwave and cable then a satellite hop over the Pacific to Hawaii. Then there was another satellite hop to the HF ground station in Australia, then HF to the ARIA and S band to the Apollo. The length of the circuit, principally the double satellite hop, caused the delay to be about 3 or 4 seconds. The capcom and the astronauts weren’t expecting that (actually none of us had really considered it). So when the first call was made by the capcom and the astronauts didn’t answer right away, then answered at the same time as the second call and confusion ensued, the capcom gave the circuit back to us as inoperative. It took a bit of fast explaining to brief the capcom. On the second pass, just prior to burning TLI for the moon, they got it right. In those early Apollo missions communication between Houston and the Apollo at TLI was a mission requirement. So it was a big deal to get the circuit through the ARIA established and make it work.
One of the biggest challenges for the HF operators on the ground and aboard the ARIA was managing frequency selections during a mission. For some reason when the ARIA supported an APOLLO launch their mission over the Pacific always happened as dawn was breaking between the ARIA and the ground stations. Well, perhaps not always, but it sure seemed like it. This presented an interesting problem because we would start out talking to a couple of aircraft on the ground in a place like Tahiti on very low frequencies and have to jump up in frequency quickly, leapfrogging first one transmitter then the other, as the sun came up and HF conditions changed very fast. By the time the aircraft had AOS on the APOLLO we would be perhaps a hour or two in to the mission and have changed frequencies 5 or 6 times. At WRCCC we had a console that allowed us to choose between several frequencies and circuits on which the aircraft voice circuit was being fed to us. We could select which one to feed back to the capcom with the push of a button. But the rule was we couldn’t change anything in the circuit within 10 minutes of AOS of the Apollo. There were a few times when HF conditions were changing so rapidly that rule just didn’t work. I recall reaching up and punching two buttons simultaneously to switch from a circuit going bad to a clear one, sometimes in the middle of a sentence. The guys at the other end never knew we did that, we just got kudos for magically cleaning up a circuit in the middle of a pass.
In the mission section of the site there is a note that the Apollo 13 call of a ‘problem’ came through an ARIA. I don’t recall that being the case. I remember being on shift in WRCCC at the time and the ARIA were all on the ground having supported the launch and TLI phases of the mission. I heard the ‘problem’ call on NASA Net 1 from another console. 13 was quite a ways away from the earth at that time. However, when 13 returned several ARIA were deployed to provide communications of the recovery, which was the usual practice because the NAVY UHF communications were so poor. The calls from the capcom to 13 to establish they had made it through reentry were through an ARIA. The blackout period lasted much longer than expected. As documented in several movies the capcom called 13 several times before they finally answered and the 10s of millions of people listening around the world knew they had not burned up in the atmosphere. Those calls and their eventual response came through an ARIA and my console at WRCCC. A very memorable moment.