The lonely world of the CMP

As the Apollo mission increased in complexity, NASA decided that after Apollo 12, mission control should have two Capcoms, one for each spacecraft. The MOCR was already partially divided between the LM and CSM monitoring functions and there were separate consoles for the LM systems (Control, who looked after the LM's guidance systems and engines, and TELCOM, later TELMU, who oversaw its electrical and environmental systems, much like the EECOM did for the CSM).

As their crewmates laboured on the surface dealing with suits and geology in the Moon's dust pit, the CMPs handled an incessant programme of data collection and observation, while running the spacecraft. In addition to their planned schedule, it was not unusual for the CMP to deal with requests from geologists for another observation, or for a flight controller to seek clarification of some nuance of the CSM's operation. This could create a steady chatter over the airwaves during each pass across the near side.

"It turned out that my favourite experiment in orbital science was the bistatic radar,'' said Ken Mattingly after his Apollo 16 flight. This experiment used the spacecraft's communication antenna to beam radio energy at the Moon as the spacecraft passed across the near side while radio telescopes on Earth received the echoes. To work, the signal from the antenna transmitted only a carrier wave and therefore could not carry information. "That meant the ground couldn't talk to me for an hour and a half. I had a chance then to go to the bathroom, eat dinner, and get an exercise period or look at the flight plan. I think you really need those kind of periods every now and then throughout the day.''

Occasionally the CMPs got time to enjoy the view and the experience of coasting across the Moon alone. On Apollo 17, because of the easterly position of the landing site, most of Ron Evans's passes across the near side were in lunar night, but it was a night time lit by Earth - much larger and far brighter than the Moon appears to us. "Boy, you talk about night flying, this is the kind of night flying you want to do, by the 'full' Earth.''

"Is that right?" said Mattingly, now in the Capcom role in the MOCR.

''Beautiful out there,'' said Evans as he watched the ancient landscape of the Moon drift by, illuminated by the soft blue-white glow of his home planet.

As Evans drifted over to the western limb, Mattingly warned of a lengthy series of updates to the flight plan to satisfy the geologists' desire for further photographic coverage. He would read them up after Evans came back around. He then asked for a stir of the spacecraft's hydrogen tanks. It was December 1972, midwinter on Earth's northern hemisphere.

"You're lucky you're up there tonight, Ron. We're having really ratty weather down here. Low clouds and rain and drizzle and cold,'' said Mattingly.

''Oh, really?'' replied Evans as he approached the edge of Mare Orientale, a spectacular impact basin barely visible from Earth and unrecognised until the 1960s.

''Yes. You walk outside, you just about can't see the top of building 2.''

''Gee whiz! Guess I picked a good time to be gone,'' said Evans.

Evans was enjoying the view when he spotted a flash on the surface, probably a meteor strike. ''Hey! You know, you'll never believe it. I'm right over the edge of Orientale. I just looked down and saw a light-flash myself.'' Jack Schmitt had seen a similar flash just after they had entered lunar orbit.

''Roger. Understand," replied Mattingly.

''Right at the end of the rille that's on the east of Orientale.''

On Apollo 15, Al Worden figured that since he was going to be reappearing from around the Moon's far side every 2 hours, it would be a fitting gesture to greet the planet in a variety of languages to symbolise that he was greeting the whole Earth and its inhabitants, not just English speakers. With help from his geology teacher, Farouk El-Baz, Worden wrote down the words, ''Hello Earth. Greetings from

Endeavour" phonetically in a selection of tongues. Then, as he re-established communication with Earth, assuming that the pressure of work had relented enough, he would choose one of these languages as his way of greeting the world.

Worden found his time alone in the CSM to be busy but not unpleasant. When asked about how hard mission control would drive him after his rest break, he said, ''It was not generally difficult to begin work in the morning, because I was usually awake by the time they called. Also, I spent roughly half the time on the back side of the Moon, and so I had about an hour each revolution when I could not talk to Houston in any event. I was up and going before talking to Houston because I did not sleep that much during the orbital phase.''

Another time, he recalled, ''My impression of the operations of the spacecraft was one of complete confidence in the equipment on board. Things worked very smoothly, and I didn't have to keep an eye on all the gauges all the time. The rest of the spacecraft ran just beautifully the whole time. The fuel cells ran without a problem. In fact, everything ran just beautifully, and I really had no concern for the operation of the spacecraft during the lunar orbit operations.''

Apollo 13 was the start of a push to use the CSM as an orbiting science platform from which to reconnoitre the lunar surface. The primary tool for this was the Hycon lunar topographic camera: a monster instrument modified from an aerial reconnaissance camera, whose 467-millimetre focal-length lens peered through the round hatch window and exposed large 114 x 114-millimetre negatives. The Hycon had an unhappy career in Apollo. It lay unused on board the Apollo 13 CM Odyssey while the crew struggled to get home after their mission was aborted. It was sent once more on Apollo 14. Once alone in his domain, and having made the circularisation burn to take the Apollo 14 CSM Kitty Hawk into a 110-kilometre orbit, Stu Roosa began a photographic pass that was to have included the Descartes region where scientists were considering sending a future mission. After about 200 exposures, the camera failed, never to work again despite the best troubleshooting efforts of Roosa and mission control.

SCIENCE STATION IN LUNAR ORBIT

Lunar science from orbit really got into its stride with the final three missions in the Apollo programme; Apollos 15, 16 and 17. Both the CSM and the LM for these J-series missions had been extensively upgraded to maximise the science return from each flight. This was as true of the orbital mission from the CSM as it was with the surface exploration carried out from the LM. In particular, one of the service module's six sectors in its cylindrical body which had been largely empty on previous missions, gained a bay of instruments and cameras that could be trained on the lunar surface passing below for the five or so days the CSM was in orbit. This scientific instrument module, or SIM bay, was operated by the CMP from the time the spacecraft entered orbit until the SM was jettisoned shortly before re-entry.

Each example of the SIM bay that flew carried two cameras; a mapping camera and a panoramic camera, both of which were heavily derived from aerial and space

The Apollo 15 CSM Endeavour showing its SIM bay.

reconnaissance cameras that were classified at the time. A suite of sensors in the bay, or deployed out on the ends of retractable booms, could divine the mineral composition of the lunar soil by sampling the various emissions coming from the surface. On Apollos 15 and 16, a tiny satellite was ejected from the SIM bay just before the crew left to come home. It monitored the particles and fields around the Moon for up to a year.

The full capabilities of the SIM bay were never brought to bear on the whole lunar surface, largely because the CSM's orbit was defined by the landing mission. This limited the reach of the cameras and sensors to a narrow swathe near the Moon's equator. At one time, planners had envisioned an I-mission that would have placed a CSM in a polar orbit around the Moon for a full month, from which its cameras could have imaged the entire surface with a consistent lighting angle, and its remote-sensing instruments could similarly have sampled the entire Moon. With Apollo in its declining years, funds for such a mission were not forthcoming and the scientists would have to wait a quarter of a century for comprehensive coverage from the Clementine and Lunar Prospector probes.

0 0

Post a comment