Apollo 14 was the first mission to use a single orbit rendezvous technique, which completed rendezvous in two hours, instead of the two orbits used previously. The new technique worked perfectly and became the standard for subsequent missions. Near the end of rendezvous the LM’s abort guidance system, which was shadowing the primary guidance system as a backup, dropped out. Attempts to reset AGS by recycling switches and breakers in the cabin did not work, nor could Mitchell access AGS through its keyboard. Also, the LM master alarm did not announce the AGS failure as it should have. No effect on the mission, but another significant anomaly for our engineers to resolve before the next Apollo launch.10
Docking was perfect this time, using the normal procedure, and Shepard and Mitchell rejoined Roosa in Kitty Hawk, bringing their precious lunar samples with them. Antares’ ascent stage was jettisoned, and its engine was fired to cause it to hit the Moon midway between the Apollo 12 and 14 landing sites. The blast set off seismic ringing within the Moon that persisted for several hours on both sites’ ALSEP instruments. The return mission was routine, and in the Bethpage Mission Support Room I rejoiced in the happy smiles of the astronauts as they strode onto the carrier deck.
On Apollo 14, we in the back rooms had again helped save the mission. NASA Mission Control and its supporting contractors, put to the ultimate test in the incredible Apollo 13 rescue, were a practiced team that responded to problems with aplomb. The resourcefulness and adaptability of a combined man-machine operation in space and on the ground had been demonstrated many times over.
Although the total LM flight anomaly count on Apollo 14 was the lowest yet, the abort-stage switch failure was a serious defect that should have been detected before installation. The initial docking problem showed the need for tighter control and verification of CM-LM interfaces. LM-8 reversed the favorable progression of LM quality and alerted us to improve quality control and take management actions to dispel complacency.
On the Moon’s surface, Shepard and Mitchell reached the limits of unaided “walking around” exploration. The Apollo program was ready for a higher level of capability, which the extended-duration missions would provide. Irrepressible Al Shepard and sober-sided Ed Mitchell had been a well-matched lunar exploration team. Now, what would their successors do with a sports car and two extra days to cruise the surface?
19
Great Explorations
Apollos 15, 16, and 17
Thanks to its foresight in upgrading the capability of the later Apollo missions, NASA was positioned to harvest a vast amount of scientific knowledge about the Moon and its origins. The extended-duration missions took advantage of increases in Saturn payload capability, eked out in incremental changes by Wernher von Braun’s engineers, and the weight savings we had swiped and scraped from the LM. Lunar stay time was increased to three days, more moonwalks were permitted, the scientific equipment package was expanded, and the lunar roving vehicle was added. The rover promised a new dimension in lunar exploration, as it greatly increased the astronauts’ mobility and endurance on the surface. Although the general public was becoming blasé about men on the Moon, scientists the world over anticipated the fruits of great explorations.
The Mountains of the Moon: Apollo 15
In June 1970 I returned to Bethpage from a year as a Sloan Fellow at MIT and plunged into the competition for the newly announced space shuttle, NASA’s major post-Apollo program. For the first time in eight years I was not assigned to the LM program, although in spirit I never left it and kept in touch as closely as my shuttle activities permitted. Having directed the engineering design of the extended duration LMs before leaving for MIT in mid-1969, I wanted to see how they had worked out. In August 1970 I attended the design review of LM-10, first of the extended-duration LMs designated for Apollo 15, where the new features were inspected and demonstrated. The redesigned descent stage had larger propellant, water, and oxygen tanks, two additional batteries, an expanded bay for scientific equipment, and a new quadrant bay to house the rover. The ascent-stage changes were minor: added lithium hydroxide canisters, expanded stowage areas for lunar sample containers, food storage, and crew equipment, and accommodations for the redesigned spacesuits.
A demonstration with the completed LM-10 descent stage was held on the Spacecraft Assembly and Test final assembly floor, with astronauts Dave Scott and Jim Irwin participating. All the equipment that the crew would use in exploration was available, either as flight hardware or engineering prototypes. The demonstration was orchestrated by Grumman’s Will Bischoff, John Strakosch, and John Rigsby and their NASA engineering counterparts. Working with the engineers who designed the expanded Apollo lunar surface experiment package and the other scientific equipment and tools, they carefully stowed each item into custom designed holders within the bays, making minor adjustments where necessary for a perfect fit. After checking the latching and deployment mechanisms, the bay doors were closed as they would be at Kennedy Space Center prior to launch.
A team of Boeing engineers and technicians showed us the features of their prototype LRV. I marveled when they folded it up like a collapsible stage prop and nestled it securely within the bay. Because the rover was six times heavier than it would be on the Moon, our engineers improvised a counterweight system to ease the jolt when the bay door was opened.
When the descent stage was all buttoned up, Scott and Irwin opened each bay following the procedures they planned to use on the Moon. Surrounded by equipment engineers, they asked questions and gave their comments on each step of the deployment. Most spectacular was opening the rover’s bay: Scott and Irwin pulled two lanyards on either side of the bay, the door swung open, and the rover unfolded itself like an insect emerging from chrysalis, ending up angled downward in the bay with its wheels locked in position, ready to be rolled onto the surface. We applauded in appreciation of Boeing’s ingenious design.
I returned the following day to watch the final part of the demonstration. Overnight all the chits were dispositioned, final fit adjustments were made, and the descent stage was again closed up as for launch. Scott and Irwin would perform another deployment, but this time in pressurized spacesuits. A technician followed each of them, wheeling a portable cart supplying the suit with air and cooling. This was fascinating; even though they were on the familiar white tiles of the assembly floor, followed by a knot of people in white smocks, the sight of two spacesuited astronauts next to the gold and black foil clad descent stage stirred my imagination. As they bent over and deployed the ALSEP and the rover, I could visualize how they would look doing these same actions on the Moon, stirring up gray lunar dust with every step, surrounded by strange treeless plains and mountains surreally lit by dazzling sunlight or totally hidden in black shadows. This was as close as I would ever get to exploring the Moon, and I relished the fantasy.
I also attended LM-10’s customer acceptance readiness review board meeting just before its delivery from Bethpage. NASA’s George Low presided, and the board’s review took only half a day, with relatively few problems. What an improvement from the early LMs! The review was held in the Plant 25 conference center, which was attractive, comfortable, and provided good acoustics and visuals. About two hundred NASA and Grumman engineers participated in three days of reviews and inspections. Chits were written and dispositioned with the usual rigor, but with less anxiety than I recalled from the early days. The LM program had grown and matured most satisfactorily.
I talked at length with Dave Scott and Jim Irwin. They were very pleased with the quality of LM-10 and excited about their mission. Scott told me the chosen landing site was beautiful and challenging. He hoped the TV images would convey some of its grandeur, because he knew their descriptions would be inadequate, even though they intended to share their sights and feelings with Earth as much as they could during the mission.
The extended-duration LMs greatly increased the scope and efficiency of lunar surface exploration. Only two years after the first manned landing, w
hich at the time had seemed like the ultimate achievement, we engineers had produced a design that opened new vistas of scientific discovery. Three days on the Moon allowed at least three moonwalks, and the rover loosened the bonds of physical exhaustion, enabling the explorers to be out on the surface for up to seven hours at a time, tackling distances and slopes that walking astronauts could not. The rover also saved the crew’s strength by carrying their tools and samples and provided precision surface navigation that minimized wasted time seeking landmarks. An advanced TV camera on rover let the whole world share in the thrill of the moonwalks and allowed the lunar geologists in the back room at Houston to take part in their students’ field trip and assist with suggestions and evaluations. Lee Silver and the other senior geologists who had tutored the astronauts not only watched them perform but actively participated in the expedition, looking over the explorers’ shoulders though a quarter million miles away. The world had never seen anything like it.
Apollo 15’s landing site was the most challenging yet attempted by the program, and a very beautiful and dramatic area. It was situated on a level plain bordering Hadley Ridge of the lunar Apennine Mountains, between towering eleven-thousand-foot Mount Hadley Delta and Hadley Rille, a sinuous three-thousand-foot canyon. Scott and Irwin were startled when the LM Falcon pitched over at nine thousand feet to see the brilliant sunlit flank of Mount Hadley Delta above them to the left. The scene ahead was unfamiliar, and Mission Control informed them that the guidance system had put Falcon three thousand feet south of where it should be. Thanks to the prominence of Hadley Rille and Mount Hadley Delta, Scott was able to correct their flight path manually and land very close to the target point. Dust obscured his vision for the final sixty feet, making this the second LM to touch down on instruments. In view of their intended three-day stay on the Moon and the long duration of their planned moonwalks, Scott and Irwin planned to sleep before setting foot on the Moon. But first Scott conducted a visual reconnaissance of the area, as Lee Silver had taught him to do at any new field site. Depressurizing Falcon’s cabin, he raised himself halfway out of the upper hatch, and for half an hour he gazed at and photographed scenes of unsurpassed beauty and grandeur: the rounded gray flanks of Mount Hadley, covered like a ski slope with the untouched snows of eons of cosmic dust, and the winding, mysterious depths of Hadley Rille, perhaps holding a key to the Moon’s history written on its walls. He was thrilled at the prospect of exploring such a vista.1
Of the many engineering improvements introduced on Apollo 15, among those most appreciated by the astronauts was the redesigned spacesuit, which was more mobile and flexible and easier to doff and don, allowing the crew to remove their spacesuits in Falcon’s cabin and enjoy the unfettered comfort of their flight suits while eating and sleeping. This did not help my personal uneasiness about micrometeoroid penetration of the LM’s cabin while on the Moon, but after the prior missions I was feeling more confident and worried less while they slept.
During the Apollo 15 mission, I dropped into the Bethpage Mission Support Room to watch critical mission events, and after-hours I watched the explorations, which were shown almost continuously from the rover’s camera over one of Mission Control’s channels. I saw most of the second moonwalk and felt more like a participant in the adventure than ever before. The rover climbed three hundred feet up the flank of Mount Hadley, maintaining good speed but giving Scott and Irwin concern about tipping over on the steeper slopes. At one point while both astronauts were gathering samples on foot, the rover started to slide downhill, but Scott quickly grabbed and held it. Scott panned the rover’s camera over the scene from their highest point, showing the rounded hills golden in sunlight, with the darker plain and light-walled Hadley Rille below. The LM Falcon was far away, a tiny speck in the unearthly panorama. (Mission rules limited the crew to driving no farther from the LM as they could safely walk back—about six kilometers.) The mountains of the Moon were hauntingly beautiful and mysterious, and palpably ancient.
On the way back down Mount Hadley, Scott and Irwin explored midsize Spur crater, collecting and documenting samples. An unusual whitish rock caught their eyes; when Scott brushed it off he could clearly see the white crystals of anorthosite, most likely from the Moon’s primordial crust. Knowing the value and import of the treasure they had found, Scott and Irwin displayed it before the camera and exulted with their scientist colleagues in the back room at Mission Control. (This sample, dubbed the Genesis Rock by a reporter covering the mission in Houston, was found to be 4.5 billion years old, probably dating from the formation of the Moon.) Returning to Hadley Base, Scott made another major contribution to science by drilling a ten-foot core sample tube into the surface, despite stubborn resistance and the pain of aching fingertips, which had been pressed too long and hard inside his pressurized gloves. (The core sample was worth the effort required to collect it. Scientists identified forty-two layers of soil, the bottom layer undisturbed for half a billion years.)
Their third and final excursion took Scott and Irwin to the edge and some distance down the sloping side of Hadley Rille. They saw and photographed layering of the canyon walls from repeated lava flows, providing convincing evidence of the active volcanism that played a part in shaping the Moon’s ancient past. They collected many more rock and soil specimens and retrieved the ten-foot core sample. Before entering Falcon, Scott parked the rover nearby and pointed its camera to capture Falcon’s liftoff.
As I saw it from the MSR in Bethpage, the liftoff was amazing. The ascent stage leapt upward very quickly in a shower of silver and gold shards of torn insulation and disappeared from the camera’s field of view. For a few seconds bits and pieces fluttered to the ground, and then the LM descent stage and those ALSEP instruments in the picture were still—frozen on the Moon for eternity. I still picture them that way whenever I look up at the Moon. Six silent sentinels awaiting the return of the next wave of lunar explorers.
Ascent and rendezvous were smooth and uneventful, and Scott and Irwin were reunited with Al Worden, who had made his own major contribution to lunar science. The scientific instrument module on Endeavour had mapped and examined much of the Moon’s surface and recorded copious data on its composition and characteristics. These explorers were returning with their spacecraft overflowing with astutely selected samples and data that would add greatly to mankind’s knowledge of the origins of both the Moon and, by proximity and analogy, Earth. Safe aboard the recovery carrier Okinawa in the Pacific, they breathed again the cool fresh air of Earth and delighted in mingling with their fellows, the postmission quarantine regimen having been dispensed with as unnecessary.
I met the Apollo 15 crew several weeks later at a dinner in Houston. Dave Scott and Jim Irwin shared with me many details of how things felt and sounded within the LM. They described liftoff and ascent as a smooth elevator ride, with the moonscape rapidly shrinking in the triangular windows, and the flaming explosive energy of the rocket engine burning only inches behind them as a steady, nonthreatening vibration transmitted mainly through their feet. They mimicked some of the sounds aboard LM: the sharp bang of the cabin depressurization valve, the whines and hums of the ECS pumps and fans, and the abrasive grinding of the steerable communications antenna. They willingly answered all my questions and repeatedly returned to their feelings of gratitude at being able to witness such wondrous beauty in another world. Thanks to their openness and sharing, and the added dimension provided by the rover’s TV, I felt deeply involved with the adventure of this unprecedented mission. There was much more to my pleasure in Apollo 15 than satisfaction in our LM’s near flawless performance. For the first time, my fantasy of stowing aboard the LM and exploring the Moon with the astronauts had found a degree of fulfillment.
The Central Highlands: Apollo 16
In April 1972 Grumman was at a fever pitch of preparation for the space shuttle competition. NASA’s request for proposals was expected within a few weeks, and we had some six hundred engineers busy compl
eting our studies and analyses and developing our main proposal themes. As deputy director of the space shuttle program at Grumman, I bore a major responsibility for the proposal, which meant long hours and weekend work. This left not much chance for me to follow the Apollo 16 mission as it unfolded, although I did try to drop into the Bethpage MSR after-hours to watch the mission control monitors, if only for a few minutes. Some nights I just had to settle for the truncated news summaries of the mission on broadcast TV.
Apollo 16 was targeted at the Descartes Highlands, near the center of the Moon north of the equator. The geologists thought the bright, extensive highland areas might have been created by volcanism in the Moon’s early history, predating the lava flows that created the Maria. After carefully studying highland landing sites, NASA concluded that the Descartes region, although very uneven and cratered, offered enough level areas to be safe for a lunar module landing. Scientists were eager for their first exploration of terrain that appeared representative of a major portion of the Moon’s surface.2
Apollo 16 had an all-southern crew with a “down home country” style: Comdr. John Young, LM pilot Charles “Charlie” Duke, and CM pilot Thomas Kenneth “Ken” Mattingly. They arrived in lunar orbit uneventfully and on schedule, but then an unexpected problem threatened the mission. After CM Casper and LM Orion separated and Orion preened for Mattingly’s predescent inspection, Casper failed one of the checkout procedures Mattingly put it through. When he checked the secondary gimbal control system3 in the service propulsion system, the steering gimbals oscillated instead of holding a steady commanded position. Although the primary gimbal control had checked out, mission rules required that both systems be operational before permitting LM to descend to the Moon. Casper and Orion held their positions in close orbits for more than six hours while Mission Control worked on the problem. They finally gave a mission go-ahead, based on the judgment that even with the positional oscillations of the gimbals, the secondary system could safely control an SPS engine firing.
Moon Lander: How We Developed the Apollo Lunar Module (Smithsonian History of Aviation and Spaceflight) Page 35