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Eyes Turned Skyward, Part III: Post #20
With the completion of the Artemis 3 test flight and Administrator Davis’ decision to take the “banker’s bet” approach to Artemis 4 in June, the next Saturn Heavy launch became a matter of intense focus for NASA’s mission control staff in Houston, and its launch staff in Florida. For many of the staff whose entry into the program had come close on the heels of the abandonment of Apollo, the day they had waited so long for and had, in some cases, feared would never come was finally at hand. Foremost among these individuals was the mission’s commander, Don Hunt. Joining NASA’s astronaut corps in 1978, he had served alongside veterans of the moon landings even as many of them had been preparing to leave for greener pastures. Through NASA’s years of focus on space stations, Hunt had built a reputation as a smart flyer and a cool operator--perhaps best exemplified by the famous radio calls during the “rough ride” of Spacelab 28. Though others like John Young had more overall seniority, by 1998 Hunt was the most senior astronaut still flying. His selection as the commander of the first Artemis manned landing was a reflection of this extensive experience, though his relatively strong name recognition was also appreciated by the Public Affairs Office. However, his selection was also made with the understanding that this would be his final flight. Just short of turning 50, he was on the verge of losing his flight status, to the Moon or anywhere else for that matter. As it was, he would be the oldest astronaut ever to fly to the Moon, two years older than Alan Shepard on Apollo 14.
Hunt’s reaction to the knowledge that this was to be his final mission was to throw himself into all aspects of planning--he pushed his chosen crew hard on flight training, encouraged their involvement in the preparation of both the manned and unmanned landers, and threw himself into the geological portions of the DREAM desert training exercises with enthusiasm. The pilot crew was filled out by pilot Natalie Duncan, on her second flight. They were joined by the Mission Science Officer, Ed Keeler. The MSO was a position that had evolved on Spacelab and Freedom. In order to coordinate the stations’ scientific operations with ongoing maintenance and flight operations, the most senior flight scientist on-orbit was selected as the Science Officer, with the responsibility of working with the station command and ground engineers to plan work schedules and ensure that the station’s scientific missions did not get overshadowed by operational concerns. The concept was adapted for Artemis, with the MSO having more specialized geological training and essentially serving as the executive officer of the flight, with near-equal responsibilities to the commander while on the surface. While the commander was responsible for seeing that the mission was safe and successful, the MSO was responsible for seeing that it was scientifically productive. The final crew member of the foursome was the Artemis program’s first international partner, cosmonaut-selenologist Luka Seleznev, of Ruscosmos. The symbolism of a Russian accompanying a crew of Americans to the Moon was palpable, an ironic contrast to the fierce competition between them in the (first) Space Race of the 1960s, and also evocative of the entreaties for Russo-American cooperation featured in Arthur C. Clarke’s Odyssey novels. And things certainly got off on the right foot: as training proceeded, the crew quickly established a rapport--Hunt and Keeler shared a fondness for puns, which contributed to the typical EVA pairings: Seleznev would pair with Hunt while Duncan would accompany Keeler--according to an exasperated Duncan, it was the only way to stop the punsters from filling the radio. The relative jocularity of the crew proved an asset during the long hours of training and the multitude of tasks facing them while the spotlight of public interest focused on Artemis.
As the hundreds of engineers and technicians involved in the program completed their preparations and reviews, the first Moon-bound Artemis launcher was rolled to the pad on crawlerback on November 18th. Once its impossibly slow journey was complete, pad crews connected the Mobile Launch Platform to ground services, and began the multi-day process of leak checks, wet dress rehearsals, and final payload checks. Meanwhile, the crew assembled at Houston to witness the launch--Hunt was determined to set the precedent that, in spite of being unmanned, Artemis cargo landers would be just as much the responsibility of the crews which would use them as their own Apollo spacecraft were. One example of this was his decision, after consulting with his crew, to provide a callsign for the lander. In the discussions, the crew selected the name
Janus, referring to the Roman god of endings, new beginnings, and choices--an apt moniker for a spacecraft with as much riding on it as the “banker’s bet,” the beginning of the Artemis landings, and the end of Hunt’s flying career. On November 23rd, preparations began for the first launch attempt. Ice and frost accumulated on the skin of the oxygen and hydrogen tanks as the massive vehicle was fueled and prepared for flight. However, those at KSC to watch the launch were to be disappointed, as diagnostic telemetry from the Pegasus and lander inside the fairing began to malfunction as the countdown reached T-25 minutes, resulting in intermittent failures to receive data and some indications of temperatures and pressures inside the fairing and the vehicle that were well outside normal limits--and in some cases outside expected physical possibility. In order to fix the issue, the launch attempt was scrubbed, and the count recycled for the alternate date--November 27th.
In spite of the Thanksgiving holiday, pad crews, launch team members, and support in Houston worked to diagnose and resolve the issue, tracing the problem to a marginal wiring harness in the connection carrying the telemetry from the rocket to the launch tower during the countdown. The overtime during a holiday wasn’t something NASA typically did in the era of Freedom, but lunar launch windows paid no heed to human customs. With the issue resolved and the wiring replaced and retested, the launch team gathered again on the 27th. This time the Saturn Heavy soared into the sky on a fiery plume and a wave of thunder. In stark contrast to the issues on the pad, the launch itself was perfectly nominal from the moment the engines lit and the hold-downs released to the completion of the Pegasus’ contribution to ascent. After a short coast, the stage relit to complete the injection of the
Janus lunar module. During the three-day coast to the moon, mission control carefully monitored the temperatures and pressures of the descent stage, providing the final proof to Artemis 2 and 3’s data about the successful extended storage of cryogenic fuels during the trans-lunar coast. Hunt requested a break in the training schedule to allow his crew to take shifts in Houston’s Mission Control Center, following
Janus through its long coast and the trajectory modifications to put it on course for its descent to the lunar surface.
The landing site for Artemis’s first lunar return had been a topic of heated debate within the program. With just six landings planned in the initial sequence, lunar scientists were determined to maximize the scientific return of Artemis and advocated for a wide range of initial landing sites--many with interesting surface features that, unfortunately, also created tricky landing approaches. Flight planners, on the other hand, were more interested in verifying the correct performance of lander systems during the first flight, implying the selection of a relatively flat and topographically uninteresting landing site which the automatics (and still more the human pilots) would have little trouble with. In turn, scientists opposed the possibility as such sites were also likely to be
geologically uninteresting and yield less new data even with the extended stays of Artemis than their preferred sites. Political interests also factored in, as the President was interested in a return to the moon which would highlight American leadership in a post-Christmas Bombing world as an example of unity. Although far from a directive from on high, certain administration officials had inquired about the possibility of mounting a return to one of the Apollo landing sites, hoping to mine nostalgia among the politically influential Baby Boomer class for the period and find a graphic example of American technological leadership, both past and present, to display for the world.
As leaders of the flight crew, with ultimate responsibility for actually flying the mission, Hunt and Keeler actively participated in these discussions, with Hunt tending to lean on the side of the flight concerns, while Keeler naturally had sympathies for the scientific concerns. However, unlike most of the members of these factions, Hunt and Keeler worked together extensively during their training, and eventually came to see much of the other’s positions--Hunt could see where and why geologists were interested in the Moon, while Keeler’s NASA flight training (a requirement even for non-pilot astronauts) meant he understood the engineering concerns about the first landing. In the end, the pair came to a mutual agreement that they took to the site selection board meetings together and managed to sell--Keeler suggested visiting one of the
early Apollo sites, one where the geological potential had not been exhausted by extensive roving EVAs. In particular, the suggestion was to land at Apollo 12’s landing site in the Ocean of Storms. While the site had been explored by Pete Conrad and Al Bean, to say nothing of the earlier Surveyor 3 lander, there were still unanswered selenological questions about the area, many of which had actually developed from Apollo 12’s efforts. Compared to other areas of the near-side, the Apollo 12 site was relatively young, as much as half a billion or more years younger than the Apollo 11 site, and had a number of interesting chemical properties. It had also been the first location on the Moon where KREEP, an unusual combination of potassium (K), rare earth elements (REE), and phosphorus (P) had been discovered, although only a single sample. As the Lunar Ice Orbiter and Lunar Reconnaissance Pioneer had discovered a significant enrichment of KREEP underneath Procellarum, there was considerable interest in better characterizing the surface abundance of the combination there. Additionally, the Surveyor and Apollo 12 landing sites themselves could provide an interesting survey site; much as Conrad and Bean’s mission had produced data about the results of years of exposure on the lunar surface, a return to the Ocean of Storms would be able to take observations of the effects of nearly 30 years of continuous exposure to the lunar environment.
With the deadlock broken, the final site selection was made in early 1998, with maps from the Lunar Ice Orbiter and LRP being tapped to map a final landing site and program
Janus’s flight computers with topology data. In order to minimize effects on the Apollo 12 site, the landing target for Artemis 4 was over a slight rise, several kilometers away--well within roving range, but enough to avoid unnecessary impact to the site, and exposing a new area to easy EVA access. On November 30th,
Janus followed along its programmed course, firing its descent engines for the first time to slow its interplanetary trajectory. With no need to leave a spacecraft in lunar orbit, no propellant was spared to enter a temporary orbit; instead,
Janus fired to drop directly into its final landing trajectory. As they had gathered for the launch, Hunt’s crew gathered at Houston for the landing, watching the telemetry and video from the lander as it began its autonomous descent to the surface. Tension in the MCC was high, and without a crew onboard to relay observations, the descent had more in common with the final descent of the JPL Mars Traverse Rovers in 1995 than the Apollo missions. As it moved through the descent phases,
Janus transmitted back codes indicating the status of its internal descent logic, to compare in Houston to the transmitted telemetry.While not as drastic as the 15-minute delay in data from Mars, the two-second light lag was enough that
Janus was entirely on its own in piloting its descent.
Sighs of relief and scattered applause broke across the room as the data confirmed that the lander had acquired the ground with its radar at just over 20 km, then again as the data was matched to its onboard maps and the lander began adjusting its descent to make the minor corrections to steer to the landing site. On the cameras fixed on the descent stage, the Moon loomed large, going from a globe to rapidly rising surface. As the surface of the Ocean of Storms rose to meet it,
Janus cut down its speed, then cut out its outboard engines to continue the burn on the center engine alone. As the fuel burnt off and the speed and altitude dropped still lower, that single engine too had to be throttled to control the descent acceleration, exactly matching the lunar gravity to proceed at a constant rate. Finally,
Janus signalled back that it had selected a final landing location, and was descending to it. In the Mission Control Room, the horizontal speeds dropped and nulled out as the lander steadied itself hundreds of meters above the site, and began its terminal descent. A plume of dust obscured the ground as it dropped the last few meters, increased at the last moment as the lander’s engine fired to kill its vertical speed. At a meter up, probes on the footpads hit the surface, and the engines automatically died as the lander dropped. Seconds later, the MCC staff watched the critical codes come back--Contact! Engine off! Acceleration readings on the stage jumped as it crunched into the lunar soil, then settled--the lander was stationary. As the room broke out in cheering, the grinning guidance controller turned to the flight director. “Platform is stable, and we are down on the moon!” Joining in the applause, the launch control loop captured Hunt’s words as he leaned over to talk to his MSO. “Well, Ed, what do you say. Feel up for a little camping trip next year?”
When the Flight Director was able to restore order to the room, the Mission Control staff began the process of configuring the lander for surface operations, converting it from a spacecraft to a stationary facility. Valves in the descent stage were opened to purge the remaining hydrogen and oxygen from the tanks, reducing the internal pressure of the propellant tanks and the risk of a rupture. Readings were also taken to determine the final landing site, which determined that
Janus had steered itself to within 800m of the center of the targeting ellipse. In addition to this accuracy, the computer’s landing had been more economical than expected performance, meaning that there were substantial quantities of residual propellant remaining in the tanks. The Lunar Crew and Logistics Module had been designed to carry 14.5 tons with margin, but now
Janus had shown that this margin might not be entirely necessary. Accordingly, Boeing and NASA engineers began analysis on how much extra payload could potentially be carried on future flights it such economy could be replicated. In the meantime,
Janus was commanded to spread its solar arrays to catch the light of an early lunar morning and charge its fuel cells for the long, cold lunar night. Over the next few months, it would keep a solitary watch over the future Artemis 4 landing site while Hunt’s crew prepared for their mission and the vehicles that would join it were processed for flight. Administrator Davis’ bet had paid off, and the Artemis lander had passed its final testing hurdle. All that remained was for its crew to join it on the surface of the moon.