High atop the world

Once in orbit, the crew could remove their helmets and gloves to give themselves a little more freedom, but for now would remain in their suits. As they busied themselves with their tasks, the cabin became cluttered as cameras and lenses were unstowed, ancillary equipment was fished out and installed, and the necessary system checks and alignments made. In addition to their spaeesuiis. the crew of Apollo 8 were still wearing life vests in case the CM had to ditch in the Atlantic after launch. As Jim Lovell was moving around, his life vest caught something and began to inflate from its internal gas supply.

"Oh, shoot!"

"What was that?’- asked his commander.

"My life jacket," he replied.

"No kidding?" laughed Borman.

Bill Anders was aware that, at this stage of the flight, their words were being recorded for later transmission to Earth and so he began a running commentary.

"Lovell just caught his life vest on frank’s strut."

"It’s hard to get off, too," commented Lovell. The three crewmen soon realised that the vest had been inflated with carbon dioxide, and if Loo much of that gas were to be dumped into the cabin it w ould overw helm the lithium hydroxide canisters that were intended to absorb the toxic gas in their own exhaled breath. Anders came up with the solution: " fell you what we’ll do: we‘11 dump ii oul with the vacuum cleaner

over the side there.1′ The CM’s vacuum cleaner worked simply by dumping cabin air overboard, taking dirt with it. By feeding the eonients of the life vest down the vacuum cleaner, the problem was solved.

Although they only had about 2 Vi hours in Earth orbit, the Apollo crews usually considered that to be enough Lime to eompleie a rigorous scries of systems checks and still have an opportunity to look out of the window at the w’ondrous sights passing below. For some crewmen, this would be their first experience of spaceflight, but this was not so for the Apollo 11 crew, all of wiiom were Gemini veterans.

“ frees and a forest down there.” said Mike Collins, as they flew somewhere over the western United States. "It looks like trees and a forest or something. Looks like snow and trees. Fantastic. I have no conception of where we’re pointed or which way we’re going or a crapping thing, but it’s a beautiful low-pressure cell out here.”

This crew, and many of the other Apollo crewmen, had flown in the cramped confines of the earlier Gemini spacecraft – a couple had even been squeezed into the tiny one-man Mercury capsule. Apollo gave them a bit more space to move around. “I’m having a hell of a time maintaining my body position dowm here,” noted Collins after he had manoeuvred down into the lower equipment bay where the eyepieces for the optical instruments were stored. “I keep floating up.”

“How’ does zero-g feel?” asked Neil Armstrong of his crew. “Your head feel funny, anybody, or anything like that?”

“No, I don’t know, it just feels like w’e’re going around upside down.” replied Collins who was still transfixed by the experience.

The Lime in Earth orbit was something that all the crews wished could have lasted longer. “Jesus Christ, look at that horizon!” yelled Collins on seeing howr quickly the Sun rose in orbit, even though he had already witnessed the spectacle during his Gemini mission in 1966.

“Isn’t that something?" echoed Armstrong.

“God damn, that’s pretty; it’s unreal.”

“Get a picture of that.” suggested Armstrong.

“Oh, sure. I will,” replied Collins who then had to contend with the compact and complex space that was an Apollo cabin. “I’ve lost a Hasselblad. Has anybody seen a Hasselblad floating by? It couldn’t have gone very far. big son of a gun like that.” "

Eugene Cernan. the commander of Apollo 17, noted how their night-time launch affected their experience in orbit. "Launching at night, we just had a somewhat different view of the Earth than most other flights have had. The first real view we got of being in orbit was pretty spectacular because it happened to be Earth sunrise and that’s a very intriguing and interesting way to get your first indoctrination to Earth orbit.”

Certainly Cernan’s LMP, Jack Schmitt, flying for the first Lime, did not hold back in describing what he saw as he saw it, a characteristic this scientist astronaut would exercise both on the Moon and in orbit around it. For example, while flying over the dark United States, he described the lights of the American towns and cities to Capcom Bob Parker. "Man’s field of stars on the Earth is competing with the heavens. Bob. 1 think we got the Gulf Coast showing up now. by the band of lights."

Half an hour later, over the daylii hemisphere, he applied some terminology with which he was familiar to the delicate patterning he saw in the great cloud systems that lay below: "Bob. we’re over what might be intermediate to low strata that have a very strong crcnulalion pattern – pulling out some geological terms here. 1 don’t think I’ve ever seen anything like it flying [an aircraft].”

The exposed desert landscapes of the Sahara brought him back to thinking about rocks. "Bob, wc had almost a completely weather-free pass over Africa and Madagascar. And the scenery, both aesthetically and geologically, was something like I’ve never seen before, for sure. There were patterns like I haven’t even seen in textbooks. Maybe I haven’t been looking enough, but some of the desert and grassland patterns had the appearance of ice crystals almost.’’

The crew of Apollo 12 had been entranced when they saw countless tiny pinpricks of light across the night-time expanse of the Sahara Desert as nomads sat by their campfires. The Apollo 16 crew also spotted this reminder of the human race’s relationship with flame, one that had lifted them off the planet.

"Look, look, John.” said Duke.

"What?’’ asked Young, ever unflappable.

"The fires. Out the right side. Looka there!-’ said Duke in some wonder. He had heard the stories from the Apollo 12 crew about them. "1 hey were right. They were really right. Beautiful!”

"What’s that?” asked Young.

Ken Mattingly, CMP on this mission, reminded his commander: "The fires of Africa. They’re there. Like he said. Isn’t that spectacular?”

"Thai is really beautiful!” said Duke.

"Can you see them. John?” asked Mattingly.

"Yeah, I see them. Yeah, yeah. Good gosh!-’

"There must be a hundred or so,” added Duke. "What are they from?-’

"Nomads,” said Mattingly. "All the nomads and stuff that are out there.”

Sharp-end forward

While the crew busied themselves to ensure that their ship was healthy, the S-IVB had not been idle as it prepared for its main burn. Throughout the one-and-a-half orbits made before TLI. a set of small rocket thrusters attached around its base kept the stack pointed forward into the direction of travel. The vehicle was still in the upper fringes of the atmosphere and this sharp-end-forward attitude presented the smallest area to the hypersonic air flow’, thereby minimising frictional heating. They also kept the cabin windows facing Earth and the spacecraft optics on the opposite side facing out to the stars for the CMP’s navigational duties.

This sharp-end-forward attitude was also required for TLI. so it made sense to maintain it throughout the Earth-orbit phase and avoid having to make large attitude adjustments that would have stirred up the propellant in the part-used tanks just prior to the burn. An early unmanned Lest (light had shown that it ought to be
possible to rotate an S-IVB, but excessive motions of the stage had to be avoided in case large slosh waves were generated within the tanks. Un­fortunately, Apollo 15’s S-IVB mana­ged to lose a quarter of a tonne of LOX when it readjusted its attitude too quickly. The stack had entered orbit in an excessive nose-down atti­tude and the slosh wave that resulted from the readjustment managed to reach a vent. Fortunately, the loss did not impact the mission.

Attitude control of the S-IVB stage was somewhat different from the technique used on the first and second stages of the Saturn V. While these stages could use their main engines to turn the ship in all three axes, the S- IVB’s single engine could only gimbal in two axes to provide control of pitch and yaw. It had no means to control roll. Additionally, unlike the two lower stages, the S-IVB was required to maintain its attitude during coast­ing flight when no power was avail­able from its main engine. The engineers’ solution was the auxiliary propulsion system (APS) which used two modules affixed to the base of the stage’s cylindrical section, each of which held four small rocket engines that burned hypergolic propellant from their own tanks. During powered flight, only the APS roll engines had to operate because pitch and yaw were effected by gimbaling the main engine. After the main engine had shut down and the stage had begun to coast, the APS modules assumed control of all three axes: roll, pitch and yaw.

While in Earth orbit, the crew avoided using their RCS thrusters as any motion imparted by them would be immediately counteracted by the APS thrusters whose commands came from the Saturn’s instrument unit. One exception was a short firing made to check their operation. Pete Conrad on Apollo 12 made a particular point of testing his spacecraft’s RCS thrusters with a few short pulses. His vehicle had sat in heavy rain prior to launch and he was convinced that this would have affected the upward-facing thrusters. “I was still worried about the water in those thrusters. I wasn’t convinced, in my mind, that we had not frozen some thrusters full of ice as there was water on the windows. Everybody thought [the water on the windows] would disappear and it hadn’t. I was concerned about those service module RCS thrusters, but the ground assured me they were working okay and it was alright with us.