Category: Space Sunday

This is the concluding part of a special Space Sunday series, celebrating the 50th anniversary of  Apollo 11 landing on the Moon, and follows on directly from Part 2: “The Eagle Has Landed!”. To follow the full series, please click over to Part 1: Lift-off! We Have lift-off!”

Part 3: “Magnificent Desolation” And The Voyage Home

I had asked [Neil] before the mission launch several times what he was going to say on the occasion of this historic moment, setting foot on the lunar surface, and he always replied, “I’m a test pilot, I’ll probably just say how dusty it is or something like that. Don’t worry.” But he came back with his now famous [line]. The media immediately wanted to know if it was one small step for a man, or just man. There was a little bit of static, so it wasn’t entirely clear.

– Astronaut Bruce McCandless, Capsule Communicator (CapCom),
Mission Control Green Team

Whether or not Armstrong had said “a man” in his statement was to become a matter of debate in the decades that followed Apollo 11, almost overshadowing that first step itself. With the indefinite article included, his comment makes sense: he is clearly referring to himself (“one small step for a man”). Without it, “man” becomes more reflective of humanity as a whole, making his comment the equivalent of “That’s one small step for humanity. One giant leap for mankind”.

Such was the level of debate with one analysis of recording suggesting he said “a man”, another suggesting he didn’t, that not long before his death, Armstrong noted a little ruefully – and quite correctly:

I would hope that history would grant me leeway for dropping the syllable and understand that it was certainly intended, even if it wasn’t said – although it might actually have been.

– Neil Armstrong

But on the Moon, and unaware of the controversy that was even then brewing around his words, Armstrong collected a contingency sample of rock and surface material in case an unexpected issue required the EVA to be curtailed. Then he took the remote-control TV camera mounted on the Lunar Module to take a panoramic shot around the Eagle before setting it on a tripod a short distance from the LM to allow Mission Control to use it to record the EVA.

That  camera is the reason why the Apollo 11 video footage looks ghostly. Its scan rate was incompatible with those used by US TV networks, so the live transmission had to be shown on special monitors with TV cameras set-up in front of them which then re-broadcast the images – with a significant loss of picture quality in the process. (It’s also worth notingthat while NASA recorded the footage onto magnetic tape, it was eventually lost through the agency’s policy of tape re-use.)

Aldrin set foot on the Moon 19 minutes after Armstrong with the words, “Beautiful view. Magnificent desolation.”

There was little time to appreciate it, however. The two men were on a tight schedule: because there was no empirical data on how well the portable life support system (PLSS) in the astronaut’s backpacks would perform on the Moon, it had been decided to limit this first (and only, for Apollo 11, which would spend less than a day on the Moon) EVA to just over 2 hours. Before that time expired, both men had to set-up the US flag, deploy the instruments of the EASEP, the Early Apollo Scientific Experiments Package, survey their location and collect and many rock and soil samples as they could manage.

The flag (purchased from a Sears store) proved a little problematic. Its telescopic pole refused to go deep into the ground, leaving Aldrin fearing it would unceremoniously topple over while on camera. Nevertheless, he dutifully saluted it as a still-commissioned US military officer before taking up position in front of the TV camera to demonstrate various means of locomotion in the low gravity for the benefit of future crews.

While he was doing that we were all wondering what Neil was doing. Well, Neil was collecting this very fine and diverse group of rocks and soil. Not only did he get a very wide distribution, but he also thought the box looked a little empty, so at the last minute he filled it with just the dirt, so to speak, what we call the lunar regolith. That sample turned out to be the best, most comprehensive sample of lunar regolith that was ever taken on any of the Apollo missions.

– Harrison Schmitt, the only geologist-astronaut in the Apollo programme,
who served as both advisor to crews and as the Lunar Module pilot for Apollo 17

Continue reading “Space Sunday special: Apollo 11 at 50 Part 3” →

This is part 2 of a special Space Sunday series, celebrating the 50th anniversary of  Apollo 11 landing on the Moon, and follows on directly from Part 1: “Lift-off! We Have Lift-off!” It was published on Saturday, July 20th, 2019, as a Space Sunday special to mark the actual date of that historic landing.

Part 2: “The Eagle Has landed”

Once the combined Command and Service Module (CSM) and Apollo Lunar Module (CM) were free of the Saturn V’s S-IVB stage, they were in constant sunlight, so to help better regulate their internal and external temperatures, the reaction control system on the CSM was used to set both vehicles spinning very gently along their longitudinal axis in what was called the “Apollo barbecue roll”.

During this “cruise phase” of the flight, the three men aboard Apollo 11 – Armstrong, Collins and Aldrin – had to perform a range of activities from keeping an eye on their spacecraft through to making broadcasts back to Earth. It was here that their curious relationship came a little to the fore.

While all three men got along very well, they were observed not to bond in the manner of other crews; all three were somewhat quiet men, with Collins and Aldrin particularly coming to refer to their relationships with one to the others as that of “amiable strangers”.

Which is not to say the three men didn’t get along; almost all of the on-board conversations were recorded by NASA, even if they weren’t broadcast, and these “off-air” conversations reveal the three men shared jokes – such as Aldrin and Collins gently teasing Armstrong about his “rookie” status in having clocked the fewest number of hours in space. However, when it came to talking for the benefit of the television audience, Mission Control sometimes had to coax words out of the crew.

The first time we saw the Moon up close, it was a magnificent spectacle. It was huge. The Sun was coming around it, cascading and making a golden halo and filled out entire window. [But] as impressive as the view was of this alien Moon seen up close was, it was nothing compared to the sight of the tiny Earth. The Earth was the main show. The Earth was it.

– Michael Collins, 50th anniversary of the Moon landing

Apollo 11 reached the Moon on July 19th, 1969, after a single mid-course corrections using the single motor of the Service Module (out of 4 planned for the flight).

Now Collins again took the controls to gently pivot the vehicles around in their own length, so that single large motor was pointing forward along their line of flight. Then, at 17:21:50 UTC, as they passed around the Moon’s far side, the engine was fired in the first of two orbital insertion burns.

This first engine burn slowed the vehicles so they they were snagged by the Moon’s gravity and placed in an elliptical orbit. A second burn of the engine followed 4 hours and 22 minutes later, circularising the vehicle’s orbit in readiness for Armstrong and Aldrin to make their historic descent.

In all thirty orbits of the Moon were performed as the Lunar Module was prepared for its descent and landing. These orbits frequently passed over the Mare Tranquillitatis, a large basalt plain on the Moon selected as the location for the first manned landing by the United States as it appeared from orbital imaging as being relatively smooth, and had already seen a successful landing by the automated Surveyor 5 mission, which arrived on the Moon on September 11th, 1967.

Shortly after Apollo 11 dropped into orbit around the moon, Frank Borman got a message from the Soviet Union that said, “Congratulations on reaching lunar orbit. We have Luna 15 also in orbit around the moon and its orbital parameters are such and such. If it presents any problem, please advise and we will move it.” We didn’t need Luna 16 moved, but I thought it was a noble gesture in those days of the Cold War.

– Bruce McCandless, Capsule Communicator (CapCom),
Apollo 11 Mission Control Green Team

At 12:52:00 UTC on July 20th, Aldrin and Armstrong entered Eagle, and began the final preparations for lunar descent, Five hours later, all was set and they undocked from the Command Module Columbia. With Michael Collins in the Command Module, Armstrong gently eased Eagle away from the CSM, then used its reaction control system to perform a slow pirouette. This allowed Collins to carry out a visual inspection of the LM, confirm its legs were deployed and that it was generally looked OK to make its decent.

For the first part of the decent, Eagle was effectively “face down” giving Armstrong and Aldrin a view of the Moon. Then the descent engine fired and the vehicle slowly moved to an upright position, and Armstrong voiced a slight concern.

We’re about a minute, maybe 2 minutes, into powered descent, face-down, and Neil says to me, and the Earth, “I think we’re gonna be a little long.” I said to myself, how in the world can he really, at this point, tell that we’re gonna be a little long? But sure enough, we were. I’ve learned that whenever Neil says anything, you’d better pay attention because there’s good meaning to it.

– Buzz Aldrin commenting on the Eagle’s descent to its landing

Continue reading “Space Sunday special: Apollo 11 at 50 Part 2” →

This week sees the 50th anniversary of the Apollo 11 lunar landing. To mark the event, this Space Sunday article and the next will look at that mission, and the three men who flew it.

Part 1: “Lift-of We Have Lift-off!”

On Wednesday, July 16th, 1969, at 13:31:51 UTC (9:31:51 EDT) five Rocketdyne F-1 at the base of Saturn V SA-506 came to life. Starting with the centre motor, then the opposing outboard pairs, the entire ignition sequence took 600 milliseconds. Held on the pad by four massive clamps, called hold-down arms, the five engines gradually built up thrust to 35,100 kN (7,891,000 lbf).

At precisely 13:32:00 UTC) (9:32:00 EDT) the huge hold-down-arms rocked back in a “soft release”, allowing the rocket, weighing almost 3,274 tons, to start its ascent, its acceleration slowed for the first half-second by a series of 8 pins connecting it to the pad to “reduce transient stresses resulting from abrupt disengagement of a vehicle from its launch stand”. When these pins dropped free from the base of the rocket, Apollo 11 was on its in a historic mission that would seen humans land on the Moon for the first time.

The two men destined to be the first to set foot on Earth’s natural satellite were Neil Alden Armstrong, just shy of his 39th birthday, and  Edwin Eugene “Buzz” Aldrin Jr., who had turned 39 in January 1969, sat atop of the massive Saturn V rocket along with Command Module Pilot, Michael Collins, the youngest of the three (if only by a couple of months). Together, they formed only the second Apollo flight crew where all three men had previously flown in space (the first having been Apollo 10, the “dress rehearsal” mission for the Moon landing).

Armstrong, Aldrin and Collins were also perhaps the most technically competent trio on NASA’s astronaut roster at the time. All had served in the military – Armstrong in the US Navy, Aldrin and Collins in the US Air Force. Both Armstrong and Collins had also built up impressive résumés as test pilots, Armstrong as a civilian and Collins in the US Air Force.

In particular, Armstrong flew with the National Advisory Council for Aeronautics (NACA), NASA’s forebear, prior to being selected for the USAF/ NASA high-altitude X-15 research programme, (he flew the X-15 seven times between late 1960 and mid-1962) whilst simultaneously engaged by the USAF in their X-20 Dyna-Soar space plane project. Collins, meanwhile, took part in high-altitude flights, taking F-104 Starfighter jets to 27.7 km (90,000 ft) in order to experience the “weightless” environment of free-fall at the top of their parabolic flight arcs, helping him to achieve 3,000 hours in the cockpit.

As well as being aviators, Armstrong and Aldrin were also academics. Armstrong held a BSc in aeronautical engineering and an MSc in aerospace engineering, and Aldrin has a doctorate in astronautics. Aldrin particularly specialised in on-orbit rendezvous, which allowed him to work on Project Gemini as an engineer (and also earned him the nickname “Dr. Rendezvous” , not always meant kindly, by other astronauts).

Despite their qualifications, both Armstrong and Aldrin almost didn’t get selected for NASA’s astronaut programme: neither had the requisite military test pilot qualifications that were initially required. However, in 1962, NASA dropped the “military” element from the test pilot requirement, enabling Armstrong to apply for the Group 2 intake – although he almost missed the cut. his application arrived after the closing date, but fortunately Dick Day, a simulations engineer at NASA who have previously worked with Armstrong saw the application and made sure it was included.

Aldrin’s break came in 1963, when NASA further revised the requirements to test pilot OR 1,000 hours flying jets. This allowed he to re-apply (his first application having been turned-down due to his lack of test pilot experience), and he was invited to join the Group 3 intake alongside Michael Collins.

A Saturn V launch is perhaps one of the most stunning sights to witness – and Apollo 11 was witnessed by around 1 million people in and around the Kennedy Space Centre. However, for the first part of their flight, the three men were pretty much passengers as the Saturn V rose into the sky.

For all their power, the five F-1 engines took 12 seconds to overcome the 100.6 m tall rocket’s mass and inertia and push it clear of the 120m tall Launch Umbilical Tower (LUT), angling it very slightly away from the tower in the process so to avoid the risk of any wind-driven contact between the two.

Immediately after clearing the tower, the rocket commenced its “roll”, a necessary manoeuvre in which the vehicle rolls around its vertical axis, allowing it to point itself along the line of flight it needs to achieve the required orbit. After that, things started to move quickly.

A minute after launch, the Saturn V was around 6.5 km (3.5 nautical miles) altitude and passing through the sound barrier. Twenty seconds later, it entered “Max Q”, the period of maximum dynamic pressure, placed on this frame as a result of it literally punching its way through the atmosphere.

At this point, the F-1 engines throttled back a little to prevent the vehicle shaking itself apart, but once through “Max Q” – a period of only a handful of seconds, they returned to full thrust, pushing the vehicle up to 62 km (42 mi) above the Earth, and taking only 2 minutes 41 second from launch to do so. At this point, and travelling at 9,960 km/h (6,164 mph), the huge first stage separated, the upper stages of the Saturn 5 pushed clear by a set of four separation motors.

From here, the four motors of the second stage took over. While the massive first stage coasted upwards behind it and then fell back to crash into the Atlantic ocean, the Second stage ran for 6 minutes, accelerating the rocket to 25,000 km/h (15,647 mph) and lifting it to an altitude of 175 km (109 mi).

With its fuel spent, the second stage separated, also to fall back to the Atlantic, while the single, re-usable engines of the all-important S-IVB stage took over. This stage initially ran for about 2.5 minutes, during which time it pushed Apollo 11 to a velocity of 27,900 km/h (17,432 mph), allowing it to assuming a near-circular orbit around the Earth averaging 184 km 98.9 na mi) before shutting down for the first time.

It was at this point that the three crew took a more pro-active role in the flight. For the next  couple of hours, as they completed 1.5 orbits of the Earth, and in tandem with mission control, they confirmed their vehicles were ready to be committed for the flight to the Moon.

Interestingly, while mission commander, Armstrong had actually clocked less time in space than either Collins or Aldrin. However, he had the greatest experience in handling in-flight emergencies, having dealt with the first in-flight failure of a critical system during a US space mission.

This occurred during his flight flight into space on the Gemini 8 mission, alongside David R. Scott. This mission was intended to be the first test of an orbital docking between two vehicles – Gemini 8 and an automated Agena target vehicle. In all, Armstrong and Scott were expected to complete four such docking as a part of the mission objectives.

However, shortly after docking, the Gemini’s Orbit Attitude and Manoeuvring System (OAMS) has suffered a serious failure, and Armstrong ordered Scott to release the docking mechanism before before vehicle broke up. Once free of the Agena (which was later stabilised by ground control allowing it to be used by Gemini 10 with Michael Collins), Armstrong took the took the unorthodox step of shutting down the OAMS and using the Re-entry Control System (RCS) to regain control. While this worked, undoubtedly saving his and Scott’s lives, under mission regulations, they no option but to immediately perform and emergency return to Earth, curtailing the mission.

Back aboard Apollo 11, their checks complete, the crew received the all clear for the critical trans-lunar injection (TLI) burn. This started mid-way through the second orbit of Earth, as the S-IVB motor was restarted and fired for 5 minutes and 47 seconds, accelerating the vehicle to around 40,085 km/h (25,053 mph), and pushing it away from Earth and into an energy-efficient trajectory towards the Moon.

As Michael Collins carried out the transposition, docking and extraction manoeuvre, either Aldrin or Armstrong took this image of the Lunar Module (LM) sitting in the top of the Saturn V S-IVB stage, awaiting the Command and Service Module (CSM) to dock with it and gently pull it free of the upper stage. Credit: NASA

Continue reading “Space Sunday special: Apollo 11 at 50” →