I am posting this on another forum, but thought some might enjoy it here.

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Just in case were not aware, we are coming up to the 40th anniversary of the Apollo 11 lunar landing.

40 years ago last October, Apollo 7 launched and conducted the first manned flight of the Apollo Command and Service Modules, spending nearly 11 days in space.

40 years last December, Apollo 8 launched - the first manned launch of the Saturn V vehicle. Without a lunar module, they flew to the Moon, went into orbit, and returned safely to Earth, all in just over 6 days.

40 years ago today, Apollo launched into Earth orbit to conduct flight tests of the lunar module. If these tests were successful, the next mission would be a dress rehearsal for a lunar landing. This was also the first Apollo mission to have a callsign apart from Apollo: the spacecraft were called Spider (the LM) and Gumdrop (the CSM). The mission seemed to run into problems when the Lunar Module Pilot, Rusty Schweickart, suffered Space Adaptation Syndrome (space sickness) and had a planned EVA canceled. The following day, however, he recovered and a modified EVA took place. The LM systems were tested, rendezvous practiced, and LM staging proved. 10 days later, the crew returned, the mission was a success, and a manned lunar landing was just around the corner.

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3-4 March 1969

Apollo 9 launches into Earth orbit under the command of Jim McDivitt. McDivitt had also commanded Gemini 4, the flight on which Ed White became the first American to walk in space. With McDivitt were Dave Scott (also a Gemini vet, and who would go on to command Apollo 15) as the Command Module Pilot (CMP) and rookie Rusty Schweickart as the Lunar Module Pilot (LMP).

This was only the second manned launch of the Saturn V, and problems still occurred. The flight seemed to be going perfectly until about seven minutes after lift-off, when pogo occurred. Pogo was severe longitudinal vibration that occurred through the launch vehicle. It is caused because various liquids (fuels or oxidisers) are flowing through the stages, causing low frequency vibrations and changing the rate at which the fuel flows. The disturbance in the flow causes slight changes in the rate at which fuel is delivered to the engines, and thus cause slight thrust changes. The effect had been seen in other rockets, but the pogo in the Saturn V could be quite severe (enough to break a fuel line on one flight). Engineers tried to fix the problem, but it was almost random in it's intensity. The pogo was not enough, however to force Apollo 9 to abort.

Once in orbit, the crew took time to adapt to the new environment, learning a lesson from Frank Borman's space sickness on Apollo 8.

Over the next four hours, they eventually docked with the LM, extracted it from the S-IV-B stage, and began their housekeeping for what would become a test pilot's delight of spacecraft evaluation over the next 10 days.

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5 March 1969

After a successful launch and extraction of the LM, the crew of Apollo 9 began the business of flight testing the LM.

The LM had been tested - unmanned - in space during previous unmanned Apollo missions but this was the first manned flight test of the LM... and the crew wanted it to succeeded. This mission had always been planned as a flight test of LM3 (the 3rd LM Grumman built) but was originally scheduled as Apollo 8. During the later part of 1968, however, it became apparent that despite Grumman's best efforts the LM would not be ready in time for the flight. It looked as though the Apollo flight schedule would be delayed.. then fate stepped in.

CIA surveillance of the USSR had revealed the existence of the Soviet equivalent of the Saturn V - the N-1 moon rocket. The possibility of the USSR conducting a manned circumlunar flight became very real. Although it would not be a manned landing, the Soviets could rightly claim that they had "reached" the Moon first. George Low of NASA then asked the question: if we're not ready to fly the LM, why not send the CSM around the Moon without it? It was an ambitious call considering it would be the first flight of the Saturn V, but it worked. Although Jim McDivitt was never asked if he wanted fly the new Apollo 8 mission, or remain with his original mission, there was no doubt in his mind: Jim wanted to fly the LM. They has shepherded the spacecraft since it's initial construction, and they didn't want to turn it over to another crew. They therefore became the crew of Apollo 9, rather than Apollo 8.

This had an unexpected and historic side effect: the backup crew for the LM3 flight also switched along with them. This meant they would now become the prime crew for Apollo 12, and not Apollo 11.

Fate just stopped Navy Commander Pete Conrad from being the first man on the Moon.

CDR Jim McDivitt and LMP Russell (Rusty) Schweikart entered the LM for it's first full day of flight testing. They would check system performance, check computers, and check the engines. Everything had to tested before NASA could risk sending a crew to the Moon in a Lunar Module. Even so, the crew of Apollo 9 faced very real - if understated - risk to themselves during the upcoming tests: they would separate into two spacecraft... and only one could return to the Earth. If for some reason the LM and CSM could not redock after separation, the LM crew of McDivitt and Schweikart would have to get as close to the CSM as possible, then make a leap across space to reach the Command Module - there only means of returning to the Earth in one piece.

The crew tested the systems, the checklists, the gauges - all appeared well. Now was time for the first of the more important hurdles: testing the LM's Descent Propulsion System (DPS), the engine that should take the astronauts safely to the lunar surface. This engine was expected to achieve more than previous engines: not only was it expected to stop then restart, it was expected to be throttleable - that is vary it's thrust according to the crew's demands. No engine had ever done this before.

Throughout the day, the crew checked systems. They then fired the DPS - still docked with the CSM - for the first time. The engine did not perform quite as expected, but this was thought to be due to small bubbles in the propellant system. It was cleared by throttling the engine.

The crew also provided live TV broadcasts to Earth, giving viewers a tour of the spacecraft. Things were going well... but the flight plan was about to take an unscheduled deviation.

Unbeknownst to the other crewmembers, Rusty had experienced a sudden bout of nausea when having his breakfast in orbit. The feeling was transient, and he was able to keep the vomit in his mouth until he was able to ejected it into a sick bag. He immediately felt well, and continued with his duties.

As the crew donned their EVA suits prior to entering the LM for it's tests, however, both crewmembers experience disorientation. This passed quickly and the crew continued with the flight plan. Rusty thought that he would adapt quickly, and remained stoic.

The last of the tests involved Rusty activating the LM's "legs", taking them from their stowed position to the landing configuration.

They were now set to separate the two manned spacecraft, one of which could never return to Earth except as a burning hulk - the most hazardous manoeuvre yet attempted by US astronauts.

Preflight crew photo (McDivitt, Scott, Schweikart):



The crew arrangement in the CSM:



Apollo 9 on the launch pad:


The LM still tucked away in the S-IV-B stage, before extraction.

6 March 1969

The day for Apollo 9 started as per the flight plan: more system tests. Routine, perhaps boring tests... but vital tests to properly flight test LM3.

Conducting these tests inside 'Spider', Rusty appeared to be over his disorientation when - without warning - he suddenly vomited again. Mission commander Jim McDivitt was now concerned. Part of the day's flight plan was for Rusty to conduct an EVA - Extravehicular Activity - transferring from the LM to the CM. It was meant to prove that a crew could transfer between the spacecraft if the CM upper hatch through to the LM could not be opened, and also to prove the EMU - the Extravehicular Mobility Unit - otherwise known as the lunar suit, could protect a person in space. McDivitt, however, could not risk the chance that Rusty would vomit inside his EMU. McDivitt requested a chat with the flight surgeons on a private channel. The success or failure of the mission was on the line.

The flight surgeons discussed the matter with McDivitt, but they left the decision up to him. He decided to wait. Throughout the day they continued with their checks, and Rusty seemed fine. Schweikart did not push the point with his commander, but he wanted Jim to know he felt fine and up to the task.

McDivitt considered and decided that a limited EVA could be undertaken. Rusty could stand out on the LM "porch" to prove the EMU, but he would not conduct a full EVA as planned.

The crew suited up, and the two spacecraft were depressurised. Dave Scott, in the CM, opened the CM hatch and stood up. In the LM, Rusty stood on the LM porch. Each of them had task to perform, recovering special film samples and experiments placed on the outside of the two spacecraft.

The limited EVA achieved most of the planned objectives.

Dave Scott conducts his "stand up EVA" from the Apollo 9 Command Module. This image was taken from the LM "porch". On the right, you can see the hand-hold that Rusty was meant to be using for his full EVA. He would have used these to move from the porch to the CM hatch and back again.



Rusty stands on the porch of Lunar Module "Spider". A better view of the EVA hand-holds.



The EVA lasted for nearly 50 minutes. The crews sealed their spacecraft, and repressurised. Rusty had felt fine throughout the EVA, and the EMU was now rated for use on the lunar surface. The next big test was to prove that Spider, this ungainly and strange looking craft, could actually fly. If it could not, then the entire plan to land on the surface of the Moon would be in ruins.

7 March 1969

Once more, Jim & Rusty donned their pressure suits and went through the connecting tunnel into Spider. Systems were powered up, the tunnel hatch closed and the docking mechanism replaced. Then, at 92 hours and 39 minutes into the mission, the spacecraft undocked. No longer was the callsign “Apollo 9” used; now they were Spider and Gumdrop. The LM slowly backed away from the CSM.


SCOTT (Gumdrop): “That’s a nice looking machine!”

McDIVITT (Spider): “So is yours.”



The two craft flew in formation, the LM staying close until it could be verified that the LM’s rendezvous radar was functioning correctly. Without the radar and associated guidance system, the LM could be lost in orbit, unable to find the Command Module – the only safe way back to Earth. Everything worked as advertised however, and so the LM moved away to simulate the manoeuvres that would take place in orbit around the Moon. Over the next several hours, the Primary Navigation & Guidance System or “Pings” was tested, the LM moving to over 180 km away from Gumdrop. McDivitt and Schweikart also tested the LM staging. On a lunar landing mission, the LM would use the Descent Propulsion System in the descent stage to get the crew safely to the surface of the Moon. When the time came to return to orbit, only the ascent stage would launch, using the descent stage as its launch pad. If a major problem occurred during the landing, the ascent stage would also be used to rapidly return the astronauts to the orbiting CSM.







The jettisoned descent stage remained in orbit for a short time, but eventually re-entered the atmosphere at 0345 GMT on 22 March 1969, impacting in the Indian Ocean off the coast of North Africa. The tests went well, and Spider – minus its bottom half – returned to dock with Gumdrop. An unexpected problem occurred as McDivitt went to dock with Gumdrop: the shiny CM was reflecting sunlight, making it difficult for McDivitt to see!

McDIVITT (Spider): “I just can’t even see the COAS, Dave. I don’t know where you are with respect to it.”

SCOTT (Gumdrop): “Okay – you want me to do it?”

McDIVITT (Spider): “No, let me work my way in here a little closer.”

SCOTT (Gumdrop): “Okay.”

SCHWEIKART (Spider): “Dave, I just can’t see it. Let me get in a little closer”.

SCOTT (Gumdrop): “You’re coming in fine. Just keep coming in easy like that. Looks like you are coming in from an angle, but you are coming in with the right attitude. You ought to go forward and to your right a little bit, relative to your body.”


The COAS was the Crewman Optical Alignment Sight. It generated a light reticule for the crew to use in aligning the LM for docking with the CM. After the experience on Apollo 9, the light intensity was raised so it could be seen against a bright CM.



Eventually, a safe docking was made. Jim and Rusty returned to the CM, sealed the tunnel, and Spider was jettisoned. The work wasn’t over for the LM, though: it was now set up for limited remote control flight. After the CSM backed away, the ascent stage engine was reignited, firing for another 6 minutes, depleting the fuel supply. This placed the ascent stage in an elliptical orbit around the Earth, 3760 nautical miles by 126 nautical miles. It would remain there for 5 years, before burning up in the atmosphere.

The LM had performed well, and NASA now had enough confidence in the Apollo spacecraft to rehearse a lunar landing. The crew of Apollo 9 had now met all the major objectives of the flight. Satisfied with a job well done, they powered down system, ate a meal, and went to sleep.

duplicate...

nice piece.... tnx!

8-12 March 1969

The LM test phase of the mission successfully completed, the remainder of the flight was relatively low key. The remaining days would be spent conducting the only 'official' experiment of Apollo 9: SO65, otherwise known as the Multispectral Terrain Photography Experiment. This involved the use of multiple Hasselblad cameras taking photographs of the Earth in the visible, infrared and other bands. Different films and filters were also used. This experiment produced hundreds of high quality images, and helped with the development of such satellites as LANDSAT.





The crew also made sightings of other spacecraft, twice optically tracking the Pegasus III (a NASA meteroid detection satellite) at ranges up to 1000 nautical miles, and sighting the ascent stage from Spider late in the mission.

The Service Module's SPS engine was also tested.

The mission complete, the crew made preparations for their return to Earth.

13 March 1969

The final day of Apollo 9’s flight began with the CAPCOM (Capsule Communicator – in other words, mission control at Houston) – waking the crew with the "alarm clock" tone rather than music that had been used on other occasions. Jim McDivitt was not bothered by this at all – he and the crew were now awake, ready to get to work and looking forward to their return to Earth.

CAPCOM: "All right. Out of the sack, troops! Let’s get to work. Today you come home."

McDIVITT: "Hot diggity dog! I think we’re all ready!"

Houston alerted the crew to a small problem; their Digital Autopilot (DAP) was still powered up, despite being given the command to power down the previous evening. It was a small matter, and would not affect re-entry. Conditions for splashdown were also passed: visibility 10 miles, wind at 5 knots, scattered clouds at 3000 feet, calm seas and a 5 foot swell with a 10 second period. Good conditions for splashdown. The crew was happy with the report, and a playful CAPCOM replied "Well, you put in an order and we strive to please."

The crew became absorbed in flight plan changes, updates, and general housekeeping duties. When Jim McDivitt mentioned he wanted to take more photos to use up the film, the CAPCOM – fellow astronaut Stu Roosa* – passed up a special request: they wanted pictures of Australia! The spacecraft would pass over Perth, in Western Australia, at night. Perth became famous when the residents of the city turned on their lights for John Glenn in Friendship 7, and now was an opportunity to repeat it. The crew also reported seeing the lights of Sydney.

Finally after 10 days, 31 minutes and 15 seconds from liftoff, the SPS engine was fired to de-orbit the spacecraft. Five minutes later, the crew jettisoned the Service Module, the cylindrical portion of the spacecraft that contained vital items such as the fuel cells, oxygen tanks, and the all important SPS engine. Its job done, the Service Module separated from the Command Module. The CM would now run on batteries and no matter what, it was coming back to Earth. Eight minutes later, the CM began to re-enter the atmosphere. For about 10 minutes, the capsule made its fiery plunge towards the surface, ionization around the capsule from its speedy transit making communications impossible.

Twenty minutes after the de-orbit burn, ground stations were relieved to hear McDivitt call "Apollo 9 here".

All three chutes deployed shortly after, and the recovery helicopters – callsign AIRBOSS – gave a narrative of the capsules descent toward the Atlantic Ocean. The capsule hit the water – only 2.3 nautical miles from the planned impact point - and recovery crews began to secure the capsule. A floatation collar was placed around it, and rafts were placed alongside so that the crew could remain safe. One at a time, they would be winched up into the Sea King helicopter and then all three were flown to the recovery carrier USS Guadalcanal, just 3 miles away, for postflight medicals and debriefing.

The crew of Apollo 9 had successfully paved the way for Apollo 10, the F mission: a dress rehearsal for a lunar landing.

( * - CAPCOMs were always a fellow astronaut, and no-one apart from the CAPCOM was allowed to speak to the crew. Exceptions were 'senior astronaut' Deke Slayton or a special event like a Presidential broadcast or the wives of the crew. Rookie astronauts would normally serve as a CAPCOM before being assigned to the flight rotation.)

Apollo 9 nears splashdown


The crew of Apollo 9 aboard the recovery vessel, USS GUADALCANAL


The CM aboard the recovery vessel


40 years later, the crew of Apollo 9 reunite in front of their CM 'Gumdrop' (from L to R: Scott, McDivitt, Schweikart). The CM is on display at the San Diego Air & Space Museum, California.

Whilst waiting for the Apollo 10 flight, I thought I might relay some peoples recollections of the era. Please feel free to add your own:

Apollo 11 Diary
By David Chudwin, M.D.

PART ONE

In 1969 I was a sophomore at the University of Michigan who spent much of my time reporting and writing for the Michigan Daily, the independent student newspaper. As someone interested in space exploration, science, and medicine, I was somewhat of an anomaly compared to my humanities-oriented compatriots. So when the announcement came that Apollo 11 would be the first attempt to land on the Moon, I immediately sought to cover the event in person, even though as a 19 year-old sophomore I was low on the totem pole at the Daily and NASA would usually not accredit college journalists.

My big break came when one of the seniors, Jim Heck, went to Washington, D.C. as an editor of the College Press Service, a group of university student newspapers which shared stories and resources. He went to bat for me and I received the following letter:

June 17, 1969

Dear Dave:

I'm now editor of the College Press Service wire network and it is only after this, and two weeks of red tape, talking to high NASA officials, etc. that I have finally gotten you and your friend some press credentials.

A few notes: 1) Please realize that your authorization for the Cape Kennedy press group is extremely important. NASA has never authorized any scholastic, non-scientific or other people for press credentials. It took a two-page letter informing the (NASA) public relations of our importance and impact to get the OK...

You received credentials over newsmen from several African countries and Kuwait. You will be the only ungraduated people there. Be nice to our capitalistic friends...

I immediately arranged air tickets to the Melbourne FL airport, a car rental, and a reservation at the Sea Missile Motel in Cocoa Beach, somewhat seedy but one of the few places that had any rooms left for this historic event. A fellow space enthusiast friend would accompany me.

I decided to write a diary of the trip, and here are some annotated excerpts of my Apollo 11 launch adventure:

"July 13, 1969: Left at 9:10 a.m. and arrived at O'Hare after pleasant drive in beautiful weather. An older lady was standing next to us. Glanced at her ticket and saw the name was Rose Cernan (mother of Astronaut Eugene Cernan). Talked to Mrs. Cernan for a second and then loaded on plane. Miracle of miracles! The plane took off on time!

Melbourne Airport -- Guess what? Saw (Astronaut) Jim Irwin (in his blue NASA flight suit) and other men saying hi to Mrs. Cernan. (Fig. 1) Went to change return flight reservation and Mrs. Cernan came up to us. She asked where we go to school and introduced us to Al Bean, Bruce McCandless, Charlie Duke and Irwin. Bean signed an autograph. They're at the airport meeting their wives. Bean was friendly, and said this was the time to come here.

"I'm next," Bean said. They readily posed for pictures. (Fig. 2) Missed airline bus so we had to wait 45 minutes. Waiting, we watched the astronauts (as they waited too).

PART TWO

July 13, 1969: Cape Canaveral -- Got to Sea Missile motel. Walked to the beach; beautiful sun, sand, surf and space. Could see the gantry towers of the Eastern Test Range.

Went back to (highway) A1A where we continued walking interminably all the way to the Hilton Hotel [we did not have a car rental scheduled until the next day]. There we signed up for 'reservations' to the Moon with TIA and saw Walter Cronkite lounging by the pool. Walking back, we stopped at the Mousetrap (bar) where we saw Bruce McCandless and F. Curtis Michel again.

July 14, 1969: Went to KSC News Center where we picked up our press passes and 5 'tons' of news releases. They had quite a news set-up [with long tables piled with information from NASA and contractors, and other tables with rows of telephones. Some of the 'goodies' included the official Apollo 11 Flight Plan and the Apollo 11 Press Kit and folders from contractors touting their contributions to the mission.]

We signed up for the long press tour which covers 4 hours. There are a large number of foreign journalists here and the babble of a number of different languages is audible. We go on press bus tour with 3 Spaniards, Swiss, and Belgian journalists. There are nine of us in a Volkswagen-type bus. It's hotter than hell outside. Our guide [a volunteer contractor employee] has worked here since 1962.

[We drive by the Mercury and Gemini launch pad sites, enter the Mercury mission control center (no longer in use), pass the pad which was the site of the Apollo 1 fire, and visit inside the Vehicle Assembly Building, taking an elevator inside to the top of the interior of world's largest structure for a dizzying view looking down.]

We drive within a mile from the Apollo 11 rocket. (Fig. 3) There is a gray mobile service structure around it and a red tower on a huge concrete pad. God, it is huge!

The crawler carries 6 million pounds at 1 mph. It is a two-story, large gray structure. (Fig. 4) It dwarfs people standing near it. We see the wire escape system and fire escape vehicles near the pad.

Later, we go to a news conference at the press center with KSC Director Kurt Debus, Manned Spaceflight Center Director George Gilruth, Marshall Director Wernher von Braun and George Mueller, head of manned spaceflight. (Fig 5)

"The landing will be a beginning, not an end... We will, in due time, have a semi-permanent or permanent base on the Moon," von Braun said.

Asked to what event he would compare the landing, von Braun said he would compare it to aquatic life crawling on land for the first time.

Ate dinner at Hilton. Later, Aldrin, Armstrong and Collins interviewed by reporters by remote. [We were at the news center and could see the astronauts, who were in isolation, on television monitors.]

Took press bus at night to observation site to see Saturn V lit up by searchlights. A bright white jewel in the dark night. searchlights shooting out at angles. (Fig. 6)

Apollo 10:
18 May 69
(The launch date was actually on 19 May 69 in Australia, but I’ll stick with the US dates for convenience)

After the success of the Apollo 9 mission, most of the pieces were in place for the first lunar landing attempt. The last test would be to do a practice mission to close to the lunar surface, to test all the equipment except the hazardous actual landing. For this important flight, NASA had its first ‘all veteran’ crew. The spacecraft commander (CDR) was Tom Stafford, who had flown on Gemini 6 and commanded Gemini 9. The Command Module Pilot (CMP) was John Young, also a veteran of two Gemini flights (Gemini 3, Gemini 10). Joining Tom Stafford in the Lunar Module would be Gene Cernan, the Lunar Module Pilot (LMP) who conducted a spacewalk during his flight on Gemini 9. The term Lunar Module Pilot was actually a misnomer. Although they were the LM systems expert and were in fact trained to fly the LM, it was always the commander who flew the LM. The LMP was a co-pilot.



At 1549 GMT, the hold-downs were released and the Saturn V, known as launch vehicle SA-505, slowly rose from Launch Complex 39B. After clearing the service tower, the rocket changed its direction – the pitch and roll – for the correct path to reach orbit. Gene Cernan, obviously impressed and excited by the launch, shouts "We're going!" and "What a ride, Babe, what a ride!". It was indeed a ride, when at 2 minutes into the flight, the Saturn began to shudder, experience a known but not fully understood problem called pogo. The pogo was relatively mild however, and the rocket continued skyward.



Twelve minutes after launch, Apollo 10 was safely in a roughly 100 mile orbit. For nearly two hours the crew tested systems on the spacecraft, confirming all the systems were healthy and ready for the ultimate challenge – a flight to the Moon. All seemed well, and Houston gave the call “Apollo 10, you are go for TLI (Trans Lunar Injection)”. TLI was the second firing of the J-2 engine on the S-IV-B, which would send spacecraft stack on its way from Earth orbit towards a lunar orbit. The engine fired for 8 minutes and Apollo 10 took the next step on its journey.

The crew now prepared to remove their LM – callsign Snoopy – from the S-IV-B. Housekeeping duties included reporting the dose of radiation received so far:

CAPCOM: "Roger Tom. Did you get a chance to get the radiation survey meter out?"

LMP: "Yes I did, Charlie, and I read zero on every scale".

A little after 3 hours from launch, the Command / Service Module stack (the CSM) separated from the S-IV-B stage.



The CSM – callsign ‘Charlie Brown’ turned around, and John Young guided them towards a successful docking with the LM. The docking probe was removed from the docking tunnel, and the hatch to the LM removed. As the hatch was removed, a flurry of small particles entered the CM. This turned out to be small pieces of fiberglass from the hatch, and was to cause the crew irritation during the flight.

At 3 hours 56 minutes Ground Elapsed Time (GET, the time since lift-off), the LM was withdrawn from the S-IV-B. CMP John Young carefully moved the stack away from the now redundant S-IV-B, increasing the distance away from what now was a hazard to them. Half an hour later, the crew fired up the Service Propulsion System (SPS) engine on the service module and moved them further away from the S-IV-B but closer to their goal.

The crew had set up the television camera prior to docking with the LM, and now commenced a dedicated broadcast back to the Earth, describing the Earth and showing what it looked like from Apollo 10.

Things were going so well on Apollo 10 that Houston advised that the first of three mid-course corrections, designed to refine the spacecraft trajectory, would not be required. The crew began preparations to get some rest after a hard day, and everyone was feeling good. So good, that a little risqué chatter appeared:

CAPCOM: "And 10, if you'd be interested, there's just a possibility of a waste-water dump during TV"

CDR: "Okay, great. We could substitute another kind if you want to…"

(Tom Stafford was referring to a overboard dump of urine…)

The crew settled into sleep, trying to get as much rest as possible before what were bound to be a very hectic following few days.


(more follows tomorrow)

19 May 69

Despite some problems with the thrusters maintaining the Passive Thermal Control (PTC) roll, the crew of Apollo 10 were awakened at 21 hours and 31 minutes GET and reported an excellent nights sleep. The PTC, otherwise known as "BBQ mode", was a slow roll of the CSM / LM stack, designed to evenly distribute the heating and cooling of the spacecraft. Spining at roughly 3 revolution per hour, this was a very important manoeurvre. The problem was not so much keeping the roll going, but the thruster firing if the roll started to spin off the axis - a wobble. The spacecraft computer would keep it stabilised, but Houston had been a little worried that the thruter firing would wake the crew. They need not have worried.

The normal routine of Apollo spaceflight then set in: preparing for "star shots" to confirm and refine the guidance systems understanding of where they were in space, course corrections, and waste water dumps. The latter could interfere with the former, as the ice crystals could look like stars in the sextant sight, so there was discussion about seperating the two to ensure there was no interference.

Once again, radiation dosimeter readings were given:

CDR: "For your friendly man on the left, my dosimeter reads 26021."

LMP: "Okay Charlie. Mine is 15030."

CMP: "And mine is 05027."

NOTE: Each dosimeter was started at a random number. The figures do not indicate the total dose received during the flight.

Tom Stafford even commented at 21 hrs 46 min GET:

CDR: "These are very small numbers."

CAPCOM: "Roger. It's pretty early."

The crew were then read the news items of the day. These included their own historic flight, Leonard Bernstein leaving the New York Philharmonic Orchestra, sports news, the daily horoscope, and news of a Siamese cat in Vancouver, Washington who was raising three orphaned skunks!

What were the crew horoscopes?

Tom Stafford (CDR): You should concentrate on things already started. Todays pace will be moderate; use this time to take inventory.

John Young (CMP): You will have a slow day today. This wil give you time to concentrate on the work ahead. You will enjoy your surroundings and companions.

Gene cernan (LMP): Give careful thought to your working and driving habits. Do something nice for your friends.

NOTE: The origin of these horoscopes is not mentioned!

Tom Stafford then reported how he recieved a highly chlorinated slug of water, when his crewmates drinks had been fine. There was discussion as to the reason for this and a resolution found. Houston asked them to also clear the water lines before mixing the water with their (dehydrated) food. Despite this, the crew were obviously in good spirits. At 23 hrs 5 mins GET, they gave a serenade to Houston: apre-recorded tape of the crew singing "Up, up and away!" (Australians might recognise that tune from the old TAA commercials. Yes, I'm showing my age).

Gene joked: "We had trouble stowing the bass drum aboard, but other than that it came out pretty well!"

They were not asked for an encore. Then at 25 hrs and 58 mins, the crew report the first sighting of the Moon. At 26 hrs 32 min GET, a small midcourse correction was made. The crew then commenced another TV transmission, showing life abord the spacecraft. Shortly after, Houston reported that the spacecraft had passed the midway point and that based on current projections, no further mid-course corrections would be required before LOI (Lunar Orbital Insertion, the rocket burn to change them from a free return trajectory around the Moon into a lunar orbit.)

When reporting that his meal tasted like a chicken salad sandwich - which it was meant to be - Gene made mention of a "corned beef sandwich". This was in reference to Gemini 3, where John Young (abord Apollo 10) pulled out a genuine corned beef sandwich and offered a bite to the spacecraft commander Gus Grissom. The sandwich came from the astronauts favourite deli, called "Wolfies". The incident initiated various negative comments from a number of sources, but the "contraband" was actually approved by Chief Astronaut Deke Slayton.

Finally, the crew reported medical and radiation dosimeter status, and once again closed their eyes in the blanket of space. At 1 day, 9 hours and 51 minutes, Houston wished the crew a good night.

20 May 69

The crew started their day, again reporting an excellent night's sleep. Houston had been monitoring the spacecraft systems overnight, and reported to them that systems in both the CSM and LM look to be in good shape, something the crew would be pleased to hear. At 154 221 miles from the Earth and moving at 3853 feet per second, Apollo 10 was still almost perfectly on the planned trajectory, and the next mid-course correction was canceled. Amongst the news items passed up to the crew was the report of Ogalala Sioux Chief Winnie Red Fox, of Philadelphia. He requested that the astronauts leave the man in the Moon alone as it was ruining the rainfall.

"It doesn't seems to rain much anymore since man started messing around with the Moon" he said.

Houston discussed minor problems with the onboard sextant, but apart from this the only items were the fibreglass from the initial docking and air bubbles in the drinking water system.

Forty seven hours into the flight, and there was another TV broadcast back to Earth. This was not a live broadcast as such, but a test transmission prior to a broadcast later in the day. The transmission was recorded at the Madrid ground station and watched by NASA later. The later broadcast would be sent through the Goldstone ground receiving station.

Meanwhile, the crew gave descriptions of the Earth, both seen through the naked eye and through the sextants small magnifying monocular lens. LMP Gene Cernan even reported seeing light reflected of the discarded S-IV-B stage nearly 4000 miles away.

Houston also passed up some changes to the LM operational procedures, which caused concern amongst the crew. After discussion with Houston about the changes and the rationale behind them, Tom Stafford was satisfied with the intent and execution of the changes.

At 52 hr 15 min GET, Apollo 10 did another overboard waste water dump and the crew waited to see if the water - which would freeze into ice crystals and reflect light - could be seen through Earth-based telescopes.

So overall it seemed that it was a pretty lazy trip to the Moon... but John Young wanted to dismiss that notion:

53 hrs 49 min GET

CMP: "Okay. It may sound like we've been loafing for the past couple of days, but we haven't. We've been real busy, and every spare minute we get we study our flight plan. So you see that pretty soon we're going to be going into orbit, and we'll have a completely different set of operations to go into that shows our pitch profile all around the Moon, for the first revolution. Tomorrows a big day, and we're very much looking forward to it. Even though we're about 180 000 miles away from Earth, you never get away from studying."

The day finished off with systems status reports, initiating the PTC roll, and preparing for the next day's activities: going into lunar orbit and preparing Snoopy for a flight to the Moon.

21 May 69

69 hrs 57 min GET. The crew are awoken to the song "On a clear day" from a Broadway show of the same name. John Young, who along with Gene Cernan were Navy officers (Stafford was Air Force) - gave a Navy wakeup call to the rest of the crew:

CMP: "Reveille! Reveille! Up all hands, heave out, trice up, clean sweep down fore and aft!"

Shortly afterwards, though, Apollo 10 lost communications with Houston. For nearly 5 minutes, Apollo 10 and Houston called but neither hearing the other.

Eventually a technician from the Madrid ground station was able to talk to the CSM, with Houston joining in shortly afterwards. The crew were then given a number of flight plan updates, one of which was yet another cancellation of a mid-course correction; Charlie Brown and Snoopy were sailing down the middle of the road. The lack of mid-course burns had another effect: the firing of the SPS engine for Lunar Orbit Insertion (LOI) would be done 11 minutes later than originally planned. This also meant that all of the orbital activities would also be delayed by 11 minutes.

The crew were then read the latest news - including the sports roundup. LMP Gene Cernan had some questions about the results:

LMP: "What was the name of that town up north?"

CAPCOM: "Let's see.. C-H-I...Chicago. Chicago."

LMP: "Oh yes - I was looking at it yesterday. I saw them out there practicing. Speaking of Chicago, did the Cubs play ball?"

CAPCOM: "Hmm - I don't have them listed, Gene; do they play ball?"

LMP: "Oh you're bad, you're really bad..."

Final preparations were then made for lunar orbit. Three days, three hours, and fifty minutes after launch, Apollo 10 began its first orbit of the Moon. If the crew were to do nothing further, they would swing around the far side of the Moon and then 'slingshot' back towards the Earth. This was known as a 'free return' trajectory, designed so that if there were a failure of the SPS engine, the spacecraft stack would simply swing around the Moon and be on the correct path to return them to Earth. This though, was not the plan. In order to enter an orbit around the Moon, the big SPS engine need to fire - or burn - twice. The first would slow the spacecraft down and place it into an elliptical orbit around the Moon. The second burn would then change the orbit to an almost circular orbit. Since the Moon itself was moving in orbit around the Earth, each day a further small burn would be required to keep the orbit circular (or nearly circular).

The mechanics of spaceflight meant the first burn of the SPS engine would occur when Apollo 10 was behind the Moon... and thus out of contact with the Earth. The controllers on Earth could only tell if the burn had been successful by being told by the crew - or by the time the crew made re-contact with the Earth. If all went well, Apollo 10 would appear from behind the Moon at a pre-determined time and regain contact with Earth. If the engine did not fire, then the spacecraft would still be traveling at a higher speed and therefore re-appear from behind the Moon much earlier than expected.

Mission control waited, wondering if the burn had been "nominal" - as engineers were prone to say. The moment approached... then passed, with no contact from the spacecraft. They now knew the engine had fired... but had it fired with the correct thrust, for the correct length of time? The spacecraft could appear at any time. If it was earlier than the predicted time, then rapid calculations would be needed to determine the corrections required. Of course, if they
were to off the planned time it meant that the engine did not produce the planned thrust, or did not burn for the required time. In either case, investigation as to why would be needed.

At 76 hrs 24 mins, Houston heard:

CDR: "Roger Houston, Apollo 10. You can tell the world that we have arrived!"

The timing was perfect. The crew immediately began to report their visual observations of the lunar surface, particularly of one spot: Site 1, the first of three possible sites for the first lunar landing. They began taking numerous photographs of the surface. The LMP also reported that the fibreglass (actually Mylar) residue was continuing to be a problem. The day ended with the crew continuing to prepare the two spacecraft for the challenges of the following day.

22 May 69

The days started with the crew still conducting system checks from the previous day; they were grateful for the rest they got prior to lunar orbit. There were tasks to be finished before resting, though. Gene referred to the 'snow' in the spacecraft: the debris from the hatch when they originally docked with the LM. He was still in good spirits, though:

84 hrs 42 min GET (Revolution 5 of the Moon)

LMP: "I didn't have to worry about inhaling it; I ate my way through it!"
.
.
LMP: "That should be a space first: snow on the Moon!"

Gene continued with reports of the Lunar Module's 'state of health'.

84 hrs 46 min GET

LMP: "Okay. When I deactivated the COMM and shut down APS, battery 1, 2, 3, and 4 had 37.8 volts. I don't know how that's possible, unless I misread it. And the commander's bus and the LM's bus are at 72.2."

CAPCOM: "Okay, we understand."

LMP: "That's not possible, is it?"

CAPCOM: "Roger. Everybody is shaking their head yes, Ed."

LMP: "The names Gene, Joe."

CAPCOM: "Okay Bill!"

They continued the spacecraft housekeeping duties, gave radiation dosimeter readings and medical reports, and then settled down to sleep.

85 hrs 35 min GET

CAPCOM: "You did a good job today, and have a big day tomorrow, so Deke says let's go to sleep."
(Deke Slayton was the Chief Astronaut)

CDR: "Yes, we concur that. We're just getting a little bushed up here, and we're just about to turn in and fix breakfast."

**************

During lunar revolution 8 and after about 7 hours of rest, the crew were awakened for their big day. This day was the reason they had sent, and would determine if the next lunar mission would be landing or not.

93 hrs 50 min GET - Begin lunar revolution 10

Despite some communication problems between Charlie Brown, Snoopy and Houston, preparations continued for Snoopy's solo flight. Snoopy's systems were activated, checked, and double checked. Everything looked good with the LM in terrific shape. Then the first of the problems began to appear...

In preparation for the separation of Charlie Brown (the CSM) and Snoopy (the LM), the tunnel between the two needed to be sealed and vented; but the tunnel would not vent. Houston worked on the problem whilst checks proceeded, and a modified procedure developed. After testing the pressure of the tunnel, it was decided that there was no major problem and that the two spacecraft could still be undocked with the tunnel pressurised to 3.5 PSI. The undocking, however, would occur behind the Moon and out of contact with Houston.

At 98 hrs 11 min GET, the spacecraft successfully separated. Snoopy maneuvered around the CSM, allowing John Young to visually inspect the LM. All appeared well and so the LM prepared for the DOI - the Descent Orbital Insertion burn. The DOI would allow the LM to start the descent towards the lunar surface.

While Snoopy headed towards the surface, John Young in the CSM would keep close watch on Snoopy, ready to swoop down and rendezvous with the LM if a problem occurred and the LM could not return to a higher orbit to dock with the CSM.

The next problem was the signal from the CSM, which would allow the LM to home on it. Even though they were only 1000 feet apart, the LM could not detect the CSM's transponder signal. Without that signal, the descent was a definite NO-GO. The crew recycled systems and the LM picked up the signal. Once again they were ready. At last Houston told Snoopy that they were GO for DOI. The LM fired the Descent Propulsion System (DPS) and commenced its descent to 50,000 feet above the Moon whilst the CSM remained in an about a 60 nautical miles orbit.

Some involved in the lunar programme questioned the necessity of a dress rehearsal for a lunar landing. After all, why take the risk of sending a crew almost to the surface and then telling them to come home? If you accepted that much risk, why not go a step further and actually land? There were a couple of reasons for this. Firstly, NASA wanted to test the systems in lunar orbit, where conditions might be a little different. Although there were simulations, controllers had to get used to the time delay in - and problems with - communications. The major reason, though, was the LM itself. The most critical factor for the LM was weight. In fact, Grumman - the LM builders - received a bonus payment for shaving ounces off the LM weight. Snoopy, or LM number 4 as Grumman knew it, had been part of the weight saving programme but it was not quite light enough. The fuel required for a landing left insufficient reserves for NASA's liking. Risk was part of spaceflight, but this risk was not justified. LM5 on Apollo 11 would be light enough to make a landing; in the meantime Snoopy would have to be content with paving most of the way. Although 50,000 feet sounds high, there were mountains on the Moon that extended up to nearly 20,000 feet. LMP Gene Cernan certainly believed that they were very close:

LMP: "We is GO and we is down among them Charlie!"

CDR: "Also Charlie, it looks like we're getting so close all you have to do is put your tail wheel down and you're there."

The LM tested the landing procedures and systems such as the landing radar, which would give the spacecraft an accurate height above the surface. All these procedures would be vital in conducting a successful lunar landing. So far, everything was working well; the only problem occurred with the camera, where a film pack jammed and a battery camera went dead. The next major event would be the staging or separation of the descent and ascent stages. This would not only simulate an aborted approach to the surface, but also the liftoff from the Moon after a lunar exploration mission was complete. Snoopy prepared for staging...

102 hrs 44 min GET

LMP: "...We'll do it this way. You ready? okay... SON OF A BITCH!"

The LM began to spin wildly, apparently out of control.

LMP: "Okay! Lets... let's make this burn on AGS (the Abort Guidance System), babe. Make this burn on the AGS!"

CDR: "Got a good staging. Let's make it on the AGS... get into gimbal lock? She didn't go... got a good stage.. somethings wrong with that gyro..."

CAPCOM: "Snoop, Houston. We show you close to gimal lock!"

The crew regained control, the descent stage having being jettisoned.

CDR: "Yes. Something went wild during that staging but we're all set. We didn't lock it..."

Part of the test routine was to test the AGS. It had two modes: AUTO and ATTITUDE HOLD. In AUTO, the system would start searching for the CSM and try to rendezvous with it. Since the CSM was on the other side of the Moon at the moment, this is not what you wanted. Instead, the AGS would be in ATTITUDE HOLD.

During the preparations for the staging the AGS mode switch had been set to ATTITUDE HOLD, but the other crewman set it into AUTO, thinking they were moving it from AUTO back into the correct mode. When in the incorrect mode, the LM was surging towards the lunar surface. If the problem had not been corrected within 30 seconds of when it was, the LM would have crashed into the lunar surface.
(Note: A collector bought the original Apollo 10 checklist from Gene Cernan; on it it shows instructions to place the AGS mode control to AUTO)

The emergency averted, Snoopy's ascent stage completed the rendezvous with Charlie Brown. The CSM docked with Snoopy, and the LM crew transferred back into Charlie Brown. The day ended with activities prior to sleep.

23 May 69

With all the Apollo 10 crew now back in the CM, it was time to cast Snoopy adrift. The LM ascent stage would have its ascent engine started by remote control and run until depletion. This would provide valuable engineering data on engine performance. The engine burnt for 249 seconds and Snoopy was launched into a heliocentric orbit about the Sun. Of note, Snoopy is the only one of the flown LMs that survived. The others either burnt up in Earth orbit, or crashed into the lunar surface (this was done deliberately for some, to provide data for the seismic sensors on the lunar surface). The crew farewelled their spacecraft.

108 hrs 56 min GET

LMP: "Is he really going to the Sun?"

CAPCOM: "Well, he's going in that general direction."

LMP: "God, I feel sorta bad about that, because he's a pretty nice guy; he treated us well today."

As they passed behind the Moon on their 18th orbit, they packed away the spacesuits they had been wearing and squared away the cabin. The crew was tired after a long and busy day.

110 hrs 20 min GET

LMP: "And the crew status is tired, and happy, and hungry, and thirsty, and horny, and all those other things."

CAPCOM: "Roger, we copy everything, and we've got solutions or pills for everything except item 4 [sic]."

Houston informed the crew that they would be given an additional four hours of sleep time, given them about 11 hours. Final flight plan changes were made, and the crew settled down to sleep.



When Houston called to wake the crew, they had already been awake for some time, getting an early start on the day. They were updated on their orbital parameters and told that Snoopy was now 23,000 miles away. Gene Cernan had an extensive consultation with Houston regarding the Hasselblad camera. He discussed how there were circumstances when the film pack appeared to jam, and then lens could not be removed. This was the same condition that had happened the previous day, when he reported that the camera batteries had died and / or the camera had malfunctioned. The cameras were very important to the mission; part of the Apollo 10 tasks were to take numerous photographs of the lunar surface, to further help with the selection of landing sites.



There was also the continuing problem of the Mylar "snow", this time from part of the LM's insulating blanket. Although the LM was gone, the Mylar remained. The problems on Apollo 10 lead to the insulation being removed from the tunnel hatches of future CMs, and modification being made to the insulating blankets of LM5 and beyond. There were no further problems with the Mylar on future missions.

The CAPCOM brought the crew up to date with the latest news and sports, and of course... the horoscopes:

John Young (CMP) - Keep all operations above board. Confidential transactions are apt to blow up later with considerable embarrassment to all. Travel is better postponed; the people you would go to see are not yet set for the visit.

Tom Stafford (CDR) - Your natural tendency for moderate, sparse consumption serves you well. Your system is a little more sensitive to strange foods.

Gene Cernan (LMP) - Conditions are bewildering. There are so many odd and unfamiliar details. Just curb your impatience; question everything and put things into place, one at a time.

The photographs of the lunar surface continued, and preparations were made for a return to Earth. On the 26th orbit, after the spacecraft had passed behind the Moon, Apollo 10 came back with an interesting report. They saw a star they couldn't identify. They then realised it was in orbit with them. Eventually, they passed close enough to see it through sextant monocular and saw... the descent stage of Snoopy, left behind after staging. It would eventually crash into the lunar surface, but for the moment it was in orbit around the Moon.

A short day, and the crew once more entered a rest period before the following day's TEI burn; the Trans Earth Injection, the firing of the SPS that would propel Apollo 10 on its way back to Earth. If the SPS engine did not fire, however, Apollo 10 would remain in orbit around the Moon with no chance of rescue.

24 May 69

131 hrs 59 min GET - Rev 29

The crew continued with the normal mission updates, including yet another report of the LM descent stage below them, tumbling end over end. Tom Stafford asked the FIDO (Flight Dynamics Officer) to once again examine the trajectory, to make sure there was no possibility of collision.

132 hrs 17 min GET

CDR: "Seeing what I saw, John, yesterday - but we sure don't like being around here playing footsy with that rascal."

CAPCOM: "Roger that. You treated him so bad on staging, he's out to get you."

They continued to take photographs of the Moon, discuss the position the LM descent stage, and report problems with spacecraft. They were taking so many photographs that they were nearly out of colour film. They still wanted to save some fir the voyage home, though.

One of the problems was fuel cell No2, whose exhaust temperature was going up and down, causing the spacecraft MASTER ALARM to sound about every 5 mins. They weren't overly concerned about the fuel cell, but they could not afford to ignore an alarm, thinking it was the fluctuating fuel cell. The fuel cells were also responsible for spacecraft power, taking hydrogen and oxygen and mixing them together, giving electricity and water as the products. If one fuel cell was not operating correctly, a revision of the spacecraft power configuration for the TEI burn might be called for. Fuel cell No1 had a problem earlier, overheating and was kept functioning by disconnecting it when temperature limits were reached. Also, the waste water from No1 fuel cell could not be properly removed, and would shorten the fuel cell's useful life. For the moment, however, it was producing the required power. The No2 fuel cell later settled down, and things looked good for a nominal burn. Houston would continue to monitor the fuel cell problems. Later ground analysis would show the No1 fuel cell problems were caused by an extended hydrogen purge, and this procedure was dropped from future flights. The problem with the No2 fuel cell was not confirmed, although similar behaviour had been seen.

Final instructions were passed, and Apollo 10 passed behind the Moon on its 32nd orbit. The TEI - Trans Earth Injection - burn would take place behind the Moon. Houston waited for the expected AOS - Acquisition of Signal time.

At the appointed time, contact with the spacecraft was regained, and the crew reported a good burn; they were on their way home. Another TV broadcast was done, showing the Moon as Charlie Brown sped away.

137 hrs 50 min GET

CDR: "Houston, 10. I hope the Aussies have their sets tuned in because it's absolutely fantastic here."

CAPCOM: "Roger that Tom, I'm sure they're all watching."

The crew continued to make reports about the appearance of the Moon as they sped away at about 6000 feet per second. They began the PTC roll, and commenced the pre-sleep checklist. CDR Tom Stafford reported that all the crew were very tired, having been awake for over 22 hours. Now that the TEI burn had been successfully conducted, and systems check, all they wanted to do was sleep.

****************

After an all too brief 6 hour sleep, the crew of Apollo 10 was again awakened. While the crew were asleep, the spacecraft had stopped decelerating. The spacecraft had now slowed during the flight, but now at 187 300 miles away from the Earth, they began to accelerate again and were traveling at 4800 feet per second, and on course. The first planned mid-course correction was canceled.

As always, the latest news was passed to the crew: Thor Heyerdahl was leaving Morocco to cross the Atlantic aboard the Ra, a craft built of papyrus and based on designs from ancient Egypt. The Houston Astros baseball team beat the New York Mets, 7 to 0, with pitcher Tom Griffin striking out 13 batters. Boxer George Foreman signed up a manager and would make his professional debut as a boxer at Madison Square Garden in June. And the horoscopes?

LMP - Discussion fills much of the morning, and you'll learn a great deal that would never have come to your attention. That is, if you listen well.

CMP - Keep your attention focused on your own affairs Saturday. The necessary chores are quite enough for the time being, and leave the thrills for another time and place.

CDR - Problems tend to get out of hand, and logic is not quite enough. There is nothing to do but ride it out with a certain amount of leniency.

This was followed by another TV broadcast, where the crew explained that the spacecraft axis was actually aligned about 90 degrees to the direction of travel. They showed images of the Earth and the Moon as each passed by the spacecraft windows. The ground also had a procedure to rid the food bags of air bubbles, a problem which occurred when they added water:

147 hrs 54 min GET

LMP: "Go ahead with your procedure there, over."

CAPCOM: "Well good. I don't know if you wanted that or not. First off it's quite lengthy. It's a full page. I'll try to go through it slowly, and then we can talk it through and ask some questions. First off, fill the entire bag, both top compartment and bottom compartment, about half full of water. Then work the water and the gas to the lower compartment by either spinning it or by just kneading it down. Then after you get it all in the bottom, spin it up and then let it come to rest slowly; and if possible, squeeze the gas - if you have any gas in the upper compartment - squeeze the gas out of the upper compartment. Then, if the bubble is present in the lower compartment and top compartment is empty, add some more water to the approximate size of the bubble. Then you want to spin it again, as in step - well, as in step 3. Now, after you spin it up again, you should have gas in the top or partially gas in the top, and gas and water in the bottom, and repeat the procedure. Add more water to the approximate bubble size and spin it again. And by the time you get finished, you should have all the gas in the top and - compartment that is, and then the bottom compartment should be just about full of water. Now, if you fill it too full, so you've got the bottom full of water and the top full of water - partially full of water, then the only way you can get the bubble out of there then is to squeeze out the bubble and the water in the top compartment. The object is to get the bottom compartment completely full of water and the gas in the top compartment, and then you can vent it off by pinching off the lower compartment. If that sounds reasonable to you guys, you can try it. It's going to take a lot of spinning, but that's what they recommend in the back room after 3 days. Over."

LMP: "Hey Charlie. With all due respect, would you play back Glynn's tape recorder in there on his desk and listen to yourself, and then give us a call?"

CAPCOM: "Okay, I guess you couldn't understand that."

LMP: "No, we understood it."

CAPCOM: (Laughing) "I told you, you might not want this!"

LMP: "Listen babe, I'm glad that's all we've got to worry about at the moment!"

For the next 15 minutes, the crew tried the procedure without success. They eventually gave up. Spacecraft commander Tom Stafford then discussed the staging problem they had with the LM, recognising they had accidentally put the mode switch into the wrong position. There was also some initial debriefing about the performance of the LM's steerable antennas.

At 152 hrs 21 min GET, Apollo 10 was 168 375 nautical miles from the Earth, and speeding along at 5000 feet per second. Yet another TV broadcast, yet more medical and radiation reports, and the crew prepared for sleep. In two days they would be home.

Evan,

Let me bring you down to earth for a moment, since you are indeed awake and apparently at the wheel, I'd like to know why you or Kathy or John G. or any of the moderators have not responded to the half-dozen or more posts by a forum member that should be violations - making up bizarre quotes and attributing them to another forum member, stepping on threads with no contributing information, endlessly repeating the same things over and over again, and attempting to get me fired from an imaginary job for an imaginary reason.

While you can classify this as just a nut case, it is threatening to me if he is trying to get me fired - and he is known to have violently assaulted another researcher in the past.

The answer, as the forum's leader has suggested, is not to make me a moderator, but to make those who are supposed to be moderators to do their jobs.

This is my third or fourth protest, and I've never protested anything like this before.

Bill Kelly
bkjfk3@yahoo.com

(I’ll combine the days until the end of the flight, as I’ll be away for the next couple of days)

25 May 69

Today was a day with a twist: the crew of Apollo 10 gave a wakeup call to Houston! First was the song “Come fly with me” followed by a chipper and DJ-like “Geno” Cernan:

162 hrs 54 min GET

LMP: “Good morning, good morning! This is Tom, John and Gene from WAP-10, broadcasting again from approximately 140,000 miles out into the universe. It’s a beautiful day out here, and it appears that it might be a beautiful day down in Mother Earth country. For those of you who are not just ready for work or are just getting up: GET UP LAZY BONES! It’s time you got up! A big day ahead! And the thought for the day is: Remember – National Secretary’s Week was last month!”

CAPCOM: “Good morning Apollo 10! You managed to wake everyone up early down here, and thank you for your brief program. And we’ll be giving your advice due consideration down here. And we’ve got a little bit of music for you…”

(Plays: Zippity Do Dah)

(Applause from spacecraft)

CAPCOM: “Roger. Thank you for the applause. And watch out for migratory bird season!”

LMP: “That was a couple of seals up here.”

CAPCOM: “You might have recognized Deke Slayton, as solo, on that song we just sent up, 10”
(Deke Slayton was the Chief Astronaut, often referred to – by the astronauts and not in his presence – as “Mother Slayton”. He was a primary force in crew assignments)

CDR: “Roger.”

LMP: “If he’s eating that food, he’s zippity-do-dahed all right!”

As per normal – and looked forward to every day by the Apollo 10 crew – was the horoscope:

LMP – This Sunday may find you in some quandary over home conditions. There should be some help available. Don’t make smart remarks about Marines.
(Gene had been making jokes about Marines to CAPCOM Jack Lousma during the flight. Jack subsequently flew on Skylab 3 and shuttle mission STS-3)

CMP – Your money has to be spent today on institutions and the use of them for various purposes. Take the time to check everything out before doing anything drastic. Finding out the “why” in a situation may be more important than any other determination.

CDR – Your relatives and neighbours expect to see you this Sunday. Do the amenities gratefully. Make the rounds; there are gifts for you here and there. Then seek solitude. Reprimand all those in your command who make smart remarks about Marines.

This was followed by the news, and updates on the weather in the recovery area. The weather would be the determining factor; there was a prime recovery area chosen, but NASA had to have contingency plans in case the weather was unsuitable. This meant an additional 2 or 3 areas, each requiring a suitable recovery force of US Navy ships and aircraft.

At 164 hrs 33 min GET, Apollo 10 was about 130,000 miles from the Earth and travelling at a speed of 5700 feet per second. Their course (with a mid-course correction) put them on a re-entry angle of 6.52 degrees, almost exactly in the middle of their corridor. The “nominal” corridor was between 5.4 and 7.4 degrees. (Even without a mid-course correction, they were headed for an angle of 6.95 degrees).

The flight continued with the day-to-day routine of spaceflight: reports on radiation, oxygen and fuel remaining, flight plan updates or corrections, and word of the “unemployed philosopher”, who continually gave his (or her) update on the effect of Apollo 10’s colour television broadcast on the world. This wavered between a return to B&W television because of the crew’s appearance, through to the current report: colour TV was making a comeback. It would make a real splash around here soon! The crew also reported that a new fangled invention called ‘shaving’ was working well aboard the spacecraft, and they all expected to look good upon splashdown…. but did they?

The crew concentrated on discussing spacecraft performance reports, and passing visual reports of the Earth. Because of the important re-entry to Earth’s atmosphere, the crew asked for an early wake-up call… and an order of bacon & eggs. What’s a CAPCOM to do?

At 177 hrs 18 min GET, Deke Slayton came on the comm channel to quickly talk to the crew before the crew slept for the final night in space. At 177 hrs and 50 min, the crew said goodnight and went to sleep.

26 May 69

A little over 6 hours later, the crew of Apollo 10 was awakened with a bugle call. Today, the return to Earth would be a big day. Firstly, the course of the spacecraft would be checked. Too shallow and it would bounce off the atmosphere, with no hope of recovery. Too deep and the capsule would go through excessive heating, burning up the capsule despite the heatshield.

After the Service Module (SM) had been jettisoned, the Command Module (CM) would only have very limited ability to change course. There was only a corridor of 2 degrees for a safe re-entry.

The capsule would enter the atmosphere, slowing down and generating tremendous amounts of heats. A little know fact was that the CM would then actually change its attitude and climb, further slowing and reducing the heat generated. It would then pitch back towards the Earth and once again re-enter the atmosphere.

Weather reports for the recovery area were discussed. The prime recovery area looked good. Before the re-entry, the crew of Apollo 10 recounted the achievements of the mission.
After 7 days 23 hours and 33 minutes from liftoff, Apollo 10 jettisoned the service module. The CM, no longer connected to the SM fuel cells, had a limited time on its internal batteries. Apollo 10 was on its way home. The spacecraft now started its descent. As they fell, the force of Earth’s gravity exerted its force. Last reports were passed: about 2 miles from their target point. Plasma began to envelope the capsule, blocking communications.

Mission control waited anxiously for the first reports, either from the capsule or the helicopter from the recovery force.
.
.
.
8 days, 3 minutes and 25 seconds from launch, Apollo 10 splashed down.


Apollo 10 after splashdown


The crew of Apollo 10 aboard the recovery vessel USS PRINCETON

Apart from a minor switch problem with the LM, Apollo 10 was a success. Everything was in place for the next attempt: Apollo 10 was a green light for a lunar landing of Apollo 11. Less than 2 months later, man would be walking on the Moon – or have died trying.

I'm going to be away during the Apollo 11 period (at an Apollo 40th anniversary celebration) so I won't do a day-by-day for Apollo 11. If you are on Twitter, you can get an excellent coverage of Apollo 11:

http://twitter.com/ApolloPlus40

I will, however, cover two points regarding Apollo 11 that always get asked: The Program Alarms and the LM fuel.

The Program Alarms

During the descent, you can hear a call of "Program Alarm 1202" and "1201". This meant that the LM's Primary Guidance and Navigation System (PGNS) was reporting an "Executive Overflow". Simply put, it was saying "I've got too much to do! I'm going to dump everything except my primary stuff".

The first question was do we need to abort? In the Mission Operations Control Room everyone looked at Steve Bales, who was responsible for that section of the spacecraft. This was not an alarm they usually encountered or practiced for. Bales, however, did recognise it. During a simulation run it had occurred and they had aborted the landing. In the debrief the SIMSUP (Simulator Supervisor) had berated the controllers for that decision. As long as the alarm was not continuous, they could still land. Bales had felt very embarrassed during that simulation and not forgotten the lesson.

"We're... we're GO on that alarm!" he reported.

Despite a similar event (the 1201) occurring later, the landing could go ahead. But what caused it?

It turned out to be an unexpected switch setting. The LM rendezvous radar - used for an ascent - was on, where it was supposed to be according to the checklist. It was decided to leave it on, ready for an abort situation. Since the radar was not actually transmitting, this would not be a problem. This was not quite the case though. The computer programme was still trying to calculate the rendezvous parameters. Since the radar was not on, some of the parameters it was using for these calculations (an angle and distance) were zero. The computer was trying to divide by zero... an impossible task, and one which was taking up a majority of the computer resources. This was resolved in subsequent missions by amending the switch setting.

The Fuel Quantity

There is a lot of confusion about this, with people believing they only had seconds of fuel left when they landed. That's not true. To begin with, there was a little more fuel they they thought; the fuel sloshed around in the tanks and the sensors got a false reading. This was corrected in later versions by putting baffles inside the tanks (my old P-76 had the same problem, the fuel gauge used to move around a fair bit!). So when the fuel quantity light came on, there was actually more fuel than they thought. The quantity light call started a 94 second countdown. You can hear Mission Control call "60 seconds" and "30 seconds". This was NOT fuel remaining though; it was a countdown to what is known as a 'Bingo' fuel call. They were counting down to a decision point, where they had to land within 20 seconds or abort now. So there was the 30 second call, and they landed 13 seconds later; they had 17 seconds before they needed to make an land-or-abort call and were not running out of fuel.