APOLLO 13

NEWMARKET U3A: WINGS, WHEELS & WATER Presentation for April 2020

Due to the Coronavirus, this month’s presentation is

designed for home study

PICTURES: LEFT the Service Module showing damage from the explosion.

RIGHT: The three astronauts; James Lovell, John Swigart and Fred Haise

Introduction & Overview

Apollo 13 was the seventh crewed mission in the Apollo space program and the third meant to land on

the Moon. The craft was launched from Kennedy Space Centre on April 11, 1970, but the lunar landing

was aborted after an oxygen tank in the service module (SM) failed two days into the mission. The crew

instead looped around the Moon, and returned safely to Earth on April 17. The mission was commanded

by Jim Lovell with Jack Swigert as command module (CM) pilot and Fred Haise as lunar module (LM) pilot.

Swigert was a late replacement for Ken Mattingly, who was grounded after exposure to rubella.

The accident was caused by ignition of damaged wire insulation inside an oxygen tank as it was being rou-

tinely stirred. The oxygen in the tank was in liquid form and needed to be stirred with a large sort of elec-

tric whisk from time to time to ensure that all the contents of the tank were at an even temperature asnd

not causing damage to the tank itself which was lined with Teflon. Liquid oxygen and Teflon are both very

volatile and unpredictable materials. Without oxygen, needed both for breathing and for generating elec-

tric power, the SM's propulsion and life support systems could not operate. The CM's systems had to be

shut down to conserve its remaining resources for re-entry, forcing the crew to transfer to the LM as a

lifeboat. With the lunar landing cancelled, mission controllers worked to bring the crew home alive.

Although the LM was designed to support two men on the

lunar surface for two days, Mission Control in Houston im-

provised new procedures so it could support three men for

four days. The crew experienced great hardship caused by

limited power, a chilly and wet cabin and a shortage of drink-

able water. There was a critical need to adapt the CM's car-

bon dioxide removal system to work in the LM; the crew and

mission controllers were successful in improvising a solution.

The astronauts' peril briefly renewed interest in the Apollo

program; tens of millions watched the splashdown in the

South Pacific Ocean by television.

LEFT: A beaker of liquid oxygen

An investigative review board found fault with pre-flight testing of the oxygen tank and the fact that

Teflon was placed inside it. The board recommended changes, including minimizing the use of potentially

combustible items inside the tank; this was done for Apollo 14. The story of Apollo 13 has been drama-

tized several times, most notably in the 1995 film Apollo 13.

Background to the Apollo Programme

In 1961, U.S. President John F. Kennedy challenged his nation to land an astronaut on the Moon by the

end of the decade, with a safe return to Earth. NASA worked towards this goal gradually, sending astro-

nauts into space during the Mercury and Gemini Projects, in preparation for the Apollo programme. The

goal was achieved with Apollo 11, which landed on the Moon on July 20, 1969. Neil Armstrong and Buzz

Aldrin walked on the lunar surface while Michael Collins orbited the Moon in Command Module Colum-

bia. The mission returned to Earth on July 24, 1969, fulfilling Kennedy's challenge.

NASA had bought fifteen Saturn V rockets to achieve the goal; at the time no one knew how many mis-

sions it would take to get top the Moon. As the project was successful in 1969 with the sixth Saturn V on

Apollo 11, nine rockets remained available for a total of ten landings. After the excitement of Apollo 11,

the general public gradually grew apathetic towards the space programme, losing interest as the missions

continued successfully with Apollo 12. In the media build up towards the launch of Apollo 13, the public

showed little interest and even less excitement apart from the possibilities afforded by the unlucky num-

ber 13. Congress continued to cut NASA's budget; Apollo 20 was cancelled.

Despite the successful lunar landings of Apollos 11 & 12, the missions were considered so risky that astro-

nauts could not afford life insurance to provide for their families if they died in space.

Planning for a centralized Mission Control began in 1959, led by Dr Christopher C. Kraft, who became

NASA's first flight director. During John Glenn's Mercury Friendship 7 flight in February 1962, Kraft was

overruled by NASA managers. He was vindicated by post-mission analysis, and so implemented a rule that

during the mission, the flight director's word was absolute—to overrule him, NASA would have to fire him

on the spot. Apollo Flight directors had a one sentence job description, "The flight director may take any

actions necessary for crew safety and mission success.”

He worked for over a decade in aeronautical research before being

asked in 1958 to join the Space Task Group, a small team entrusted with

the responsibility of putting America's first man in space. Assigned to

the flight operations division, Kraft became NASA's first flight director.

He was on duty during such historic missions as America's first crewed

spaceflight, first crewed orbital flight, and first spacewalk.

Kraft was responsible for shaping the organization and culture of NASA's

Mission Control. In 2011, the Mission Control Centre building was

Dr Christopher Kraft: NASA’s

first Flight Director.

LEFT: Mission Control Oper-

ations Room just before the

Apollo 13 accident. The

astronaut on the TV screen

is Fred Haise, pilot of the

Lunar Module

Mission Insignia, Call-signs and Motto

The Apollo 13 mission insignia depicts the Greek god of the Sun, Apollo, with three horses pulling his char-

iot across the face of the Moon, and the Earth seen in the distance. This is meant to symbolize the Apollo

flights bringing the light of knowledge to all people. The mission motto is Ex luna, scientia (From the

Moon, knowledge). In choosing it, Lovell adapted the motto of his alma mater, the Naval Academy, Ex

scientia, tridens (From knowledge, sea power).

On the patch, the mission number appeared in Roman numerals as Apollo XIII. It

did not have to be modified after Mattingly's replacement by Swigert since it is

one of only two Apollo mission insignia—the other being Apollo 11—not to in-

clude the names of the crew. It was designed by artist Lumen Martin Winter,

who based it on a mural he had painted for The St. Regis Hotel in New York City.

The mural was later purchased by actor Tom Hanks, who portrayed Lovell in the

movie Apollo 13, and is now in the Captain James A. Lovell Federal Health Care

Center in Illinois.

The mission's motto was in Lovell's mind when he chose the call sign Aquarius for the lunar module, taken

from Aquarius, the bringer of water. Some in the media wrongly reported that the call sign was taken

from a song from the musical Hair. The command module's call sign, Odyssey, was chosen not only for its

Homeric association but to refer to the recent movie, 2001: A Space Odyssey, based on a short story by

science fiction author Arthur C. Clarke. In his book, Lovell indicated he chose the name Odyssey because

he liked the word and its definition: a long voyage with many changes of fortune.

The Apollo 13 Mission

The Saturn V rocket used to carry Apollo 13 to the

Moon was numbered SA-508, and was almost iden-

tical to those used on Apollos 8 to 12. Including the

spacecraft, the rocket weighed in at 2,949,136 kilo-

grams. The S-IC stage's engines were rated to gen-

erate 440,000 newtons less total thrust than Apollo

12's, in preparation for future, heavier loads. Ex-

tra propellant was carried as a test since future J

missions to the Moon would require more propel-

lant for their heavier payloads. This made the vehi-

cle the heaviest yet flown by NASA and Apollo 13

was visibly slower to clear the launch tower than

earlier missions.

The Apollo 13 spacecraft consisted of Command Module 109 and Service Module 109 (together CSM-

109), called Odyssey, and Lunar Module 7 (LM-7), called Aquarius. Also considered part of the spacecraft

were the launch escape system which would propel the command module (CM) to safety in the event of a

problem during lift-off, and the Spacecraft–LM Adapter, numbered as SLA-16, which housed the lunar

module (LM) during the first hours of the mission.

This is the form in which the Apollo moon shots travelled to the moon. Once on the way out of Earth orbit the Com-

mand & Service Modules separated from the Lunar module, turned round and attached it again as in the picture above.

Launch and trans-

lunar injection

The mission was launched

at the planned time,

2:13:00 pm EST on April

11. An anomaly occurred

when the second-stage,

centre engine shut down

about two minutes early.

This was caused by severe

pogo oscillations. Starting

with Apollo 10, the vehi-

cle's guidance system was

designed to shut the en-

gine down if these oscilla-

tions started. Pogo oscilla-

tions had occurred on Ti-

tan rockets (used during

the Gemini program) and

on previous Apollo mis-

sions, but on Apollo 13

they were made very

much worse by the move-

ment of the liquid fuels in

their tanks. Engineers

were ready to sort this out

but there wasn’t enough

time before the mission

left. A post-flight investi-

gation revealed the engine

was one cycle away from

catastrophic failure. In

spite of the shutdown, the

four other engines and the

S-IVB third stage burned

longer to compensate, and

the vehicle achieved very

close to the planned circu-

lar 190 kilometres parking

orbit, followed by a trans-

lunar injection (TLI) about

two hours later, setting the

mission on course for the

Moon.

Pogo oscillations are called that because they

are rather like the up-and-down movement of

a pogo stick and they are started independent-

ly in the propellant liquid by its own flow. Ra-

ther a complicated business but if left to carry

on they can become very dangerous. The only

real way to stop them is to shut down the en-

gine causing the vibrations. Of course if this is

done at the wrong moment then the whole

mission and the crew might be in danger.

Apollo 13 was going to have dampers fitted

that would stop these oscillations but there

wasn’t time to get them done.

The Russian H2 Super-Heavy Lift launch

vehicle. All four attempted launches

blew up on take-off, the second one

falling back on to its launch pad and

causing the largest non-nuclear explo-

sion ever recorded. These failures were

due in large part to pogo oscillation.

RIGHT: The launch of Apollo 13 from Ken-

nedy Space Centre on 11 April 1970

A post-flight investigation revealed the engine was

one cycle away from catastrophic failure. In spite

of the shutdown, the four outboard engines and

the S-IVB third stage burned longer to compensate,

and the vehicle achieved very close to the planned

circular 190 kilometers (100 nmi) parking orbit, fol-

lowed by a translunar injection (TLI) about two

hours later, setting the mission on course for the

Moon.

About 2.25 days into the mission as the crew were

carrying out routine activities – approaching

56:00:00 hours, Apollo 13 was about 180,000 nauti-

cal miles (210,000 mi; 330,000 km) from Earth.

Haise was completing the shutdown of the LM after

testing its systems while Lovell stowed the TV cam-

era.

The pressure sensors in one of the oxygen tanks

had been erratic so the astronauts were asked to

switch on the stirring system. 95 seconds after that

the astronauts heard a loud bang.

The Accident and Aftermath

"Okay, Houston, we've had a problem here," were the words actually spoken first by

Swigert but history reports it as “Houston, we have a problem”, words scripted into all the

dramatic versions of the story.

There had been a loud bang, looking out of the windows there was debris of all shapes and

sizes outside and a cloud of gas escaping from the side of the Command Module.

The explosion had been caused by an electrical fault in the oxygen tank when Swigert switched on the

stirring fan. It was a human error caused by poor wiring in the tank. The cable to the motor was not

properly shielded and when the current was switched on, a spark crossed from the cable to the casing of

the motor. In the oxygen-rich atmosphere the result was a sudden disastrous explosion. One of the tanks

was destroyed, the second badly damaged. The Command and Service modules had only a tiny reserve

tank left. This would not be enough to provide power to the engine and to all the controls as well as for

the crew to breathe for the three days it would take to go round the moon and return to Earth.

On Apollo 10 there had been a training session which used the Lunar Module as a ‘lifeboat’ to get the

crew home and this is where all the ground crews started looking. There was oxygen in the Lunar Mod-

ule—enough for two men for 54 hours, not enough for three men for three days. And certainly not

enough to provide electricity. Another difficulty was that the production of electricity produced water as

a by-product for drinking and cooling. No electricity meant no water. The astronauts were allowed 0.2

litres per day.

They could only survive in the lunar module if the oxygen could be made to last. The Command Module

had ‘scrubbers’ which cleaned the CO2 out of the air so it could be reused. The Lunar Module did not

have these. If the oxygen tanks in the Lunar Module could use the Scrubbers in the Command module

they might survive.

In an exercise worthy of Blue Peter, the astronauts, sup-

ported by the ground crews on Earth designed a Heath

Robinson arrangements to allow the used air to be piped

through the Command Module scrubbers and returned

for re-use. Lengths of tube from their space suits, plastic

covers from the instruction files and yards of Duck Tape

were used to create the apparatus in the photo on the

left.

There was no heating available in the Lunar Module and

the temperature fell to 3.0 degrees Celsius.

There are other considerable difficulties that were extremely complicated.

The Command Module power was shut down completely by the explosion

and there was great concern that everything might not return to normal

when powered up for re-entry. Navigation had to be done manually to set

courses for return to earth and this was difficult because all the debris out-

side obscured the stars, apart form the sun.

LEFT: Lovel in the freezing LM

The last problem to be solved was how to separate the Lu-

nar Module and move it a safe distance away from the

Command Module just before re-entry. The normal proce-

dure, in lunar orbit, was to release the LM then use the

service module's engine to pull the Command and Service

Module away, but by this point the SM had already been

released. Grumman, manufacturer of the LM, assigned a

team of University of Toronto engineers, led by senior sci-

entist Bernard Etkin, to solve the problem of how much air

pressure to use to push the modules apart. The astronauts

applied the solution, which was successful. The LM re-

entered Earth's atmosphere and was destroyed, the re-

maining pieces falling in the deep ocean. Apollo 13's final

midcourse correction had addressed the concerns of the

Atomic Energy Commission, which wanted the cask con-

taining the plutonium oxide intended for an experiment on

the moon, to land in a safe place. The impact point was

over the Tonga Trench in the Pacific, one of its deepest

points, and the cask sank 10 kilometres (6 mi) to the

bottom.

Nobody believes me, but during this six-day

odyssey we had no idea what an impression

Apollo 13 made on the people of Earth. We

never dreamed a billion people were follow-

ing us on television and radio, and reading

about us in banner headlines of every news-

paper published. We still missed the point on

board the carrier Iwo Jima, which picked us

up, because the sailors had been as remote

from the media as we were. Only when we

reached Honolulu did we comprehend our

impact: there we found President Nixon and

[NASA Administrator] Dr. Paine to meet us,

along with my wife Marilyn, Fred's wife Mary

(who being pregnant, also had a doctor along

just in case), and bachelor Jack's parents, in

lieu of his usual airline stewardesses.

Worldwide interest in the Apollo program was

reawakened by the incident; television cover-

age of which was seen by millions. President

Nixon cancelled appointments, phoned the

astronauts' families, and drove to NASA's

Space Flight Center in Maryland, where Apol-

lo's tracking and communications were coordi-

nated.

The rescue received more public attention

than any spaceflight to that point, other than

Apollo 11. There were worldwide headlines,

and people surrounded television sets to get

the latest developments. Pope Paul VI led a

congregation of 10,000 people in praying for

the astronauts' safe return; ten times that

number offered prayers at a religious festival

in India. The United States Senate on April 14

passed a resolution urging businesses to pause

at 9:00 pm local time that evening to allow for

employee prayer.

Jack Gould of The New York Times stated that Apollo 13,

"which came so close to tragic disaster, in all probability

united the world in mutual concern more fully than an-

other successful landing on the Moon would have".