Apollo 13 is approaching the fourth day of
its ill-fated flight. Nine hours ago, an explosion
crippled their command module. They have battled
against failing systems and a dying spacecraft
ever since. It’s now all about creating
what opportunities they can from moment to
moment, and this is how they hope to buy their
survival.
Across the United States, millions tune in
to the television coverage. Veteran CBS news
anchor Walter Cronkite leads the nation through
the crisis.
(Walter Cronkite) The flight of the Apollo
13 to the Moon is in serious jeopardy this
morning, and is not going to make a Moon landing
and this is indeed the gravest emergency probably
yet in the American space programme.
Their life support and power are running out.
They are now on a path that will take them
home, but travelling too slowly to get them
back to the right place on Earth in good time.
(Gene Kranz) Our job was basically to try
to figure out what on board the spacecraft
was still usable and to come up with a game
plan to get them home. We had a command module
that was our re-entry vessel. It had the heat
shield but only had about two and a half hours
of electrical power left on it. We had the
service module which was where the explosion
had occurred that was virtually useless. We
had the lunar module that was attached to
the other end of this stack through a small
tunnel and that was our lifeboat.
We’re going to be outside all known design
and test boundaries of the spacecraft and
we’ve got to come up with the answers. And
the crew was quite concerned that they still
didn’t have the game plan in hand.
From the BBC World Service this is 13 Minutes
to the Moon season 2
I’m Kevin Fong and this the incredible story
of the flight of Apollo 13 told by the people
who flew it and saved it
(Mission audio) OK Houston, we’ve had a
problem here. We got more than a problem.
We lost 02 tank 2 pressure. That can’t be.
Let’s make sure we don’t blow the whole
mission. There’s one whole side of that
thing missing. That’s the end right there.
Episode Four Power Brokers
Flight director Gerry Griffin is coming on
shift to take charge of mission control for
this next, critical, stage of the mission.
And he remembers exactly where he was when
he learned that Apollo 13 was in trouble.
(Gerry Griffin) I went out to play a softball
game. The game was finished. At just about
the time we finished, they came out and got
me and said, You’d better get back to the
control centre, we’ve had a problem. I actually
walked back into the control centre still
in my softball uniform. And I could tell as
soon as I walked in the room that it was serious.
The looks on their faces were enough. Lunney,
standing behind Kranz, both of them with stern
looks on their face. I knew something bad
had happened, and sure enough it had.
Gerry Griffin takes up his position in the
mission operations control room, amidst rows
of flight controllers at their consoles. He
begins his task of fending off the myriad
threats facing the spacecraft and crew.
Meanwhile in a small room in the depths of
the mission control building Apollo lead flight
director Gene Kranz has assembled another
group of flight controllers, away from the
immediate fray, and this becomes known as
the Tiger Team.
Griffin’s job is to deal with what’s happening
right now. But Kranz’s Tiger Team is tasked
with anticipating what lies in the future,
and solving the urgent problems that will
threaten the lives of the crew as the rescue
mission unfolds.
Jim Kelly, an expert on the command module’s
electrical power system, is chosen to join
Kranz’s special group as it gathers in the
small room.
(Jim Kelly) It’s about maybe 15 by 15, 20
by, small room. There was standing space only.
Kranz had called his key people in. Those
people that he called, if they had somebody
that they wanted, they grabbed them.
(Gene Kranz) This is a data room. It’s a
room that is used only when there’s trouble,
and you can sense trouble in this room, it’s
got two overhead TV monitors, it’s got one
small com panel in there, but it’s just
filled with grey government desks around all
sides where people can spread out their records
and start going over them.
(Jim Kelly) You know it wasn’t panic, it
wasn’t chaos, it was just, you know, we
just didn’t know it. We had no concept of
what was going on. At that point, we knew
we were in trouble.
(Kevin Fong, presenter) At that point did
you worry that this might be a crew that you
were about to lose?
(Jim Kelly) On the back of our mind, in answer
to your question, Yeah that was probably there.
(Gene Kranz) I made sort of a brief opening
speech because I had a lot of new players
who were starting to show up from the engineering
community, we had astronauts who were reporting
right on board.
(John Aaron) I think he could read the mood
in the room so he started to give a pep talk.
But flight controller John Aaron isn’t buying
it.
(John Aaron) He’s giving a rah rah talk…
You know, guys we got this thing powered down,
we got the web guys in there, they are doing
good work. We’re going to be able to get
this thing all set up and we’ll get this
thing back on a free return trajectory, we’ll
loop around the Moon and come back to the
Earth, we’ll get to the Earth, we’ll power
up the command module and come home. And I
raised my hand and I said, Gene, you can’t
do that. He said, Why not EECOM? I said, You
don’t have enough power to do that.
In a room full of senior engineers 27-year-old
Aaron has just interrupted Nasa’s most senior
flight director, pointing out a fundamental
problem.
If this was a normal mission, the command
module Odyssey would be running on power from
the service module almost all the way to the
critical phase of re-entry. It would then
switch to its own three small batteries only
for the final 30 minutes to splashdown. But,
with Apollo 13’s service module well and
truly out of action and Odyssey shut down,
those three batteries don’t have enough
energy in them to bring the command module
back to life for several hours and keep it
operating all the way through re-entry. Kranz
pauses, acknowledges what he is being told,
and fires back with a snap solution of his
own. He puts John Aaron in charge of the problem.
(John Aaron) What that allowed (us) to do
is, it says, you know, rather than having
a whole huddle of committees all around the
centre, all around the nation trying to get
their version of what the power sequence should
be, he appointed one man to manage that critical
resource. That’s a brilliant maneuvre on
his part and he did it in about 30 milliseconds
I would say. So then he left the room and
so then we were sitting there and the rest
of the guys looked at me and says OK, John,
how are we going to do this?
The newly-elevated John Aaron gazes at the
room of engineers in front of him, already
knowing that there won’t be enough battery
power to run all of their systems. Knowing
too that Kranz has made this his problem.
Sacrifices will have to be made. Difficult
decisions and bruising conversations lie ahead.
(Jim Kelly) John said, he says, just leave
us alone for a minute, and he and I, they
all evacuated and went somewhere and got coffee,
I dunno what they did, but John and I were
left in this room by ourselves.
(John Aaron) So Jim and I scratched our heads
and so forth, and that’s what the whole
thing began. It became a brokering between,
you know, how much we had versus how much
you want, and do you have to have it. It’s
a classic way to do it.
(Jim Kelly) The first thing we came up with
was bare minimum, you know, we didn’t even
know what we had at that point but yet … yet,
we had no idea how much energy we had but
yet we were looking at ways to get home, and
I guess that’s the whole thing – you put
the donkeys before the cart. But in this case,
we had the cart before the donkeys. And I
put all that back to the simulations we had
– we weren’t accepting failure.
There are no easy answers. Even power for
apparently essential systems cannot be guaranteed.
(Jim Kelly) Our challenge was to control the
energy in the batteries, to make sure any
procedure or anything we came up with could
not exceed the capacities that we had. This
is what we can afford to have, you guys go
put some switches to it.
(Kevin Fong) But all of that means that you
and John become the bearers of bad news, for
people who want to know whether they can power
their systems or not.
(Jim Kelly) Yeah and that did happen. I was
kind of a buffer for John, you know, I was
his buffer. Gary Coen who is a guidance and
navigation front room guy, and Gary says,
Jim, I really gotta have the guidance, I gotta
have the computer, and I say, Gary, I don’t
have enough, I know what I have but I can’t
give it to you right now.
(Kevin Fong) But that episode that you describe,
of telling the guidance officer that the automated
guidance system upon which the crews have
always depended to find their way in space,
that they’re asking for to guide them through
a very delicate, very accurate, re-entry,
coming to you and asking for that to be, to
have power for that, and you’re saying,
you can’t have it.
(Jim Kelly) In my mind, the first thing we
had to do is, what is a bare-bone, necessary
thing that I really need to survive.
(Kevin Fong) What was it like for you, because
you’re working pretty hard across the four
or so days of recovery of this. What’s it
like for you, eating, sleeping, working – how
does that look like for you?
(Jim Kelly) Well, Brenda brought me clean
clothes, my wife, my bride. I always call
her my bride. Cheryl brought John the same
stuff. We took cat naps in our chair, power
naps, whatever you want to call it nowadays,
and one nap, I remember taking a rest back
in my chair but I don’t remember how I got
on the floor.
While the controllers on the ground begin
days and nights of argument over the limited
power budget, the astronaut crew is focusing
on a more immediate problem: they don’t
know precisely which way the spacecraft is
pointing.
This – the space craft’s orientation,
or attitude – is all important for their
guidance and navigation. If you don’t know
which way the vehicle is pointing when you
fire the rocket engine, you can’t be certain
where that engine will take you.
Usually they would use the Apollo guidance
computer and star sightings to determine their
orientation – using them like cosmic landmarks.
But right now they can’t see the stars.
(Gene Kranz) One of the things that was giving
us a problem was that this explosion that
occurred had sort of a, cloud of debris around
the spacecraft and frozen particles of oxygen
and we normally navigate with stars and we
couldn’t see stars anymore. All we could
see was the Sun, the Earth and the Moon.
The debris twinkling like glitter around the
spacecraft, camouflages the stars making them
impossible to identify. This is a serious
problem because somehow they need to check
the accuracy of Jim Lovell’s hasty alignment
of the spacecraft’s orientation. But mission
control realises that there is one star that
the crew can still identify – the Sun. Astronaut
Jim Lovell explains the radical solution.
(Jim Lovell) In the computer of the lunar
module was 37 heavenly bodies, mostly stars
but also the Sun, the Moon and the Earth.
And if we asked the guidance system to point
our optics at a body, a star or something
like that, it would do it. And so I asked
the guidance system to point our optics to
the sun.
Using the sun for alignment is less than perfect,
far more inexact than using distant stars,
but it is essential that this rough alignment
check works and flight director Gerry Griffin
knows it.
(Gerry Griffin) They couldn’t do a real
platform alignment in the lunar module – and
we came up with a little test whereby looking
through a telescope, and if they could see
any part of the Sun, we were close enough.
(Kevin Fong) And that’s one of the things
I find fascinating about it – the AOT, the
alignment optical telescope, is a precision
instrument. It’s out there to find points
of light in the sky, so you know precisely
which way your point is. And yet here, you’re
going to accept the Sun – and not just the
whole Sun, any part of it.
(Gerry Griffin) Any part of it! If you could
just see it, that was a big moment. A big
moment. If that had not worked we were in,
we were in trouble.
Jim Lovell punches instructions into the computer,
commanding the spacecraft to maneuver so it’s
pointing the telescope towards an area of
sky where the Sun should be.
If Lovell has set up the computer correctly,
if they are properly aligned, it should be
able to find the Sun. Fred Haise peers through
the eyepiece, as the telescope pans across
the sky, waiting and hoping to see it edging
into view.
(Mission audio) There’s the Sun. Give me
the AOT. Call it Jack, you can see it better.
(Jim Lovell) If you listen to the discussion
between Fred and myself – I think I see
it, is it coming?, I dunno, a little bit more
– ah, it’s coming!
Mission audio: We got it. Houston, Aquarius?
Go ahead Aquarius. OK. Looks like the sun
check passes …
Jim Lovell announces that the sun check has
been a success to the audible relief of Gerry
Griffin.
(Mission audio) Fantastic. We understand it
checked out. We’re kind of glad to hear
that.
(Gerry Griffin) Jim Lovell and I talked about
it later, that there weren’t many people
that knew how important that was. They knew
it, and I knew it for sure, the whole team
did that was on duty, and I can recall I could
hardly read my writing, my notes, I was so
nervous, when they said it’s OK. You know,
you figure those kind of things out when you
get in trouble.
And for flight dynamics officer Dave Reed
the Sun was all they needed: perfect was the
enemy of good enough.
(Dave Reed) Was it as precise as going to
a star? No. But was it sufficient to get exactly
done what we needed? Absolutely.
Dave Reed, was part of a self-styled elite
group within mission control whose role absolutely
depended on that sun alignment check. They
were responsible for shaping the course of
the spacecraft, and tracking it, as it flew
through space. This group of controllers saw
their role as being the stuff of proper rocket
science. And they gave themselves a name:
‘The Trench’.
(Dave Reed) The Trench got its name early
on during the Gemini series. There were three
positions in the flight dynamics area. One,
to my left, was the retrofire officer. Then
there was myself in the middle, which was
trajectory determination and maneuver determination
and to my right were my guidance officers.
So the three of us together formed a triad
and given we got this name ‘trench’ and
it stuck. It’s become somewhat legend now,
there’s books out on it. But that’s who
we were.
Senior Flight Dynamics Officer, Jerry Bostick
(Jerry Bostick) Well we were a proud bunch
on the front row. Mission control centre was
tiered and we were down in the front row,
which was like a trench.
(Kevin Fong) Now I’ve heard people describe
the trench as the last line of defence in
human space exploration.
(Jerry Bostick) The first line of defence.
The trench was the first line of defence in
man’s space flight operations. As I said,
we were a proud bunch.
There’s no disputing the fact that The Trench
played an essential role, or that they were
counted on to make huge decisions with total
confidence.
(Dave Reed) You want a confidence number.
I always give you 100 percent! Anybody makes
me for a decision down there in that trench
I always gave them 100 percent! I remember
they sent up a crew in to test me in a situation.
They wanted to find out if it was possible
to put a percentage call on decisions we were
making. So they threw a bunch of tests at
me and they debriefed me and they said, well,
when you made that decision, what was your
idea, how accurate were you, I mean were you
60, 40, 70 … I said, I was 100 percent,
and they said you can’t and I said, I was.
I said, don’t ever think that a controller
in this room is going to go up to the flight
director and say, Flight, I think I got a
70 percent idea that you know, this might
work, you know, 30 percent or so out – you
wouldn’t last two seconds in that room.
I said, Look, you make a decision, that’s
a decision, that’s black and white. If it
didn’t come out right, eat it later but
you're not gonna go up to the guy and say,
Eh leave it to you, flip a coin. No, (it)
doesn’t work that way.
With the guidance platform now aligned, and
with Apollo 13’s crew having clawed themselves
out of immediate danger, there is time for
the astronauts to take a moment and collect
themselves. Haise and Swigert are drawn to
the windows and the view outside: the Moon,
so close at hand, so beautiful and so completely
out of reach. Fred Haise.
(Fred Haise) We were tourists again. We had
cameras, cos, well, we had lots and lots of
film that we’d never use, and so we were
busily shooting pictures. And Jim, Jim was
still down I think, realizing this was his
second time and he’d lost a landing and
he’d been there, looking at the Moon, for
quite a few revolutions on Apollo 8, so he
wasn’t that interested in our picture taking.
(Kevin Fong) Was he irritated do you think
at that time?
(Fred Haise) I don’t think irritated, more
than just still in the background I’m sure
he was severely disappointed.
(Kevin Fong) You approach it at just a little
over 100 miles, isn’t that right?
(Fred Haise) About 130. About 130 miles.
(Kevin Fong) What was your impression of it,
looking at it?
(Fred Haise) I was most impressed about how
rugged it seemed. We only saw half the backside.
At the time we flew it was a half moon. So
if you were on Earth, you saw half the Moon
and conversely, we saw half the Moon on the
backside. But the areas we saw, that half,
overall were much too much of a rugged looking
beat up, a bigger abundance of craters. The
only smooth areas, and we shot good pictures
of ‘em, was both named by Russia, since
they got around there the first time, and
had naming rights. One was Sikorsky and that
was a beautiful dark fairly large crater with
a solo little mountain in the centre, and
the other one was Tsiolkovsky. So we got good
pictures of those but everywhere else it was
just a muddled landscape, I mean, beat up.
(Mission audio)
Let’s get the cameras squared away. Let’s
get all set to burn. We got one chance now.
Jim Lovell there almost scolding his rookie
crew, telling them to put the cameras away.
Their respite has been brief. The time for
tourism has passed. The next order of business
is getting home to the right place at the
right time.
Their earlier efforts have put them on a course
that will get back to Earth and into the Indian
Ocean. But timing is everything. It determines
how far they have to stretch their limited
life support and power, and just as importantly
it decides which ocean they’ll arrive in
and who will be there to rescue them.
Trench flight controller, Chuck Dietrich
(Chuck Dietrich) The recovery position in
the Indian Ocean was not very good. What we
would do if we really had to come back to
a place like that, we’d have to depend on
commercial shipping to pick the vehicle up.
That really wasn’t a good plan at the time.
(John Aaron) The trajectory guys came up with
this brilliant plan that says we’re going
to go round the Moon. The trajectory guys
didn’t like to land in the Indian Ocean.
Nobody wanted to land in the Indian Ocean.
We could speed this process up but those guys
figured out that if you just said, two hours
after you exit the Moon we’re going to do
a big manoeuvre and send this thing home.
The crew is approaching pericynthion - the
point of closest approach to the Moon, the
point at which the spacecraft is travelling
at its fastest and where it takes the least
amount of fuel and thrust to alter its path
back to Earth. Now, in a normal lunar mission,
this is where the crew would fire their main
engine to accelerate them away from the Moon
and bring them back to Earth – a nail-biting
manoeuvre in itself - out of contact with
the Earth and in radio silence on the far
side of the Moon.
But Apollo 13 is way off its original flight
plan, travelling too slowly to get home to
the right place and in time before life support
and power are exhausted.
It needs to speed up dramatically. And so
they come up with a plan to do a burn two
hours after they have passed pericynthion,
called the ‘PC+2 burn’.
If it worked, it would get them back on time
and into an ocean where the crew had a better
chance of being recovered by US Navy ships.
Flight director Gerry Griffin
(Gerry Griffin) We came up with this PC+2
as pericynthion which is a point of closest
approach to the Moon, plus two hours. So,
go around the Moon, two hours later, do this
maneuver. We calculated it that we could do
it using the descent engine on the lunar module,
get them home about a day earlier and also
get the landing point back in the Pacific,
close enough that we could get a carrier.
(Kevin Fong) So, I mean, this is one of the
parts of the story that I find so amazing
– that you’re choosing oceans at this
point.
(Gerry Griffin) Oh yeah, well, you know, when
you go into deep space, I tell the youngsters
at Nasa today, that deep space is different
than low earth orbit – (a) you can get ‘em
home in a hurry from low earth orbit - you
can come down virtually on any rev. We were
three and a half days from home. What we did
is position oceans, landing points, where
you had recovery forces. You’ve got to think
differently, totally differently,
It would be a long burn, with the engine firing
for four and a half minutes, but it would
get them back 10 hours earlier. The ‘PC+2
burn’ was one of the most critical maneuvers
of the whole mission. But that decision, and
the shape of the solution, was left to the
young flight controllers in the trench. Gerry
Griffin deferred entirely to the expertise
of people younger and more junior to him.
And that, as he explains, is the nature of
space flight operation
(Gerry Griffin) I think you’ve got to have
a team like that in order to do this kind
of thing. Space flight is tough. It’s not
easy, it’s really, really hard – but get
the right people on it and motivate them and
empower. We had decisions in those days made
at these very low levels. Today, everything
tends to elevate decisions to the higher levels
but we, throughout the programme, we made
the decisions at the right level.
(Jim Kelly) We had the faith and the confidence
of those people in mission control. And part
of that goes back to the simulations. When
you run these simulations day after day, and
you make a mistake, you’re not the only
one that knows it. The crew knows it, the
flight, the guy next to you knows it, the
little bug on the floor knows it. You learn
very fast who you can trust, who you can go
to bat with, and who you have to second guess.
And normally the second guessers never got
there.
And later when Gerry Griffin and Glynn Lunney
present the plan to Nasa’s most senior hierarchy,
they too understand the critical nature of
the decision and how it has to be made.
(Gerry Griffin) The two of us went to brief
Nasa management. Went up into a viewing room
of the other floor of the control centre and
we were looking, here’s these two young
guys, we were looking into the eyes of people
like George Low, Bob Gilruth, Chris Kraft,
Deke Slayton. I think von Braun was there
(Kevin Fong) So this is human space exploration
royalty?
(Gerry Griffith) Yes, it was the leaders of
space. And here you have these two young guys
that supposedly have all the answers, so we
briefed them on all the options. Finally,
Glynn’s the one who said, we favour is the
‘PC+2’. Unlike maybe what would happen
today – well, have you thought about …? We
thought we might get that question. Why haven’t
you thought about this, why haven’t you
done that? There was just a long silence.
Finally the head of the agency, Tom Paine
said, What can we do to help you? That was
it. I remember walking back into the control
centre – and I hadn’t thought of this
till just now – and saying, I put my headset
on and said, Guys, we’ve got a plan.
Aboard Apollo 13, the crew prepare to arm
the lunar module’s engine. The propulsion
system wasn’t designed for this - it’s
meant to land the fragile, spider-like LEM
on the Moon. Now it will be used to drive
the lunar module and the attached 15-tonne
command and service module, accelerating all
of that to nearly 3,400 miles per hour.
(Mission audio) Apollo 13, now 54 hundred
and 26 nautical miles out from the Moon, travelling
at a speed of 45 hundred, 52 feet per second.
Aboard the lunar module Jim Lovell looks down
at the Moon for landmarks, finding craters
in the cross hairs painted onto the window,
making sure that their orientation is still
correct. And finally they’re ready to go.
(Mission audio) Ground confirms ignition.
We’re burning, 40 percent. Houston copies.
Attitude looks good at this point. Roger.
This is still risky. Their main command and
service module engine is out of action, so
they’re dependent instead on the weaker,
lunar module propulsion system. For the crew
and mission control, it’s a novel but critical
maneuver. Jim Lovell.
(Jim Lovell) First of all we are using the
lunar engine so the thrust of the lunar module
engine wasn’t the same as the thrust of
the command module.
(Mission audio) Aquarius, Houston. You’re
looking good.
(Kevin Fong) This is a strange way to use
the lunar descent engine. What did you think
of that? I mean it’s a long burn to get
yourself on that ‘PC+2’ trajectory.
(Jim Lovell) You had to trust it.
(Mission audio) Reports to flight director
Gene Kranz indicate all systems are looking
good. Coming up on three minutes into the
burn.
(Jim Lovell) We were very careful to watch
as this thing was burning ahead on the guidance
of the computer system. You know, the countdown.
As we kept burning, it kept counting down
and down and down until, it kept burning all
the way to zero.
(Mission audio) The onboard display shows
less than a minute to go on the burn now.
(Jim Lovell) … which meant that we had gathered
the velocity increment necessary to get us
out. If it had, watching the computer system,
and it started going down, down, down and
stopped …
(Mission audio) Don’t forget descent reg
1 off. Ten seconds to go.
(Jim Lovell) … then we’d have been really
worried about, can we start it up again? Are
we, do we get ourselves a really odd long
orbit around the Moon or do we get something
that was just going to drift off you know,
out into space some place? So that’s why
that was so important.
(Mission audio) Shutdown. Roger shutdown.
That was Commander Jim Lovell reporting shutdown.
The engine is off. We’re 79 hours and 32
minutes into the flight.
(Jim Lovell) The lunar module was just incredible,
throughout that whole mission.
(Gerry Griffin) Yeah, wish we could have gotten
it back so we could say grace over it like
we did the command module. The lunar module
saved us. That burn, man, that old engine
just stayed right at it.
(Mission audio) Apollo control. 79 hours 33
minutes. 57 hundred and 7 nautical miles out
from the Moon as this time. I’d say that
was a good burn.
Until now mission control has been operating
in a low power state, leaving just enough
of its systems running to guide the ‘PC+2
burn’. But it’s time for some real austerity.
There is barely enough battery power left
in the lunar module to keep even essential
systems running. Flight director Gene Kranz.
(Gene Kranz) The power level, you can explain
this very simply. It was about the equivalent
of 200 watt light bulbs in your house, or
about a quarter of what today’s microwave
uses. And that’s what we had to sustain
us, it was our survival level to get the crew
all the way back to Earth.
They desperately need to save battery power.
So mission control begins to switch off almost
every system in the spacecraft. Merlin Merritt
is one of the flight controllers responsible
for the lunar module’s electrical and life
support systems
(Merlin Merritt) The agreement was that we
had with Glynn and Gene Kranz and the powers
that be you know, we were going to power this
thing down to a bare minimum.
(Kevin Fong) So no lights, no navigation computer?
(Merlin Merritt) No navigation computer. I
think there was maybe some, one little residual
lighting but the heaters were off, the Inertial
Measuring Unit I think was off, the computer
was off.
This is a miserable turn of events, both for
the crew and the team in mission control.
It will reduce the spacecraft to little more
than a husk coasting in space: leaving the
astronauts freezing cold, in darkness, robbed
of nearly every comfort. Bill Peters was the
flight controller in charge of sharing out
the lunar module’s tiny budget of electrical
power.
(Bill Peters) One flight controller would
say, Well I need the Inertial Measurement
Unit or I need the radio. There were hundreds
of boxes that could be turned on or off. And
those discussions were back and forth and
negotiated. You know, people would realise,
well, you know, if we don’t do this then
we won’t make it. Eventually they were negotiated
down from a 60 amp level to a 12 amp level
in terms of requirements. We had I forget
how many circuit breakers and switches in
the ship. You know, a couple of hundred that
you could individually turn off components.
And those components were evaluated and decided,
Do we really, really, really need that or
not.
Now that is a massive reduction. Peters is
trying to get down to a power consumption
of just 12 amps per hour. And to put that
into context, it’s only around enough battery
power to run a pair of car headlights at full
beam. Only in the case of Apollo 13 if the
battery dies, so does the crew.
(Bill Peters) Well we turned off anything
to do with the propulsion system, anything
to do with guidance navigation, the computers,
the gyroscope, the ... All the things that
allow you to navigate and control the ship.
In other words we left it as just something
that you could sit inside of and breathe.
Up until the point that I was sitting on the
console and we watched them power down completely
I had butterflies in my stomach for days,
being quite uncertain as to what would really
happen, cos we had never operated at that
level. That was only in analysis we did in
the office, for using a computer to say, OK
yeah, we could do that maybe – But we never
did it so with this power level actually went
down to 12 amps, my butterflies went away,
I was euphoric I guess, saying ‘hotdog’,
our plans have worked. Now all we have to
do is survive for a few more days.
For Fred Haise the drop in power is more than
just an abstract concept.
(Fred Haise) The power down was actually more
than I had assumed we could go to. Again,
things had been worked underground with people
thinking about it and we went down to about
12 amps versus 18 so, and even more power
usage. The heat inside is generated from equipment
running, so we were not in a very good thermos
bottle. Probably in the LEM, with three of
us in there, we were in the mid …, we weren’t
to freezing with zero Celsius as you know
it, rather 32 degrees Fahrenheit, but we’re
probably mid 30s.
There is one more difficult power challenge
to face up to. Bill Peters is busy stretching
out the dwindling battery power in the lunar
module to keep the astronauts alive in their
lifeboat on the way back to Earth. But John
Aaron is in charge of managing the power in
the command module for re-entry, and he has
problems of his own.
For re-entry, everything in the command module
– the navigation, guidance computer, the
parachutes and the thrusters – has to run
on three small batteries.
But in the opening hour after the explosion
the mission control team were forced to use
these batteries to keep the command module
running, draining some of their energy.
So John Aaron needs to recharge them. And
there’s only one place he can steal the
spare electrical power from, and so he sends
Jim Kelly to get it.
(John Aaron) I said, Jim, you know those lunar
module back room guys better than I do. Go
over there and ask those guys to save us a
little power so we can recharge these batteries.
(Bill Peters) And I looked at what I had in
the power budget and I said, Well, we’ve
saved some for emergencies, such as a battery
failure or instrumentation inaccuracies and
that sort of thing. We’ve saved some extra
power, and I looked at it and said, Well,
yes, we could do that, yes absolutely. So,
we gave up our spare power budget to the command
module so they could recharge their batteries.
(Jim Kelly) Since it was a battery charging
a battery, and the cable resistance in the
cable and stuff, I think it was, the efficiency
was horrible. I mean it was just absolutely
horrible. You know, we might have needed maybe
30 amp hours but it took them almost 80, or
100, amp hours of their battery to give us
30 amp hours of energy. Without the batteries
in the command module, without any capability
to replenish the power that was taken out,
there was no electricity to bring this crew
home.
(Jim Lovell) It was getting cold, it was,
got damp, you know, as it got cold the moisture
came out of the atmosphere. And we were worried,
and we’d go back into the command module
and it got so cold that Swigert was with us
most of the time so it got beads of moisture
all through and that worried us.
Gerry Griffin knows exactly what conditions
are like on board the spacecraft and - as
the battle for survival continues - his thoughts
are with the crew
(Gerry Griffin) Every Apollo mission that
I was involved in, I felt like I was in the
cockpit with them. I think most of us did.
Every time we did a manoeuvre I’d try to
say, OK, if I was there, what would it look
like?, what would it feel like? We knew how
cold it was for them for one thing. We also
knew that all three of them were in the lunar
module, which is not very big. And thank goodness
it was zero G, because they could fill spaces
you couldn’t on the ground. But if you just
went inside the lunar module and said three
guys are going to live in here for three and
a half days or whatever you say, whoah! We
all knew what they were going through. They
knew what they were up against.
In Episode 5, the moon continues to recede
behind them - the crew is on their way home,
but there is no guarantee they’ll get there
alive and new dangers face Lovell and his
crew, not least suffocation.
(Jim Lovell) We were exhaling carbon dioxide
and slowly that gas was building up.
(Mission audio) Our CO2 value is getting high.
We had a [garble] ECS light
(Jim Lovell) We were being poisoned by 
our own exhalation.
13 Minutes to the Moon is an original podcast
from the BBC World Service.
Our theme music is by Hans Zimmer and Christian
Lundberg.
This episode is written by me, Kevin Fong,
and producer Mark Rickards.
In the trench with us is Series Editor Rami
Tzabar.
Technical production is by Giles Aspen, and
our story editor is Catherine Winter of In
the Dark at APM Reports.
Thanks to Nasa and the Johnson Space Center
Oral History Project for the archive interview
with Gene Kranz. Additional thanks to Simon
Plumpton and Issa Tseng for their help with
the mission audio.
Find out more about the people and the tech
behind this amazing story by going to bbcworldservice.com/13minutes
where you can also find Season 1 of our podcast,
the story of the first Moon landing.
We’d love it if you shared this podcast
with your friends on social media – our
hashtag is #13minutestothe moon and where
you can, please do leave ratings and reviews
in your podcast app.
The World Service Podcast Editor is Jon Manel
and the Senior Podcast Producer is Rachel
Simpson. And thanks to our digital team.
