Apollo 13 Case Study part 1

70 Pages·2008·4.48 MB·English

Scientific Technical Information (STI) I Disclosure
Export Control Rationale

Title of Presentation: Apollo 13 Case Study part 1 & 2
Author/Speaker: Mike Interbartolo

The information is already in the public domain in its entirety through a non-NASA medium
and/or through NASA release on NASA websites.

A large percentage of the documents obtained for the library are available to the public at either
the NASA History Office's Apollo Lunar Surface Journal (ALSJ), or the NASA Technical Reports
Server (NTRS). Here are the URLs for these sites:

http://history.nasa.gov/alsj/frame.html
http://ntrs.nasa.gov/search.jsp

In particular, the Apollo Operations Handbooks were obtained from the former, and the Apollo
Experience Reports from the latter. We also obtained a large number of GNC documents from
the Virtual AGC site, which is a public non-NASA site with documents largely obtained from the
National Archives (NARA-SW):

http://www.ibiblio.org/apollo/
AAppoolllloo 1133 CCaassee SSttuuddyy ((ppaarrtt 11 ooff 22))
Objectives
Describe the Service Module Electrical Power
(cid:137)
System hardware
Describe the circumstances which led to the
(cid:137)
Apollo 13 accident
SSummariize tthhe MMiissiion CConttroll andd crew
(cid:137)
reaction
2
Outline
This briefing is Part 1 of 2
(cid:137)
Overview of electrical system hardware
(cid:190)
Failure chain reconstruction
(cid:190)
In-flight oxygen tank explosion
(cid:190)
IImmmmeeddiiaattee MMCCCC rreeaaccttiioonn
(cid:190)(cid:190)
Part 2 is a separate briefing
(cid:137)
MMCCCC rreeggaaiinnss iinnssiigghhtt
(cid:190)(cid:190)
Impact to various systems
(cid:190)
IInn-fflliigghhtt rreeccoovveerryy
(cid:190)(cid:190)
Entry
(cid:190)
Post-flight changes and lessons learned
(cid:190)
3
Electrical Power System Overview
Service Module
(cid:137)
Provided majority of power required
(cid:190)
oonn tthhee ttrriipp
Cryogenic H and O tanks fed three
(cid:190)
2 2
fuel cells
CCommand Module
(cid:137)
Rechargeable batteries primarily for
(cid:190)
eennttrryy,, aallssoo ssuupppplleemmeenntt ffuueell cceellllss ffoorr
peak loads
Powered some heaters and lights on
(cid:190)
tthhee LLMM
Lunar Module
(cid:137)
Six batteries,, normallyy used onlyy for
(cid:190)
lunar descent and ascent
4
Fuel Cells
Fuel cells & cryo
(cid:137)
located in Service
MModdulle
Cryo O & H stored in
(cid:137)
2 2
ttaannkkss ((22 eeaacchh))
Fuel cells (3) provided
(cid:137)
pprriimmaarryy ppoowweerr ttoo CCSSMM
for duration of flight
5
Cryo Tank
ID–nNuteeorr nmtoaa llz lyhe eproear-tfgeo,rr msta eknde kesp
To keepp tanks
ppeerriiooddiiccaallllyy tthhrroouugghhoouutt tthhee
tbhueil dta unpk ap rgersasduireiznet dof
homogeneously
mission
high and low
mixed, Apollo config
– Mixed tank yields better
pprreessssuurree //
hhaadd ffaannss ttoo “ssttiirr” tthhee
temperature, pressure, and
temperature / density
tanks
quantity telemetry readings
– On Appollo 13,, crew
stirred the tanks several
times with no problems
prior to the explosion
6
COMMAND/SERVICE MODULE POWER SYSTEM
Fuel cell 3 powers SM Bus B, Main B, and AC2
Fuel cells 1 and 2 power SM Bus A, Main A, and AC1
Entry and
Batteries disconnected from Main Buses
Post-Landing Apollo 13 configuration
Battery A
att ttiime off acciiddentt
Service Module
Battery
SM Bus Bus
A A
70 A
A
CCFeeullell 11l IInveArCtte r 11 70 A Bus B
O2 n
AC Bus ai
Fuel 1 M
20 A C
Cell 2 D
H2 Inverter
DC &
AC AC Non-ESS
Inverter 3 Control Bus 1
FFLLTT s
CCiircuiitts uu
Bus Non-ESS g B s
Bus 2 n u
Fuel AC ndi y B
Cell 3 Inverter 2 AC 2Bus ostla Rela
Lunar P y
To ECS Module and atter
ht B
g
20 A Fli
B
Cryogenic s
Subsystem Bu
70 A n
ai
SM Bus M
B 70 A C
D
From AC Bus 1 or 2
Battery From DC Main Bus A and B
charger To Entry/Post-landing Battery
Entry and
Bus
Battery Charger switches
Post-Landing
B
Battery B
Entry and
Post-Landing
BBattttery CC
Pyro Bus A
Pyro Battery A
Pyro Bus B
Pyro Battery B 7
Failure Chain Reconstruction (Part 1)
October 1968, North
(cid:137)
Fuel cell shelf
American Rockwell
Tank removed from Apollo
(cid:190)
10’s SM for mods
DDuriing removall, ttankk shhellff
(cid:190)
was accidentally dropped 2”
Cryo O
2
tank shelf
PPaasssseedd aallll tteessttss,, bbuutt ffiillll lliinnee
(cid:190)(cid:190)
probably displaced by 0.1”
Cryo H2 tanks
8
Displaced Fill Line
9