Apollo 12 Lightning Analysis

94 Pages·2015·2.56 MB·English

1 ----
~----------
~ /-~-
·. .-,;.. / ' / ,/..
~~-·I '..:; ~
.. • ~
...
!" .. _. •• I
tVi fJ.._Q -
'
- ?'1. k.' ' pt; 4 s;;;:;c? . -- ....
~·j~
. ' ;
ti?0--'7~'
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
.....,...
--1----
--- ---- -------~~- -- ~ '+ '
'(NASA-TM-X-628SU) ANALYSIS OF APOLLO 12 N72-73~78 ~ -
LIGHTNING INCIDENT h. Godfrey, et al
(N.\SA) Feb. 197~ 87 p
Unclas
' .
CC/99 34130 !
- ----~~--- --- ---
ANALYSIS OF
APOLLO 12 LIGHTNING INCIDENT
~-----
-~
PREPARED BY
MARSHALL SPACE FLIGHT CENTER
KENNEDY SPACE CENTER
,-- '
MANNED SPACECRAFT CENTER
..
'·
-
----
---
---
----·--- --·
FEBRUARY 1970
r
---· ---
NATIONAL TE~CHNICAL
IEJ'IOD4IGID n
I ~~cFJCE
-IWIBI,YA. ~ !A
-----~--
'
-\-dl-,"-''\- ~
----------- - -- --
----~-

MSC-01540
ANALYSIS OF APOLLO 12
LIGHTNING INCIDENT
PREPARED BY
Marshall Space Flight Center
Kennedy Space Center
Manned Spacecraft Center
~
R. Godfrey
Manager, Saturn Program
Marshall Space Flight Center
E. R. Mathews
Manager, Apollo Program
Kennedy Space Center
APPROVED BY
Rocco A. Petrone
Apollo Director
Progr~
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
January 1970
ii
TABLE OF CONTENTS
Section Page
PREFACE iv
SUMMARY 1
INI'RODUCTION 2
LIGHTNING PHarOGRAPHS 3
A'IMOSPHERIC ENVIRONMENT . 12
EFFECTS ON SPACE VEHICLE 18
Spacecraft 18
Launch Vehicle 23
Latmch Complex 24
CAUSE OF DISCHARGES . 25
Electrostatic Discharge Theory . . • . 25
Vehicle-Triggered Lightning Theory 26
FLORIDA METEOROLOGICAL CONDITIONS ASSOCIATED WITH
ELECTRIFIED CLOUDS • • • • . • • . • • • . . • 29
Effects of Atmospheric Conditions on Launch Window 30
Criteria 31
VEHICLE DESIGN CONSIDERATIONS . 37
Spacecraft 37
Launch Vehicle 42
Launch Complex 44
CONCLUSIOliS • • • • • 48
. . . . . . . .
IDRRECTIVE ACTIO!f 50
REFERENCES AND BIBLIOGRAPHY . 51
iii
Section Page
APPENDIX A -- LIGHTNING AND RELATED INSTRUMENTATION . . . . . A-1
APPENDIX B -- EXPLORATION OF SOME HAZARDS TO NAVAL EQUIPMENT
AND OPERATIONS BENEATH ELECTRIFIED CLOUDS B-1
APPENDIX C -- CIRCUIT ANALYSIS C-1
Automatic Abort System Circuit Analysis . C-1
Ordnance Circuit Analysis ...... . C-2
•
PREFACE
Appreciation is extended to the following personnel for their exper
tise and help in the understanding of the Apollo 12 lightning incident
at the special December meeting of the American Geophysical Union in
San California.
Francisco~
Dr. Louis J. Batten Dr. J. D. Robb
Institute of Atmospheric Physics Lightning and Transients Research
University of Arizona Institute
Dr. S. C. Coroniti Dr. J. D. Sartor
Panametrics, Inc. Laboratory for Atmospheric Sciences
National Center for Atmospheric
Research
Dr. George A. Dawson Dr. E. L. Schuman
Institute of Atmospheric Physics Research Laboratories
University of Arizona Environmental Science Services
Administration
Dr. Hans Dolezalek Dr. William Scott
Atmospheric Sciences Program Department of Atmospheric Sciences
Office of Naval Research University of Washington
Department of the Navy
Dr. H. W. Kasemir Dr. Martin A. Uman
Research Laboratories Research and Development Center
Environmental Science Services Westinghouse Electric Corporation
Administration
Dr. L. B. Loeb Dr. B. Vonnegut
Department of Physics Department of Atmospheric Science
University of California, Berkeley State University of New York at
Albany
Dr. Forrest Mozer Dr. William P. Winn
Space Sciences Laboratory Laboratory for Atmospheric
University of California, Sciences
Berkeley National Center for Atmospheric
Research
Dr. M. M. Newman
Lightning and Transients
Research Institute
To other participants of this meeting, a special thanks is given
for their analytical contributions and consultations which were gracious
ly offered during the analysis of the phenomena associated with the light
ning incident.
Dr. Marx Brook Dr. E. Philip Krider
New Mexico Institute of Mining NASA-NRC Resident Research Associate
and Technology Manned Spacecraft Center
Dr. Arthur A. Few Mr. Charles B. Moore
Department of Space Science New Mexico Institute of Mining
Rice University and Technology
Dr. Donald R. Fitzgerald Dr. Richard E. Orville
Air Force Cambridge Research Department of Atmospheric Science
Laboratories State University of New York at
Albany
Dr. G. Freier Dr. E. T. Pierce
School of Physics Staff Scientist
University of Minnesota Stanford Research Institute
y
·-·
1
SUMMARY
The Apollo 12 space vehicle was launched on November 14, 1969, at
11:22 a.m. e.s.t. from launch complex 39A at Kennedy Space Center, Florida.
At 36.5 seconds and again at 52 seconds, a major electrical distl.lrbance
was caused by lightning. As a result, many temporary effects were noted
in both the launch vehicle and spacecraft. Some permanent effects were
noted in the spacecraft and involved the loss of nine non-essential in
strumentation sensors. All noted effects were associated with solid-state
circuits, which are the most susceptible to the effects of a discharge.
Analysis shows that lightning can be triggered by the presence of
the long electrical length created by the space vehicle and its exhaust
plume in an electric field which would not otherwise have produced nat
ural lightning. Electric fields with sufficient charge for triggered
lightning can be expected to contain weather conditions such as the clouds
associated with the cold front through which the Apollo 12 vehicle was
launched. The possibility that the Apollo vehicle might trigger lightning
had not been considered previously.
The Apollo space vehicle design is such that a small risk of trig
gered lightning is acceptable. In accepting this minimal risk for future
flights, launch rule restrictions have been imposed with respect to opera
tions in weather conditions associated with potentially hazardous elec
tric fields.
2
INTRODUCTION
Before the Apollo 12 flight, the only consideration of the effects
of lightning on the space vehicle was for the period prior to flight.
The methods and procedures used to cope with possible lightning prior to
launch have been in existence since the inception of the launch complex.
The possibility of the vehicle becoming involved with lightning after
lift-off was not a launch consideration, unless natural lightning activ
ity was actually present in the launch complex area.
This report discusses the significant elements of the lightning in
cident during the Apollo 12 launch. The report is addressed to what hap
pened and why, and what meteorological conditions could produce lightning
with the presence of the launch vehicle. This report also recommends
action for minimizing the possibility of creating a similar incident on
future Apollo flights. An assessment of the spacecraft and launch vehi
cle electrical design to determine the effects of lightning is included.
The investigative results represent the combined efforts of the ap
propriate personnel at the Manned Spacecraft Center, the Marshall Space
Flight Center, and the Kennedy Space Center. The primary contributions
to the understanding of the physics associated with the incident and of
how to apply the present knowledge of atmospheric electricity to the
Apollo Program have been provided by recognized experts in the field.
A number of authorities on atmospheric electricity have enthusiastically
and voluntarily provided consultation and literature in this area.