NASA_FRC_Space_Propulsion_Concept_1990
a
using
Space
Fusion
Energy
Reactor
N91-28217
Conversion
Configuration
Field Reversed
SPACE TRANSPORTATION TECHNOLOGY
A New Technical
and Power
for Space
Propulsion
PENN STATE
Approach
PROPULSION
SYMPOSIUM
of Wisconsin
F. Santarius,
Headquarters
R. Schulze,
University
H. Miley,
University
Norman
George
Illinois
NASA
John
25-29,
JUNE
of
A
USING
SPACE
FUSION
ENERGY
G. H. MILEY
REACTOR
N. R. SCHULZE
J.F. SANTARIUS
APPROACH
PROPULSION
FOR SPACE
CONVERSION
AND POWER
CONFIGURATION
FIELD REVERSED
A NEW TECHNICAL
THAT OF THE ORGANIZATIONS TO WHOM THEY REPORT
THE CONTENTS OF THIS PAPER REFLECT THE OPINION OF THE INDIVIDUAL AUTHORS, NOT NECESSARILY
reduce costs, and enable new missions by providing
referred to as the Field Reversed Configuration
the space program can fulfill High Energy
fusion engine system that can be optimally
system from a high performance
of high payload mass fractions
features which would benefit
an energy option to fission.
energy would be providing
in a manner not otherwise
costs, and space mission
program and in particular
deuterium and helium-3,
like the Manned Mars
The time has arrived
offers a new method
offers many inherent
had been developed
The fusion energy
the aforementioned
the FRC potential
design approach,
power propulsion
outpost missions
flight operational
Space Missions
fusion provides
Fusion energy
were available
to demonstrate
a high specific
can potentially
the attainment
when burning
In addition to
and planetary
transportation
and concept
space flight.
while doing
advantages,
use today,
capabilities.
FRC’s will
demanding
for space.
technology
conversion
conversion
conversion
for space
such that
for space
spacecraft
to initiate
by FRC’s
programs,
designed.
increased
By using
so within
a space
possible.
powered
enabling
increase
reduced
(HESM)
ABSTRACT
science
require.
Mission
shorter
energy
energy
energy
enable
safety,
safety,
FRC’s
(FRC)
fusion
fusion
fusion
times.
which
If the
flight
high
—
is
or
as
on
be
for
for
will
the
the
the
the
not
are
Yet
two
that
and
that
one
and
and
This
focus
plans
those
being
taken
being
future
paper
space
space
power
power
theme
levels.
energy
Current
a high
mission
impulse
develop
meeting
on the
pursued
to gain
seconds
concern,
missions
systems.
electrical
capability
adequate
Emphasis
measures
program’s
articulates
Therefore,
propulsion
propulsion
propulsion
propulsion
to assure
is placed
generation
that does
technology
the future
completed,
in specific
is whether
developing.
needs will
in chemical
low energy
requirements
the demand
in particular,
requirements.
is anticipated
basis where
a requirement
space mission
space mission
INTRODUCTION
met on a timely
R & D activities
to be for high energy
for high energy missions
to perform the missions.
now for a well-planned
that can be anticipated,
such great dividends
can be circumvented
use of an alternate
to be the situation.
that high specific
role in achieving
the U. S. space
energy missions
energy missions
the development
of advancements
paper will not
propulsion/power
of high energy
a high energy
new capability
It is the intent
accomplishment
not necessarily
of a relatively
one designed
by developing
to the extent
infrastructure
and a major
are possible
high specific
transportation
and impulse
requirements
Now is the
the use of
the authors
recommends
experimental
commencing
Its potential
to address.
commitment
continuation
and space
to achieve.
with more
capabilities.
to achieve
in bringing
it can not
to assume
This class
our ability
challenging
of making
too costly
opportunity
importance
exploration
the future
but which
investment
investment
the world
constitutes
for space
economics
to realize
That will
propulsion
leadership
Therefore,
presented
capability.
capability,
capability.
the type
challenge
ambitious
in space
to press
capability
now for
missions.
Quantum
be easy
e!ectrical
program,
pro£jram
research
missions
depends
benefits.
perceive
program
perform.
a major
initiation
systems
possibly
requires
become
of high
national
ultimate
thinking
science
mission
mission
a long
a high
forward
forward
forward
source.
severe,
modest
Energy
by the
striking
travel’s
in this
energy
energy
energy
energy
proper
Space
power
power
space
fusion
space
space
space
space
report
inhibit
timely
future
which
offers
some
grow.
alerts
early.
could
leaps
crisis
upon
bring
have
have
what
That
onto
they
long
lead
use.
high
time
time
time
very
This
new
The
The
The
well
and
and
that
test
this
this
are
the
the
the
the
the
will
will
for
for
for
be
as
us
of
of
to
of
of
to
of
to
in
in
a
It
of
of
of
its
will
the
THE
can
and
and
with
with
such
Mars
need
those
Since
which
future
future
power
shows
issues
Space
HESM
regard
in the
safety,
POWER
POWER
Policy”
to the
require
serious
as the
logistics
element
become
Manned
Manned
involved
use for
vehicle’s
missions
electrical
chemical
repeated
missions.
functions:
is a key
two high
propulsion
particularly
anticipated
exploration
settlement,
(ANOM89).
economics,
OF SPECIFIC
consumption
An analysis
for Manned
be ignored.
performance,
to be more
shortcomings
transportation
environmental
local Martian
“US National
implementation
(High Energy
Mars Missions
Mars Missions,
fully addressed.
to be successful,
Space Missions),
with the implementation
and manufacturing.
of a high energy
for high electrical
to be considered
for beam power
by the University
for extraterrestrial
the performance,
as a propulsion
from its further
on the planets
accomplishment
as a potential
aforementioned
It will provide
in this paper.
the mission’s
on propulsion
and methods
the utilization
to accomplish
be important
as discussed
environmental
for providing
are 2 major
consideration.
for electrical
transportation
requirements.
requirements.
consideration
on chemical
in turn will
for meeting
technological
requirements
of electricity
improvement
the 1960’s,
conditioning
applications
aerobraking
engineering
and safety
of Arizona.
or as an
application,
to nuclear
operational
is recently
propulsion,
has been
technology
anticipated
in nuclear
generation
the focus
production
propulsion
propulsion
settlement
settlement
by which
capability.
for Mars
resources
resources
combined
simplicity,
detracted
approach
approach
utilization
capability
missions,
planetary
planetary
is not a
whatever
including
electrical
systems.
electrical
is being
renewed
enabling
resolved
effective
subjects
is high
systems
systems
systems
pursued
address
logistics
optional
subject.
a total
through
manner
method
support
specific
thermal
thermal
interest
provide
system
fission.
reduce
energy
energy
energy
energy
a cost
logistic
habitat
Fusion
source
power.
power.
power,
proper
issues
issues
fission
option
based
power
power
power
power
space
space
space
space
space
There
Some
which
levels
which
either
given
there
large
Also,
each
local
local
High
over
high
joint
with
was
The
The
The
The
has
key
but
the
the
the
the
the
the
the
the
the
the
will
will
yet
for
for
as
of
of
of
of
to
is
A
in
of
But
tion
that
and
solar
times
could
result
which
power
power
effects
space.
features
Manned
possess
potential
as well
radiation
features,
systems,
by faster
economic
increased
spacecraft
impact of
population,
the impact
is achieved
the Earth’s
to galactic
performance
as adverse
high energy
psychological
high specific
the capability
is to develop
from radiation
the preference
and protection
flight systems.
from exposure
and the overall
for other safety
space missions.
from long flight
and physiological
to the environment
in reduced hazard
space flight safety
trip times resulting
mass also reduces
the space traveller,
From the perspective
having greater mass
as well as to provide
potential will obviously
to provide more safety
design margin, and back-up
from the aspect of safety to
is to place the minimal mass into orbit. Minimal
The problem is, how does one resolve these two counterbalancing
in the 1960’s as an option and considered
the FRC (Field Reversed Configuration),
to LEO to perform one Manned Mars
to the Manned Mars Mission as defined
in Earth orbit and from the ground
Manned Mars Mission requires.
Its large magnet mass prohibits
the number of LEO launches.
launch safety by minimizing
of a large NERVA category
if a flight weight propulsion
system can be designed
to LEO also minimizes
has been demonstrated.
that will be necessary
to realize the desired
There will always be
likely to demonstrate
such as a compact
the large payloads
from the presence
is not a concept
to a point where
having a specific
and the cost of
the performance
the performance
for development.
flight operations
to be of benefit
Also minimized
delivering, will
has not been
which is most
the experiment
was examined
and programs.
system mass
a light weight
power source
too, of safety
High specific
demonstrated,
the missions.
to implement
transportation
of 1 kW/kg,
requirements
it had been
the number
the greatest
revolutionize
the energy
advantages.
atmospheric
it. Nuclear
as capable
optimization
is currently
fusion first
not appear
The most
a question,
on Earth’s
developed,
considered
conversion
net power
for power.
of Shuttle
advantage
for space
The solu-
developed
propulsion
propulsion
necessary
resources
to qualify
perceived
pollutants
a reactor
is fusion
example,
attractive
launches
of mass
systems.
potential
tokamak
Properly
Even if
required
requires
to offer
the low
are the
improve
concept
Nuclear
to offer
energy.
Instead
provide
forces?
electric
energy
energy
energy
energy
testing
fission
toroid,
option
power
travel.
is the
space
fusion
space
fusion
space
fusion
future
which
It still
flight.
then.
does
flight
e.g.,
only
The
that
can
But
For
not
the
will
An
for
of
is
by
on
top
first
This
high
EXISTS
could
those
paper
space
MISSION
ENERGY
A HIGH
issues
priority
toward
energy
current
Mission
benefits
total of
required
systems.
chemical
program.
to meet
designed
considers
significant
propulsion
propulsion
REQUIREMENT
The flight
years total
A program
be reduced
system will
development
requirements
hypothesized
an expedited
the chemical
flight duration.
in undertaking
require 1 to 2
as a matter of
to test evaluate
those missions
basis with initial
7 fold from that
an advanced mission
by a factor approximately
less than 6 months whereas
time could be reduced to a
results anticipated within 5 to 10 years.
Space program resources must be directed
the FRC reactor burning D-3He could be accomplished
and solar system exploration
relate to large energy
to, nor a replacement
that can be attained
in the multimegawatt
the Field Reversed
l a and b) and (2)
(1) a high energy
the highest priority
deuterium-helium-3
capability needs
term applications.
as a competitor
space mission
be pursued at
is the optimal
which should
The practical
Configuration
for the near
development
consumption
and higher;
conventional
confinement
The thesis
for science
applications
low energy
this report
this need.
presence.
analyzed.
approach
missions,
missions.
magnetic
foreseen
category
currently
to meet
systems
namely,
reactor,
fusion’s
burning
is that
(Figure
energy
is not
results
reveal
fusion
fusion
fusion
those
were
level
very
The
The
for,
the
by
all
of
of
I
I
MULTI
THESIS
lacking.
- Manned Mars:
- Technology
advancement
- Requirement
_IW’S TO GW’S
will requlre time.
for HESM exists:
hinges upon high
- Space program’s
Start R & D now slnce development
elements being made available for the
HIGH ENERGY SPACE MISSION _HESM) CAPABILITY:
energy converslon NASA space transportation
- Science outposts Including sample returns: outer planets, comets, asteroids, others
- Oort Cloud/Stellar
interstellar space, and nearest stars.
- Enables: sclentiflc exploration
of the entire solar system,
Mlssion Beneficiaries
from a high energy
- Electrical Power
from High Energy
including manned
Hioh Performance
Infrastructure.
- Economics
as discussed
crew safety
the reduced
- Reliability
exploration:
*Systematic
exploration
- Logistics
to reduced
for space.
Pronulsion
plus other
to galactic
a variable
pertaining
Improved
capability
of Mars,
exposure
- Safety
systems,
reducing
because
thereby
coupled
benefits
Mission
specific
Thesis.
cosmic
factors
results
Figure
Figure
crew’s
power
safety
flight
times
later.
time,
flight
High
rays
with
the
la.
lb.
of
in
of
of
for
will
the
the
that
and
over
over
parts
more
factor
stress
lesser
safety
higher
factors
longer,
energy
reduce
contain
intense
thereby
savings
through
impulse
greater,
can be
systems
program
reducing
problem.
systems,
achieved
of more
demands
presence
missions,
distances
Reliability
inherently
increased
of dollars
capability,
increasing
the mass
and lower
the launch
redundancy
exacerbates
the quantity
into remote
sophisticated
gains must
the conduct
as the flight
high specific
a permanent
mass-economy
on Mars will
times become
in implementing
be incorporated
reduce moving
in launch costs
return missions.
low performance
such as sample
load requirement
New approaches
manned missions,
the accomplishment
as a new technical
like those to Mars.
like manned Mars.
into the flight systems
future science missions
The brute force method
Reliability will be an ever
of mass which must be placed
fewer or no parts that are subject
into low Earth orbit. Many 10’s of billions
more emphasis will be placed on self
reliance which in turn will necessitate
to erosion must be incorporated
basis but which will not be
flights there on a frequent
power will be required
space mission enabling
that will be enabled
the manufacturing
of man on Mars,
space missions
and to forward
and to support
by the space
is to address
the essential
the objective
new thinking
on solutions.
infrastructure.
A permanent
high energy
the concern
the Martian
a permanent
in terms of
flight costs.
the use of
and which
To achieve
this paper
accomplish
to support
technology
a part of
resources.
Significant
approach.
program’s
exorbitant
therefore,
regarding
capability
presence
presence
planetary
electrical
electrical
products
logistical
habitats.
become
of man
support
(Figure
require
needs
power
space
future
future
Thus,
must,
some
there
High
the
life
for
of
of
to
Objective
I Address the concern, the need, and present a plan I
multiple planetary outpost missions using just one spacecraft as a launch platform on
trip times to the outer planets with more massive and better equipped science
faster and therefore safer manned Mars missions, manned missions beyond
science missions to the inner planets, power generation
rendezvous with sample returns, polar solar science,
interstellar plasma science, understanding
astronomy, Oort Cloud exploration
A few of the high energy missions
a single mission, comet/planet
the basic method to address
remote planetary materials
space system requirements.
HIGH ENERGY MISSIONS
that can be accomplished
the system requirements,
for high energy mission
in-situ stellar science,
fusion were available
is that a requirement
Figure 2. Objective.
Those missions
the heliosphere,
and unmanned
for permanent
the missions,
and science,
and mapping
plus others.
that appears
requirements,
which meet
and relative
recommends
fundamental
advantages;
a particular
processing
The thesis
advantages
interstellar
addressed.
capabilities
determine
payloads,
outposts,
particular,
examines
a design
approach
manned
include:
science
energy,
options,
to offer
system
solution
intrinsic
and in
certain
system
and it
energy
energy
needs
Mars,
paper
exists
which
faster
thus
This
be
of
to
if
3.
are
The
upon
flight
times
based
Figure
(FRI89).
systems
constant
relatively
I to 10 kW/kg
propulsion
- Reduced
calculations
acceleration
low thrust,
requirements,
massive payloads
Future Programs:
!mpulse: Sxl03 to 106 seconds
System Requirements
Greater distances More economical mission=
-High Specific power: -Variable, high specific -Variable thrust: 1 to 104 N -Jet power: 20 MW to 30 GW -Burn durations: 2 months to many years -Mission duration: 6 months to hundreds o! years -Reuse/orbital -Orbital maintainability: -Operational -Operational -High relia.bllity -High payload mass tractions: 10% to ou’_
in LEO (Low Earth Orbit)
each way with a space
system requirements
a 133 MT manned
the same mission
time of 3 months
a 61 MT payload
be accomplished
mining, material
and life support
future missions,
Mars Missions.
in a reasonable
it is anticipated
4a summarizes
in a trip flight
EXPLORATION
vehicle mass
and to return
as trip times
accomplishing
the Manned
key mission
of moderate
of propellant
4a and 4b)
(-610 MT)
for a rapid
and power
and fusion
of 1 kW/kg
is included
safety simplicity
(designated
PROGRAM
in addition
size while
processing,
to perform
unmanned.
power/inert
ap where
The flight
a specific
particularly
operations
propulsion
propulsion
propulsion
to deliver
O_p = jet
programs.
objectives
of values
MANNED
- Flight
functions.
to Mars,
economy
to Earth
A range
to Mars
specific
as well
required
showing
(FRI88).
systems
manned
low to none
will be
payload
offering
(Figure
system
vehicle
vehicle
energy
benefit
design
launch
having
MARS
Figure
Figure
power
power
mass)
future
levels
refueling
using
tunar
initial
large
time.
flight
High
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data
time
that
and
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for
for
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4a. Manned Mars mission
.-1,100 MT is placed
using high energy
system having
of 10 kW/kg
approximately
be achieved
a propulsion
characteristic
one month,
the mission
performance
performance
be reduced
propulsion.
time could
low Earth
to a very
a specific
to Figure
attractive,
an initial
provided
of only
curves.
vehicle
Figure
4b for
power
Refer
mass
I_l_er. Oltam:l October
trend
short
orbit.
flight
SAIC, So_eumburg,
That
time
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val(Je of h_gh o_pto the manned Mars program is clearly
the anticipated need for more massive
Manned Mars m;ssion performance
power, O_p—1kW/kg to 10 kW/kg,
and 61 MT inbound manned
50%. The mission parameters
in space as with commercial
using high energy propulsion.
shown cover a wide mission
in Figure 3 will be important
of mission must ultimately
The specific parameters,
perform those missions
is low — slightly greater
— and safety — goals
— from manned Mars,
system performances,
as shown in Figure
The Shuttle’s mass
the HESM category.
with Alpha Centauri.
than 1%. Economy
by the development
the payload mass
by Figures 4a and
133 MT outbound
The O_p of 0.067
it is approximately
that yield a high
of space mission
to a rendezvous
day wide body
range, perhaps
a full spectrum,
payload mass
by substantially
the suggested
The economy
105 seconds).
is considered
can produce
and masses
transportation
of propulsion
at a variable
are attained
high specific
requirements
To achieve
as specified
for nuclear
Figure 4b.
businesses,
to conduct
successful
Preliminary
propulsion.
presented.
4b where
In current
increasing
the flight
traversed,
payloads,
illustrated
distances
approach
planetary
example,
achieved
payloads
or other
carrying
missions
to outer
a target
(-103 -
required
is high.
systems
reduced
fraction,
electric
indicate
impulse
returns,
aircraft
specific
specific
fraction
fraction
sample
quicker
studies
greater
airlines
kW/kg
power
where
all at
fusion
times,
costs,
is to
time,
flight
The
that
are
the
4a.
out
for
be
to
Flight
years
Time,
…
…
i
i
if
per
For
with
cost
total
flight.
using
today
Thus,
target
to its
flights
space
space
Larger
launch
require
current
roughly
savings
will be
logistics
vehicles
of $12B
A space
example,
launched
to Mars,
presence
an initial
assuming
launches.
launches,
frequency
per year.
equivalent
propulsion
propulsion
of a flight
limitations,
enormous.
technology
above the
the current
technology,
each flight
the energy
to conceive
It is difficult
in LEO for
performance
the Martian
requirements
infrastructure
consideration
less than 2
will obviously
vehicle would
of ~37 Shuttle
but an accurate
1,000 MT mass
of man on Mars.
for nuclear-electric.
But using current
innate performance
of a viable permanent
an order of magnitude
is basic to the implementation
in the range of 1 to 10 kW/kg,
the Earth to LEO transportation
cost number, will be at a price
a $320M cost per Shuttle launch,
the mission with a more massive system
varying from 1.6 years for Europa to 7.4 years
or better flown at higher
from Earth to LEO and in performing
cost analysis must be accomplished
to the safety of manned missions,
to accomplish speeds.
the outer planets with round
1 or 2 seconds’improvement
into orbit by approximately
into LEO to accomplish
space science missions.
While fusion may offer
from the moons of
program will better
value to the space
immediate mission
by the development
power and variable
power of 1 kW/kg
mission, payload,
science missions
The high energy
only one Shuttle
for a 10 kW/kg
in the capability
return missions
engine system.
very interesting
can be stated.
and particularly
the technology
to a reusable,
outbound-61MT
system would
fusion energy
vehicle mass
developmental
transportation
high specific
high specific
the number
infrastructure
the greatest
is, a space
soil sample
(Figure 5).
less mass
for Charon
that yields
PERFORMANCE
the space
the same
is needed.
propellants
propellants
exploration
propulsion:
in specific
A specific
propulsion
propulsion
a 131MT
to deliver
trip flight
to launch
resolution
6 Shuttle
launches,
to Mars
be sent
program,
research
enabling
impulse.
systems
requires
inbound
Instead,
enables
payload
which !
system,
impulse
resides
greater
include
energy
reduce
benefit
placed
launch
having
placed
SCIENCE
before
permit
based
MISSION
space
fusion
space
being
using
times
That
high
The
still,
not
or
of
to
of
of
b
i
I
_pl
_pl
Opl
Opl
_,,%
---
Titan
14:27
: _pl0
Triton
<lsp>,
: ¢p10
: cZpl0
Europa
Charon
: CCpl0
27 : 68
57 : 50
33 : 77
18 : 40
74 : 29
81 : 27
60 : 26
25 : 30
19 : 74
Mission
Pj, MW
Miranda
t, years
Mo, MT
6.3 : 63
26 : 3.4
62 : 3.8
Mp, MT
36 : 5_3
1.56:1.56
320 : 32
108 : 27
Av, km/s
243 : 6.8
196 : 223
O_pl : _pl0
209 : 209
233 : 233
C¢pl : _plO
35.7 : 118
17.7 : 64.1
26.2 : 81.2
2.99 : 2.56
7.42 : 7.42
5.34 _ 5.34
5.85 : 6.85
C_pl : C_pl0
(Round trlpI
seconds x103
I Sample return missions:
20 MT outbound; 10 MT inbound
II Science Program Benefits
in 120 years, while a 10 kW/kg specific power propulsion system completes
obviously of a magnitude that a new energy source is mandated.
the trip in 55 years, using a 7 GW reactor power output.
It is shown to range from 15 MW to 60 MW. The propulsion
L Manned Mars Missions.
payload was flown to the planetary destination
time, exclusive of the stay time for science
in less than only 2 years using the same
a 10MT payload Oort Cloud rendezvous
is much less than the more massive
times are for the round trip flight
is demanding, with the specific
systems for planetary missions
mission at 20,000 AU, a 700
soil can be analyzed in depth.
scenarios a very substantial
in Figure 5. Three separate
payload and 10 MT returned
can be quickly performed,
to perform such missions
The energies here are
system will accomplish
In the analyzed mission
Figure 5. Performance
a 1 kW/kg propulsion
cargo of extraterrestrial
and a 10 MT payload
asteroid visits at 1
system performance
Fusion is a logical
planetary missions
where its precious
source operating
returned to Earth
20 MT outbound
and capabilities
impulse ranging
are summarized
of high specific
The jet power
To complete
and 140,000
The mission
power(cid:0)specific
AU distance
MW power
parameters
advantage
propulsion
the site.
for outer
gathering
seconds.
between
payload.
seconds
required
(FRI89).
40.5 : 137
impulse
mission
35.1 : 130
20 MT
314 : 283
317 : 317
17,000
Those
41 : 4.1
25 : 73
19 : 32
that
i.e.,
at
of
for
But
offers
Alpha
stellar
power
nearly
closely
reactor
system
specific
actually
requires
mission,
Proxima
even a
a 3-star
reducing
Because
technical
capability
neighbor,
exhibiting
replicates
the flight
properties
Advanced
challenge.
brightness
candidate,
or slightly
our sun’s
the same
technology
and mass.
this is not
the greatest
,-290 years.
development
With fusion,
Our nearest
at 10 kW/kg
to 40 kW/kg,
to commence
characteristics,
fly-by mission,
vehicle mass.
Alpha Centauri,
less, depending
the performance
upon the initial
now in view of
system operating
For a rendezvous
power of 1 kW/kg
time to -180 years.
for a 10MT payload
such a development.
the mission difficulty
system — o_, 13,and
the lead time required
— at 4.3 light years distance,
really a mission for a specific
but serious R & D must begin
design which takes ~400 years
technology might be able to increase
the ability to produce sufficiently high thrust variable specific impulse (104 to 106 seconds);
key factors which serve as the basic high energy system mission
the ability to develop a specific power system of 1 kW/kg, or 10 kW/kg in the
reliable propulsion and vehicle performance for months to many years (e.g.,
the ability to perform the missions safely from both the standpoint of public
reactors ranging from 20 MW to 30,000 MW jet power production;
Table 1. Future spacecraft energy system needs (SCH90).
for as long as 50 years of continuous fidng operation);
mission vehicle system requirements.
The ability to perform the complete
unlike any other known energy
source, we can commence
for a vehicle of this size and a
for the mission early.
case of the stellar mission;
the next generation
the United States
safety and flight safety.
class of missions
now be pursuing
these marvelous
program should
herein resides
REQUIREMENTS
and planning
it is essential
requirements,
high energy
consideration
compatibility
architecture
considered
a national
to assure
its innate
spacecraft
missions
because
VEHICLE
thereby
posture
SYSTEM
several
future.
in the
space
space
which
Table
upon
with
for
of
1,
of
the
space
severe
vehicle
reactor
specific
impulse
similarly
proceed
imposed
to meet
to GW’s
propulsion
developed.
The most
and thrust
An orderly
progressive
PROPULSION
requirements
requirements
for example,
enhancement
will ultimately
The capability
by the vehicle
are established
the fundamental
allow NASA to
science payloads
on the propulsion
we can determine
program build-up
These are shown
system are to be
for stellar missions.
system requirements
to the more difficult,
SYSTEM REQUIREMENTS
by the stellar mission.
10’s MW for unmanned
the high energy mission
for high energy missions.
in Table 2 below (SCH90).
FOR HIGH ENERGY MISSIONS
Table 2. Propulsion system requirements
to 100’s MW for manned missions
from the lesser demanding missions
From the mission and vehicle requirements
-
provide power for variable propulsive thrust and specific impulse requirements,
-
provide a remote, reliable, and efficient space restart capability,
-
produce a very wide range of output power levels (throttable),
-
be designed for the presence of a “free” continuous vacuum,
-
provide sufficient power also for the generation of electricity,
-
meet long system life time requirements of years,
to the space mission architecture.
can only be met by an effective
- operate in a low acceleration environment
for HESM and specific energy
- minimize propulsion system mass,
for high energy missions (SCH90).
- be designed for long operational
times - thrusting and quiescent
- use only radiation for cooling,
ready access for maintenance.
for each are compared
(low thrust and zero gravity),
system requirements
Space propulsion
- The greater
energy options
on a program
than 7 orders
despite a lack of
fusion energy
The potential
The available
as discussed
of magnitude
is conducted
is the initial
improvement
one which
importance
and other
conversion
in specific
properties,
in fusion.
efficiency
reflecting
program,
for high
including
chemical
research
rationale
OPTIONS
ENERGY
interest
energy
energy
priority
safety,
Figure
SPACE
space
fusion
over
the
for
of
in
of
at
its
the
this
and
The
with
data
than
time.
upon
class
Solar
serve
make
bases
fusion
fusion
based
option
fission
source
source
source
cannot
energy
energy
herein.
energy
fission,
matter-
shown.
relative
serious
authors
a more
potential
desirable
antimatter
but have
propulsion
the other
for space
technology
considered
considered
concerning
as another
reservations
the mission
subsequently,
high specific
the demands
competitiveness
that will meet
Energy Options
as a high energy
ENERGY SOURCES: SPECIFIC ENERGY, J/KG
Fusion (D-3He) Fission
3.5 x 1014 8.2 x 1013
and their estimated
those mission
are subjective
A comparison
the chemical
requirements
undeveloped
due largely
the nuclear
- Specific
are shown
evaluations
for space.
- Except
1.3 x 10 7
the three
for space
presented
Chemical
in Figure
capability
to meet
sources
systems
systems
options.
energy
relative
energy
energy
energy
to the
Figure
earlier
merits
status
these
the
for
of
of
of
i/
3
?
?
?
?
v’
v’
v’
v’
v’
v’
v’
v’
v’
v’
v’
v’
v’
v’
v’
is’
<1
Reuse
Fusion
Figure
Fission Chemical
Operational safety
- Comparisons
Operational simplicity
Variable thrust: 1 to 104 N
Jet power: 50 MW to 10 GW
Low to no space maintainability:
Desired Parameters and Values
High Specific power: 1 to 10 kW/kg
Burn durations: 2 months to 50+ years
High payload mass fractions: 10% to 50%
Cost effectiveness for high energy missions
Variable, high specific impulse: 5x103 to 106 seconds
Mission duration: 6 months to 5 years for solar system missions
Preliminary analyses and/or educated guesses. All require thorough analysis, design, and testing to validate whether the parameters can be met.
in the figure is ranked highest on a scale of 1 to 3 for the use of fusion,
is a major motivation
Total energy content of plasma
of high speed components
fuel storage and magnetic
braking on Mars mission.
trips to Mars (~3 months
the use of fusion energy.
braking, not aerodynamic
such as SSME turbines.
uDon the attributes
Fuels do not chemically
react with each other.
- Activated materials
the use of
impact on the Earth.
resolve by standard
for HESM.
listed in Figure
- Non radioactive
safety practices
of environmental
from neutrons:
is very small.
by minimizing
° Decreases
- Cryogenic
the numbers
Attributes:
substantially
design and
-
Absence
-
Absence
of energy
Safety
fusion
- shielding
Propulsion
implications
one way).
concerning
- Safety
Issu(_$:
options.
launches
neutrons
SAFETY
cooling:
Safety
to LEO
based
resolve
Faster
Figure
fuels.
for
of
v’
It
for
that
and
time
fight
level
Note
have
safer
mass
mass
these
While
offers
there.
fusion
space
power
Faster
all of
Where
events
effects
(without
periods.
dosage)
systems
confined
reducing
escape),
radiation
(reduced
launches
than 37,
in space,
the high
significant
integrated
propulsive,
and solar
advantages
in a small
number of
reduce the
occurrence),
deterioration
is obviously
(probabilistic
physiological
requirements
the hazards
are required
the required
psychological
to the flight
the concerns
high specific
flights rather
to place the
of propulsion
issues may
from galactic
high energies
“workarounds,”
weightlessness
from extended
times minimize
not aerodynamic,
crew that occur
and consequently
very substantially.
from an extended
for a Manned Mars
to place the mass necessary
Mission into LEO using 5 Shuttle launch equivalent
those associated with high speed turbopumps.
to assure safety to ground handing personnel
with solid propellant motors, are eliminated
into contact with the first wall. Damage
fuels it can be reduced to the low
and effective means of confining
the neutron flux from the burning
which can occur when internal
to liquid and solid propellant
fusion fuels is not anticipated
if the plasma should come
is not going to “blow-up,”
to be entirely eliminated,
flight operational mode.
for braking maneuvers.
value of approximately
to the reactor magnet
That aids the design
for the next programs
system performance
hazard is termination
the thrust particles.
system divergences
structural materials
is the worse case.
is also eliminated.
and high kinetic
it where desired.
field lines direct
by the selection
fission products.
is the avoidance
as an inherently
are experienced.
some shielding.
high to activate
with the proper
a very reliable
as experienced
and to require
that eliminate
That provides
these matters
to the public
It is important
For example,
are therefore
of high level
the use of
The primary
the plasma,
for example.
and holding
and greater
the reaction
the working
conventional
substantially
at this time
components
importantly,
the fusion
in contrast
operational
considered
concerning
radioactive
radioactive
eliminated.
associated
sufficiently
propulsion
The total
opposition
elements.
therefore,
to errors
attendant
tolerance
Magnetic
however,
Magnetic
at 1015
Although
selection
hazards,
is small
and is,
systems
systems
typically
process
ions/cc.
transfer
content
provide
erosion
permits
as are
options
plasma
reactor
energy
energy
energy
Pu_)lic
nozzle
is still
“fluid,”
1-2%.
Wear
fields
more
safer
Most
flight
fuels
_lnd
with
The
and
i.e.,
but
of
of
of
of
of
of
of
The
other
Other
fluids.
stored
facility.
energy
FUSION
special
include
hazard.
suggest
hazards
hazards
selection
practices
and 3He
cryogenic
resolution
secondary
REACTIONS
cryogenics,
of neutrons
the authors
The proper
the neutron
the neutron
if necessary,
is the proper
are controlled
fusion energy
its advantages
and propulsion
with shielding,
flux, combined
fusion reaction
the subject of
Let us address
and the use of
accelerator-target
can be realized.
in the magnetic
The two primary
for working with
fuels which minimize
fields and high voltages.
hazards are the presence
and the means by which
Deuterium can be extracted
by standard, well developed
from sea water using solar energy
3He is to breed it on each using a
static loads, and high fields/voltages.
can be mined on the moon. An option for obtaining
i.e., those listed in Figure 9a and 9b (group A).
fuse is indeed quite large. However, during
fuel applications we shall be concerned
The status now is that we have currently
number of nature’s elements which will
with the equation, E = mc 2. The energy
come to a point where the fusion
primarily with just three reactions,
light weight nucleons join to form
this is usually a small contributor
only being down a factor of 3-5.
reacting mass and the residual
by the mass loss between
the right set of conditions,
is very close to breakeven,
long that a net positive
FUEL OF PREFERENCE
of mass to a specific
burned in secondary
for space use. The
In fusion reactions,
on space energy
energy production
the discussions
yield of energy
fusion fuel pair
The conversion
is the selection
The challenge
°K) sufficiently
rest mass of
in accordance
has been in
is determined
a satisfactory
the products
the reaction.
to as fusion
of containing
are referred
appears as
in achieving
the ash is
Of foremost
to the total
confinement
of charged
temperature
of a proper
depending,
importance
the fuels
of energy
the initial
controlled
nucleons;
designing
the high
reactions
(108-109
neutrons
although
products
selected
particles
reaction
quantity
capable
scheme
plasma
results.
energy
power.
and/or
kinetic
SPACE
fusion
fusion
fusion
stable
Some
“ash.”
under
other
upon
the
for
of
i
2.4
3.o
14.1
Proton
Tritium
Tritium
Neutron
Neutron
÷
I-
ENERGY
Deuterium
Hdlum 4
Helium 3,
FUSION REACTION
RELEASED, MeV
B. Other Desired (Aneutronic) Reactions .,.,..,_ ,,,m,)
A. The most important fusion reactions for space
Figure 9b. Fusion fuels for space applications.
Fusion Reactions for Space Applications
listed in group B as purely
fuels for space app;_ca_ons.
but these reactions
= p (14.68 MeV) + 4He (3.67 Mey)
= n (14.07 MeV) + 4He (3.52 MeV)
- O
= n (2,45 MeV) + 3He (0,82 MeV)
are energetically
in the reaction
are preferred;
very difficult
i.e., without
= 3 4He (8.7 MeV total)
applications
to achieve,
aneutronic,
D-D side readtlon)
products,
neutrons
Fusion
Those
Figure
aneutronlc:
HMlum 3
- D +3He
Deutm’ium
2, D + D
- D + T
nearly
9a.
(50%)
(50%)
- p+
11B
Proltl_n
14.6
illm
Hid
.7
m
i
ii
fuel
from
level
where
similar
greater
Council,
reached
required
(MIL87).
particles,
conditions
conducted
by Figure
is present
reactions).
for space
for space
net power
Board for
As shown
to produce
is required
conclusions
(and much
applications,
of advanced
fusion energy
An assessment
less demanding
The confinement
10 the preferred
i.e., a high energy
14.68 MeV protons
is deuterium-helium-3
than the D-T reaction
the reacting elements.
in the form of charged
to initiate the reaction
nearly all of the energy
the National Research
very low by comparison.
than the other aneutronic
by the Air Force Studies
The net power gain is, therefore,
Fusion Fuel of Choice for Space
to burn it are less than an order of magnitude
thrust end electrical power conversion systems. These are not thermal conversion systems.
Figure 10. Space fusion fuel preference.
The D-3He fuel cycle is particularly
= 90%) and the replacement
Note also that high specific
- 3He rare, requires lunar mining or Ixse¢ling (b_x,_
thrust by being propelled
- Fuel production does not require nor generate
over other high energy
- ChJmed aarltcles as fusion products (ash)
are charged particles.
thus, made possible
the D-3He reaction’s
energy into:
. _ctrlcal
can readily produce
- Permits the design o! highly efficient
due to high 15(i.e.,
more than 95% of
since the charged
from the plasma
is made possible
and is preferred
to permit direct conversion of
ratio of plasma
in the form of
to achieve reaction condilons
alpha particles
- Non radioactive isolopes
and protons,
fuels whose
- Minimal neutron flux
off particles
to magnetic
magnetically
a magnetic
Fortuitously,
the energy
by plasma
radioactive products
of burning
parameter
is present
controlled
of heavy
important
attractive
of which
particles,
- More difficult
pressure
pressure
currents.
products
particles
can be
Disadvantages:
charged
reaction
capable
namely,
sources
through
nozzle.
reactor
energy
power
bleed
by a
That
coils
the
av_k,
for _)
as
is,
Ihruet
of
or
on
and
their
other
There
proton
airless
initiate
design
directly
bodies.
thermal
helium-3
helium-3
imparted
systems.
available
Similarly,
Sufficient
penetrate
estimated
converted
respective
the usual
to contain
with those
parameters
and decay
alternatively
acceleration
is sufficient
With regard
to propulsion
a meaningful
the mutually
to be present
power without
onto lithium-6
can be mined
1-2% (CHA89).
to approximately
and/or electrical
tritium (MIL88).
to its availability,
‘,.109 kg (WIT86),
To fuse nucleons,
mass inefficiencies
it can be expected
via the production
test program without
and losses associated
By the proper use of
It can be bred using
lunar mining preceding
kinetic energy must be
to the ions to overcome
a fusion program (KUL87).
on the moon and has been
now on Earth for accomplishing
the neutron flux can be reduced
several conditions must be met.
area (a), cm, 2 and the relative ion velocity
by <o’v> which is the average product
rate coefficient with the energy
fuse is a statistical matter
for selected fuels (SAN88).
It is referred to as the
Fusion Reaction Rate
and with a sufficiently
the proper point of
the fusion reaction’s
the energy density.
a large quantity
rate coefficient.
Fusion rate of
high energy
The product
/Y
the reaction
(v), cm/sec.
penetration.
Figure 11.
is required
in nucleon
determines
of energy
expressed
reactions.
to result
nucleons
repulsive
Coulomb
(velocity)
Whether
rate of
colliding
reaction
reaction
reaction
reaction
and to
ION TEMPF.RATURE O,eVI
nuclear
section
Hence,
(Figure
or not
impact
nuclei.
forces
fusion
nuclei
cross
/
The
two
per
at
of
of
to
of
is
,lO, .f
iii
ii
I00
to
of
I000
o- E
Ti,
(n),
The
high
high
figure
by the
number
achieve
I | OT \
burning.
of merit
parameter
Ti, Figure
Conditions
confinement
confinement
ion density
temperature,
is measured
The plasma,
of a plasma
at a sufficiently
at a sufficiently
ions/cm 3, and
for an adequate
must be confined
time (_), seconds,
n_ and temperature
Required to Achieve
Fusion - Lawson Curve
n: plasma denslly, #/c¢ _: conTinement time, eeconda T: temperature {energy level), keV
n’c z 2 x 1015 cm -3 sac where
Ti = 10 keV for DT and for
and 100% efficient
by the background
as bremsstrahlung
from the plasma
from conduction,
and synchrotron
are immediately
to the plasma.
of n_: required
(nl: z 5x1014
33% energy
for example),
first estimate
The charged
is sufficiently
the charged
is the point
an excellent
to electricity
12 presents
the plasma
the plasma
assumptions
are slowed
confinement
temperature
at a given
parameters,
convection,
self-sustain
conversion
Breakeven
of energy
breakeven
reinjected,
as typical
and their
by fusion
converted
Neutrons,
and any
efficiency
products.
products,
products,
radiation.
condition
condition
30 keV,
although
radiation
provides
cm-3sec
Lawson
product)
burning.
to heat
reaction
balance
Lawson
Lawson
Lawson
transfer
it were
product
product
heating
heating
criteria.
defines
plasma
occurs,
density
without
D-3He,
reactor
output,
energy
energy
certain
criteria
serves
losses
Figure
Figure
where
curve.
fusion
fusion
fusion
When
When
would
which
made
these
input.
value
large
(cm’= =ec)
such
ions,
then
total
time
This
cold
The
and
and
and
i.e.,
fuel
fuel
fuel
can
lost
this
(n_
Ti=
the
the
the
the
the
Ti.
as
C o
i0 _t
iO Is
i013
i014
of
of
of
at
i0 _
a
0.1
if
n_
i
I0°
10”
10”’
JET
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of
TFTR_
for
the
the
the
can
The
over
burn
input
OOUB LET.II_/”
value
made
PROGRESS
years,
leader
Figure
further
in the
energy
without
plasma
heating
is said
proceed
auxiliary
progress
systems.
magnetic
and the
of which
the past
Progress
is rapidly
13, shows
converging
confinement
of 7 orders
experiments.
of magnitude
the tokamak,
from external
on breakeven
to be ignited,
an improvement
in the Eout/Ein,
IN MAGNETIC FUSION RESEARCH
MEANS OF ACCOMPLISHMENT
nt; and Ti, simultaneously.
both parameters,
and gravitational
key experiments
not at a level
- Progress
that satisfies
from fusion
experiments,
magnetically
experiments
been met
operational
individually
of several
production
by which
in energy
in Figure
is shown
(SAN88).
plasmas,
plasmas,
n_ and
although
confined
confined
T have
inertially
different
regimes
(Figure
Figure
occur:
status
fusion
There
made
three
ways
both
later
ALCATOR-C
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Approaches
Confinement
a simple magnetic
or are uncertain,
at demonstrating
system — and
is not a space
by this report,
coil windings.
on the figure)
a light weight
from magnet
a cold fusion
the extensive
coil windings.
high energy
by magnetic
the longest.
- Means
confinement,
approaches,
confinement
confinement
confinement
— an open
but without
— a closed
to achieve
accelerator.
at a small
is provided
are under
parameters
researched
suggested
discussed
has been
(-1 mm)
the focus
15 shows
for muon
fusionable
presented
pertaining
for short
principles
approach
a simple
magnetic
Magnetic
densities
to both,
catalysis
targeted
process
Lawson
system.
Plasma
periods
without
reactor
Figure
beams
except
inertial
Efforts
report,
Figure
option
fields
mirror
under
which
reach
pellet
study
force
torus
next,
time.
laser
fuels
uses
uses
high
very
The
The
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CURRENT
Configurations
Magnetic Confinement
Tandem Mirror O
_ _5 m
_
Spherical Torus O
Table 3. Fusion Options and Comparative Evaluations (CHA89).
Field Reversed O
that most closely meet
Charged Particle Extraction
Propellant Thermalization
CLOSED SYSTEM . SIMPLE 10RUS
0 o
0
- Basic magnetic
CONFIGURATION
Specific Impulse
(Power)/Weight
Power Density
requirements,
for magnetic
confinement
considering
approaches
techniques.
REVERSED
confinement
Parameter
_ - Poor
Average
capability
evaluate
(Power)
reactor
(FRC)
options
design
FIELD
space
space
Figure
Thrust
Thrust
When
Table
]
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Table
beneficial.
principles
space,
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reactor
current
(Figure
optimal
plasma
concept
concepts
magnetic
Configuration.
approach
3 shows
Reversed
applicable
considered
plan Is outlined.
16), hence
confinement
and shown to be
Configuration
the authors.
the proposed
A FRC developmental
the design and operating
known as the Field Reversed
Its applicability potentially
to the space program Js examined
Field Reversed Configuration
This paper discusses confinement magnetic
ion flux is illustrated
- FRC content.
17 by the arrows
Field Reversed
Configuration
characteristic
The FRC’s
in Figure
ion flux.
plasma
Figure
Figure
in the
(FRC)
torus.
Neutral
Neutral
beams
beams
f
of
of
of
of
the
the
the
the
are
18).
The
Yet,
field
field
field
lines
state
force
good
(refer
linear
inner
which
stems
thrust.
nature
in the
current
plasma
design.
to the
provide
Plasma
poloidal
density,
[3 good
external
features
direction
compact
scheme,
surfaces
potential
systems.
of direct
confining
magnetic
attractive
magnetic
produces
to Figure
operation,
production
A toroidal
topological
for steady
and linear
is provided
confinement
confinement
confinement
The closed
be initiated
and overall
high power
of methods.
which may
lines would
attractiveness
this machine
be conducive
by a number
and sustained
from its high
and a reversed
of both toroidal
Field Reversed
The FRC combines
by the two end magnets
in an FRC (HOF86).
(FRC) Formation
to the ignition
are produced
Configuration
for achieving
The plasma
the plasma.
- Plasma
compressing
the plasma
is to inject
temperature
a magnetic
the fusion
is to heat
to contain
advantage
generated
in Figure
increased
possibility
by large
formation
formation
magnetic
magnetic
the fuel
requiring
ramping
currents
device’s
a rapid
Another
a high
internal
resides
plasma
plasma
without
ignition
current
energy
neutral
quickly
shown
linking
Figure
beam.
FRC’s
innate
ability
steps
field.
/-FLUX.CONSERVING
coils
One
field
with
with
with
PREIONIZATIONIo)
The
The
that
and
_ ,_OPEN FIELD /
EQUILIBRIUM(4)
COMPRESS,ON
CONTRACTION
are
the
the
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an
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by
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r-
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at
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power
These
energy
reactor
reactor
by the
plasma
Topical
one of
towards
features
National
particles
resulting
balance.
products
(TUS88).
attractive
providing
observes
reactivity,
illustrated
in Table
statement
presented
2, where
parameters
Laboratory,
the FRC’s
efficiencies.
the Eighth
electrostatic
approximate
is indicated
in a paper
performance
as a viable
an attractive
little radiation
system such
are compared
power density
These charged
the surrounding
can be diverted
Fusion Meeting
allow substantial
the Los Alamos
direct converters,
in very high plant
“The FRC is ideal
The optimism for
the FRC scientists
the FRC edge layer
made by Dr. Tuszewski,
of a 1 GW FRC reactor
Its high plasma beta and
losses, and most of the fusion
for use of the D-3He fuel cycle.
as CTOR and for a conceptual
in the form of 14.7 MeV protons.
the 14 MeV neutron production with D-3He can be reduced by about a
the D-3He system is that gross FRC stability may be achieved
This may not be the case for the D-T pulsed system at s ~ 30,
one at Los Alamos and another at
help of high energy
the alpha particles.”
at s ~ 10 with the
with the University
for a pulsed D-T
crucial) advantage
FRC experiments
are in operation,
the D-T system.
of Washington.
Two terrestrial
100 compared
larger plasma
in Figure 19.
are presented
in conjunction
and possibly
fundamental
steady-state
elongations.
The FRC’s
advantages
Technology
in spite of
to that of
large-orbit
(possibly
protons,
Another
Spectra
system.
beams,
neutral
D-3He
One
of
+
II n
- High power denslty
Thermallzatlon of pro
thrust + electrical power
- Burns D-3He efficiently
FRC Advantages
, Reactor mass mlnlmizatlon
-
Allows direct conversion of energy
-
High Beta (ratio of plasma pressure to magnetic field pressure)
FRC Status: Space Requirements Compatibility
the FRC with space reactor design
for the space application
Figure 20. Compatibility
the space requirements
to have very desirable
to be a good match.
Inherent advantages
the FRC to meet
by Figure 3 is
The capability
— Figure 20.
requirements
Figure 19.
as defined
it appears
considered
properties
lew_ 1 N to 10K N ID
(SCH90).
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FUSION
ENGINE
DESIGN
reactor
reactor
require
Engine
nozzle.
moving
release
specific
support
by the
impulse
designs
directed
stability,
inherent
features
absence
a space
magnetic
topology.
subjected
controlled
is fueled
scrape-off
evaluation
propulsion
advantage
operational
to erosive
necessarily
by pellets
to achieve
conclusions
establishing
as plasma
its external
parameters,
due to the
requirements
is produced
investigation,
of magnetic
are injected
by virtue of
lack of any
to propulsion
of a portion
as subjective
developmental
and of parts
are essential,
be considered
are simultaneously
the long life time
The FRC is ideally
Table 4. FRC High Power Design Parameters.
the power magnitude
by the manned
be characterized
in the propellant
mirror magnets.
by the injection
by a magnetic
106 - 103 seconds
and propellant
and controlled
Ion Gyro Radius
thermalization
thermalization
of propellant
axis through
Plasma Volume
accomplished
and specific
of propellant
Plasma Radius
Stability Factor
the external
is produced
is important
is produced
by changes
by heating
its efficient
The thrust
is attained
the extent
parameters
by a field
as shown
flow rate.
of plasma
imbalance,
from the
to assure
Total power
A reactor
0 - 0.8 kg/s
controlled
programs
(CHA89).
a fusion
program.
0.4-50 kN
4 below
Elongation
required
Propellant
at one
impulse
by the
Plasma
release
by the
directly
engine
0.5 GW
nozzle
Addition
Thrust
Figure
Thrust
0.01 m
Specific
Impulse
varied
space
would
80 m3
thrust
Table
along
layer.
Factor
Thrust
1.5 m
end,
use.
The
and
into
into
are
the
the
the
the
for
by
of
of
,
I
_
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co_
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field
th_=t
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propellent
Fusion Engine Using a FRC Reactor
only at 106 seconds;
Fusion Propulsion
to Weight Ratio
by the injection
Performance
the highest,
is increased
performance
performance
comparable
as specific
operational
decreases.
conversion
by Figure
a thermal
a variable
a diluent;
propulsion
propulsion
is shown
mag_e’Jc _0zZ;e
(CHA89).
(SAN89).
attained
concept
system.
impulse
impulse
to any
specific
thermal
modes:
.E ._,
plasma
22 for
engine
engine
Fusion
Fusion
Fusion
design
Thrust
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Figure
Figure
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physically
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are shown
the plasma
TECHNICAL
CONCERNS
and plasma
this concept
the magnetic
The concerns
from the wall.
FRC Concerns
- Plasma formation
that need to be addressed
-
Plasma stability at net power
-
Lack of program priority and urgency to develop
need to be addressed
Insufficient data base
- Fuel burn efficiency
° Demonstration
of thermalization
FRC parameters
are as follows
of propellant
and testing.
limitations
requiring
SCHg0):
(CHA89,
further
(Table
FRC’s
The
that
Figure
m,
—
i
of
the
fact
that
ash,
Much
result
placed
relatively
Consider
concerns
from the
the status
FRC resides
Thermalization
considerations.
on the FRC.
is to provide a
Limited volume:
the reactor size.
in the least developed
Table 5. FRC limitations.
Reactor plasma efficiency:
efficiency of the propellants,
maintenance of ptasma stabitity.
- Fuel efficiency: One important subject
for investigation is the means to improve
upon the fuel burn-up factor which is ~3%.
One approach taken to produce greater power
and reaction products must be studied in detail.
Its size is considered to be volume limited based upon stability
Ions injected to orbit the plasma are anticipated to assist in the
greater elongation factor. This consideration may be the ultimate limitation on
Reactor Knowledge
FRC development
FRC experiments
n’_T performance
the advancement
- Comparison
its demonstrated
is not hearty
_arge_y due
Les’s Developed
Elmo Bumpy uen_e
experiments,
in essence,
summarizes
experiment
to ignition
knowledge
knowledge
as shown
24 which
as great,
in Figure
emphasis
(SCH90).
Slellarator Reversed
to date.
consider
Tandem Mirror
Field Reversed
, Well’Developed
relative
(Figure
reactor
to the
Classification
Conflaur_tion
Figure
shows
Confinement
Field Pinch
fusion
When
chart,
of Reactor
base.
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Base
Knowledge
Moderately
other
Developed
been
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the system capabilities
SYSTEM ISSUES
Simultaneously
is the ability
development
- Status
experiments
to achieve
the mass
to meeting
to provide
technology
constraints
necessary
conditions
to Figure
controlled
VEHICLE
capability
(SAN88).
that will
systems.
specific
produce
SPACE
burning
relative
power
satisfy
fusion
fusion
thrust
these
Refer
from
with
the
the
the
for
for
of
to
of
I
- Neutron flux
System Issues
-
Thermal control
-
Reactor space starts
status for program costing
of energy will be stored
fusion system issues
two key technology
R&D consideration
and to minimize
flux abatement
the spacecraft
in Figure 27.
to be further
and neutron
need to be
is the most
The means
an in-space
is important
the system
fundamental
low mass,
researched.
applications
engineering
to simplify
to provide
technology
technology
constraints
constitutes
the other
expended.
production
addressed
supporting
for space
key topic
Significant
of highly
is shown
capability
research.
(SCH90).
no such
to make
effective,
systems
is being
practical.
selection
electrical
research
in order
in need
Thermal
COSTS
reactor.
specific
as the
aboard
energy
control
D-3He
restart
restart
restart
Figure
issues
needs
power
power
space
fusion
space
space
space
fusion
mass.
within
levels
since
effort
large
flight
task
The
The
The
The
that
fuel
Yet
are
the
to
of
of
i
Costs
= 0 $.
program.
- DOE total
timely investigative
- FRC funding ~ $SM/annum.
fusion funding for application
to the production of utility company electrical power ~ $325M/annum.
- Program cost status/projections
a series of large step, high
risk FRC experiments
for a FRC program
is shown in Figure
orogram approach
for an engineering
being maintained
The anticipated
to be to design
of understanding
The magnitude
recommendation.
cost estimating
to demonstrate
to be capable
is appropriate
be performed.
for achieving
and warrants
by a science
is considered
are no more
developmental
demonstrating
be accepted
to implement
beam flux.
in an FRC.
Experimental
is required.
SCHEDULE
emphasized
successfully
conversion
is believed
This must
of burning
the depth
for space
by-passing
to ignition
inventions.
verification
The best
and has,
judgments
to space
at quickly
It should
approach,
approach.
expedited
estimated
schedule
estimates
the cost
programs
research.
educated
of being
a space
program,
empirical
definitive
program
injection
capable
in fact,
by the
justifies
stability
desired
energy
plasma
plasma
a path
D-3He.
reactor
heated
neutral
fusion
stable
Figure
needs
aimed
fusion
fusion
beam
taken
using
More
been
level
prior
than
high
gain
This
49o
The
and
that
risk
risk
but
the
the
the
be
an
as
of
of
to
—
|
|
Schedule
NASA commitment
for rapid development.
Could be 20 to 30 years
- Ultimate FRC availability
and nature’s cooperativeness
*Small size + simplicity: provides unique opportunity
- No spacefusion energy program: o_time
for space use: depends on
- At the proposedlevel: demonstrationof viability
regarding plasmastability in 5 to 10 years,maybeless
- At the current level of DOEfunding: maybe50-100years
i.e., NASA has a vested interest.
to the developmental
upon the last point,
Program success
Program schedule
status/projections
be considered,
KEY POINTS
responsibilities
that must
for space,
significant
for space
research.
reference
depends
several
Figure
Figure
fusion
points
largely
fusion
there
With
are
of
5.
transfer
for 3 months
Points
Io Id_rs w/o leng_y
Significant
to Consider
significant contributions were made.
_rmn _s =O”- G space qualified *.caret! -enhanced
-
Nationalfusion program addresses the use of fusion energyfor
-
Fusion’s availabilityfor the space program’s immediateneedsIs
-
The MissionArchitecture for planning NASA’s future manned and
-
A space fusion research program existed at NASA Lewis,and in it
being determined by the Earth’s energy supply and demandsituation.
if developedsufficiently rapid, it could expedite manned Mars explorationand eliminate some major steps in the currentplanning:
current science missions would incorporate the use of fusionenergy now, If developed.
commercialelectrical power generation on Earth. That application is a function of international energy costs and fusion energy’s competitivecosts.
and experimentation
- Considerations
to the commercial
new opportunities
“U. S. National
— as discussed
p 1 (ANON89))
its environment,
and to expand
further United
and, wherever
(“US National
and economic
in international
in undertaking
a permanently
the technical
accomplishing
the mission
an excellent
in advanced
technological
requirements
and activity
preeminence
to establish
applications,
environment
to continue
to preserve
the United
the United
appropriate,
the United
to improve
applications
to develop
architecture
the Earth,
cooperative
technology,
to engage
appropriate
to expand
capabilities
exploration
technology
technology
technology
knowledge
to further
population
from the
availability
November
in critical
orbit will
in space;
on Earth
objectives
in space
2, 1989,
to obtain
is based
presence
presence
scientific,
universe;
matching
and the
program.
available
systems;
research
research
In order
for use
activities
activities
activities
system.”
a space
pp 2-3)
science,
manned
manned
manned
and to
content:
element
benefits
conduct
conduct
aspects
system,
be (1)
through
through
fusion’s
general
report’s
Policy,”
Policy.”
beyond
beyond
human
related
energy
goals.”
I int¢
sector;
space-
Fusion
in this
overall
overall
quality
Space
Space
States
States
States
States
Figure
efforts
create
space
space
space
space
space
space
space
fusion
human reseerch
policy
make
much
result
serve
flight;
Earth
entail
goals
Earth
upon
(ibid.
solar
solar
such
“The
“The
shall
That
orbit
are”
with
and
and
that
and
that
and
and
civil
civil
can
key
Esrthlunar
the
the
the
the
the
the
the
the
life
(5)
(2)
(4)
(2)
(3)
for
for
as
of
of
of
of
…
of
of
of
of
to
of
lllfety
in
in
a
at
rather
energy
fulfilled.
release
into its
specific
program’s
Otherwise
capability,
propulsion
the space
application
reasonable
refinements
than minor
performance
technological
and variable
provided that
goals become
timely missions
the technology
intense systems.
for high leverage
space operational
high performance
space transportation
in the lesser energy
for meeting the space
source due to its high
needs. We recommend
That will be required for
for providing that energy
support of those missions.
leveraging of research funds
greater and greater distances
can be appropriately developed
Fusion energy has the potential
logistical support beyond the Earth-moon
regime to achieve the economy necessary for
position of advancing with the needs of exploration
The space program will be compelled to incorporate
as the lesser energy demanding missions and space
infrastructure more efficient systems that offer quantum leaps in
high energy sources to move large payload masses and to conduct
payoffs to assure that a US space vision for the future will materialize.
It available as an element have INPen uMd end Incorporated Into a more ambitious space science end exploration
space mission requirements end becoming perhaps the key element United SUites _ue t Mission Architecture for Soacip Policy.
Figure 30a and b presents the conclusions of the authors:
useful on Earth, but hot for q:_ee applications. aommltrnen|
3.A successful DOE fusion research program will produce fusion reactors
Mars - using fusion energy conversion - would be substantially _umed.
and science research programs.
Figure 30a. Conclusions.
S.The space progrsm’m launch operetfonml
the development coew meny umss over.
In the space tr0nsportetion infristructure,
performarme advantages wlllRiI.Y for
G_Ltt for manned logistic flights to
to space tuslon oc_rgy conversion.
Inherent features for accomplishing
will not be in a
4.Fusion would greatly onherme
currently belna nlanned end,
1.Fusion energy offers very
CONCLUSIONS
infrastructure
conversion
for mennecl missions.
Conclusions
6.Fuelon enargy’e
energy
There Is I
2.Fulton’s
program.
IppllcItion
sttractiyt
fulflllmeflt
nroarami
in ipece
lack of
In the
of the
cou_
Is for
J_
_
m
of
soece
beyond
exolorstlon
O.lt will be s
Improve our
s substantial
$.Development
fission Is thermal.
Conclusions
- The mission ensblina
missions, we must commence
technically very chsllenolpg job.
capability will enhance manned space flight Jl_.
-
Soeca science will be enhanced by enabling missions that
-
Power will be available to accomplish future high energy missions.
and fission for space p.ower end propulsi?n of fusion case not depeno The development
It may not be quick to develop. and for eftergy
fusion unrereted technoloales. the development basil of s chsrged particle system;
-,re upon of fission first. Fusion energy conversion operates on the
To provide the energy for future mlsJlone now under consideration future sntlclpstad s space fu_lon program now.
understanding of the solar system and nearest stars and star systems. Fusion would enable current planning and s new soaca science program beyond our current visions.
As the first step, design, build, and test a FRC capable of burning deuterium-helium-3 power.
The United States should take a world leadership role in the development of fusion energy for space appflcations. We propose the following specific measures:
NASA initiate a space fusion research program to develop high specific power propulsion the order of 1 to 10 kW/kg,
- Recommendations.
RECOMMENDATIONS
Recommendations
Recommendations
which-produces
systems - on
are provided
Conclusions.
in Figure
Figure
Figure
30b.
net
31’
.
,
in
of
for
flux
and
is a
That
level
level
offers
under
fusion
toroid,
thrust.
design
(FRC).
energy
energy
reduce
a very
reactor
reactor
directly
without
design;
Burning
concept
charged
injection
particles
naturally
topology
regimes,
although
systems.
preferred
approach
to thrust
and that
inherently
net power
conversion
to ignition.
of plasma
its external
lends itself
substantially
is proposed
the neutron
the efficient
The primary
Configuration
The specific
a high beta
it is classified
as a compact
the reaction’s
concern with
large part of
plasma energy
the inefficiencies
into the plasma
to the generation
and will produce
to aid in plasma
moon in a sufficient
is the Field Reversed
stability while operating
associated with thermal
deuterium and 3He will
by full scale experiments.
CONCLUDING REMARKS
subject which will have to be addressed
If the United States does not act, some other country
One 3He fuel supply option to lunar mining is the
fusion energy now. With only the present
the “U. S. National Space Policy.”
of charter and program focus
to be high risk, but extremely
on Earth now to commence
to be high risk research,
the void by undertaking
use could be made of
space missions which
as advanced missions
by NASA. Otherwise
space program can
has been determined
that can be realized
reactor experimental
as a profit making
the United States’
in the foreseeable
in space become
risk is considered
program — one
to be mandatory
— will not occur
the development
the development
to the enormous
3He is available
flight programs.
unless a major
such desirable
to be available
a FRC D-3He
proton-lithium-6
that must be
be anticipated
Space fusion
the future of
in comparison
test program.
is considered
is considered
is mandated.
— a different
is considered
be expected
from energy
insignificant
In summary,
requirements
development
to produce
to stagnate
constrained
too distant
undertaken
the space
to support
least until
in the not
high gain,
companies
conversion
application
performing
redirection
for space
implement
the lunar
properties
program’s
available,
available.
capability
missions.
becomes
Helium-3
a space
excellent
electrical
electrical
research
research
intended
and for
systems
venture,
reaction
quantity
benefits
Enough
stability
Neutral
on the
energy
energy
energy
energy
energy
energy
enable
Fusion
space.
having
raising
supply
future.
power
fusion
fusion
space
fusion
future
future
to fill
beam
utility
that
that
fuel
can
the
but
for
for
for
for
at
of
of
If
c
J
E
D
AU
Isp
GW
11B
3He
energy
helium-3,
SYMBOLS
boron-1 1,
velocity of
light = 3xl08m/s
isotope of boron
isotope of helium
isotope of hydrogen
gigawatts (109 watts)
specific impulse, seconds
astronomical unit = 1.5x101 lm
initial vehicle mass, MT (= propellants + inert vehicle + payload)
propellant mass,. MT (includes fuels and diluent)
ion density, number of ions per cubic centimeter
gyrating around field lines in a magnetic field)
cm-3s (fusion plasma = plasma losses)
radius of a charged particle’s orbit
Lawson parameter,
kiloelectron volts
gyroradius, cm,
thrust, newtons
million electron
jet power, kW
(characteristic
metric tons
P ej s
megawatts
kilograms
seconds
neutron
energy,
meters
proton
joules
mass
volts
flight
MeV
time
MW
keY
MT
Mo
Mp
n¢
kg
m
m
N
n
n
s
T
T
(Zp
z_v
(zpl
km/s
(zpl o
Greek
velocity
change,
propellant
propellant
propellant
incremental
system specific
field pressure, %
tem perature.oK
power where Otp=10kW/kg
system specific power, kW/kg
tritium, isotope of hydrogen
ratio of plasma pressure to magnetic
system specific power where O_p=lkW/kg
plasma’s ion temperature, OKor keV
payload mass fraction, % (payload mass/initial
Nuclear Engine for Rocket Vehicle Application
Field Reversed Configuration,
High Energy Space Mission
Large Torus, magnetic
Fusion Test Reactor,
Low, Earth Orbit
Torus, magnetic
Joint European
fusion reaction
vehicle mass)
cross section,
time, seconds
confinement
confinement
confinement
experiment
experiment
experiment
parameter,
Princeton
Tokamak
magnetic
reactivity
ACRONYMS
NERVA
thermal
nuclear
(fission
rocket)
HESM
cm3/s
TFTR
cm 2
FRC
LEO
PLT
JET
<OV>
‘t
v
to
J.,
ES
D. C.
FRI89
FRI88
Norman
Subject:
CHA 89
ANOM89
2, 1989).
Analysis.”
of Fusion
Chapman,
Propulsion
Propulsion
13, 1988,
J., Letter,
(November
Symposium
Friedlander,
Friedlander,
“Completion
REFERENC
and Schulze,
A., McAdams,
dated October
15, p 1154 (1989).
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Fusion Technology,
Schulze, NASA Headquarters,
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Advanced Missions Using Fusion Propulsion,”
R., Miley, G., Heindler, M., and Kernbichler, W., “Fusion Space
“United States National Space Policy,” White House, Washington,
Schulze, N. R., “Space Fusion Energy
and Mission Design, NASA Goddard
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in Physics Research, A271, 197-202
for D-3He Fusion Power,” Nuclear
for a High Energy Class of Space
Review Draft, NASA Headquarters
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A. L., Milroy, R. D., Slough,
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UWFDM-764,
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Miley, G.H.,
D. C (1987).
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G.L., et al,
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Laboratory,
AAS/GSFC
Miley, G.,
Propulsion,
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“Formation
“Advanced
Missions,”
Santarius,
Santarius,
Advanced
“Magnetic
University
University
Concept,”
Kulcinski,
Hoffman,
Alternate
(October
Scalable
88-2821
National
IECEC,
HOF86
SCH90
“Status
SAN88
SAN89
(1988).
(1988).
TUS88
as an
KUL87
Center
Fusion
L. C.,
“Lunar
1987).
Space
MIL87
MIL88
Using
Low-
3He,
24th
J.F.,
UR-
and
J.F.
M.,
N.,
of
of
WIT86
Fusion
Fusion
Source
Power,”
Wittenberg,
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Technology,
of 3He for
J.; Kulcinski,
G. L., “Lunar
L. J.; Santarius,
v 10, p 167 (1986).
1.4.4
PRESENTATION
PRECEDING PAGE BLANK NOT FILMED
PROPULSION
ADVANCED
CONCEPTS