The Future of Space Depends on Dependable Propulsion Hardware for NonExpendable Systems

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The Future ofSpace Depends on Dependable
PropulsionHardware for Non-Expendable Systems
Prof. Claudio Bruno University of Rome Prof.
Paul Czysz St. Louis University
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Ad AstriumPossible?
What opportunities have we rejected? How far can
we travel with our hardware capabilities? What
do we need in terms of hardware performance to
travel farther within human organizational
interest?
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Prof. Bruno
Outer Planets Kuiper Belt Heliosphere
Prof. Czysz
Earth-Moon Inner Planets
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Why Is Our Progress Stagnant ?
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Space and Atmospheric Vehicle Development
Converge, So the Technology of High Performance
Launchers Applies to Other Airbreathing Aircraft,
Aeronautics and Astronautics 1971
Buck, Neumann Draper were Correct in 1965
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What If These 1960s Opportunities Were Not
Missed ?
Star Clipper
FDL-7MC
M12 Cruise
176H
SERJ
Combined Cycle
LACE
8 flts/yr For 10 yr
42 flts between Overhaul PW XLR-129
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VDK-CzyszSizing SystemIdentifies theSolution
Space(DesignConvergence)for theIdentifiedRequ
irements
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Necessary Volume and Size for Blended Body
Convergence
Blended Body
Impractical Solution area
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The Solution Space for Four Configuration
Concepts Identifies Configuration Limitations
ft2
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Solution Space for a SSTO Mach 12
Ejector-Ram-Scramjet Cycle
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SSTO Solution Space for Rocketand Combine Cycle
Engines
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A Two Stage To Orbit System Has More Versatility
Dave Froning McDonnell Douglas Astronautics,
Hunting Beach Circa 1983
Payload Configuration or Volume Does
Determine Configuration or Size
Twice the Payload of an All Rocket TSTO
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Mig/Lozinski 50-50
Aerospatiale
Since The 1960 s There Were And
Are Many Good Designs
Daussalt
Sänger
Canadian Arrow
MAKS
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SSTOLacks theVersatility Flexibility,of a
TSTOand isTwice theMass
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Staging Above Mach 10 Minimizes TSTO System
Weight
TSTO system
Dwight Taylor McDonnell Douglas Circa 1983
Toss-Back is all metal toss-back booster staging
at Mach 7 is low cost, fully recoverable
and sustained use at acceptable mass
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We Need a Good Recoverable Rocket
Cargo
ISS Crew
From McDonnell Douglas Astronautics, Huntington
Beach, circa 1983
It can be a rocket and does not have to be an
ejector rocket/scramjet
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Unless the WR is Less Than 5.5 HTO is
aSignificantPenalty
HTO is not a Management Option !
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Takeoff Mode is Not Arbitrary
MR lt 5
MR gt 5
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AirbreathingOption PaysAt SpeedsLess
Than14,500 ft/sec
Confirmed by A Blue Ribbon Panel Headed by Dr. B.
Göthert in Circa 1964 After Reviewing Available
Data
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LACE Offers AnExisting RocketBenefit Almost
Equal to a Combined Cycle
OWE Solution Spaces Overlap. Marginal Difference
in OEW
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Popular Choice not the Better Choice
Thrust _at_ Mach 6.7 compared 1
0.25 to thrust _at_ takeoff
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10 year Operational Life, 30,000 lb payload, Up
to 10 Flights/year per Aircraft for
FourPropulsion Systems
Expendable
Sustained Use
By H. D. Froning And Skye Lawrence Circa 1983
Sustained Use
LLC Constant
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Cost Data is Consistent, Fly More OftenWith
Sustained Use Aircraft
By H. D. Froning And Skye Lawrence Circa 1983
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Its the FLIGHT RATE, not technology
Shuttle OKeefe
5 B747s Operated At Same Schedule And payload
As The Space Shuttle
Charles Lindley, Jay Penn
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Whats Wrong with This Picture ???
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Can This Be Our Future Infrastructure ?
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We Need a Nuclear Electric Shuttle
V. Gubonov NPO Energia Bonn 1972
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Two Possible Lunar Shuttles
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The Moon Can Be A Development Site for Both Moon
Mars Hardware
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Moon or Mars Conditions are similar
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Moon-Mars Human InfrastructureNeeds to be Proven
by Application
We need to lift Habitats, Food, Water, Green
Houses and Soil Handling Equipment In Addition
to People
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Cape Verde on Victoria CraterNot Similarthe
Moon
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Chemical Propulsion is a Poor Option to Mars
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We Seem to be Trapped by Chemical Propulsion
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Professor Claudio Bruno Will Now Take Beyond
Mars Toward the Heliopause
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NP - Times and distances of present/future
interplanetary missions
Manned constrained by physical (and
psychological) support
air, victuals
cosmic solar radiation, flares
bone/muscle mass loss
enzymatic changes, ?
Unmanned public support, apathy _at_ gt 1-2 years
funding difficult
To reduce constraints, risks, and ensure public
(financial) support
faster missions with less mass (cost mass!)
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MASS CONSUMPTION IS ENORMOUS WITH CHEMICAL
PROPULSION
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• NP - What it really means to
  increase Isp
• If J energy/unit mass,
• 1-D, ideal, propellants acceleration
• J (1/2) Ve2 Ve
  exhaust velocity Isp m/s
• thus
• Isp Ve (2J)1/2
• ? to raise Isp, J must be increased much more

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• NP - Mission Time and
  Power
• Conclusion faster missions, lower mass
  consumption feasible with / if
• non-zero acceleration ? not boost-coast
• higher Isp
• ? thrust power Isp3
• ? faster missions high Isp large power
• Low Isp of propellants (e.g., RP-1 and LOX) due
  to low J
• J of RP-1/LOX 12.7 MJ/kg
• ? need to find higher energy density materials

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• NP - Energy Density in
  Chemical Propulsion
• Any future increase in chemical
  J?
• Metallic H, theoretical Isp 1000-1700 s
  
• existence, stability, control of energy
  release ? unsolved issues
• J increases by O(10) at most,
  but Isp
• ? Must increase J by orders of magnitude ?
  Nuclear energy

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NP Nuclear Energy

• mass energy

m a mc2

• a depends on fundamental forces

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Potential Energy
NP
Compare alphas and energies

• a and energy density J ( J E/m ac2 )

• No known a between 3.75 x 10-3 and 1
• Even a 1 produces not directly useable
  energy (e.g., g ?rays)

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NP Isp
Propulsion
Isp/c as function of a the limit Isp speed of
light !
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NP
Thrust Power P
Lets look at the power needed by F

• P F Isp F V
• P scales with V3 high thrust
• (fast) missions need much
• larger P, affordable ONLY with
• nuclear power

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NP Propulsion Strategies
Schematics of NTR Nuclear Thermal Rocket
Figure 7-6 Conceptual scheme of a Nuclear
Thermal Rocket (Bond, 2002)
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NP Propulsion Strategies
Schematics of NER Nuclear Electric Rocket
Figure 7-7 Conceptual scheme of a
Nuclear-Electric Rocket. Note the mandatory
radiator (Bond, 2002)
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Propulsion NP
NTR US Developments (1954-1972)nothing like
old wine
M.Turner, Rocket and Spacecraft Propulsion,
2005
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Propulsion NP
NTR US Developments (1954-1972)
The Phoebus IIA solid-core nuclear reactor on its
Los Alamos test stand (Dewar, 2004 ). Nominal
power 5 GW, ground tested at 4.2.
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Nuclear Propulsion Strategies
NEP
Two main NEP classes charged species accelerated
by

• Coulomb Force (only electric field imposed)

• Lorentz forces (electric and magnetic field)

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COMPARE PROPULSION EFFICIENCY

• Must set ground rules (otherwise, apples
  pears)
• Here based on Itot,s (Isp toperation)/(MP
  m) Isp3 ?tot/PR
• Itot,s is a distance traveled/unit
  fuel mass, as in cars
• Normalize Itot,s using Itot,s of LOX/LH2 ? a
  performance Index, I

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Example Manned Mars Mission Compare NEP, NTP
and Chemical Propulsion
CHEMICAL PROPULSION (CP)
Hohmann transfer
NUCLEAR THERMAL PROPULSION1
Elliptic transfer
NTP trip is reduced only by 5.66
NUCLEAR ELECTRIC PROPULSION
DEPENDS ON REACTOR POWER ..
1 IAF 7-C3.5. Nuclear propulsion for human
exploration the Mars and Moon case, Lorenzoni
et al, 2009
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NEP Enables Faster Mars Missions
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NEP Mission Time vs Power

• With respect to CP, changing reactor power
  mission time decreases by
• 28 (100 MWe)
• 36.7 (150 MWe)
• 46.5 (200 MWe)
• 60.4 (300 MWe)

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NEP vs CP Larger DV (1/2)
17.01 km/s 8.9 km/s
WITH CP
47.7 lower
WITH NTP 1
1 IAF 7-C3.5. Nuclear propulsion for human
exploration the Mars and Moon case, Lorenzoni et
al, 2009.
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NEP Enables Large DV
NEP
?V (km/s)
POWER (Mwe)
Initial mass 120 to160 ton
Compared with CP total ?V is 406 to 574 higher
? MASS CONSUMPTION?
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Propellant and Mass Consumption with CP and NTP
Depends on the initial mass of the spacecraft,
but at the end of the mission the final mass is
only 1-5 of the initial mass Initial mass
109.8 ton Propellant Mass Ratio gt 47
CHEMICAL PROPULSION
NUCLEAR THERMAL PROPULSION1
1 IAF 7-C3.5. Nuclear propulsion for human
exploration the Mars and Moon case, Lorenzoni et
al, 2009.
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NEP Lowers Mass Consumption
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NEP Mass Consumption vs. Power
NEP

• Compared to CP, mass and propellant consumption
  is only a small of initial mass
• 30.61
• 33.85
• 33.93
• 33.06

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NEP Enables Extra-Planetary Missions

• Formulation based on Stuhlinger, 1964

• Assume no flybys, Newtons law Tsiolkowskis
  equation

payload
total mass of spacecraft
propulsion power system
propellant
residual spacecraft mass at time t
velocity of spacecraft at time t
exhaust velocity, assumed Isp (ideal expansion)
a W/Mw, specific power of the total
propulsion powerplant kW/kg
St distance traveled at time t
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NEP Enables Missions to 73 AU
Power as function of Isp 20-year mission and
initial mass M0 as parameter
Power as function of Isp 8-year mission and
initial mass M0 as parameter
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NEP Mission time vs. alpha 100 540 AU
100 AU
100 AU
540 AU
540 AU
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NP Some Conclusions

• The combination of Isp and power of the Gridded
  Ion System for a M3 result in predictions for
  both mass and mission times that are
  significantly better than with other CP and NTR
  propulsion systems.

• A NEP-powered M3 appears not only feasible, but
  also more convenient than CP- and likely also
  NTR-powered missions in terns of cost, besides
  being the only way to drastically reduce HUMEX
  travel time and thus GCR dose for the crew.

• To enable a future NEP M3, investing in this
  propulsion technology is necessary. That is an
  unlikely prospective in the current financial
  climate, but would spare much time and effort to
  our future generations.
• NTR systems may be the only propulsion enabling
  quick reaction missions, e.g., to counter
  unexpected asteroid threats

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When We do go to Airbreathing First StagesThe
Launch Propellant Reduces to 40 of Rocket
15.0
10.0
5.0
TSTO Launcher Cargo Canister
0.0