Transcript Rocket Science - topsofscv.org

Rocket Science
Early Developments & Future Systems
by
Joseph A. Castellano, Ph.D.
RESEED Silicon Valley
Outline
 Rocket
Types
 The Minuteman ICBM Program
 Rocket Fuel Research at Thiokol Chemical
Company in the 1960s
 Future Rocket Propulsion Systems
Types of Rocket Engines
1. Liquid-Fueled Engines that use “Cryogenic”
liquid oxidizers such as Liquid Oxygen (LOX).
They may also use a Cryogenic fuel such as
liquid hydrogen (LH2).
2. “Reaction Motors” that use oxidizers and fuels that
are liquid above 0o C.
3. Solid-Fueled Engines that use solid oxidizers and
fuels mixed together.
Features of Liquid-Fueled Rockets
Uses liquid oxygen as the oxidizer – requires
low temperature storage and extensive preparation
before launch
Fuel can be liquid hydrogen, which requires low
temperature storage, or kerosene which does not
Liquids are fed into combustion chamber and ignited with
electrical spark
Engine can be turned OFF by shutting down the
supply of liquids
Liquid-Fueled Rocket Engine
Fuel
Oxidizer
Pumps
Combustion
Chamber
Throat Nozzle
Combustion
Products
Features of Liquid-Fueled
“Reaction Motor” Type Rockets
Uses liquid oxidizer that does not require
low temperature storage – examples: Nitric Acid or
N2O4 (nitrogen tetroxide)
Fuel can be dimethyl hydrazine or aniline, which do not
require low temperature storage.
Liquids are fed into combustion chamber where they react
instantly to produce combustion.
Engine can be turned OFF by shutting down the
supply of liquids
Rocket can be stored indefinitely and is ready to go at a
moment’s notice
Liquid-fueled Rockets
Left: “Bullpup” engines on the assembly line at
Thiokol. These engines used nitric acid for the
oxidizer and aniline for the fuel.
Right: Air-to-ground missiles used in the Vietnam
War were powered by Bullpup engines.
Liquid-fueled Rocket
Russian rocket on display at a parade in Moscow’s
Red Square in November 1957.
Liquid-fueled Rockets
The USA’s Saturn V rocket on display at the Kennedy
Space Center in Florida.
Liquid-fueled Rocket Belt
This reaction motor uses a catalyst to decompose 90%
hydrogen peroxide into a hot gas mixture (O2 + H2O)
at high pressure to produce the thrust.
Features of Solid-Fueled Rockets
Fuel and oxidizer are solids mixed together with a
polymer “binder,” cast into the shape of the rocket’s body
and enclosed in its casing
Electrically ignited near the nose of the rocket
Fuel burns from top to bottom, and from the center outwards
until all the fuel is consumed
Once ignition begins, engine cannot be turned OFF
Rocket can be stored indefinitely and is ready to go at a
moment’s notice
Solid-Fueled Rocket Engine
Igniter
Flame Front
Solid Fuel/Oxidizer Burned
Mixture
Propellant
Throat Nozzle
Combustion
Chamber
Solid & Liquid Rocket
Engines Combined
Solid Rocket Boosters
Liquid Hydrogen
Tank
Liquid Rocket
Engine
Space Shuttle Launch
Solid-fueled Rockets
Mass: 36,030 kg
Length: 18 m
Width: 1.7 m
Speed: 24,000 km/hr
Altitude: 1,120 km
Range: 9,600 km
Minuteman III
Intercontinental Ballistic Missile (ICBM)
Minuteman III Construction
Nose Cone
Reentry Vehicle w/ Payload
Guidance System
Post-Boost Vehicle Engine
Aerojet/Thiokol Stage 3 Engine
33,800 lbs. thrust
Body Section 3
Aerojet Stage 2 Engine
60,625 lbs. thrust
Body Section 2
Cable Support
Thiokol Stage 1 Engine
202,600 lbs. thrust
Body Section 1
Minuteman III
Missile Components
Stage 1 Nozzle Assembly
Stage 1 Solid
Propellant Core
Minuteman III
Stage 2 Engine
Minuteman III Missile in
Underground Launch Silo
Minuteman III Missile
Launched from Silo
Minuteman III Launch Path
1 - Silo launch
2 - First stage separates (60 sec.)
3 - Second stage ignites (120 sec.)
4 - Post-boost vehicle separates (180 sec.)
5 – PBV re-enters atmosphere
6 – Multiple warheads released
7 – Warheads armed
8 – Warheads strike targets
Rocket Fuel Research during the
“Cold War”
Soviet Union:
Research mostly in liquid fuels
and oxidizers, but secret research in solid fuels
for military ICBMs.
U.S.A.:
Intense secret research to find better solid oxidizers
and fuels for military ICBMs.
Each side spied on the other to find
the nature of the other’s secret research.
Photo of Laboratory and Manufacturing Plant in 1969
U.S. Secret Rocket Fuel Research at
Thiokol Chemical Company in the 1960s
Experimented with exotic gases such as:
HNF2
Difluoramine
FN=C-NF2
NF2
Perfluoroguanidine
(PFG)
N2F4
Tetrafluorohydrazine
U.S. Secret Rocket Fuel Research at
Thiokol Chemical Company
Chemical reactions of N2F4 with hydrocarbons:
CH3-CH=CH-CH3 +
2-Butene
N2F4
Tetrafluorohydrazine
CH3-CH-CH-CH3
NF2 NF2
“Bis” Difluoramino Compound
with a Vicinal structure
U.S. Secret Rocket Fuel Research at
Thiokol Chemical Company
Chemical reactions of HNF2 with ketones:
O
CH3-CH2-C-CH3 + HNF2
2-Butanone
Difluoramine
NF2
CH3-CH2-C-CH3
NF2
“Bis” Difluoramino Compound
with a Geminal structure
U.S. Secret Rocket Fuel Research at
Thiokol Chemical Company
Chemical reactions of perfluoroguanidine
with alcohols led to compounds with
three NF2 groups on one carbon atom
 These materials were powerful oxidizers,
but highly sensitive to shock and could
explode easily, so it was necessary to
work in a remote laboratory behind a
thick plastic shield.
Remote Barricade Laboratory
Thiokol Chemical Company - 1964
Remote Barricade Lab Vacuum Rack System
1.
2.
3.
4.
Insulated steel wall
Blow-out roof
Thermostat
Electrical heaters
5. PFG cylinder
6. Storage flasks
7. Liquid N2 traps
8. Remote-control jacks
9. Teflon valve
10. Thick glass reactor
11. Magnetic stirrer
12. Tubes for PFG
13. To vacuum pump
Formation of Powerful “Tris” Oxidizers
CH3CH2CH2CH2OH +
FN=C-NF2
NF
2
n-Butanol
Perfluoroguanidine
NF2
CH3CH2CH2CH2OCNFH
NF2
Intermediate Product
F2 Fluorine
NF2
CH3CH2CH2CH2OCNF2
NF2
Powerful “Tris” Oxidizer
+
HF
Hydrofluoric Acid
U.S. Secret Rocket Fuel Research at
Thiokol Chemical Company
 Some “Bis” compounds were made as polyurethanes
to create solid oxidizer-fuel combinations.
 “Tris” oxidizers were mixed with various polymers
to form solid propellant materials that initially
showed great promise for use in rocket fuels.
What happened to the secret
rocket fuel research programs?
The research and the spying made no impact on the
space program of either the U.S. or the Soviet Union.
The difluoramine compounds had inadequate
stability and performance to be practical as rocket
propellants for weapons systems.
Both sides continued to use other materials and the
work was declassified a few years later.
Future Rocket Propulsion Systems
 In order to travel beyond our solar system, future
rockets must be able to travel at very high speeds,
ultimately at or near the speed of light.
 Some of the concepts being explored to achieve this
goal are:
Ion Engines using a gas plasma
Solar-powered electric propulsion
Nuclear-powered rockets
Anti-matter propulsion
Ion Engines are Close to Reality
 A new type of ion engine called VASIMR® uses
argon, xenon or hydrogen gas injected into a tube
surrounded by a magnet.
 A series of radio wave devices turn the cold gas into
a superheated plasma (ionized gas).
 The expanding magnetic field at the rocket’s nozzle
converts the plasma’s thermal motion into a
directed flow, thereby producing thrust.
 Solar or nuclear power will be used to generate the
electricity needed to operate the system
VASIMR® Design
(Variable Specific Impulse Magnetoplasma Rocket)
 Ion engines like these have very low thrust, but very high
specific impulse, so the rocket moves faster and uses much
less fuel than chemical rockets once the spacecraft is beyond
earth’s gravitational field.
Space Travel with Ion Engines
Artist’s concept of a solar-powered spacecraft built
with 4 VASIMR® rocket engines headed to the moon.
Travel to Mars is expected to take only 3 months
compared to 9 months for conventional systems.
Bibliography
1. Castellano, J.A., “Rocket Science & Russian
Spies,” American Scientist, 96, 490 (2008).
2. Kalugin, O. with Montaigne, F., “The First
Directorate,” St. Martin’s Press, New York, 1994.
3. VASIMR® is a development of the Ad Astra Rocket
Company, Houston, Texas:
http://adastrarocket.com