Transcript Launch System - Troy University

Launch System
• Launch Vehicle
• Launch Complex
• Orbit Insertion
• Orbit Maneuvers
Booster Design
• German V-2
– Fins for stability and
steering
– Exterior skin with
Propellant tanks within
• U.S. Launch Vehicles
– Engine gimbals
– Wall of tank and skin of
vehicle one and the same
– Multiple Stages
– Single stage
Launch Vehicles
Expendable
Air Force and commercial US systems
Divided into small, medium, and heavy classes
Next generation of expendable vehicles in
development
Manned
Space Shuttle
Reusable
Test vehicles only
Launch Ranges
Launch ranges provide tracking, telemetry,
communications, command & control, and other support
necessary for safe and successful space lift operations,
and aeronautical and ballistic missile tests.
Launch Fundamentals
Launch Events
Shroud
Protects the spacecraft
Step 7: Mechanical deployments
Step 6: Satellite initial checkout
Upper stage
Orbit insertion rocket
engines and propellant
tanks
Main vehicle
Step 5: Orbit insertion
Step 4: Shroud opening
Step 3: Main engine cut-off and separation
Primary liquid or solid
rocket propellant tanks
Booster packs
Solid strap-ons for some
rockets to increase
initial thrust
Engine / nozzles
Mechanism for
combining propellants
and focusing thrust
Step 2: Booster cut-off and separation
Step 1: Ignition and launch
Usual Launch Sequence
V
Step 1
Launch into parking orbit
(With orbit insertion burn)
North
Pole
V2
Step 2
Minimum energy transfer
Burn 1 to change path
Burn 2 to change to higher orbit
N
V1
Step 3
V
Orbit plane transfer
(With vector thrust burn)
Launch Ranges
Ranges usually located to minimize overflight of
populated areas and reduce
potential debris hazards
Launch site latitude limits the inclination of the
satellite’s orbit
The minimum inclination of the orbit is equal to the latitude
of the launch site
To get to a lower inclination, satellites need to go through
an orbit plane transfer
DOD LAUNCH LOCATIONS
CAPE CANAVERAL AFS /
KENNEDY SPACE CENTER
(EASTERN SPACE LAUNCH
RANGE)
VANDENBURG AFB
(WESTERN SPACE
LAUNCH RANGE)
•
•
•
•
•
•
•
•
•
TITAN IV
TITAN II
ALTAS
DELTA
SHUTTLE
TITAN IV
TITAN II
ALTAS
DELTA
37 DEG
SPACE LAUNCH AZIMUTH
30 DEGREES LATITUDE
112 DEG
201 DEG
158 DEG
Launch Window
The “launch window” is the period of time during
which the launch must occur to achieve a desired
orbit
Duration of window is determined by desired orbit,
launch location, weather, and launch vehicle
performance
Examples of issues:
Vehicle may require specific orbit for rendezvous
Vehicle may require orientation to get correct solar array
exposure before reaching final orbit
Launch Fundamentals
Science
force = (mass) x (acceleration)
f = (m)(a)
The thrust of a launch vehicle must oppose gravity and
atmospheric drag
To get into orbit, a vehicle must achieve a velocity of
mach 24 (24 times the speed of sound)
FORCE
Thrust = Pounds or Kg
FORCE & TIME
Impulse = Pounds per sec
= Newtons per sec
FORCE & TIME & FUEL
Specific Impulse (Isp)
Isp =
Thrust (lb)
fuel weight (lb) burned in 1 sec
Mass Ratio of a Vehicle
Mass Ratio (MR) is the ratio between the booster
mass before the rocket engine burn (mf ) divided by
the booster mass after rocket engine burn (m0 ).
MR = mf /m0
PROPULSION: GETTING INTO AND
AROUND IN ORBIT
V
V
NORTH
POLE
LAUNCH INTO PARKING ORBIT
(WITH ORBIT INSERTION BURN)
ORBIT PLANE TRANSFER
(WITH VECTOR THRUST BURN)
V2
V2
NORTH
POLE
V1
HOHMANN (MINIMUM ENERGY) TRANSFER
(BURN 1 TO CHANGE TO ELLIPTICAL ORBIT AND
BURN 2 TO CHANGE TO HIGHER ALTITUDE
CIRCULAR ORBIT)
NORTH
POLE
V1
FAST TRANSFER
(BURN 1 TO CHANGE TO LARGE ELLIPSE AND BURN
2 TO FORCE INTO NEW ORBIT)
Launch from Vandenberg
• Launch site latitude
• Desired Orbits
– Inclination
– Apogee
– Perigee
37 deg N latitude
80 degrees
250 NM
100 NM
104 degrees
250 NM
100 NM
• What is the launch azimuth for each orbit?
• What velocity (V) must the payload have in each
desired orbit at perigee and apogee?
Launch Azimuth
* cos Inclination = cos Latitude x sin Azimuth
sin Azimuth = cos Inclination/cos Latitude
North
Posigrade Orbit, i.e., with Earth’s rotation
sin Az = cos 80/cos 37 = sin 12.56 degrees
Launch Azimuth = 167.44 degrees
Retrograde Orbit, i.e., against Earth’s rotation
sin Az = cos 104/cos 37 = sin -17.63 degrees
Launch Azimuth = 197.63 degrees
167
198
* Formula from page 81 Space Handbook, Analysts Guide.