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

– Single stage

• U.S. Launch Vehicles

– Engine gimbals

– Wall of tank and skin of vehicle one and the same

– Multiple Stages

Launch VehiclesExpendable

Air Force and commercial US systems

Divided into small, medium, and heavy classes

Next generation of expendable vehicles in development

MannedSpace Shuttle

ReusableTest 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 FundamentalsLaunch Events

ShroudProtects the spacecraft

Main vehiclePrimary liquid or solid

rocket propellant tanks

Engine / nozzlesMechanism for

combining propellants and focusing thrust

Booster packsSolid strap-ons for some

rockets to increase initial thrust

Step 2: Booster cut-off and separation

Step 3: Main engine cut-off and separation

Step 4: Shroud opening

Step 5: Orbit insertion

Step 6: Satellite initial checkout

Step 7: Mechanical deployments

Upper stageOrbit insertion rocket

engines and propellant tanks

Step 1: Ignition and launch

Usual Launch Sequence

Launch into parking orbit(With orbit insertion burn)

North Pole

V

Step 1

Orbit plane transfer(With vector thrust burn)

VStep 3

Minimum energy transferBurn 1 to change pathBurn 2 to change to higher orbit

N

V1

V2

Step 2

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

201 DEG

158 DEG

37 DEG

112 DEG

VANDENBURG AFB(WESTERN SPACE LAUNCH RANGE)

• TITAN IV• TITAN II• ALTAS• DELTA

VANDENBURG AFB(WESTERN SPACE LAUNCH RANGE)

• TITAN IV• TITAN II• ALTAS• DELTA

CAPE CANAVERAL AFS / KENNEDY SPACE CENTER(EASTERN SPACE LAUNCH RANGE)

• SHUTTLE• TITAN IV• TITAN II• ALTAS• DELTA

CAPE CANAVERAL AFS / KENNEDY SPACE CENTER(EASTERN SPACE LAUNCH RANGE)

• SHUTTLE• TITAN IV• TITAN II• ALTAS• DELTA

30 DEGREES LATITUDESPACE LAUNCH AZIMUTH

SPA

CE

LA

UN

CH

A

ZIM

UT

H

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 FundamentalsScience

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)

Thrust = Pounds or Kg Impulse = Pounds per sec Specific Impulse (Isp)= Newtons per sec Isp = Thrust (lb)

fuel weight (lb) burned in 1 sec

FORCE FORCE & TIME FORCE & TIME & FUEL

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

NORTH POLE

NORTH POLE

NORTH POLE

LAUNCH INTO PARKING ORBIT(WITH ORBIT INSERTION BURN)

ORBIT PLANE TRANSFER(WITH VECTOR THRUST BURN)

HOHMANN (MINIMUM ENERGY) TRANSFER(BURN 1 TO CHANGE TO ELLIPTICAL ORBIT AND BURN 2 TO CHANGE TO HIGHER ALTITUDE CIRCULAR ORBIT)

FAST TRANSFER(BURN 1 TO CHANGE TO LARGE ELLIPSE AND BURN 2 TO FORCE INTO NEW ORBIT)

V

V

V2

V1V1

V2

Launch from Vandenberg

• Launch site latitude 37 deg N latitude

• Desired Orbits – Inclination 80 degrees 104 degrees– Apogee 250 NM 250 NM– Perigee 100 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

Posigrade Orbit, i.e., with Earth’s rotationsin Az = cos 80/cos 37 = sin 12.56 degreesLaunch Azimuth = 167.44 degrees

Retrograde Orbit, i.e., against Earth’s rotationsin Az = cos 104/cos 37 = sin -17.63 degreesLaunch Azimuth = 197.63 degrees

* Formula from page 81 Space Handbook, Analysts Guide.

North

167

198