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 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 Main vehicle Primary liquid or solid rocket propellant tanks Engine / nozzles Mechanism for combining propellants and focusing thrust Booster packs Solid 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 stage Orbit 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) V Step 3 Minimum energy transfer Burn 1 to change path Burn 2 to change to higher orbit N V1V1 V2V2 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 LATITUDE SPACE LAUNCH AZIMUTH

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) Thrust = Pounds or KgImpulse = Pounds per secSpecific Impulse (Isp) = Newtons per sec Isp = Thrust (lb) fuel weight (lb) burned in 1 sec FORCEFORCE & TIMEFORCE & TIME & FUEL

Mass Ratio of a Vehicle Mass Ratio (MR) is the ratio between the booster mass before the rocket engine burn (m f ) divided by the booster mass after rocket engine burn (m 0 ). MR = m f /m 0

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 V2V2 V1V1 V1V1 V2V2

Launch from Vandenberg Launch site latitude37 deg N latitude Desired Orbits –Inclination80 degrees104 degrees –Apogee 250 NM250 NM –Perigee100 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 rotation sin Az = cos 80/cos 37 = sin degrees Launch Azimuth = degrees Retrograde Orbit, i.e., against Earth’s rotation sin Az = cos 104/cos 37 = sin degrees Launch Azimuth = degrees * Formula from page 81 Space Handbook, Analysts Guide. North