Satellites launching procedure and vechicles

LAUNCHING PROCEDURES

By,M.MUTHUKUMAR.

• Launching is depends on the orbit of satellite to be launched.• Satellites are directly injected into Lower Earth

Orbit(LEO) with the help of Launch Vehicles. • Shuttle flying into an orbit are inclined at 28.5 degree to the

Equator of Earth Surface.• Rockets have capabilities to put satellite into orbit which are

above 120 miles from earth surface

Introduction

Launch Vehicles are classified as

1. Expendable Launch Vehicle - Delta & Ariane Rockets

2. Reusable Launch Vehicle - Space Shuttle or STS

Types

Expendable Launch Vehicle

An expendable launch system is uses to carry a payload into space. The vehicles used in expendable launch systems are designed to be used only once (i.e. they are "expended" during a single flight), and their components are not recovered for re-use after launch.

Reusable Launch Vehicle

A reusable launch system is capable of launching a payload into space more than once. No completely reusable orbital launch system .The Space Shuttle was partially reusable:

• Space Shuttle main engines• two solid rocket boosters

were reused after several months of refitting work for each launch. The external tank and launch vehicle load frame were discarded after each flight

To launch satellite above 200 km direct injection by rocket is not possible. In such cases ,the satellite is placed into transfer orbit between destination orbit it is known as “Hohmann Transfer orbit”

Video -> https://www.youtube.com/watch?v=EDbWsBzfkiM

Hohmann transfer orbit is tangent at the perigee of LEO and destination orbit. It carry

• Perigee kick motor• Apogee kick motor• Propulsion system• Auto piloting• System required for satellite

Perigee kick motor – Provide required thrust at perigee which injects satellite

into transfer orbit from circular to elliptical.

Apogee kick motor – It changes the velocity of satellite which require transfer orbit

from elliptical to circular.

1. Circular low earth orbit

2. Hohmann elliptical transfer orbit

3. Intermediate drift orbit

4. Circular geostationary orbit

Launching Procedure

consider a satellite is made at the point A with an altitude,

λ and Azimuth angle

From naiper rule,

cos i = cos λ sin Az cos imin = cos λ

or imin = λ

Problems in Launching

Problems such as :• Vibration• Emission of Gases• Weather at launching time• Error during Countdown

LAUNCHING VEHICLES AND PROPULSION

Launching of a satellite into orbit is an extraordinary complex and costly operation.

Launch vehicle includes • Engines• propellant storage and pumps• guidance and control

India First Launch Vehicle SLV-3 (1980)

PSLV Launch more then 55 satellite into orbit

SLV ASLV

Principle of rocket propulsion

Video -> https://www.youtube.com/watch?v=ebhOnf65N9Q

Space Shuttle Launch From EarthVideo -> https://www.youtube.com/watch?v=OnoNITE-CLc

Space Shuttle Return To EarthVideo -> https://www.youtube.com/watch?v=XCeukUsCodk

Life Cycle of Space Shuttle

Thank you