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Sunday, January 5, 2014

GSAT-14 satellite launch using GSLV D5 flight

GSAT-14 is a communications satellite to be placed in a Geo-synchronous orbit at 74 deg East Longitude.  Already there are 3 more satellites in that location which were launched earlier.

GSLV D5 flight will carry this satellite to 213Kms and place it in a Transfer orbit. This orbit will be raised by successive firing of  Liquid Apogee Motor (LAM) which a small rocket like structure attached to the GSAT-14. This motor can be switched on and off for predetermined durations to impart deviating force which will raise the orbit through a sequence to Geo-sync orbital height.

The flight of GSLV D5 is expected to start ( ignition ) at about 1618IST on 5th Jan2014.

Configuration of GSLV for this flight is :

There is a central core rocket and to it are attached 4 strap-on rockets.This is the first stage which carries the satellite along with upper stages upto a height of about 70 kms in 2.5 Minutes. The rocket would have achieved a velocity of 2.4 Kms /sec at the end of this sequence.

Here the second stage is ignited and first stage is separated thus a lot of dead weight is discarded.

The second stage is on for about 4.3 minutes and carries the rocket upto 132kms. once its job is over, 2nd stage is also separated. By the time the second stage has finished its job the rocket would have achieved 4.9Kms/sec speed.

Immediately after this seperation the ( for the first time in India's history ) the indigenously developed CRYOGENIC engine is ignited. This is a liquid propellant engine ( previous stages were Solid propellant rockets similar to Diwali patakha rocket )  which can control its ignition and thrust in a controlled fashion ( unlike solid propellants which can't be controlled once ignited ).

This cryo stage has a long burn of 12+ minutes and which carries the satellite from 132Kms to 205 Kms and increased its speed to 9.78Kms /sec.

At this stage the Satellite GSAT-14 is separated form the last stage and becomes Earth Satellite at 213Kms altitude.

Launch can be viewed at following online sites:  (  BEWARE: This link got overloaded during Mangalyan launch )


Launch is successful!!

Just for info ..  A sample of what was being shown during telecast is shown here.

Upper graph is the Velocity of the rocket during flight ..  white line is drawn before the launch showing expected  velocity and as the flight progresses, the white blinking dot shows the actual velocity at that instant. You will find that the achieved velocity is continuously following the expected graph. Actually the blinking dot is the actual velocity measured by instruments on board and being transmitted to control room.

Similarly the lower graph is the expected altitude ( Red curve ) and as the time progresses actual altitude is shown in green.

As told earlier the cryo has varied its thrust from 7/5 tons >9.5Tons>8 T > 7.5 again which is impossible in solid engines used in earlier stages. That is the beauty of crygenic engine ,,  you control the thrust at your will over a large range.Anyway nw we ( ISRO ) seems have overcome the problems of cryo scarcity..  good!!


Here is how the GSAT-14 orbit looks like from a point above South pole.

The satellite makes 2.28 revolutions every day. We have shown 2 orbits out of that. The satellite  revolves around  Earth with following parameters:

Apogee:      35777 Kms
Perigee:      160 kms
Period :       630 min
Semi major axis :      24347 kms
Semi minor axis :      16602 kms
Inclination         : 19.4 deg
Eccentricity       :  0.73

Here is how the GSAT-14 was revolving around Earth in an orbit it was launched using GSLVD5 flight. I am deliberately using the word 'WAS' because currently the satellite is in the next stage of orbit subsequent to orbit raising maneuver carried out by ISRO. We will upload latest orbit as soon as info is available about the new orbit.

1st one minute of video is a view over india ..  watch the day light move into night. Subsequently same orbit is observed from  North pole.

Note that the animation is very fast as compared to real time.

BTW ..  do you know that GSLV D5 is the 1st launch in 2014?  No country has yet launched any new rocket this year.          Hooray!!

Here is a representation of the orbit of GSAT-14  in initial orbit that it was launched and the orbit after 1st Orbit Raising Maneuver ( ORM ).

 View from equator shows the two orbits. 1st orbit is a smaller one with more inclination an the second orbit ( after ORM ) is the larger one with
reduced inclination.

In a view from above North pole the two orbits are clearly seen with changed shape.

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