why five earth orbits for chandrayaan?

[nijojosseph]

Can any one explain why there is five earth orbits for this mission instead of two.The isro announced it as calibration of telemetry control but i think much more experiments are being done by isro in each orbits

[Prasanna]

The exact reason has not been mentioned.
I think the reason for multiple orbits to reach lunar transfer orbit may be due to inadequate deep space information. Calibration of the deep space network data may be one of the reasons. This will allow future lunar injections to be more precise.It will also allow a greater margin for any error during lunar capture compared to a direct lunar orbit transfer with a single lunar injection.The original diagram at the isro website called for a LEO, GTO and then a firing via a Hohmann transfer orbit with midcourse correction to reach lunar capture followed by recorrection. That may have a lower margin of error. also this will not give sufficient tracking and calibration data of the new Indian deep space network.

[nijojosseph]

Originally Posted by mooniac

I'm a layman so by my limited understanding..

5 orbits..


reason 1 to buy time!

to calibrate deep space network etc. as prasanna said.

its india's first launch into deep space..

we're toddlers in comparison Nasa's deep space network Goldstone-Madrid-Canberra, where NASA is ahead by many years..

There is also coordination with exterior Sites during the early phases:
http://www.isro.org/Chandrayaan/html...acenetwork.htm

.. so with hardly any 'experience' in this its good to take things slowly. the stakes are high..


Reason 2 Extented orbits also gives the opportunity to plan and simulate orbital transfer strategies for future, possibly interplanetary missions. As I am sure India will not have the extravagant budget of NASA to conduct seperate launches to test for all the steps leading to more complicated missions.


and to avoid babbling about stuff i don't know too much about: here's the official orbit plan and diagram:

http://www.isro.org/Chandrayaan/html...n_sequence.htm

Thanks for the above informations. My other doubt is why TMC is B&W instead of color