Hi I would like to know for my 3 objects that I am allowed to bring into a game what are the exact rules? like isn't it the first has to be a light object. and then can I have both a 3d object and a special object?

For example I want to use

1 light object
1 satellite 3d object
1 crimson gem

Is this allowed, or would I have to have a regular heavy object?

From the 2011 Core Rulebook:

OBJECTS IN YOUR FORCE

You may bring up to three objects as part of your force to a game. The first two objects added to your force must be different types (heavy, light, or immobile), and the third object can be any type, though you must have at least one heavy and one light among your three objects. Any or all of these objects may be special objects, but each special object must not have the same name as any other special object on your force.

thank you!

and from my understanding the satellite counts as a heavy, right?

I think you mean the:

COM DISH†
Heavy: Continual. When this object is used in an attack,
modify the attacker’s damage value by +1 for the attack.
Availability: Legion of Super Heroes Starter Game

not the:

SATELLITE†
Light: Continual. Give a character holding this object a
power action. Remove this object from the game and place a
debris token in the square occupied by the character and in
any two adjacent, unoccupied squares.
Availability: Supernova S002

But you could have both and the gem, if you wanted.

yes thats what i meant thanks