Question

Material used to make the body of the mars orbiter

Answer 1

 Carbon Fiber Reinforced Polymer -  CFPR

Answer 2

The special material is

       Aluminum and Composite Fibre Reinforced Plastic -  or,

            Carbon Fiber Reinforced Polymer -  CFPR

  CFPR

         -  has a very high strength for a given weight

         - reflects well heat

        -  does not rust

        - durable

 

It may not be the best.  But it is practically the most fitting substance that can be used to optimized on multiple criteria.