SpaceX has recently announced its plan to pursue a reusable launch vehicle test program called Grasshopper, and released a video which describes its vision of what such a reusable system should look like:
We all know that ISRO plans to eventually test RLV-TD, a small shuttle-like Reusable Launch Vehicle Test Demonstrator, on its path towards achieving cost reduction through reusable platforms. But I was recently thinking about another approach which could be taken, which might be more similar to SpaceX's approach. But whereas SpaceX plans to first test reusability in the bottom stage, and then work up to the higher stages, I think ISRO should start from the top and work its way down to the bottom stage.
I was thinking that after ISRO fully proves its Cryogenic Upper Stage across repeated flights, that perhaps it might be nice to try to make this Cryogenic Upper Stage reusable, by endowing it with a heat shield to survive re-entry, as well as landing control systems to achieve a powered landing. Thus, such a successfully returned Cryogenic Upper State might possibly be refurbished for re-use on further flights.
ISRO has always emphasized its desire to do more with lower budgets, keep costs down, etc. It's with this in mind that ISRO has talked about a small shuttle-like RLV demonstrator, etc. A reusable Cryogenic Upper Stage would help to achieve the goals of cost reduction.
The successful SRE-1 and SRE-2 (Space Recovery Experiment) missions have shown that India's heat shield technology works for re-entry from LEO. It will also have to be proven for a future manned Indian space capsule. Use of this technology on a Cryogenic Upper Stage could then further the goal of reusability and cost reduction.
How much modification would have to occur for the Cryogenic Upper Stage to achieve reusability? I'm thinking ISRO could modify the Cryogenic Upper Stage to equip it with Soyuz-style landing rockets, for controlled landing and touchdown. So the CUS would get a heat-shield, parachutes for further deceleration, and then finally Soyuz-style landing rockets to do the final touchdown.
What is the feasibility of this idea? Opinions?