There are many advantages we can gain from building a vacuum test facility. The main advantage would be experience gained in designing and operating a large vacuum chamber. This would be very important if we are going for manned mission (testing the space-walk suits or space stations) and also it would give us experience for building our own nuclear fusion reactors if say for example ITER succeeds.
Building a vacuum dabba to test pressurization for stuff like space walks and space stations is easy. You just need a sealed building.
But here what you are talking about is building a vacuum chamber and firing rockets in it. You have the evacuate mass from the chamber at least at the humongous rate at which the rockets put out the gas jets and also keep the overall environmental limits like heat etc the same as what it is in space..Requires a massive heat sink and also massive pump to evacuate.. Wont be readily available off the shelf and you will need to engineer all that from scratch. A fiver year project minimum.
I stand among the four Beasts
from Sanjay's link of the P4 test stand used to test upper atmosphere engines, it looks like a small and compact building, with some part underground no doubt. http://www.esa.int/esaCP/ESA5NUZK0TC_Ex
I doubt this cost $1b or even $500m to setup...my wild guess would be $10 mil for the physical building and $90mil for the equipment.
there is a ISRO meeting in Triv tomorrow. hope the demand for such kit comes out of it also and the PMO slaps around a few people to cough up the cash.
Right in the link, it talks about simulation codes for ignition etc and then verifying that in the chambers. That is exactly what we need to do and it can be done quickly , if we throw the toffees and sweeteners to the PIGS in the Madrassas and get them Oinking NOW.
DLR and ISRO go back a long long long way and have a great history of collaboration . If it is an ESA/DLR facility, we should debug the engine, send the stage there to the ignition test facility and get it tested or to the Roosies or whoever is willing to lend it to us.
If that cannot be done, rather than build this kind of facility, do the simulation, instrument a stage fully and mount it on top of an ASLV / PSLV booster stage and validate your simulation/ codes whatever and prove your stage, before putting it on top of the GSLV.
Of course, kick the babu monkeys in the nuts very hard and get all the "forex" and travel and other budgets "approved" and "NOC" granted and signed in triplicate and laminated and whatever, get the MTR ready to eat stuff packed and ordered in bulk ( they eat animals and other terrible stuff in Jurmany and Russhia.. no curd rice and sambar and rasam saar, what to do) , shop for moderately winter clothing bought from Commercial street in Bangalore (leave out the thermals and other things you are advised to buy as a FOB, I doubt the ISRO folks will have to take the buses in the city or ride bicycles in the snow like PIGS have to do as grad students)... But basically get cracking. Not too much time to waste and wet dream over building 1960s like facilities that will take a decade or so to come up.