The international context
STEP (USA): 10-18    (10-17  from Phase A Studies in Europe)
(requires payload to be maintained close to absolute zero
temperature)                                 In the SMEX competition
mSCOPE (France): 10-15                 Phase B  Study
GG (Italy): 10-17                                    Advanced Phase A Study
                            The costs
        STEP : GG : mSCOPE=1 : 20% : 13%
GREAT (balloon test): 10-15 , competitive with mSCOPE,
lower cost, repeatibility… (ASI-NASA study)