The previously linked pdf puts the up/downlinks around 2.0/2.2GHz; the same band used for the Apollo missions, which figures given the era (http://en.wikipedia.

The previously linked pdf puts the up/downlinks around 2.0/2.2GHz; the same band used for the Apollo missions, which figures given the era (http://en.wikipedia.org/wiki/Unified_S-band http://en.wikipedia.org/wiki/Unified_S-band). Currently, the entire Deep-Space Network is on ~8.4GHz. Re-equipping a multinational network for S-band could quite possibly a significant budgetary issue given how little love have been NASA getting in recent years.