Orbital Sciences [ORB] is in discussions with rival launch providers, two domestic and one European, over hosting future NASA Cargo Resupply Services (CRS) missions while its Antares launch vehicle is out of service following its Oct. 28 launch failure. “Indications…are favorable that these launch operators do have available capacity that is suitable for Cygnus launches as early as second quarter 2015 extending all the way into mid- to late-2016,” company CEO David Thompson told investors Wednesday. Orbital is aggressively looking…