Synonyms to exact mates

Gemini, ATDA, ATS, Alouette, Anna, Apollo, Ariel, Atlas-Score, Biosatellite, Castor and Pollux, Comsat, Cosmos, Courier, Diapason, Discoverer, ERS, Early Bird, Echo, Elektron, Explorer, GATV, Injun, Intelsat, Lofti, Luna, Lunar Orbiter, Lunik, Mariner, Mars probes, Mercury, Midas, Nimbus, OAO, OGO, OSO, Pageos, Pegasus, Pioneer, Proton, Ranger, Relay, Samos, San Marco, Secor, Siamese twins, Sputnik, Surveyor, Syncom, Telstar, Transit, Tweedledum and Tweedledee, Twin Stars, Vanguard, Viking, Voskhod, WRESAT, Zond, artificial satellites, fraternal twins, identical twins, pair of twins, spacecraft, twins, dead heat, deadlock, draw, even break, fair shake, knotted score, neck-and-neck race, photo finish, stalemate, standoff, the same, tie