The Soyuz launcher can put about a third of the mass in low Earth orbit compared with Proton, Falcon 9, Ariane 5, Atlas V. Is that enough to crew and resupply a space station in Lunar orbit, or at an Earth-Lunar Lagrange point, a so called Deep Space Gateway?
The delta-v from LEO to an EML points seem to be less than 1 km/s, but it took Saturn V about three days to ship three astronauts to the Moon, how long would it take for a Soyuz launcher, at less than a tenth of the capability, to do the same? And could the Soyuz spacecraft support the crew for that long? Could planned commercial spacecrafts like Dragon, CST-100 and Dreamchaser bring 3 (or 7) crews to a DSG? Or would it require the SLS with Orion to reach?