The Russian Progress has always been a prime ISS cargo option. Europe for a time provided the ATV (Automated Transfer Vehicle) which flew 5 cargo missions to the ISS, the last being in July 2014. Japan also has the H-II Transfer Vehicle, but this flies at the most maybe once per year.
Much more recent, and more frequent, are SpaceX’s Dragon and Orbital Science’s Cygnus cargo vehicles, which takes the load off the Progress.
Sierra Nevada, which once was a consideration for manned transport to the ISS with their Dream Chaser, now has a NASA contract for a cargo version of their Dream Chaser. The first two flights will be lofted by ULA in 2020 and 2021.
While Boeing and SpaceX won the nods from NASA for manned transport, Sierra Nevada continued on their own with Dream Chaser. Naturally, Sierra Nevada must now concentrate on the Dream Chaser Cargo System, I, for one, am hoping the manned Dream Chaser stays alive and becomes a reality at some point in the future.
Face it… Dream Chaser is a beautiful craft, and the concept of gliding in for a landing at an airport near home is an improvement over a splashdown far out in the ocean or thumping down in some remote grassland.
