SpaceX is the private spacecraft company founded by billionaire inventor Elon Musk, who also created the popular Tesla Motors.
SpaceX has picked up the slack since NASA stopped launching rockets on their own.
With their latest launch, they sent an inflatable capsule to the ISS, which is going to be an interesting experiment in the long term durability of inflatable habitats in space, which has major implications in space travel, as these are far lighter and easier to launch into space than traditional rigid capsules.
But the real amazing thing about the launch was the successful landing of the first stage rocket booster. Typically, the first rocket engine separates and then falls into the ocean, rendering it unusable for future missions. The true achievement of this launch is that it can help radically reduce the cost of space launches, since the main rocket can be reused. It came to a stable landing on a small platform in the ocean, which is an incredible feat of scientific achievement! It is basically like shooting a bullet into the air, and having it come down and land in a shot glass that you laid out for it. Previous attempts had failed, and this is the first time it has worked properly. The technology is not perfect, but every launch is an improvement.
This has truly been an incredible week for Elon Musk, as preorders for the new Tesla Model 3 topped 375,000 in just one week!