chris carani and "bloomberg news" reporter alex barinka.cex successfully docked its capsule at the international space station but unsuccessfully landed part of its rocket. how big a blow is this to spacex and elon musk? we will explain. ♪ >> you are watching the best of "bloomberg west." i am cory johnson. spacex had a capsule arrive at the international space station carrying groceries, belated christmas presents, and other supplies. but the attempt to land a reusable rocket was not successful. elon musk tweeted -- for more, i spoke with a former commander of the space station. >> what is sophisticated about it is that it can hold position using a bunch of different propellers underwater. using a gps, it can stay in one place really precisely, which is what you need when that piece of the rocketship is coming back and trying to land on it like a big broomstick -- imagine if you could balance a broomstick while you are out at sea. it is a specific thing to do. but the came back into port yesterday. they came close but not perfect yet. >> l