Remember that readers' poll?
Article should be saying:
"The reusable cargoship dropped into the ocean yesterday evening around 400 km off the coast of Mexico after resupplying the ISS and its crew. The Dragon was ferried to a port near Los Angeles where it will be prepped for its return to SpaceX's test facility in Texas.
Some of the cargo brought back by the capsule is due to be returned to NASA in the next couple of days, including research samples from the station's microgravity environment. The ship delivered 400 kg of gear to the ISS, including scientific research and crew supplies. It returned with nearly twice that mass of stuff."
There - fixed that for you! Notice the "weight" -> "mass" fix in the final line too.