The Expedition 61 crew aboard the International Space Station is preparing to bid farewell to a U.S. space freighter. The astronauts are also exploring what microgravity does to biology and botany to improve life for astronauts and Earthlings.

Station mission managers and SpaceX officials rescheduled the departure of the SpaceX Dragon resupply ship from the complex from Sunday night to early Tuesday due to a forecast of high seas in the Pacific Ocean splashdown zone. Dragon is now scheduled to be released on Tuesday, Jan. 7, at 5:03 a.m. EST when the Canadarm2 robotic arm will set the craft free following its unbolting from the Earth-facing port of the Harmony module. Dragon will parachute to a splashdown southwest of Long Beach, California, Tuesday at around 10:41 a.m. loaded with station hardware and research results for analysis.

Flight Engineer Andrew Morgan started Friday morning with Commander Luca Parmitano of ESA (European Space Agency) loading science freezers inside Dragon before next week’s departure. The freezers are packed with a variety of scientific samples that researchers will study to understand microgravity’s impact on a broad spectrum of biology and materials.

Mice, whose physiology is similar to humans, are being examined today to learn how to prevent muscle and bone loss in weightlessness. Doctors are studying ways to minimize the effects of spaceflight by observing the effectiveness of myostatin and activin in mice aboard the station. NASA astronauts Jessica Meir and Christina Koch scanned and imaged the mice today in a bone densitometer measuring their bone mass.

Flight Engineer Andrew Morgan harvested moss today in the Kibo laboratory module collecting and stowing samples for further analysis. The Space Moss study, sponsored by the Japan Aerospace Exploration Agency, is exploring ways to grow strains of plants suited for the gravity conditions of spaceflight, the Moon and Mars.

Veteran cosmonauts Alexander Skvortsov and Oleg Skripochka started their day videotaping and photographing life on the orbiting lab. The duo then split up servicing Russian life support systems, packing a Progress cargo craft and charging batteries in a Soyuz crew ship.