The Expedition 61 crewmembers started taking turns “weighing in” Wednesday before a slew of space gardening and life science activities. The orbital residents are also nearing the start of a series of spacewalks to repair the International Space Station’s cosmic particle detector.

Isaac Newton’s Second Law of Motion allows for the calculation of mass in space using a variant of the equation — force equals mass times acceleration. Each crewmate attached themselves to a device this morning that applies a known force to the subject. The resulting acceleration provides a value used to calculate an astronaut’s mass.

It is harvest time once again aboard the orbiting lab. NASA astronauts Jessica Meir and Christina Koch cut leaves from Mizuna mustard greens grown inside ESA’s (European Space Agency) Columbus lab module. Half of the space crop is destined for crew tasting while the other half was stowed in science freezers for analysis on Earth.

NASA Flight Engineer Andrew Morgan is getting ready for Friday’s spacewalk with ESA Commander Luca Parmitano. Morgan reviewed robotics activities planned for Friday’s excursion and checked spacewalking gear. The duo will set their U.S. spacesuits to battery power at 7:05 a.m. EST inside the Quest airlock signifying the start of their spacewalk. NASA TV begins its live coverage at 5:30 a.m.

Parmitano focused on science today attaching electrodes to himself after his “weigh-in” to measure any changes to his body fat. Afterward, he collected noise level measurements in Russia’s Zarya module. He then set up samples in the U.S. Destiny lab module to explore how fluids behave in microgravity to improve medical conditions on Earth.

Cosmonaut Oleg Skripochka handed over radiation detectors to Meir for deployment in the station’s U.S. segment. He later joined cosmonaut Alexander Skvortsov and recorded video to share historical space accomplishments with Russian audiences.