Brain and muscle research were on today’s schedule of human research aboard the International Space Station. The Expedition 61 crew also ensured the plumbing and air conditioning systems stay in tip-top shape.

The brain is able to optimize its blood flow even if the cardiovascular system cannot maintain an ideal blood pressure. Flight Engineer Jessica Meir explored the brain’s capacity to regulate that blood flow in space today. She used Doppler gear to measure her blood pressure in her finger artery and blood flow velocity in her cerebral artery. Scientists may use the data to help astronauts adjust to microgravity and ease the return to Earth after months or years in space.

NASA astronauts Christina Koch and Andrew Morgan collaborated on the Myotones muscle tone in space study. The duo took turns measuring their arms and legs before scanning them with an ultrasound device. Observations may help doctors improve rehabilitation techniques for astronauts on long-duration missions and sedentary patients on Earth.

Commander Luca Parmitano of ESA (European Space Agency) put on his plumber’s hat today and replaced hydraulic components in the station’s bathroom located in the Tranquility module. He also deactivated science hardware that was tracking ocean-going vessels.

Cosmonauts Alexander Skvortsov and Oleg Skripochka stayed focused on the upkeep of the Russian segment of the orbiting lab. The duo charged Soyuz spacecraft batteries and cleaned fans and filters in the air conditioning system in their portion of the space station.