Washington, Mar 30 (IANS): Mark Vande Hei, who spent 355 days in low-Earth orbit- the longest continuous stay in space by an American - has safely returned to Earth along with two cosmonauts aboard a Russian spacecraft.
Vande Hei, along with Anton Shkaplerov and Pyotr Dubrov, began the journey back to Earth at 3.21 a.m. EDT (12.51 pm IST) on a Soyuz MS-19 spacecraft and had a parachute-assisted landing on the steppes of Kazakhstan, southeast of the remote town of Dzhezkazgan, at 7.28 a.m. EDT (4:58 pm IST).
His journey home has been a source of concern amid the Ukraine conflict. After the war began, a month ago, several sanctions were imposed on Russia by the US and many European countries, which affected long standing relations on economic, political as well space cooperation.
While media reports speculated about Vande Hei being left on the ISS, Russia officially denied the speculation.
"The US astronaut due to return to Earth soon will do so as scheduled on board Russia's space capsule vehicle on March 30," a report in TASS, a Russian state news organisation, said.
Vande Hei arrived at the International Space Station on April 9, 2021 and spent the longest period - 355 days. Previously, the record was held by retired NASA astronaut Scott Kelly, who spent 340 days on the ISS in 2015 and 2016, the space agency said.
During his tenure on the ISS, Vande Hei contributed to dozens of studies, including six science investigations supported by NASA's Human Research Programme, or HRP.
For one investigation, Vande Hei helped grow and evaluate vegetables harvested with the space station's Vegetable Production System, or Veggie. The investigation seeks to develop a food production system that can help astronauts meet their dietary needs with fresh vegetables cultivated in space.
Vande Hei also provided biological samples for an investigation that collects a core set of measurements, called Spaceflight Standard Measures.
The investigation seeks to characterise "normal" changes in the human body during spaceflight. For instance, wrist-worn sensors that measure activity levels and light exposure can help researchers better understand the sleep-wake cycle of astronauts.
Blood and saliva samples collected by crew members throughout their mission can also help scientists assess changes in various hormones, proteins, and cells that reveal how the immune system changes in space.
In addition, he contributed to a separate investigation collecting biological samples from the crew aboard the space station and placing them in a storage bank, from which researchers can draw upon the samples to study spaceflight-induced changes in human physiology.