NASA’s Sunita Williams explores watering plants in space: When will Starliner astronauts return to Earth?

NASA astronauts Sunita Williams and Butch Wilmore, who are overstaying in space, are busy utilizing the extra time carrying out experiments, emergency drill and research on the International Space Station.

'How plant absorb water in microgravity?'

On Wednesday, NASA (National Aeronautics and Space Administration) reported that Indian-origin Sunita Williams and Butch Wilmore, who skyrocketed to space on Boeing's Starliner spacecraft on July 5, "continued exploring ways to effectively water plants in the weightless environment".

The two NASA astronauts took turns in the "Harmony module", testing how root models and plants of various sizes would absorb water in microgravity.

Harmony is a utility hub, providing air, electrical power, water, and other systems essential to support life on the station. It also provides international docking adapters on its space-facing and forward ports for commercial crew vehicles, NASA explains.

Earlier, NASA's press release on July 16 said NASA astronauts Butch Wilmore and Sunita Williams spent the majority of their day testing ways to water plants growing without soil in the weightless environment of microgravity.

"Williams first set up the Plant Water Management hardware in the Harmony module then tested a variety of liquid flow methods while video recording the results. Following her work, Wilmore ran more tests using hydroponics and air circulation techniques to learn how to effectively nourish a variety of plants on spacecraft and space habitats," NASA said.

Vein scans

Before this, NASA shared an update on July 15, informing that Starliner Pilot Sunita Williams and Commander Butch Wilmore participated in vein scans using the Ultrasound 2 device.

As part of the research, the NASA astronauts took turns imaging each other’s neck, shoulder, and leg veins as doctors on the ground monitored the process in real-time.

"Afterward, Wilmore scanned the veins of NASA Flight Engineer Matthew Dominick helping researchers understand how microgravity affects the human body," NASA said.

Meanwhile, Sunita Williams worked on a pair of differing studies. Her initial research focused on manufacturing high-quality optical fibers in microgravity.

Williams had then also "investigated using fluid physics such as surface tension to overcome the lack of gravity when watering and nourishing plants grown in space".

Emergency drill

As per NASA's update on July 12, the seven-member Expedition 71 crew joined the two NASA Starliner astronauts to practice an emergency drill in collaboration with mission controllers.

As part of the drill, the teams aboard the orbital outpost and on the ground coordinated communications and reviewed procedures in the unlikely event of a pressure leak, chemical leak, or fire aboard the space station.

Sunita Williams and Butch Wilmore also completed life-support work, "refilling temperature loops with water in the Tranquility module’s internal thermal control system".

What else NASA Starliner astronauts are working on?

Wilmore and Williams reviewed the procedures for using the Fluid Systems Servicer, which drains, purges, and circulates fluids on systems aboard the space station. The probable happened on July 10.

A day later, the two NASA Starliner astronauts took turns during the morning pedaling on an exercise cycle while attached to heart and breathing sensors "that measured their aerobic capacity".

"The duo then split up as Wilmore serviced a pair of research freezers that preserve scientific samples and Williams installed hardware on an experiment that explores atmospheric reentry and thermal protection systems," NASA reported.

When will Sunita Williams and Butch Wilmore return to Earth?

Astronauts Butch Wilmore and Suni Williams are crew-members of NASA’s Boeing Crew Flight Test mission. They should have been back weeks ago. Their test flight should have lasted eight days, ending on June 14.

However, Helium leaks and thruster failures almost derailed their arrival at the International Space Station, and has kept them there much longer than planned.

Now, the earliest they could return may be the end of July, NASA's commercial crew program director Steve Stich said in a press conference last week. "The goal is to get them back before SpaceX delivers a fresh crew in mid-August, but that, too, could change," he had said.

The two astronauts said they expect to return once thruster testing is complete here on Earth. They said they're not complaining about getting extra time in orbit, and are enjoying helping the station crew.

“I have a real good feeling in my heart that the spacecraft will bring us home, no problem," Williams told reporters.

Boeing's Mark Nappi stressed that in an emergency, Starliner and its crew could return right now. While the company does not believe the thrusters are damaged, "we want to fill in the blanks and run this test to assure ourselves of that."