Science without gravity at the International Space Station

The diary for the six-month mission for the four astronauts to be tasted aboard the SpaceX Crew-2 mission today is about one hundred experiments in the diary


In two decades around the Earth the International Space Station has become a leading cosmic laboratory, with astronauts researching everything from black holes to disease and even microgravity gardening.

The ISS, which rotates about 250 miles above Earth, is as large as an indoor soccer field and divided as a hive is space where the crew can conduct experiments with guidance from grassroots researchers.

Astronauts are often the guinea pigs as well. More than 3,000 scientific tests have been conducted at the ISS since its staffed tours began in 2000.

“Oh a science perspective, there have been some major discoveries, ”said Robert Pearlman, space historian and co-author of“ Space Stations: The Art, Science, and Reality of Working in Space ”.

The latest mission – called “Alpha” left Alpha Centauri, the star system closest to ours – will be no exception. On Thursday, U.S. astronauts Shane Kimbrough and Megan McArthur, the Japan Aerospace Exploration AgencyAkihiko Hoshide and the European Space Agency‘s Thomas Pesquet blown away for the ISS aboard the SpaceX Crew-2 mission.

A SpaceX Falcon 9 rocket with the company's Crew Dragon spacecraft is rolled to Launch Complex 39A as preparations continue for Crew-2's mission at NASA's Kennedy Space Center in Cape Canaveral, Florida;  PIC: AUBREY GEMIGNANI / NASA VIA AP

A SpaceX Falcon 9 rocket with the company’s Crew Dragon spacecraft is rolled to Launch Complex 39A as preparations continue for Crew-2’s mission at NASA’s Kennedy Space Center in Cape Canaveral, Florida; PIC: AUBREY GEMIGNANI / NASA VIA AP

They are likely to be busy. Alongside works to maintain the space station itself, there are about one hundred experiments in the diary for their six-month mission. These include an acoustic technique that uses ultrasonic waves to move and manipulate objects or liquids without touching them.

Pesquet France has said his favorite planned research is a study examining the effects of weight gain on brain organoids – a brain stem created using stem cell technology.

Scientists hope this research can eventually help space agencies prepare for long-range space missions that will expose crews to space rigor for long periods of time, and even help fight brain disease on the Earth. “It really sounds like science fiction to me,” joked Pesquet, an aerospace engineer.

There is ongoing research into so-called “tissue chips” – small models of human organs that contain different cell types and are used to study things like aging in the immune system, kidney function and muscle loss.

“We don’t quite understand why, but in microgravity, cell-to-cell communication works differently than it does in a cell culture flask on Earth,” said Liz Warren, senior program director at the US ISS National Laboratory United States, adding cells also assemble differently.

“These features allow cells to behave more like them inside the body. Thus, microgravity seems to provide a unique opportunity for tissue engineering. ”

Another important element of the mission is upgrading the station’s solar power system by installing new compact panels that roll open like a giant yoga mat.

Crew-2’s launch day coincides with Earth Day, and by the time the crew return they will have also contributed to environmental research by extracting 1.5 million images of phenomena such as artificial night-time lighting, algal blooms, and spraying Antarctic ice shelves.

The experiments are designed for the long-term, beyond individual missions, said Sebastien Barde of Cadmos France, who organizes microgravity science experiments in space.

The study of weightlessness – or microgravity – has gone from “innovation to something standardized”, with increasingly accurate measurement methods, says Barde. “Twenty years ago, there was no ultrasound machine on board,” he added.

Claudie Haignere, the first French woman to fly in space, visited the ISS in 2001 and remembers her as somewhat “poorly equipped”. Now she says she prides herself on “exceptional labs”.

The astronauts are also waiting longer – six months, versus two weeks for the first staffed flights – giving researchers more time to measure the effects of microgravity on them.

Spaceflight changes the human body. It weakens muscles and bone and affects the heart and blood vessels. Some of the effects are similar to the accelerated development of aging and disease on Earth. As guinea pigs for this research, the ISS crew have also collected data on black holes, pulsars and cosmic particles to help broaden our understanding of the Universe.

With the ability to grow supplementary food considered an important step to help humans venture deeper into Space, they have even done some experimental gardening. In 2015, astronauts sampled their first space-grown salad and have since tried to grow radishes. Pearlman said the findings range from those related to human health – such as treatment for salmonella – to experimental engineering.

“One very promising technology at the moment is imminent in 3D printing body parts,” he said.