SpaceX launches baby squid and water bears

Astronauts on the International Space Station are about to get a special delivery.

SpaceX launched its 22nd cargo resupply mission to the space station on Thursday at 1:29 p.m. ET. The spacecraft is carrying more than 7,300 pounds of supplies, scientific research experiments and technology demonstrations. The vehicle will dock at the space station on Saturday.

Along for the ride are 5,000 tardigrades, also known as water bears, and 128 baby glow-in-the-dark bobtail squid.

Both will be involved in experiments on the space station, including assessing how water bears tolerate the space environment. Researchers also wants to know if the lack of gravity affects symbiotic relationships between the squid and beneficial microbes.

Other experiments heading to the station include a portable ultrasound, remote operation of robotic arms using virtual reality, analyzing how kidney stones form in space, studying the oral microbiome (that's in your mouth), and producing more stress-resistant cotton. More than a dozen of the experiments heading into orbit belong to student researchers.

Hundreds of scientific experiments are underway each day on the space station; it's an orbiting laboratory, after all. Astronauts oversee these experiments and report back their observations to scientists on Earth. The research helps us gain a better understanding of life in zero gravity, as well as discover benefits that can be applied on Earth.

The astronauts are also getting some fresh fruit and veggies in their cargo delivery, including Gala apples, navel oranges, cherry tomatoes, onions, lemons, mini peppers and avocados.

The cargo vehicle is even loaded up with new solar panels, which will increase the amount of energy available onboard the space station. Compact panels were used to make the ISS Roll-out Solar Array, or iROSA, which unfurls like a long rug. The array will be installed outside the space station by astronauts during two spacewalks in June.

Water bears and celestial umami

Beneath a microscope, tiny tardigrades look like bears. They are commonly found in water -- and at times, serving as the nemesis in "Ant-Man and the Wasp" -- but tardigrades are known for their ability to survive and even thrive in the most extreme environments.

"Tardigrades are a group of microscopic animals that are renowned for their ability to survive a number of extreme stresses," said Thomas Boothby, assistant professor of molecular biology at the University of Wyoming and principal investigator for the Cell Science-04 tardigrade experiment, in a news conference last week.

"Some of the things that tardigrades can survive include being dried out, being frozen and being heated up past the boiling point of water. They can survive thousands of times as much radiation as we can and they can go for days or weeks with little or no oxygen."

In fact, tardigrades can tolerate these extremes better than most forms of life, and what's more extreme than space? It's not the first time tardigrades have gone to space -- and there may even be some of them on the moon, after a mission carrying them crashed into its surface.

"They've been shown to survive and reproduce during spaceflight, and can even survive prolonged exposure to the vacuum of outer space," Boothby said.

Boothby's experiment is designed to see how tardigrades adapt to life in low-Earth orbit, which could lead to a greater understanding of the stressors humans face in space.

"Ultimately this information will give us insights into how one of the toughest organisms on Earth is able to survive the rigors of spaceflight," he said. "And our hope is that these insights will provide avenues for developing countermeasures or therapies that will help safeguard astronauts during prolonged space missions."

The UMAMI experiment stands for Understanding Microgravity on Animal-Microbe Interactions, and Jamie Foster, professor in the department of microbiology and cell science at the University of Florida, is its principal investigator. She is eager to see how healthy beneficial microbes communicate with animal tissues in space.

"Animals, including humans, rely on our microbes to maintain a healthy digestive and immune system," Foster said. "We do not fully understand how spaceflight alters these beneficial interactions. The UMAMI experiment uses a glow-in-the-dark bobtail squid to address these important issues in animal health."

Bobtail squid, which are only about 3 millimeters (0.12 inches) long, work as the perfect model to study this for two reasons. These squid have a special light organ inside the body that can be colonized by a species of luminescent bacteria. The squid can then use that bacteria to glow in the dark. This symbiotic relationship is between a single species of bacteria and one type of host tissue, so it's easy for researchers to follow how this process unfolds, Foster said.

The squid also have an immune system that is very similar to the type that humans have. Researchers will be able to learn if spaceflight alters the mutually beneficial relationship between animals and their microbes.

"As astronauts explore space, they're taking with them a company of different microbial species," Foster said. "And it's really important to understand how those microbes, collectively called the microbiome, change in the space environment and how those relationships are established."