FYI.

This story is over 5 years old.

Tech

A New Crew of Mousetronauts Is Headed to the International Space Station

The mice will be observed via a live video feed, as well as expected to carry out tasks designed to test their muscle function.

On April 8, SpaceX is set to resume resupply flights to the International Space Station, carrying with it some special crew members. Tucked inside the Dragon cargo ship is a crew of 20 mousetronauts that will help scientists better understand how muscles deteriorate during spaceflight.

Rodents, in particular mice and rats, have a long history in spaceflight dating back to the 1950s. At least 27 shuttle missions carried rodent passengers into orbit. Each of those missions was short-term, lasting no longer than two weeks. On board the ISS, scientists are able to house mice for periods of 30 to 90 days, which will substantially increase our knowledge of the effects of microgravity on different organ systems.

Advertisement

So why mice? Mice are just one type of "model" organism, meaning a widely-studied organism used to help understand biological processes. Other types of model organisms include fruit flies and certain types of yeast. The benefit of conducting research with these types of organisms is commonality in DNA sequences, and shorter lifespans, which allow researchers to perform more experiments (even multi-generational ones) in a short amount of time.

The Rodent Research Facility. Image: NASA

In orbit, mice will be used to test how bones and muscles respond to a microgravity environment. Understanding how these systems behave in the absence of gravity will help researchers counteract the effects and even develop treatments to fight many diseases here on Earth. Since mice have been used in orbital experiments for decades, they have proven to be an invaluable tool in understanding how the human body will respond to the harsh environment of outer space.

Mice have a much shorter lifespan than humans, with the typical mouse living approximately two years. When we look at what happens with rodents as they age, they display many of the same degenerative processes over those two years that humans display later in life. The pathways and processes involved in breaking down body systems occur at a more rapid pace in animals. Thanks to the shuttle program, we understand how these processes work over shorter periods, but are lacking in longer duration studies. This is why longer studies are beneficial; researchers get a much clearer picture of what is happening.

Advertisement

The mice will be observed via a live video feed, as well as expected to carry out tasks designed to test their muscle function

This particular experiment, dubbed Rodent Research-3-Eli Lilly and sponsored by the eponymous US pharmaceutical company, will focus on determining what factors affect muscle size and function in space. Researchers from Eli Lilly will be testing an experimental treatment they hope will one day help patients combat muscle wasting diseases such as ALS and Muscular Dystrophy.

"This flight in particular is important to our overall research program on the ISS," explained Julie Robinson, NASA's chief scientist during a pre-launch teleconference. "SpaceX is a workhorse for us, carrying many late load payloads. This capability allows us to conduct important biological research with live animals."

You may be wondering how the mice handle the launch. NASA assures us that since the rodents are much smaller than humans, the G-forces they experience during launch are a lot less than what a human would experience. "We do careful ground-based studies in advance," Ruth Globis, a NASA project scientist said. "We know from shuttle that the mice tolerate it very well. Dragon is a much smoother flight."

Once they arrive on station, the all-female rodent crew will get to work. They will be divided into two groups: one that will receive a series of subcutaneous injections—which contain a special myostatin inhibitor which is thought to slow the rate of muscle degeneration—and a control group. The same experiment will be conducted on the ground and the data will be compared.

According to Rosamund Smith, principal investigator on the experiment, "Muscle wasting is seen in diseases such as muscular dystrophy, ALS, cancer cachexia and even musculoskeletal frailty associated with aging," she explained. "We're hoping the experiment results will give us scientific insight into how better to treat patients who are suffering from muscle atrophy."

The mice will be observed via a live video feed, as well as expected to carry out tasks designed to test their muscle function. A specialized machine will even test their changes in their gripping strength over the course of the 6-week mission. Once the mission ends, the mice will be dissected and eventually sent back to Earth for further analysis.

The benefit of the ISS is that scientists can get a bigger picture of how muscle size and function deteriorates over time. The company hopes to take the results of this experiment and apply it to the development of drugs in order to better treat patients.

"With the help of CASIS and the ISS, we are doing research we cannot conduct here on Earth," said Kenneth Savin of Eli Lilly. "We are thrilled to work with NASA, and for many of our scientists this is the dream of a lifetime."