Space mice — NASA's rodent astronauts

NASA has sent mice to the ISS to learn more about the effects of microgravity and how humans would fare on long space trips like voyages to Mars. This most recent experiment is far from the first rodent space mission.

The International Space Station (ISS) has seen many interesting experiments. From growing lettuce in space to studying twins (one in space and one on Earth) to compare the different developments their bodies went through.

One study carried out by NASA doesn't involve human subjects, but animal ones: the researchers sent mice up to the ISS to see how organisms react to microgravity.

"Since the environment of space alters multiple, interacting biological systems — including bones, muscles, the heart, blood flow, and the immune system – sometimes it is better to study everything at once in the entire organism," NASA states on their "rodent research" site. "This can be achieved by working with research model organisms, such as mice and other rodents."

While it might not seem like it at first glance, humans and mice actually have quite a lot in common, which makes the little rodents perfect guinea pigs, so to speak. Another plus is mice's faster development, so effects of microgravity can be studied on a shorter timescale.

Nature and Environment | 19.04.2018

All of this is why NASA has run several different experiments with mice in space. We have footage of the most recent set of space mice:

The start of it all

NASA first launched its rodent mission in 2014. Its primary interest was to see whether mice could actually survive the journey into space on an uncrewed vehicle and life on the ISS — and that the astronauts onboard the space station could work with the little rodents. Rodent Research-1 lasted 37 days and laid the groundwork for what was to come. Before this, rodents flew aboard 27 space shuttle missions between 1983 and 2011, but those only ranged from four to 18 days in duration.

Developing treatments for muscle- and bone-diseases

The second rodent mission, launched in 2015, focused on the effect space travel had on mice's muscles, bones and neurological systems. Once results could be transferred to human health research, they could "help scientists discover ways that therapies could act on muscle- and bone-related diseases, which could facilitate the development of new treatments," NASA says.

A year later, the space administration partnered with a US pharmaceutical company to look into developing new treatments for skeletal muscle wasting and weakness. And in 2017, Rodent Research-4 focused on how bones grow and heal in microgravity and on Earth. The results will be useful for astronauts as well as for people with injuries down on Earth.

The first animal to orbit Earth wasn't a rodent, but dog Laika in 1957

Effects of a Mars mission

Several other rodent missions have examined effects of microgravity on blood vessels in the brain and eyes and how the body readapts to Earth's conditions after an extended stay in space.

The mice on NASA's most recent space mission are part of a study that's supposed to generate insights on how humans could survive voyages to Mars and beyond. They live in a habitat box that has been significantly improved from earlier versions. Scientists can now observe the mice easier, and cameras were installed in positions that made it less likely for them to be obstructed by fluids or small pieces of dirt.

Initial observations have shown scientists that the mice were nonplussed about their floating state at first. But within days, they returned to normal routines like grooming — and then began to take advantage of microgravity by running laps along their enclosure's walls. While many factors still need to be examined, this activity level bodes well for humans that will go on long space journeys in the future.

Happy birthday, ISS! The International Space Station at 20

A 19,000 kilo building block

The first module of the International Space Station was sent into orbit 20 years ago. It was the Russian-made Zarya, a "Functional Cargo Block" — also known as FGB. Zarya came in at 19,000 kilograms (41,000 pounds) and was 12 meters (39 feet) long. It was commissioned and paid for by America and built by a Russian space company. It was the start of two decades of international cooperation.

Happy birthday, ISS! The International Space Station at 20

Larger than a six-bedroom house

The International Space Station is home to an international crew of six people, who also work there. It travels at a speed of five miles per second (8kps), orbiting Earth every 90 minutes. Eight solar arrays provide power to the station and make it the second brightest object in the night sky after the moon. You don't need a telescope to see it.

Happy birthday, ISS! The International Space Station at 20

Expedition 1

This was the ISS's first long-term crew: American astronaut William Shepherd (center) and his two Russian fellow workers, cosmonauts Yuri Gidzenko (left) and Sergei Krikalev (right). They moved into the ISS on November 2, 2000, and stayed for 136 days.

Happy birthday, ISS! The International Space Station at 20

Up to one year

On average, space station crews, also known as expeditions, stay in space for about five and a half months. Some crew members, however, have broken that record — for example, NASA astronaut Scott Kelly (photo) and Roscosmos cosmonaut, Mikhail Kornienko. They lived and worked in space for a whole year.

Happy birthday, ISS! The International Space Station at 20


This is Canadian astronaut Chris Hadfield strumming his guitar on the ISS at Christmas 2012. Since 2000, crew members and Space Flight Participants (self-financed space tourists) have come from 18 different countries. The most have come from the USA and Russia. Other teams have included people from Japan, the Netherlands, Italy, France, Germany, Brazil and South Africa.

Happy birthday, ISS! The International Space Station at 20

Shuttle bus

Crew members and supplies arrive at the ISS via transfer vehicles and space freighters. This photo shows space shuttle Atlantis, which operated until 2011, docking onto the space station. These days, astronauts arrive at the ISS in a Soyuz capsule.

Happy birthday, ISS! The International Space Station at 20

Out for a walk

There have been more than 210 spacewalks — "EVA" in astronaut terms — at the ISS since 2000. This photo shows astronaut Mike Hopkins on a spacewalk on December 24, 2013.

Happy birthday, ISS! The International Space Station at 20

Extraordinary exterior

The ISS has several robotic arms. This one, Canadarm2, is 57.7 feet (17.58 meters) long when fully extended, and has seven motorized joints. It can lift 220,000 pounds (100 tons), which is the weight of a space shuttle orbiter. This photo shows astronaut Stephen K. Robinson anchored to Canadarm2's foot restraint.

Happy birthday, ISS! The International Space Station at 20

Blue Dot mission

Crew members spend about 35 hours per week conducting research. On his first mission, dubbed "Blue Dot," German ESA astronaut Alexander Gerst observed and analyzed changes to the human body that occur in microgravity. Gerst's second mission at the ISS started in June 2018. In October 2018, he became the first German astronaut to command the ISS.

Happy birthday, ISS! The International Space Station at 20

Back home

When their time at the ISS is over, astronauts are taken away in a Soyuz capsules. They fall to Earth with a parachute to ease their landing. Welcome home!