Cosmic Rays - Blog Posts
Here’s a great example of the kinds of experiments astronauts perform on the International Space Station, just like I talked about in Episode 19! I absolutely want to high-five whoever called is ISS-CREAM.
From Frozen Antarctica to the Cold Vacuum of Space
A new experiment that will collect tiny charged particles known as galactic cosmic rays will soon be added to the International Space Station. The Cosmic Ray Energetics And Mass for the International Space Station payload, nicknamed ISS-CREAM, will soon be installed in its new home on the Station’s Japanese Experiment Module Exposed Facility. ISS-CREAM will help scientists understand more about galactic cosmic rays and the processes that produce them.
Wait, what are cosmic rays?
Cosmic rays are pieces of atoms that move through space at nearly the speed of light. Galactic cosmic rays come from beyond our solar system.
They provide us with direct samples of matter from distant places in our galaxy.
Why do these things go so fast?
Galactic cosmic rays have been sped up by extreme processes. When massive stars die, they explode as supernovas. The explosion’s blast wave expands into space along with a cloud of debris.
Particles caught up in this blast wave can bounce around in it and slowly pick up speed. Eventually they move so fast they can escape the blast wave and race away as a cosmic ray.
Where can we catch cosmic rays?
Cosmic rays are constantly zipping through space at these super-fast speeds, running into whatever is in their path – including Earth.
But Earth’s atmosphere is a great shield, protecting us from 99.9 percent of the radiation coming from space, including most cosmic rays. This is good news for life on Earth, but bad news for scientists studying cosmic rays.
So… how do you deal with that?
Because Earth has such an effective shield against cosmic rays, the best place for scientists to study them is above our atmosphere – in space. Since the 1920s, scientists have tried to get their instruments as close to space as possible. One of the simplest ways to do this is to send these instruments up on balloons the size of football stadiums. These balloons are so large because they have to be able to both lift their own weight and that of their cargo, which can be heavier than a car. Scientific balloons fly to 120,000 feet or more above the ground – that’s at least three times higher than you might fly in a commercial airplane!
Credit: Isaac Mognet (Pennsylvania State University)
Earlier versions of ISS-CREAM’s instruments were launched on these giant balloons from McMurdo Station in Antarctica seven times, starting in 2004, for a total of 191 days near the top of the atmosphere. Each of these flights helped the team test their hardware and work towards sending a cutting-edge cosmic ray detector into space!
How is going to space different than flying balloons?
Balloon flights allowed the team to collect a lot of cosmic rays, but even at 120,000 feet, a lot of the particles are still blocked. Scientists at the University of Maryland, College Park, who operate ISS-CREAM, expect to get about 10 times as much data from their new home on the International Space Station.
That’s because it will be both above the atmosphere and fly far longer than is possible with a balloon. As you might imagine, there are large differences between flying something on a balloon and launching it into space. The science instruments and other systems had to be changed so ISS-CREAM could safely launch on a rocket and work in space.
What will ISS-CREAM do?
While on the space station, ISS-CREAM will collect millions of cosmic rays – electrons, protons and atomic nuclei representing the elements found in the solar system. These results will help us understand why cosmic rays reach the wicked-fast speeds they do and, most important, what limits those speeds.
ISS-CREAM launches to the International Space Station aboard the latest SpaceX Dragon spacecraft, targeted to launch August 14. Want to learn more about ISS-CREAM and some of our scientific balloons? Check out our recent feature, NASA’s Scientific Balloon Program Reaches New Heights.
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