Last Week's Ariane 6 Carried a Neat Little Cubesat

Tuesday (July 9)'s First Flight of the Ariane 6 carried an interesting little scientific payload, especially to those of us who follow the solar activity, solar flaring, Coronal Mass Ejections and more.  Called CURIE, for CubeSat Radio Interferometry Experiment, it was really a pair of cubesats launched as one, which will then be spread apart a known distance and used to attempt determine the sources on the sun of low frequency signals from the sun that are emitted during these events.

According to NASA, scientists first detected these radio signals decades ago. While they know that they occur during solar storms, they don’t know exactly where they come from. Do they come from the spread out part of a solar CME, like this one, or do they come from well under the sun's surface?

CURIE will investigate where solar radio waves originate in coronal mass ejections, like this one seen in 304- and 171-angstrom wavelengths by NASA’s Solar Dynamics Observatory. Image credit: NASA/Goddard Space Flight Center

CURIE is made up of two spacecraft that launched bolted together as one, later separating into two in orbit. From their separate vantage points, the satellites CURIE A and B will make it possible to measure the same radio waves from two locations at the same time. Using the technique of radio ‘interferometric analysis,’ the origin of detected radio waves can be reconstructed. 

The CURIE mission aims to advance our understanding using a technique called low frequency radio interferometry, which has never been used in space before. This technique relies on CURIE’s two independent spacecraft — together no bigger than a shoebox — that will orbit Earth about two miles apart. This separation allows CURIE’s instruments to measure tiny differences in the arrival time of radio waves, which enables them to determine exactly where the radio waves came from.

Don't let the 304 and 171 angstrom wavelengths of the dramatic photo influence your thinking. The two CURIE Cubes will measure from 0.1 to 19 MHz, which corresponds to a wavelength of 3000 meters (at 0.1 MHz (100 kHz)) to 15.79 meters at 19.0 MHz. 304 and 171 angstroms are enormously higher in frequency than these Cubesats can measure: 9.8 and 17.5 GHz. The baseline of the interferometer - how far about the two satellites will be - affects what it can measure, and with a separation of two miles, I'd say they're expecting the answers to be in the bottom part of that 0.1 to 19 MHz range (2.0 miles is 3218 meters). I'd guess more like 1 MHz than 10 MHz.

Still, it's a pretty neat sounding experiment. I haven't designed interferometers before but have been around them - optical and radio. Here's hoping they get some nifty results.  

And don't forget - sometimes the most important answer in science isn't that you found what you expected it's that what you found that makes no sense whatsoever. Not, "Eureka! I've found it!"; it's "That's weird."