SCOTT DETROW, HOST:
Seeing a total solar eclipse along its path of totality is a rare, often once-in-a-lifetime event. It only lasts a few minutes, which is enough time to wow and awe observers but not nearly enough time for scientists who study the sun and its outer atmosphere called the corona. A new mission from the European Space Agency wants to solve this problem. Last week, a pair of satellites rocketed into orbit with a simple goal - to create more solar eclipses, ones that last hours instead of minutes. Here to tell us more about this and how it works is Damien Galano. He's the project manager for this mission, called Proba-3. Welcome.
DAMIEN GALANO: Thank you for having me.
DETROW: Let's just start with a question that I think anybody hearing that introduction is asking - how exactly does this work? How do two satellites create solar eclipses?
GALANO: So there are two satellite, and basically, we want to recreate the condition of a total solar eclipse. So the first spacecraft - we call it the Occulter spacecraft and - plays the role of the moon and to block out the light from the sun. And the other spacecraft - that we call the Coronagraph - will have to be positioned precisely in the shadow cast by the Occulter spacecraft at a distance of about 500 feet.
DETROW: So this is creating an eclipse for the second satellite. How much beyond that will this eclipse last and reach? I mean, somebody might be thinking, can I see this from Earth? I assume the answer is no, but I want to ask.
GALANO: No, no. This will be done when the spacecraft are at their maximum altitude at about 40,000 miles. And when they are far from the gravity of the Earth, that is a perturbation for us to be able to control precisely the spacecraft. And they will maintain this formation for about six hours.
DETROW: Six hours - and will this be a one-time experiment or will this be able to be recreated over and over with these two satellites?
GALANO: We expect to be able to recreate it every orbit. So the period of the orbit is 20 hours.
DETROW: Oh, wow.
GALANO: So every orbit, every 20 hours, we expect to be able to have a consecutive six hours of eclipse condition.
DETROW: I love this image of two satellites almost dancing with each other in this aligned orbit. Can you tell us why you want to do this, though? What are you looking for? What does a solar eclipse allow scientists to study?
GALANO: So the solar corona matters because it's intimately linked to the sun, the way the sun - our star - works and all the physics. We know that it's in the corona that originates the solar wind, so the constant flow of charged particles expanding from the sun. So observing the corona help the solar physicist to better model how the sun works and to better understand the activities inside this corona and how it can affect the Earth. That's through what we call the space weather.
DETROW: So the satellites launch, they're in orbit now. When are you expecting the first attempt at creating an eclipse?
GALANO: So we are performing at the moment the commissioning of the spacecraft. So little by little, we are activating the different equipment, the different functions on board. We expect if everything goes well that in March, we should be able to have the two spacecraft aligned to observe for the first time and take the first images of the corona with our system.
DETROW: That's Damien Galano, the project manager for the Proba-3 mission at the European Space Agency. Thanks so much, and good luck.
GALANO: Thank you, Scott. Bye-bye.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
