Solar eclipse on order: ESA probe Proba-3 about to be launched from India
With Proba-3, ESA not only wants to prove how precisely space probes can fly. The two probes are to explore our sun in a completely new way.
How Proba-3 is to explore the sun
(Image: ESA)
Proba-3, a test mission of the European Space Agency (ESA), is to be launched on Wednesday to test the high-precision formation flight of two satellites. If everything goes smoothly, the two satellites will later orbit the Earth at a distance of 150 meters from each other and study the sun. To do this, one will cast a shadow on the other, which will then be able to focus on the sun's corona. This should make it possible for the first time to explore the direct vicinity of the sun up to 1.1 times its radius. The probes will be launched at 11:08 a.m. by an Indian rocket.
A solar eclipse almost any time
As the ESA explains, the two probes will then create their own solar eclipse, so to speak, in order to make the corona visible. While this opportunity only occurs every 18 months or so on the Earth's surface, Proba-3 will have more than six hours of it every day. To do this, they are supposed to circle the Earth in an extremely elliptical orbit that takes them up to 60,000 kilometers away from our home planet every nineteen and a half hours. Only there is the influence of gravity low enough to enable extremely precise alignment without excessive fuel consumption.
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ESA calls the two satellites in the mission "Occulter" and "Corongraph", the former is responsible for the shadow and the latter for observing the sun. The mission is to be launched from the Satish Dhawan Spaceport (SHAR) in south-east India. A four-stage PSLV-XL rocket will be used. This was chosen because of its high performance and "reasonable" price tag. After all, it is a technology demonstration with a tight budget. The launch is to be broadcast live on the streaming channels of ESA and the Indian Space Agency ISRO.
The two probes should actually be in orbit by now, but there was a delay on the home straight, so to speak, during transportation to India. The spacecraft was not accepted by the air freight company, the ESA explained. The reason was the batteries that had already been installed. They therefore had to be removed and stowed in a separate box. This was the only way that Proba-3 could be flown to the subcontinent on November 2, which the mission is now due to leave a month later.
(mho)
