Two spacecraft developed by the European Space Agency launched Thursday atop an Indian rocket, beginning a mission to test new formation flight techniques and observe a rarely seen slice of the Sun’s etheric corona.
ESA’s Proba-3 mission is purely experimental. The satellites are equipped with advanced sensors and ranging equipment that will allow the two spacecraft to orbit around the Earth in step with each other. Proba-3 will attempt to achieve millimeter-scale precision, several orders of magnitude better than the requirements for approaching spacecraft to dock with the International Space Station.
“In short, this is a space experiment to demonstrate a new concept, a technically challenging new technology,” said Proba-3 project manager Damian Galano.
The two Proba-3 satellites were launched from India aboard the Polar Satellite Launch Vehicle (PSLV) at 5:34 a.m. ET (10:34 UTC) on Thursday. PSLV placed Proba-3 into an extended orbit with a minimum point of approximately 356 miles (573 kilometers) and a maximum point of approximately 37,632 miles (60,563 kilometers), with an inclination of 59 degrees to the equator.
India’s PSLV will accelerate beyond the speed of sound shortly after launch on Thursday’s Proba-3 mission.
credit:
Isro
After the initial checkout, two Proba-3 satellitesThe vehicles, each smaller than a compact car, will be separated from each other to begin technology demonstration experiments early next year. The larger of the two satellites is known as the coronagraph spacecraft and carries a suite of scientific instruments for imaging the sun’s corona, or outer atmosphere. The small spacecraft, named Occulter, is equipped with navigation sensors and low-impact thrusters to help it get to a position less than 500 feet (150 meters) from its accompanying coronagraph.
From the perspective of the coronagraph spacecraft, this is just the right distance for the 4.6-foot (1.4-meter) disk attached to Prova 3’s Occulter spacecraft to obscure the Sun’s surface. The occultation blocks the Sun’s bright light, casting a shadow just 3 inches (8 centimeters) on the coronagraph satellite, revealing the wispy, super-hot gas that makes up the solar corona.
