The deep-space telescope Herschel took its final bow on Monday, climaxing a successful four-year mission to observe the birth of stars and galaxies, the European Space Agency (ESA) said.
The largest and most powerful infrared telescope in space, Herschel made over 35,000 scientific observations and amassed more than 25,000 hours of science data, it said.
“Herschel has been turned off,” ESA director general Jean-Jacques Dordain told journalists at the Paris Air Show.
“It is not a surprise, it was expected, it was scheduled,” he added.
Herschel has run out of a supply of liquid helium required to cool its instruments to near absolute zero (minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit) in order to make its observations.
“As it heats up it becomes unusable,” said Dordain, explaining why the data link with Herschel was shut down at 1225 GMT Monday.
Its mission officially ended on April 29, but the satellite was used in its dying weeks as an “orbiting testbed”, said an ESA statement.
“We had a sophisticated spacecraft at our disposal on which we could conduct technical testing and validate techniques, software and the functionality of systems that are going to be reused on future spacecraft,” said Herschel’s spacecraft operations manager, Micha Schmidt.
“This was a major bonus for us.”
The satellite has now been placed in a safe, “disposal” orbit around the Sun.
“The last thruster burn came today, ensuring that all fuel is depleted,” said the ESA statement.
Read more at: Phys.org