Engineers of the European Space Agency (ESA) have developed an effective method for removing icy deposits from the optical system of the cosmic Euclid telescope. The results of this procedure have far exceeded initial expectations.
The Euclid telescope, launched in 2023, faced the issue of accumulating water ice crystals on its high-precision optical elements. Despite the ice plane’s thickness being measured in nanometers, scientists observed a reduction in light intensity from distant galaxies due to this phenomenon.
Heating the entire spacecraft was not a viable option due to the sensitive scientific instruments onboard that could be damaged. Therefore, the engineers devised a unique phased approach where each mirror was heated sequentially in a controlled manner. Observations were conducted to assess the impact of this procedure on incoming light.
“It was midnight at the ESOC mission center when we started defrosting the first two mirrors,” said Misha Schmidt, the telescope’s operating manager. The team maintained constant communication with the ground station in Malargua, Argentina, to promptly address any deviations.
The scientists carefully heated the coldest mirror of the main telescope, the main suspect in ice formation, from an extreme temperature of -147°C to -113°C. “It was like magic!” exclaimed Misha. “Almost immediately, we noticed a 15% increase in light from the distant corners of the universe. I was confident we would see improvement, but not to such an astonishing extent.”
The success of the initial stage allowed scientists to pinpoint the exact location of ice deposits. While further icing is anticipated in the coming months, the optical decontamination procedure may now be incorporated into the telescope’s regular servicing routines.