Scientists are trying to melt a thin layer of ice that is increasingly clouding the vision of the "dark universe detective" space telescope Euclid, the European Space Agency said on Tuesday.

It is the latest of several technical setbacks for the wide-eyed telescope, which blasted off into space in July on a mission to chart a third of the sky.

By doing so, the ESA hopes Euclid will reveal out more about the nature of dark matter and dark energy, which are thought to make up 95 percent of the universe but remain shrouded in mystery.

During checks in November, the team on the ground first noticed that they were losing a little light coming into the telescope's visible light imager, Euclid instrument operations scientist Ralf Kohley told AFP.

Simulated effects of microgravity, created by 60 days of constant bed rest, severely disrupts rhythmic gene expression in humans, according to a new study from the University of Surrey published in iScience.

Astronauts exposed to microgravity experience changes to physiology, including immune suppression, increased inflammation, and reduced muscle mass and bone density. With the increase in human spaceflight, it is important to understand changes in the molecular mechanisms underlying these changes.

Lead author Professor Simon Archer, Professor of Molecular Biology of Sleep at the University of Surrey, said, "This unique study represents the largest longitudinal dataset of time series gene expression in humans. Human gene expression varies rhythmically over the 24-hour day, and it is important to collect time series data rather than from just single time points to get a full picture of what occurs in the body when exposed to simulated microgravity.

"It also raises questions about the impact of constant bed rest on our bodies as we have identified a dramatic effect on the temporal organization of human gene expression.

Another of the instruments planned for flight aboard NASA's Interstellar Mapping and Acceleration Probe (IMAP) is ready for installation on the spacecraft.