- News

Key components of the ESA-led Mercury mapper BepiColombo have been tested in a specially upgraded European space simulator. ESA’s Large Space Simulator is now the most powerful in the world and the only facility capable of reproducing Mercury’s hellish environment for a full-scale spacecraft.

The Mercury Magnetospheric Orbiter (MMO) has survived a simulated voyage to the innermost planet. The octagonal spacecraft, which is Japan’s contribution to BepiColombo, and its ESA sunshield withstood temperatures higher than 350 degrees centigrade.

This is a taste of things to come for the spacecraft. BepiColombo will encounter fully ten times the radiation power received by a satellite in orbit around Earth and, to simulate this, the Large Space Simulator (LSS) at ESA’s ESTEC centre in the Netherlands had to be specially adapted: the lamps from the simulators were being used at their maximum power and the mirrors that focus the beam were adjusted.

Instead of producing a parallel beam of light 6 m across, they instead concentrated the light into a cone just 2.7 m in diameter when it reached the spacecraft. This created a beam so fierce that a new shroud with a larger cooling capacity had to be installed to ‘catch’ the light that missed the spacecraft and prevent the chamber walls from heating up.

BepiColombo consists of separate modules. The MMO will investigate the magnetic environment of Mercury. It is kept cool during its six-year cruise to Mercury by the sunshield. These are the two modules that have now completed their thermal tests.

In addition to enduring temperatures of 350°C, ESA’s Mercury Planetary Orbiter (MPO) will go where no spacecraft has gone before: down into a low elliptical orbit around Mercury, of between just 400 km and 1500 km above the planet’s scorching surface.

At that proximity, Mercury is worse than a hot plate on a cooker, releasing floods of infrared radiation into space. So, the MPO will have to deal with this as well as the solar heat. The MPO begins its tests in the LSS in the summer.

For more information about the BepiColombo mission, visit ESA's BepiColombo mission pages.

This article originally appeared on the ESA website