ESA Mirror array in Large Space Simulator

Credit: ESA-A. Le Floc'h

This vast enclosure, made to appear larger still by an array of mirrors at its end, is ESA's Large Space Simulator.

Europe's largest vacuum chamber, the LSS subjects entire satellites to space-like conditions ahead of launch.

This 15 m-high and 10 m-diameter chamber is cavernous enough to accommodate an upended double decker bus.

Visitors to this year's ESTEC Open Day will have the chance to see it for themselves.

Satellites are lowered down through a topside hatch. Once the top and side hatches are sealed, high-performance pumps create a vacuum a billion times lower than standard sea level atmosphere, held for weeks at a time during test runs.

ESA BepiColombo in ESTEC's LSS

Credit: ESA

The 121-segment mirror array seen in the image reflects simulated sunlight into the chamber, at the same time as the walls are pumped full of –190°C liquid nitrogen, together recreating the extreme thermal conditions prevailing in orbit.

Embedded sensors and measurement devices check whether a mission's thermal engineers have done their job well, and if the test satellite maintains an acceptable internal temperature range without buckling or other unwanted temperature-driven effects.

The LSS, seen here during a past refurbishment, is an essential part of ESA's Test Centre in the Netherlands, the largest facility of its kind in Europe, providing a complete suite of equipment for all aspects of satellite testing under a single roof.

ESA Open Day: Bepi-Colombo Mercury modules on view

Clad in white to stay cool, these modules making up BepiColombo – the ESA–Japan mission to scorching Mercury – will be on show to the public at this Sunday’s ESTEC Open Day, part of World Space Week.

BepiColombo must withstand temperatures of 450°C as it surveys the Solar System’s innermost planet, so long ground tests were essential.

This is the ‘engineering model’ of the spacecraft, basically identical to the flight model but built specifically for testing.

The Mercury Transfer Module, bottom, will transport the mission to Mercury using chemical and electric thrusters.

The Mercury Planetary Orbiter, above it, will study the planet with a variety of cameras and other sensors.

An additional module, Japan’s Mercury Magnetospheric Orbiter, not seen here, will study Mercury’s mysteriously strong magnetic field.

BepiColombo is on display as part of the ESTEC Open Day this Sunday, when ESA’s technical heart opens its doors to the public.

Visitors will have a chance to meet astronauts, talk to the scientists and engineers designing and running ESA missions, and handle retrieved hardware that has flown in space.

Visitors have to register through this link: www.esa.int/estecopenday2013. Because ESA are obliged to limit the total number of visitors, to ensure a great experience for all who do attend, they urge you to book as soon as possible to avoid disappointment.

ESA ESTEC Open Day - Video Overview