Photos: BepiColombo stacked for launch to Mercury

The BepiColombo spacecraft is pictured in launch configuratin shortly before stacking atop the Ariane 5 rocket in French Guiana. Credit: ESA/CNES/Arianespace – Photo Optique Video du CSG – S. Martin

Ground crews at the Guiana Space Center in South America have spent the last few months preparing the BepiColombo spacecraft, a tandem mission with European and Japanese science orbiters bound for Mercury, for launch aboard an Ariane 5 rocket.

Liftoff is scheduled for 0145 GMT on Oct. 20 (9:45 p.m. EDT on Oct. 19) from Kourou, French Guiana.

The BepiColombo spacecraft stands roughly 21 feet (6.4 meters) tall at launch and weighs 8,997 pounds (4,081 kilograms) fully fueled with hydrazine and xenon propellants for the 7.2-year journey to Mercury.

Workers at the spaceport in French Guiana have spent the last few months readying the BepiColombo spacecraft for launch. Key steps included filling of the spacecraft with propellant, and stacking the major parts of the vehicle together for the cruise to the solar system’s innermost planet.

This illustration shows the major components of the BepiColombo mission. At top is the Japanese Mercury Magnetospheric Orbiter. Below that is the spacecraft’s sunshield, which will cover the Japanese orbiter during the interplanetary cruise. Third from top is the European Mercury Planetary Orbiter, and at bottom is the European-built Mercury Transfer Module. Credit: ESA/ATG medialab

BepiColombo’s European-built Mercury Planetary Orbiter carries 11 instruments, a suite comprising a high-resolution mapping camera, a laser altimeter, an accelerometer, and a set of spectrometers on a downward-facing science deck that will remain pointed toward the planet throughout each orbit.

The Japanese-made Mercury Magnetospheric Orbiter’s five science sensors will study the plasma environment around Mercury, attempt to image the planet’s sodium-rich tenuous atmosphere, and measure Mercury’s magnetic field.

The spacecraft also includes the Mercury Transfer Module, a section with four steerable plasma engines and solar arrays designed to steer BepiColombo through the inner solar system through a series of gravity assist encounters with Earth, Venus and Mercury before finally arriving in orbit around the innermost planet in December 2025.

The BepiColombo modules will separate after arriving at Mercury, with the European and Japanese orbiters heading to different orbits. The Mercury Transfer Module will be jettisoned along with a sunshield that will keep the Japanese part of BepiColombo at the right temperature during the interplanetary transit from Earth to Mercury.

BepiColombo will become the second mission to orbit Mercury after NASA’s MESSENGER spacecraft, which explored the planet from 2011 through 2015.

The photos below show the BepiColombo spacecraft’s launch preparations in French Guiana after a series of Antonov cargo flights delivered the major pieces of the mission to the launch base from Europe.

The spin-stabilized Mercury Magnetospheric Orbiter shortly after arriving in Kourou, French Guiana. Credit: JAXA/ESA–M. Basile
The Mercury Planetary Orbiter, with its hand-sewn insulation panels to protect it from extreme temperatures on the mission to Mercury. Credit: ESA – S. Corvaja
One of the Mercury Transfer Module’s two solar arrays undergoes a deployment test. Credit: ESA – S. Corvaja
A technician sews insulation panels on BepiColombo’s Mercury Transfer Module in French Guiana. Credit: ESA – S. Corvaja
The Mercury Planetary Orbiter. Credit: ESA – S. Corvaja
A technicians sews thermal blankets on BepiColombo’s Mercury Transfer Module. Credit: ESA – S. Corvaja
Several major pieces of the BepiColombo mission are visible in this image inside the processing facility at the Guiana Space Center. In the foreground is the Mercury Transfer Module, and one of the MTM’s solar panels, the sunshield, and the Mercury Planetary Orbiter are visible in the background. Credit: ESA – S. Corvaja
The Mercury Planetary Orbiter and Mercury Transfer Module undergo electrical compatibility testing. Credit: ESA–B.Guillaume
The solar wing on the Mercury Planetary Orbiter is deployed during a test at the Guiana Space Center. Credit: ESA – M. Pedoussaut
The BepiColombo “ministack” is on the move at the Guiana Space Center. The Mercury Planetary Orbiter and Mercury Magnetospheric Orbiter are connected together in this image. Credit: ESA/CNES/Arianespace/Optique video du CSG – P.Baudon
The BepiColombo Mercury Transfer Module (left) and the “ministack” of the Mercury Planetary Orbiter and Mercury Magnetospheric Orbiter (right) are prepared for chemical fueling. Credit: ESA/CNES/Arianespace/Optique video du CSG – P.Baudon
Technicians prepare to mate the Mercury Transfer Module with the two BepiColombo science orbiters. Credit: ESA/CNES/Arianespace/Optique video du CSG – P.Baudon
The BepiColombo science orbiter “ministack” is lowered on the Mercury Transfer Module. Credit: ESA/CNES/Arianespace/Optique video du CSG – P.Baudon
The BepiColombo spacecraft is lifted in preparation for attachment to its Ariane 5 launcher. Credit: ESA/CNES/Arianespace/Optique video du CSG – JM Guillon
Credit: ESA/CNES/Arianespace/Optique video du CSG – JM Guillon
The BepiColombo spacecraft is lowered onto its Ariane 5 launcher in the final assembly building at the Guiana Space Center. Credit: ESA – M. Pedoussaut
The sunshield is lowered over the Mercury Magnetospheric Orbiter. Credit: ESA – M. Pedoussaut
The Mercury Magnetospheric Orbiter will be protected by a sunshield during BepiColombo’s outbound cruise from Earth. Credit: ESA – M. Pedoussaut
The Ariane 5 rocket’s payload fairing is prepared for encapsulation of the BepiColombo spacecraft on top of the launcher. Credit: ESA-Manuel Pedoussaut
Credit: ESA-Manuel Pedoussaut
The BepiColombo spacecraft is encapsulated inside the Ariane 5’s payload fairing. Credit: ESA-Manuel Pedoussaut

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