A mission to the planet Mercury got off to a flashy start with tonight’s launch of an Ariane 5 heavy-lift rocket, but there’s a long way to go before the double-barreled BepiColombo probe gets to its destination.
Liftoff from the European Arianespace launch complex in Kourou, French Guiana, came off flawlessly at 10:45 p.m. (6:45 p.m. ET). The $1.5 billion mission, named after the late Italian astrophysicist Giuseppe “Bepi” Colombo, is a joint project of the European Space Agency and the Japan Aerospace Exploration Agency, or JAXA.
Over the course of seven years, the spacecraft will trace a complex path with an Earth flyby in 2020, two Venus flybys and six Mercury flybys. All those close encounters are carefully designed to slow down BepiColombo’s speed enough to put it into a stable orbit around Mercury in 2025. (It was Colombo who suggested such a series of gravity-assist maneuvers could work for a Mercury mission.)
The transport spacecraft will use an innovative type of solar electric-powered ion thruster system to adjust its course along the way.
When the probe arrives at Mercury, two orbiters will go their separate ways. One of the orbiters, known as the Mercury Planetary Orbiter, will make a wide-spectrum survey of the planet using a suite of 11 instruments, including cameras, spectrometers, a radiometer and a laser altimeter.
The other half of BepiColombo’s science mission will be conducted by the Mercury Magnetospheric Orbiter, provided by JAXA and nicknamed Mio. That orbiter carries instruments that are primarily dedicated to the study of Mercury’s magnetic field.
BepiColombo is designed to endure Mercury’s harsh environment, including the glare of solar radiation and temperatures that swing between 840 degrees Fahrenheit on the planet’s sunlit side and 300 degrees below zero on the dark side.
This is only the third mission to Mercury, following NASA’s Mariner 10 in 1974-1975 and Messenger in 2011-2015. BepiColombo will follow up on the oddities that previous observations have turned up — including the iron core that accounts for about 60 percent of Mercury’s mass and 85 percent of its radius, and the water ice that lies within permanently shadowed craters.
During the buildup to tonight’s launch, ESA Director General Jan Wörner said the appeal of Mercury and the BepiColombo mission isn’t strictly scientific.
“The fascination is the most important thing,” he said. “Fascination leads to inspiration, and inspiration leads to motivation, and that’s what we need for our society.”