From Ars Technica · · 2 min
Europe's $2 Billion BepiColombo Probe Prepares to Orbit Mercury
After eight years and nine planetary flybys, BepiColombo is shedding its cruise module for a risky insertion into Mercury's orbit.
In brief
After eight years and nine planetary flybys, BepiColombo is shedding its cruise module for a risky insertion into Mercury's orbit. Reaching Mercury's orbit takes more energy than flying past Pluto, requiring complex flybys, electric propulsion, and joint orbiter technology. Originally reported by Ars Technica.
Final approach to Mercury
Europe and Japan's nearly $2 billion BepiColombo mission has reached a critical milestone after an eight-year interplanetary voyage.
Harder to reach than Pluto
Entering orbit around Mercury requires more orbital energy, or delta-v, than sending a spacecraft flying past distant Pluto.
An unprecedented trajectory
To slow down enough for Mercury's gravity to capture it, BepiColombo required nine planetary flybys and powerful electric ion propulsion.
Jettisoning the cruise module
With the long cruise complete, the spacecraft successfully detached its Mercury Transfer Module, which provided power and propulsion during transit.
Three spacecraft in one stack
BepiColombo traveled as a three-part stack comprising the discarded transfer module, Europe's planetary orbiter, and Japan's magnetospheric orbiter, Mio.
High risk near the Sun
Separating the module just 39 million miles from the Sun posed significant risks, forcing the remaining orbiters to immediately take over power and thermal control.
“This is something that we will only see after separation if it has worked”
First light for main cameras
Separation unblocked BepiColombo's primary scientific cameras. Telemetry confirms the remaining orbiters are generating power and recharging batteries.
“We have confirmation that the power margins on the spacecraft are positive”
Overcoming propulsion setbacks
Despite losing partial thruster power in 2024 and extending cruise time by a year, the probe has logged 6 billion miles and will orbit on November 21.
Honoring an orbital pioneer
The mission honors Giuseppe 'Bepi' Colombo, the mathematician who devised planetary flyby trajectories for NASA's Mariner 10 mission in the 1970s.
Unlocking polar ice and composition
Scientists aim to analyze Mercury's composition in new wavelengths and inspect dark polar crater floors that may harbor water ice.
“We want to look at it in new colors beyond what we can see with our own eyes”
Dual orbiters, unprecedented views
Releasing two orbiters into distinct altitudes will let Europe and Japan simultaneously measure Mercury's surface features and its interaction with solar winds.
“Having two spacecraft there is groundbreaking”
What to remember
Reaching Mercury's orbit takes more energy than flying past Pluto, requiring complex flybys, electric propulsion, and joint orbiter technology.
