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How does it compare / relate to MESSENGER ? 6 July 2005 03:58 (UTC)

Without the lander, the science outcome will not so much different.--Stone (talk) 20:33, 4 June 2008 (UTC)

Also, comment about this in the intro: 'The mission is still in the planning stages' - this isn't true; my mother is a part of the team and the satellite is in the process of being built. Is this page just outdated? — Preceding unsigned comment added by (talk) 22:25, 20 November 2011 (UTC)

Will the Craft be pointing the opposite direction to Travel?[edit]

I read this sentence... This drive will be especially tested by the unusual need to actually push against the direction of travel, instead of with it; the ship will be falling toward the sun, accelerated by its gravity, and will have to constantly fight to keep its velocity slow enough to eventually enter Mercury's orbit.... does this mean that the Ion Thruster Engine will actually be facing the Sun? (i.e. the Spacecraft being "the wrong way round"?) --Hibernian 17:26, 5 September 2006 (UTC)

Yes, though the drive will not necessarily facing the sun directly, it will be facing into its intended direction of travel. --Kaz 20:23, 9 September 2006 (UTC)
A few lines above that it says "it will keep propelling the craft for years, building up far more speed per mass of fuel in the long run" which probably should be rephrased somehow. Rod57 (talk) 13:34, 19 January 2011 (UTC)

Just a question about the splitting after lunar trajectory[edit]

After reading of the splitting after lunar trajectory, i wondered myself a theoretical question. This might not be how this craft will be build but i just wonder how this works out in space.

Well here goes my question, if the chemical backpart-engine part would contain a gyroscope (or as a part would itself spin fast). And next we would split the machine in two by a simple spring. Then would a gyroscope effect add extra mass /contra inertia ? Resulting in that speed (arrow length) of both parts would be like this frontpart<-----v2--------- . --v1-->backpart Where V2 would be larger then v1, i just wonder of a gyroscopic effect could be handy for this. Its not directly related to this mission, but i'm curious to know. (talk) 21:53, 19 February 2010 (UTC)


The ministerial meeting in November 2008 is the critical cornerstone of the mission, due to budget problems the ministerial has to give money for the project. Three big ESA missions are on the list for the money ExoMars, Solar Orbiter and BepiColombo and the chance that all three get enough money is not foreseeable, because the decission of the ministers is not clear yet.--Stone (talk) 08:21, 18 October 2008 (UTC)


There is also a page; needs dismbiguation. (talk) 13:02, 17 January 2011 (UTC)

Done. Rod57 (talk) 13:51, 19 January 2011 (UTC)


AOCS is an unexplained term. (talk) 13:07, 17 January 2011 (UTC)

Can we add images[edit]

Are there any images of the components and full stack that can be added to the article ? Rod57 (talk) 11:32, 19 January 2011 (UTC)

Given that this is an ESA programme there are unlikely to be any free-use images. Any image uploaded would have to have a fair-use rational. ChiZeroOne (talk) 11:53, 19 January 2011 (UTC)
Hi there, in line with ESA's relatively new Open Access Policy, there's a bunch of images (check the individual licenses please) and even videos (1 - 2) now available under CC BY-SA 3.0 IGO
See also 's project list. Mtrova (talk) 15:53, 6 July 2017 (UTC)
I think Fæ managed to catch all of the CC'd BepiColombo images there, and all should be in Commons:Category:BepiColombo. Additionally, I didn't find anything useful on Flickr that we didn't already have. Huntster (t @ c) 10:03, 10 July 2017 (UTC)

Design of MSE lander[edit]

Can anyone add how far the design of the MSE got, and what technological problems remained ? Rod57 (talk) 02:21, 21 January 2011 (UTC)

Obsolete cruise[edit]

The graphic of the cruise from Earth to Mercury seems to be obsolete. It shows the old plan for a start in 2014, with an Earth flyby after one year and only two Mercury flybies. That cruise would have taken about 4 years instead of 6. I'm not sure why the video on the homepage shows that old track, though, and I can't find any visualization of the planed track for start in 2017. Given that, I think that the graphic should be removed. Renerpho (talk) 08:35, 19 May 2015 (UTC)

Well, your wish was granted, in a roundabout way. Turned out that the cruise graphic was a copyright violation, taken from the CNES website (archived link) years ago. Huntster (t @ c) 10:06, 10 July 2017 (UTC)


Can someone explain how and exactly when BepiColombo gets captured by Mercury? This ESA site doesn't explain it very well. Eric Kvaalen (talk) 13:23, 7 August 2017 (UTC)

Eric Kvaalen, BepiColombo will perform several flybys of Mercury, and each one will slow the spacecraft down. Normally a spacecraft flies by a planet and uses its gravity to speed up (and change trajectory); in this case, BepiColombo is doing the exact opposite: using Mercury's gravity to rob it of velocity. When it comes time for its orbital insertion, it's my understanding that Mercury will approach the spacecraft from behind, allowing the vehicle to "slide" or "drift" into a highly elliptical initial orbit with only minimal corrective engine burns. The two component spacecraft will then separate and each will maneuver into their own science orbits. Huntster (t @ c) 23:41, 7 August 2017 (UTC)
Thanks, Huntster. But I have two problems with what you say. First of all, let's say, as an approximation, that Mercury has a circular orbit. Then its speed around the sun is constant. Assuming it doesn't use its thruster, BepiColombo is on an elliptical orbit around the sun at any given time (except when under the influence of Mercury's gravity). There is a particular speed (in the sun's frame of reference) that it will have whenever it crosses Mercury's orbit, and in fact since it crosses Mercury's orbit at the same angle each time (whether crossing inwards or outwards) it will have the same speed relative to Mercury. So let's say it leaves Mercury after the first flyby with a particular "hyperbolic excess speed". When it comes back to Mercury (still assuming it doesn't use its thruster) it will again have that same hyperbolic excess speed as it approaches Mercury, and then after speeding up and slowing down (in Mercury's frame of reference) it will depart with that same hyperbolic excess speed, but in a new direction and therefore a new orbit. This means it can change its orbit and its period at each flyby, but it will always come back to Mercury with the same speed relative to Mercury! Which is not actually the case. I suppose this is because it does use its ion thruster as it orbits. Or maybe because the orbit of Mercury is not exactly circular.
The other problem I have is that in a two-body system, one body (BepiColombo) cannot sidle up to the other and just get into orbit around it. If it comes fromm "infinity" with a certain hyperbolic excess speed, then it will end up leaving towards infinity with that same hyperbolic excess speed. So how can BepiColombo get into orbit "without an orbit insertion manoeuvre being required" as that ESA site says? Maybe since it's actually a three-body system it is possible -- in other words the sun somehow makes it possible. But that same site goes on to say that a "small manoeuvre" is needed to get captured -- that means a small impartation of momentum from thrusters. So it's not clear. Eric Kvaalen (talk) 06:53, 8 August 2017 (UTC)
Eric Kvaalen, yeah, the available explanations are pretty inadequate, possibly intentionally so that laymen's eyes don't glaze over. I would assume that the mechanics work exactly because both Mercury's natural orbit and BC's approach orbit have quite the eccentricity compared to other planets, and because of the three-body system with the Sun. This approach and capture is so meticulous, I'd guess it's one of (if not the) most complex ever attempted. Not that it is particularly dangerous or risky, just very precise and time-involved. After all, it won't enter orbit until December 2025. And yes, based on what I've read, there is definitely some engine firing that takes place to enable orbital capture, but it is significantly less involved than a traditional insertion. And that's an important distinction...the spacecraft isn't inserting itself into Mercury's orbit, but is almost literally being captured into its initial orbit by Mercury's gravity well, with only a little input by the spacecraft itself. Hopefully someone more knowledgeable can chime in with the particular details. Huntster (t @ c) 08:38, 8 August 2017 (UTC)