So Sorry - your claim was that no Canons have been in space. The c500 is not a 'video camera' - it is a cine camera - big difference but if your point is it is not specifically made to take stills I will give you that one (although the 4k stills that can be taken from the video are really high quality).

What you may have meant to say is that the high end cameras of choice in space are Canons and Hasselblads. The everyday common cameras sent are less expensive (cheaper) Nikons !

So now we can agree ! Not telling anyone that your Nikon is better or worse than my Canon gear, but the people who buy it by no means imply better quality. Especially when it comes to the government procurement process (dealt with it for a few years) ! That also applies to the Canon market share ! Sure it is a component of a purchase decision but its minimized when 2 very good brands are in competition.

Canon may be better at 'marketing', but it is the market leader, which usually requires good product as well as good 'marketing'. Marketing certainly includes advertising and outbound activities, but it also includes understanding the market requirements and then bringing those products to market effectively. Running a good business that supplies things that people want to buy and can afford/justify the expense.

Canon took the market initiative lead from Nikon when they took the lead in autofocus technology in 1987 with the EOS system and EF lenses. It was a bold move since it broke compatibility with the older manual focus lenses, but it was a very successful move. If we look at the CIPA and BCN market data - which is not complete - it is clear that Canon covers more categories than most other vendors, and at least in Japan is doing very well with mirrorless cameras. There are many categories of consumers.

This is not say that Pentax, Leica, Olympus, Fuji, Panasonic, Sony, et al don't make excellent products that are the best fit for various individuals, as of course does Nikon, but Canon took the overall market leadership, and in some areas the technology leadership. Sony seems to lead in sensor technology currently, and Nikons use Sony sensors as far as I know.

Market analysis is a complicated area, and usually requires data and other information to reach a defensible conclusion. The publicly available information that we have on the camera market is patchy, it indicates trends, but stitching together a complete market model takes information that isn't in the public domain.

That much said, each of us should buy what we want and go use it.

The whole Nikon in space had to do with the coatings on Canon lenses not being suited to space. So...Nikon may be more suited to space. Each camera design has to do with a market from the POV of the manufacturer. Canon makes lens and body combinations that satisfy a range of shooters (sports, wedding, portrait come to mind) with more participants than Nikon (I think studio and landscapes when I think of Nikon.) As a result, they sell more systems. I think Nikon has made some great strides in the last five years. But they have to overcome a HUGE user base already invested in Canon at a time when many new to photography are looking at mirrorless rather than DSLRs.