Are you counting from date of launch or date of arrival? Long travel times want to know :-)

@PipFoweraker Arrival. I don't think you can consider it as successful without arrival.

@AlexLiesman What about return to Earth? Does this market resolve YES as soon as we plant an American flag on Mars soil, or do we have to wait to make sure the astronauts don't die on the way back?

The next successful manned mission to Mars might be done by the Chinese

@Willa Interesting claim. Why don't you make a market about it?