I'd have to calculate a load of bullshit up that made enough calculable sense to those wishing to do the math, so that whatever time it took by fictionally calculating the distance and his average speed, I can then shout out (in maybe 9 years) that the man has achieved the goal set out.
The difference between walking around the world and flying to Pluto is that you can easily lie about the distance to Pluto and how fast a spacecraft can be. So why 3 billion miles in 9.5 years? It could have been 3 billion miles in one year, anyway they could have as well made up a very fast spacecraft or 300 million miles in one year if they had lied about the distance. 9.5 years is a very long waiting game for everyone, some like Venetia Burney, who witnessed the launch did not even make it to see the arrival of the probe.
If I want to spin you lies for a long time and amaze you at the same time, I have to play the game carefully.
In time the distances traveled will get faster and shorter, just like the man walking around the world on his hands.
The next time he does something, we add rubber palm pads and then springs and so on so we can knock off so much time.
In your space, they will invent hyper drives and all kids of bollocks that will have mars trips as good as going to the shops, just as soon as they get the Hollywood effects believable for the viewing audience.
Make the distances further away so people cannot challenge it with any authority.
Piss easy to pull off for these people.
Let's face it. In this day and age when people can see the moon landing shit for what it was, the likes of you are gripped to it like a frigging limpet as being 100% true.
If you're going to believe that in this day and age then you'll believe they went to pluto in an inflatable dingy and snorkelling gear.