Also if you aren't careful she might just kick the stud in the head and kill him. There are a lot of risks for a statistically improbable event where you could just have a gelded male that is useful for work and easier to control, which is why someone would own a mule besides wanting a violent and obstinate pet.

Progress in technology tends to increase at an exponential rate if it is being seriously pursued.

The first sustained powered and controlled flight by man happened in 1903

...We landed on the moon 66 years later.

In that context, if it took 47 years to get here, we're only at the beginning of the ramp, and it's possible that it will be something humanity overcomes well within the next 50 years.