Mars Orbit? Really?
However, they are going to wait 6 hours to fire the second stage for a third burn which would actually put it in orbit. They want it to be exposed to radiation and test how well the booster holds up before the final burn.
Regardless, like other posts have said, they haven't actually left Earth orbit yet. There's one more burn in about 5 hours.
But actually, it seems they decided to just empty the tanks and get as much delta-v as possible, and it'll go all the way into the asteroid belt as a result.