Hopeless dreamer, or a true visionary? SpaceX and Tesla CEO Elon Musk can split opinions at times, and perhaps no more so than with his ultimate goal – to colonize Mars.

His latest comments, though, are sure to ignite further discussion. In a series of tweets over the weekend, Musk has said that he doesn’t just want to stop at Mars. He wants to send humans further into the Solar System – and he apparently has a plan to do so.

Musk has long hinted at something called the Mars Colonial Transporter (MCT). This is supposedly a plan to take 100 people to Mars, and set up the first colony there. On September 27 at the International Aeronautical Congress in Guadalajara, Mexico, Musk is going to reveal more details about this plan. SpaceX will be hosting a live stream of the talk at 2.30pm EDT (7.30pm BST) right here.

But there’s a twist in the tale. Musk says the MCT is not limited to just going to Mars. “Turns out MCT can go well beyond Mars, so will need a new name…” he tweeted on Friday.

There were a number of proposed suggestions that Musk seemed to like, including Ultimate Mars Ship II, Heart of Gold (from the Hitchhiker’s Guide To The Galaxy), and Millennium, perhaps in line with the Falcon naming system used on SpaceX’s current rockets. Musk said the latter name might be an option for the rocket booster itself to launch the whole thing.

In the end, he appeared to pluck for something a bit simpler: The Interplanetary Transport System (ITS). Now, of course, we still don’t know any concrete details about the MCT, much less so the ITS. But one could speculate that Musk may have his on eye on other potential worlds for colonization.

Jupiter’s moon Europa, for example, might be a candidate. While its surface is bathed in deadly radiation, under its icy crust we think there is a vast ocean that could be fed heat by hydrothermal vents at the sea floor. Saturn’s moon Titan, meanwhile, has a thick atmosphere and a climate system not wholly dissimilar to our own. It’s also the only place other than Earth with bodies of liquid on its surface – albeit lakes of liquid hydrocarbons rather than water.

And Venus, too, a little closer to home, is worth taking a look at. While its surface temperature is hot enough to melt lead, there’s a region of the atmosphere 50 kilometers (30 miles) above the ground where the temperature and air pressure mimic that on Earth – which has often been touted as a destination for a floating colony.

Whatever Musk has got up his sleeves, we’ll be waiting eagerly to hear what he’s got to say next week.