SpaceX chief executive officer and technology pioneer, Elon Musk, will be speaking at the International Astronautical Congress (IAC) in Adelaide, Australia, on Friday about his plans to send people to Mars and colonize it. He is expected to present an updated and more realistic version of the initial plan, called the Interplanetary Transport System, which he unveiled during last year's IAC.

The plan modifications that Musk is expected to reveal revolve around making the transport system more affordable by scaling down the size of rockets and creating feasible means to finance the project.

Recently, the inventor hinted at some of the changes that he will be making on his Mars colonization plan via Twitter. "A 9m diameter vehicle fits in our existing factories," he said, when a commenter ask him to give some details about the Mars plan. He also said he has postponed unveiling his new plan in order to present it at the IAC.

Originally, the Tesla chief envisioned a rocket and spaceship that would measure over 400 feet in height and 40 feet in diameter. If built, this would have been the largest rocket ever created.

In the revised plan, the size of the rocket would be scaled down to approximately 30 feet in diameter, which would also mean that the vehicle would be shorter.

In June, Musk tweeted that version two of the plan addressed the most fundamental flaw in the original plan, which is the financial aspect. He also suggested during the International Space Station Research and Development conference in Washington, DC, in July that scaling down the size of the Mars vehicle would allow it to be used for Earth-orbit activities as well as Mars transport. "Maybe we can pay for it by using it for Earth orbit activity," he said. "That's one of the key elements of the new architecture."