NEW YORK, April 29 (Reuters) - SpaceX is telling investors that no one can fire Elon Musk from his role as chief executive and chairman of the board without the billionaire founder's consent, according to an excerpt of its IPO filing reviewed by Reuters. The filing states that Musk "can only be removed from our board or these positions by the vote of Class B holders" - super-voting shares with ten votes apiece that he will control after the IPO, making his removal effectively a self-vote.