In 2002, Elon Musk began his quest to send the first rocket to Mars. He ran into a major challenge right off the bat. After visiting a number of aerospace manufacturers around the world, Musk discovered the cost of purchasing a rocket was astronomical—up to $65 million. Given the high price, he began to rethink the problem. So, he asked himself, what is a rocket made of? Aerospace-grade aluminum alloys, plus some titanium, copper, and carbon fiber.