Update: On Tuesday evening SpaceX would not confirm that a large deal had been reached. "Toray is one of a number of suppliers we work with to meet our carbon fiber needs for Falcon rocket and Dragon spacecraft production, and we haven’t announced any new agreements at this time," a company spokesman told Ars. "As our business continues to grow, the amount of carbon fiber we use may continue to grow."

Original story: SpaceX appears to be betting big on carbon fiber composites, which could increase the capacity of its future rockets to get people and supplies into space—and eventually to the surface of Mars. According to a report in Nikkei Asian Review, SpaceX has signed an agreement with Toray Carbon Fibers estimated to be worth $2 billion to $3 billion. The total price and delivery dates have yet to be finalized.

It is not immediately clear exactly when, and in which launch vehicles, these lightweight composites will be employed by SpaceX. But the company is not alone in its interest—NASA and other aerospace companies have been experimenting with the materials because of their potential to increase the amount of payload that can be carried by a rocket. They could also lower overall manufacturing cost.

The scale of the deal seems telling, however. If the value of the deal as reported is correct, in the billions of dollars, it seems probable that the carbon fiber composites would be used in SpaceX's proposed Mars Colonial Transporter rocket. This is the very large (but still under development) rocket the company plans to use to transport humans to Mars. SpaceX is already far along in the production of its Falcon Heavy rocket, which is based on the Falcon 9 core stage. The first stage of the Falcon 9 rocket, which SpaceX has successfully been landing this year, has tank walls and domes built from an aluminum lithium alloy.

Carbon fibers, which are generally woven into a fabric, possess desirable qualities such as high tensile strength, low mass, high temperature tolerance, and low thermal expansion. This has made them very popular with aircraft manufacturers, such as Boeing and Airbus. Toray, headquartered in Japan, is a leading provider of carbon fibers to airplane manufacturers. In a bit of irony, Toray is likely to produce carbon fibers for SpaceX at its Decatur, Alabama-based factory, which is located in the same city where SpaceX competitor United Launch Alliance manufactures its rockets.

The carbon fiber deal may represent another sign, along with the company's recent movement of the Raptor engine to a Texas test facility, that SpaceX is making substantial progress toward developing and launching rockets to Mars, including potential human missions sometime in the 2020s. Investing $2 billion or more on carbon fibers suggests the scale of SpaceX's Mars ambitions are grand indeed.