SpaceX has released the first edition of a Payload User's Guide for its Starship launch system, which consists of a Super Heavy first stage and the Starship upper stage. The six-page guide provides some basic information for potential customers to judge whether a launch vehicle meets their needs for getting payloads into space.

The new guide is notable because it details the lift capabilities of Starship in reusable mode, during which both the first and second stages reserve enough fuel to return to Earth. In this configuration, the rocket can deliver more than 100 metric tons to low-Earth orbit and 21 tons to geostationary transfer orbit.

The killer application, however, is the potential to refuel Starship in low-Earth orbit with other Starships, enabling transportation deeper into the Solar System for 100 tons or more. "The maximum mass-to-orbit assumes parking orbit propellant transfer, allowing for a substantial increase in payload mass," the document states. SpaceX has yet to demonstrate this technology—which has never been done on a large scale in orbit—but the company's engineers have been working on it for several years and partnered with NASA last summer.

The user's guide also provides information about the size of the payload fairing in the cargo configuration of the vehicle, with a width of 8 meters and an extended volume capable of encompassing payloads as long as 22 meters. This would be, by far, the largest usable payload volume for any rocket that exists today or is in development. For human flights of up to 100 people, according to the document, "The crew configuration of Starship includes private cabins, large common areas, centralized storage, solar storm shelters, and a viewing gallery."

Initially, the company says it is planning to launch both from Kennedy Space Center in Florida and its Boca Chica launch pad in South Texas.

What the new document does not include is pricing information for Starship, nor a date when the rocket will be ready for commercial customers. Cargo flights, certainly, will happen years before humans fly on Starship.

Over the last year, SpaceX has rapidly built a development site for Starship in South Texas and has assembled a factory-like production line with a goal of building one Starship a week by the end of 2020. It is not clear whether the company will reach this goal, but there is no question that the company is moving fast as it designs and tests new prototypes of the second stage.

Despite this pace, it seems reasonable to expect that Starship and Super Heavy remain a couple of years away from flying satellites into space. Nevertheless, the prospect of putting such large and heavy payloads into space has to be at least somewhat tempting to potential customers.