WASHINGTON — Space Exploration Technologies Corp. (SpaceX) of Hawthorne, Calif., edged out Blue Origin in the race to take over an old space shuttle launch pad at the Kennedy Space Center in Florida by showing NASA it had more guaranteed launches on tap than its Kent, Wash.-based competitor.

“Blue Origin’s multi-use approach involved uncertainty regarding the extent other users would use the pad,” NASA selection official Richard Keegan wrote in the 13-page source selection document, which was released Dec. 19. “In contrast, SpaceX’s approach for exclusive use and its proposed manifest was specific, firm, and included customers on contract.”

Blue Origin, according to the source selection document, had secured no commitments to use Launch Complex 39A other than its own. The company planned to launch its Orbital Launch Vehicle from the pad sometime prior to 2021, according to the source selection document. The exact date of the first launch, and Blue Origin’s proposed launch cadence, was redacted from the document NASA released.

Moreover, Blue Origin was counting on SpaceX to patronize the multiuser pad even though it had secured no commitment from the Falcon 9 operator to do so.

“It was unclear whether SpaceX would elect to use LC-39A if Blue Origin were selected as the site operator,” Keegan wrote. “Given the multi-factor rationale provided by SpaceX as to why an exclusive pad use arrangement was necessary to support its concept of operations, I found there is a significant possibility SpaceX would choose not to use LC-39A as a part of a multi-user arrangement.”

In order to sell NASA on its multiuser concept, Blue Origin provided the agency with letters of interest and a memorandum of agreement from “other launch vehicle providers” with potential interest in launching from the proposed Blue Origin-operated pad. Those companies were not identified in the source selection document. However, government launch services provider United Launch Alliance of Denver publicly supported Blue Origin’s bid to take over the pad.

To demonstrate its technical capability, Blue Origin cited its experience building and operating launch facilities at its West Texas Launch Site, from which the company has, according to the source selection document, launched four suborbital vehicles on test flights.

Finally, Blue Origin said it would bear the financial risks if the revamped pad failed to attract as many launches as the company hoped.

Ultimately, however, NASA decided that a lack of firm launch commitments might prevent what the agency said was its top objective for the facility: making “the fullest commercial use of space.” The agency also said Blue Origin’s proposal was potentially burdensome for prospective launch customers who would be required to develop “their own facilities and vehicle interfaces” to use the pad.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.