"[Q]uestions have been raised about whether competition among US launch providers is sustainable given market conditions, both domestically and internationally," the report noted.
In 2015, there were 86 global launches of which only 22 were considered commercial launches, the GAO pointed out.
The US Department of Defense "is gathering and analyzing information on predicted launch demand. However, history has proven that it is difficult to reliably predict the demand for launch services," the report warned.
Many factors influence the quantity, size, and frequency of satellite launches for both government and commercial use, such as the demand for satellite telecommunication services or the constellation health of satellite systems, the GAO observed.
The US Air Force relied on a single space launch provider — the United Launch Alliance, which has used the Russian RD-180 engines to put up satellites for ten years, the report noted.