WASHINGTON — Anomalies discovered during a Sept. 12 hot-fire test, coupled with upcoming missile tests at the Vandenberg Air Force Base in California, have delayed the inaugural launch of Space Exploration Technologies Corp.’s (SpaceX) Falcon 9 v1.1 rocket to the end of September, the company’s chief executive said Sept. 15.

Will do another static fire of rocket to make sure all is good & AF needs to test ICBMs, so probable launch Sept 29/30.

— Elon Musk (@elonmusk) September 15, 2013

Following the hot-fire test, “we saw some anomalies stemming from how the pad interfaces with the vehicle,” SpaceX spokeswoman Emily Shanklin wrote in a Sept. 16 email. “These are the kinds of things you can only find out when you static fire.  We’re making the necessary adjustments and will static fire again for good measure before launch.” 

Launch had been scheduled for Sept. 15, until SpaceX discovered problems during a two-second hot-fire test at Vandenberg’s Space Launch Complex 4. Musk broke that news on Twitter, too.

Full thrust achieved on 2 sec static fire. Some anomalies to be investigated, so launch date tbd.

— Elon Musk (@elonmusk) September 13, 2013

The launch now scheduled for the end of September, in which Falcon 9 1.1 will carry the Canadian Space Agency’s Cassiope space weather satellite and several secondary payloads, is critically important for SpaceX’s business plan. 

If the rocket and its new 5.2 meter-diameter fairing work as intended, Hawthorne, Calif.-based SpaceX will be clear to begin launching commercial communications satellites to geostationary orbit. The first such launch would be from Cape Canaveral Air Force Station, Fla., for fleet operator SES of Luxembourg. 

Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...