7:28 p.m. Update: SpaceX CEO Elon Musk said Falcon 9’s launch is targeted for Sunday pending a data review from a static-fire test completed Friday evening.

WASHINGTON — A Federal Aviation Administration environmental review found no issues with plans by SpaceX to land its Falcon 9 first stage at Cape Canaveral, bringing the company a step closer to winning final approval to attempt such a landing on an upcoming launch.

The FAA, in a document formally known as a finding of no significant impact, concluded there would be no major environmental issues linked to SpaceX’s plans to land Falcon 9 first stages at a decommissioned launch site the company now calls Landing Complex 1.

“After reviewing and analyzing available data and information on existing conditions and potential impacts,” the document states, “the FAA has determined issuance or modification of a launch license to conduct Falcon landings at [Cape Canaveral Air Force Station] would not significantly affect the quality of the human environment” as defined in federal law.

The document, signed Dec. 4 by FAA Associate Administrator for Commercial Space Transportation George Nield and posted on the agency’s website, reviewed various environmental factors associated with the proposed landings, including air quality, noise and visual impacts. None of the factors, the FAA concluded, posed a significant environmental impact.

The document notes that final approval from the FAA for a Falcon 9 first stage landing would require either a new launch license or a modification to an existing launch license. An environmental review, such as the one completed by the FAA, is one part of the overall launch license application process.

SpaceX currently has launch licenses for several upcoming missions, including the launch of 11 Orbcomm satellites planned for this month. Those licenses will require modifications regardless of plans to land the first stage since they refer to the Falcon 9 version 1.1, whereas SpaceX plans to use the upgraded Falcon 9 on those launches.

Neither the FAA nor SpaceX have commented publicly on any requests by SpaceX to modify existing launch licenses or seek new launch licenses, either to accommodate an attempted landing or to take into account the use of the upgraded Falcon 9. They have also not disclosed how soon before the launch the FAA would have to approve a new or revised launch license.

Any attempted landing by the Falcon 9 first stage at Cape Canaveral would also require range approval from the U.S. Air Force. Sources at Cape Canaveral have said the Air Force has informed them that the overall launch complex will be closed to non-essential personnel for a landing.

The date of SpaceX’s next launch is uncertain. The company previously announced it would conduct a static fire test of the Falcon 9 on its launch pad Dec. 16, followed by a launch attempt about three days later. However, that test was postponed first to Dec. 17, and then to Dec. 18.

SpaceX Chief Executive Elon Musk, in a tweet late Dec. 17, suggested delays in the static fire test were linked to plans to chill the rocket’s liquid oxygen propellant to colder temperatures than previous launches. “Deep cryo liquid oxygen presenting some challenges,” he wrote.

Cooling the liquid oxygen to temperatures of less than –205 degrees Celsius is designed to make the propellant denser and improve its performance. “We’re cooling the propellant, particularly the liquid oxygen because it’s two-thirds liquid oxygen, close to its freezing point,” Musk said in a Dec. 15 speech at the Fall Meeting of the American Geophysical Union in San Francisco when discussing upgrades to the Falcon 9.

Musk said this is the first time someone has attempted to use liquid oxygen chilled to those temperatures in a launch vehicle. He added that, despite the difficulties SpaceX was experiencing on the pad at Cape Canaveral, they successfully demonstrated it at the company’s Texas test site.

Others in the industry, however, are skeptical of the benefits of supercooled propellants. “That’s why we don’t bother. Lots of complexity for little gain,” tweeted George Sowers, vice president of advanced concepts and technologies at United Launch Alliance, in response to Musk’s tweet early Dec. 18.