• Elon Musk's SpaceX is set to join the Federal Aviation Administration as a co-defendant to fight an environmental lawsuit brought after the first Starship test flight.
• The groups suing the FAA are alleging the agency should have conducted a more in-depth environmental study on the likely impacts of SpaceX activity before allowing the company to launch its Starship rocket.
• SpaceX CFO Bret Johnsen said Starship delays could harm the company financially and disrupt the deployment of its Starlink satellite internet service.

Elon Musk's SpaceX is set to join the Federal Aviation Administration as a co-defendant to fight a lawsuit brought by environmental groups following the company's first test flight of Starship, the world's largest rocket, which ended in a mid-flight explosion last month.

In a motion filed Friday in court, SpaceX requested that federal judge Carl Nichols allow the company to join the FAA as a defendant against environmental and cultural-heritage nonprofit groups that sued the aerospace regulator earlier this month. 

The plaintiffs "do not oppose" the company's intervention, per the filings. Jared Margolis, a senior attorney with the Center for Biological Diversity and lead counsel for the plaintiffs, said it's "standard and expected for the applicant to intervene in a case where their permit is at issue."  

The groups suing the FAA alleged that the agency should have conducted a more in-depth environmental study on the likely impacts of SpaceX activity before allowing the company to launch the world's largest rocket, Starship, from its Starbase facility, a spaceport on the Gulf Coast near Brownsville, Texas. 

The groups also alleged that the "mitigations" the agency required of SpaceX were not enough to avoid "significant adverse effects" to endangered species, their habitat and tribes in the area that count the land and wildlife sacred.

Friday's SpaceX filing outlines the potential consequences for the company if the environmentalists win the lawsuit, noting implications for its business and finances — as well as arguing there would be damage to the "substantial national interest" and possible scientific benefits of Starship.

"If the Court were to rule in Plaintiffs' favor, the FAA's decision could be set aside, and further licensing of the Starship/Super Heavy Program could be significantly delayed, causing severe injury to SpaceX's business," the company wrote.

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The lawsuit seeks for the FAA to conduct an environmental impact statement (EIS) — a lengthy and thorough procedure that would likely sideline SpaceX's Starship work in Texas for years.

The company also wrote in the motion that "the FAA does not adequately represent SpaceX's interests" in the lawsuit, since it's a government agency. It noted that the FAA "has a direct and substantial economic interest in the outcome of this case that the government does not share."

The FAA in a statement to CNBC said it "does not comment on ongoing litigation issues."

At stake for SpaceX

SpaceX Chief Financial Officer Bret Johnsen submitted a declaration alongside the motion to further detail potential damages to the company if it lost the lawsuit. In the statement, Johnsen wrote that "SpaceX has invested more than $3 billion into developing" the Starbase facility and Starship system since July 2014.

This year alone the company expects to spend about $2 billion on Starship development, according to comments CEO Musk made following its first fully stacked launch attempt last month.

Johnsen also highlighted the pipeline of contracts that SpaceX is building for future Starship missions.

SpaceX currently has a major NASA contract worth up to $4.2 billion to use the rocket to land astronauts on the moon. Additionally, the company has signed commercial customer contracts — including three separate missions for wealthy individuals Jared Isaacman, Yusaku Maezawa and Dennis Tito — for Starship that Johnsen wrote are "worth hundreds of millions of dollars at this time."

Starship also is crucial to the future of the company's Starlink satellite internet business, which has over 1.5 million customers. Johnsen noted that "SpaceX has invested billions of dollars into Starlink" to date.

Musk has previously highlighted the interdependence of those two businesses, with Johnsen further reiterating that SpaceX needs Starship flying in order to launch its second generation, or "V2," Starlink satellites.

"Without Starship … not only will SpaceX be harmed financially by its inability to launch v.2 satellites, but also hundreds of thousands of people … are waiting until the Starlink constellation is upgraded and can serve them," Johnsen wrote.

Finally, Johnsen noted that losing the lawsuit would cause the company to "substantially reduce" investment in its Starbase facility, which would harm its interests, as well as local employees and communities.

Fallout from first launch

The dramatic and explosive first Starship launch saw the company achieve several milestones for the nearly 400-foot-tall rocket, which flew for more than three minutes. But it also lost multiple engines during the launch, caused severe damage to the ground infrastructure and ultimately failed to reach space after the rocket began to tumble and was intentionally destroyed in the air.

SpaceX is in the process of cleaning up damage to the launch site, which carved a crater into the ground and smashed debris into the tower, nearby tanks and other ground equipment. The launch also created a plume of dust and sand, with particulate matter reported as far as six miles from the launchpad.

The test flight also sparked a 3.5-acre fire on state park land.

Phil Metzger, a planetary scientist on research faculty at the University of Central Florida, is studying the substance of samples of the particulate matter. He thinks "SpaceX dodged a bullet" with the launch, telling CNBC that the amount of "concrete blowing around" could have destroyed the rocket on the launchpad.

"It could have been much worse than it was. I think they made a mistake by taking a risk and launching off the [concrete] surface, trying to do it that way one time. But it was like a 70% success. They cleared the tower, tested their first stage, got a lot of good data, found a problem with the staging and hopefully will be able to have that fixed and have a better outcome in the next test," Metzger said.

Metzger did not assess the ecological impacts of the launchpad debris, and rocket explosion on endangered species that live in and migrate through the area. The Texas regional office of the U.S. Fish and Wildlife Service and independent researchers are among those studying the environmental impacts of the Starship test flight and explosion.

SpaceX's motion also made the case for why Starship is ultimately beneficial to scientific endeavors. The company wrote that the rocket's unprecedented capabilities "will allow scientists to focus on previously impossible scientific missions and pursue the fastest, easiest way to get their missions from concept to execution."

"For instance, with its large capacity, Starship could economically put large telescopes and heavy science experiments in orbit, and cargo, people, and even colonies on moons and other planets," SpaceX wrote.

Read the company's filing to establish itself as a defendant alongside the FAA:

Correction: The Starship test flight caused a 3.5-acre fire on state park land. An earlier version miscategorized the land.