Chinese and Russian intelligence agencies are targeting American private space companies, attempting to steal critical technologies and preparing cyberattacks aimed at degrading U.S. satellite capabilities during a conflict or emergency, according to a new warning by American intelligence agencies.

The National Counterintelligence and Security Center, the F.B.I. and the Air Force issued a new advisory to American companies Friday morning. The broad warning to industry said that foreign intelligence services could be targeting space firms, their employees and the contractors that serve those companies.

Space companies’ data and intellectual property could be at risk from attempts to break into computer networks, moles placed inside companies and foreign infiltration of the supply chain, officials said.

“Foreign intelligence entities recognize the importance of the commercial space industry to the U.S. economy and national security, including the growing dependence of critical infrastructure on space-based assets,” the Counterintelligence Center warning said. “They see U.S. space-related innovation and assets as potential threats as well as valuable opportunities to acquire vital technologies and expertise.”

While the United States still builds and launches multimillion dollar reconnaissance and communications satellite, much of American innovation in space is being done by commercial companies, including those that conduct launches and others that build and field satellites.

Intelligence agencies are increasingly dependent on the private-sector space industry, and U.S. officials are worried about the interest Chinese and Russian spy services have shown in those companies, based on recent F.B.I. investigations and intelligence collection on foreign intelligence plans. American officials believe innovations by SpaceX, Blue Origin and other private companies have given the United States a huge advantage in space, one that is envied by foreign adversaries.

Security measures vary greatly from company to company, and some U.S. officials believe the space industry needs to tighten protections against attempts by Chinese and Russian intelligence agencies to infiltrate them.

Since 2017, the Justice Department has charged Chinese, Russian and Iranian nationals in various schemes to steal space-related technology. Last October, five Russian nationals were accused in an indictment of trying to illicitly acquire “semiconductors and microprocessors used in satellites, missiles, and other space-based military applications” from American companies. In 2019, a Chinese national was sentenced to federal prison for trying to acquire a radiation-hardened power amplifier used in space applications.

And some companies have disclosed infiltration attempts. In 2020, United Launch Alliance, a joint venture of Boeing and Lockheed Martin which puts many national security satellites into orbit, suggested a Chinese firm had tried to infiltrate its supply chain. The supplier did not succeed in extracting critical intelligence.

American officials also believe rendering ineffective space-based communications and imaging satellites is likely to be the opening move of any future conflict. As Moscow launched its invasion of Ukraine in February last year, hackers linked to the Russian government conducted a cyberattack against Viasat, a U.S.-based communications firm, in an attempt to disrupt Ukraine’s ability to command its troops.

As the war has gone on, Russians have focused on jamming satellites. SpaceX’s low-earth orbit satellite network Starlink has also proved critical to Ukraine’s war effort.

The warning issued Friday advises companies to track anomalous incidents on their computer networks to look for potential breaches, develop protocols to identify potential foreign agents inside the business, conduct due diligence on potential investors and prioritize the protection of the most important intellectual properties.