After an American Apollo and Soviet Soyuz spacecraft docked in orbit during the height of the Cold War, in 1975, the two leading space powers gradually worked more and more together on civil space activities. Over time, they forged a successful and, among astronauts and engineers at least, even a comfortable bond. But of late, that bond is fraying, and long-term it may unravel entirely.

The most immediate issue involves Dmitry Rogozin, appointed to lead the Russian space corporation Roscosmos in May 2018. Overtly political, Rogozin shares Vladimir Putin's antipathy toward the West. Following the Crimean crisis in 2014, Rogozin was one of seven Russian officials sanctioned by the Obama administration. In response, he taunted NASA, which relied then (and still does) on Russian Soyuz spacecraft to reach the International Space Station.

"After analyzing the sanctions against our space industry, I suggest to the USA to bring their astronauts to the International Space Station using a trampoline,” Rogozin, then a deputy prime minister of Russia over defense and space, tweeted in Russian at the time.

When NASA Administrator Jim Bridenstine visited Russia and Kazakhstan last year, he reciprocated with an invitation for Rogozin to visit the United States and lecture at Bridenstine's alma mater, Rice University in Houston. But because of Rogozin's controversial past, and the existing sanctions, several US Senators vocally opposed his visit. This forced NASA to indefinitely delay the visit earlier this month.

This week saw an attempt at fence-mending. Bridenstine and Rogozin held a teleconference to discuss cooperation on the ISS program and other projects. It is not clear how well the call went, as NASA is shut down, and the agency did not release details. According to one source familiar with White House space policy, despite some bluster from Russia, there have been no immediate repercussions to the US-Russian space relationship due to the withdrawal of the invitation. However, this kerfuffle is sure to have bruised some egos on the Russian side.

And relations were already a bit uneasy after unfortunate Russian insinuations about sabotage by NASA astronauts on the space station late last year. This baseless charge left doubts in the minds of both NASA and Russia's space leaders about the relationship.

But these are just the most visible problems. There are more serious, underlying tensions. These stem from NASA's fear of a systematic decline in the quality of Russian hardware and practices, such as what may have actually occurred with the Soyuz leak and, separately, a Soyuz rocket failure last year. Put simply, Russia's human space program appears to be a fading force. And as Russia's prominence in space declines over time, there is the question of what role it is reasonable to expect the country to play in US spaceflight activities after the end of the ISS program sometime during the 2020s.

A slow decline

The early Soviet successes in space were based on a number of very specific features of their aerospace industry, noted space author and historian Jim Oberg says. During the heyday of the space race in the 1960s, aerospace workers received special privileges, such as access to certain stores, hospitals, and resorts, and the best graduates from Soviet schools were funneled into the space program. They also had some leeway on intellectual freedom during the Soviet era.

In recent years, most of these benefits are gone. No longer are Russian aerospace workers at the cutting edge of world-leading space activities—they're building the same or similar rockets and spacecraft that Russia has built since the 1960s and 1970s. The big-money days are gone, too, and there aren't even resources to keep aging sites from becoming overrun with trash. Generally, Russian space workers are poorly compensated. Over time, quality has suffered.

"Their space industry appears to have lost—for the indefinite future—the capacity to fabricate station-class modules, just as for the last three decades they have lost and failed at every attempt to rebuild their ability to launch and operate science probes to the moon and planets," Oberg said. "It’s a cruelly accurate quip to assert that one can count the number of successful Russian deep-space missions in those 30 years on the fingers of no hands."

The reality is that Russia presently has a serviceable orbital taxi in the Soyuz rocket and spacecraft, but beyond the partnership on the International Space Station, Russia has little prospect of building a station of its own within a decade. And every year, Oberg said, more of its experienced cadre of engineers and technicians retire, taking their hard-won knowledge and judgment with them.

"It is not a good trend for them or for the rest of the world that benefits from their productive presence, in cooperation and in competition, out in space," Oberg said.

No longer equals

Back in the 1990s, the United States and Russia could be regarded, roughly, as equals in human spaceflight capabilities. NASA had its superior space shuttle, but Russia had far more experience with orbital modules and space stations after its Mir program. Now, Russia has lost that edge, and when NASA's commercial crew vehicles come online later this year and begin operational service soon thereafter, Russia will no longer be essential to NASA and the United States in space.

"I think we are going through a long transition in the relationship," said John Logsdon, a noted space historian. "When Russia joined the station partnership, it demanded and got, on the basis of its human spaceflight experience, treatment as first among US partners. Now, 25 years later, it is no longer a space superpower, but one among several second-tier countries."

As a result, Russia's ability to make major contributions to NASA's proposed Gateway near the Moon, and other plans, is in question. The Russians are not blind to this, but it's not something leaders like Rogozin are likely to accept easily as they pioneered human spaceflight. So far, the Russian response seems to be proposing large, ambitious civil space projects—such as their own lunar landings or large rockets—as if they had the funding to carry them through. They don't, of course, and some Russian commentators have warned the space program is nearing the "dark ages."

Over the next few years, as NASA starts flying sleek, modern-looking commercial vehicles into space, and US companies, such as United Launch Alliance, become less reliant on Russian technology (specifically, the RD-180 rocket engine) to reach space, the relationship may bend further—or it may break. The reality is that, while Russia may see itself as an equal, NASA and its commercial partners will look at China and Chinese companies as their principal rivals in space.