When 75-year-old Russian scientist Anatoly Maslov, a specialist in high-speed aerodynamics, was arrested on treason charges in June 2022, his colleagues were alarmed.
"The persecution of scientists in the field of aviation has become a regular thing in our country," more than 400 of his colleagues wrote in an open letter that has since been deleted.
In a closed session on May 21, a St. Petersburg court convicted Maslov, who is now 77 and has spent almost two years in jail, of giving classified information to German agents in 2014 -- a charge he and supporters say is groundless. He was sentenced to 14 years in prison.
"Fourteen years for a 77-year-old who had a heart attack while in pretrial detention is a death sentence," a relative of Maslov's who asked not to be identified out of safety concerns told RFE/RL. Maslov formerly headed a laboratory at the Institute for Theoretical and Applied Mechanics (ITPM) in Novosibirsk, a longtime scientific hub in Siberia.
Maslov before his arrest (file photo)
Since 2018, at least 12 specialists in the field of hypersonic aerodynamics have been charged with treason. At least three of the researchers, most of whom are older adults, have died in custody. Like Maslov, many of them have been sentenced to long prison terms, while others have been held for months in pretrial detention.
Lawyers involved in the cases suspect the rash of treason charges is related to President Vladimir Putin's personal interest in hypersonic weaponry.
"It's a favorite toy of Putin's," Yevgeny Smirnov, a lawyer with the legal-aid organization First Department, which provides defense consulting in cases that allegedly involve state secrets, told RFE/RL. "He has repeatedly announced that only Russia possesses hypersonic weapons."
The cases, all of which are handled by the Moscow headquarters of the Federal Security Service (FSB), have one purpose, Smirnov said: "To demonstrate that all the world's intelligence services are gunning for Russian researchers."
"And our security agencies achieve this goal the only way they know how -- by putting innocent people in prison," he said.
'Like a Meteorite'
Putin has been touting the prospects of hypersonic weapons for nearly two decades, part of his frequent saber-rattling about Russia's military capabilities. During his nationally televised Direct Line question-and-answer session in September 2005, he said Russia was developing hypersonic weapons that he claimed would be "practically invulnerable."
A recent report by the BBC counted more than 70 examples of Putin boasting about the weapons in public appearances since then. He highlighted them in a particularly bellicose state of the nation speech in 2018.
In that address, he mentioned the Kinzhal hypersonic missile, which has since been deployed against Ukraine in the first battlefield use of hypersonic weapons ever. He also mentioned the Avangard hypersonic missile, which he said "travels to its target like a meteorite" at up to 20 times the speed of sound.
The Russian military reportedly accepted the first unit of Avangard missiles into service in December 2019. In comments to the U.S. House Armed Services Committee this March about Russia's intercontinental ballistic missiles (ICBMs), a senior U.S. Air Force commander said Moscow had "expanded its force of ICBMs armed with the Avangard" over the past year.
'Conveyor Of Repression'
The accused scientists have all denied revealing classified information, saying their articles and speeches were strictly vetted by in-house security committees at their institutes.
Advocates for the scientists say the FSB simply ignores that fact.
"The FSB operatives arrive at some institute that is connected in some way with hypersonic research and look for researchers who have taken part in international conferences or such programs," lawyer Smirnov said. "Having identified several victims, they prepare allegations that during a conference or international program the scientist supposedly passed on secret information to foreign colleagues who might use it to create weapons for NATO countries."
Many of the cases involve speeches or articles that are at least 10 years old.
The programs involved were often approved by the Russian government during the 2008-12 presidency of Dmitry Medvedev, when Putin was prime minister, Smirnov noted.
The government "approved the cooperation of a number of Russian institutes with European organizations doing physics research," he said. "Then, [a few] years later, they start coming to these people with searches and criminal cases, accusing them of treason for participating in those projects."
All of the research institutes connected with what are often called the "hypersonic cases" participated in the FP7 space cooperation program, which started in June 2011 and ended in May 2013.
In Maslov's case, his relatives said, the allegations were largely based on the testimony of a colleague named Aleksandr Kuranov. Kuranov, the 76-year-old former director of a St. Petersburg-based state research institute who worked on the Soviet-era Ayaks hypersonic aircraft, was given the minimum sentence of seven years in prison on treason charges in April. The court announcement said "mitigating circumstances" compelled the judge to impose the shortest possible sentence.
Workers recover a fragment of a Kinzhal hypersonic missile that struck Kyiv in January.
A researcher at ITPM who was a co-author of papers with at least one of the arrested men and who spoke on condition of anonymity said the institute has cut all foreign contacts and canceled hypersonic research.
"It is difficult to work under such conditions," the scientist said. "Not just because of the restrictions but because of the lack of defined, comprehensible rules. We are waiting…for common sense to prevail."
The investigations into "hypersonic cases" show no signs of abating, Smirnov said.
The year "2023 showed that the conveyor of repression of Russian scientists has not stopped and isn't going to be stopped," he said. "What does this mean? At least two to five more imprisoned researchers this year."
Written by RFE/RL's Robert Coalson based on reporting by RFE/RL's North.Realities, Siberia.Realities, Russian Service, and Current Time