05-16-2023, 05:08 PM
In a televised address to Russia’s Federal Assembly in 2018, President Vladimir Putin announced an escalation of the ongoing arms race with the U.S., which had withdrawn from the Anti-Ballistic Missile (ABM) Treaty in 2002. Having rejected the decades-long arms-control agreement, the U.S. had developed and begun building a network of defenses to intercept long-range ballistic missiles, threatening Russia’s ability to deter attacks on its homeland. He had warned Americans that Russia would be forced to respond to these deployments, Putin told his audience, but they had refused to listen. “So listen now!”
Among other systems, Russia was developing new hypersonic weapons, Putin declared: missiles that fly long distances through the atmosphere at more than five times the speed of sound, or faster than Mach 5. (Mach 1 is the local speed of sound. Speeds between Mach 1 and Mach 5 are supersonic, whereas those exceeding Mach 5 are hypersonic.) According to him, one of these, called Avangard, was a highly maneuverable missile that could glide thousands of kilometers with an initial speed greater than Mach 20, making it “absolutely invulnerable to any air or missile defense system.”
Putin’s announcement, accompanied by intimidating simulations of the new weapons snaking across the globe at unbelievable speeds, added fuel to a dangerous new arms race. The weapons involved in this competition are touted not only for their speed but also for their stealth and maneuverability. Intercontinental ballistic missiles, which follow an elliptical path into space before plunging down toward their target, reach speeds above Mach 20, but they have predictable trajectories for most of their flight and typically can maneuver only briefly, after they reenter the atmosphere. In contrast, hypersonic weapons would fly deep within the atmosphere most of the time, using lift generated by airflow to weave around and try to evade interceptors. Approaching at such low altitudes, these weapons would avoid detection by ground-based radar systems until close to their target, making them more difficult to stop.
In an assessment after Putin’s speech, U.S. military officials stated that hypersonic weapons, which China was also developing, would “revolutionize warfare.” The Pentagon, which had been working on similar systems for a decade and a half, ramped up its own efforts; last year Congress dedicated $3.2 billion to the research and development of hypersonic weapons and defenses. Russia and China now claim to each have deployed at least one such system. The U.S. has six known hypersonic programs, divided among the air force, army and navy. Proponents say that these weapons are incredibly fast and agile and virtually invisible.
We disagree. We belong to a small but vibrant community of physicists and engineers scattered around the globe who study new weapons systems to understand their potential impacts on global security. This tradition is deep, going back to participants in the Manhattan Project and Russian scientists such as Andrei Sakharov, who sought to mitigate the danger to the world from the nuclear weapons they had helped create. As investigative physicists, we glean what information we can about new and usually secretive technologies, analyze it and share our evaluations with the public.
Our studies indicate that hypersonic weapons may have advantages in certain scenarios, but by no means do they constitute a revolution. Many of the claims about them are exaggerated or simply false. And yet the widespread perception that hypersonic weapons are a game-changer has increased tensions among the U.S., Russia and China, driving a new arms race and escalating the chances of conflict.
https://www.scientificamerican.com/artic...c-weapons/
