China’s hypersonic FOBS has spooked the US: Know why

Financial Times on Sunday broke a story on China testing an advanced hypersonic fractional orbital bombardment system (FOBS) in August this year, in news that has apparently caused consternation among the US intelligence community, and startled many others about the technical advancement made by the communist nation.

“The test showed that China had made astounding progress on hypersonic weapons and was far more advanced than US officials realised,” the report said.

The test

The FOBS comprises an intercontinental ballistic missile (ICBM) that launches a warhead into low-earth orbit, around 150 km. When the payload approaches its target, an onboard retro rocket detaches the payload and causes it to return to Earth.

According to the FT report, the FOBS tested by China attained a speed of 33,800 km/hr – more than 27-times the speed of sound in air – and circled the planet once before descending on a target in China, missing it by just around 40 km. A hypersonic FOBS with such speed is hard to track, intercept or destroy.

The technology

Along with China, the US, Russia and at least five other countries are working on hypersonic missile technology. Such missiles are more agile than normal ones and, like ballistic missiles, can deliver a nuclear warhead.

It was the erstwhile Soviet Union that had first developed the FOBS in the 1960s. The trajectory of a FOBS is very different to that of a ballistic missile. ICBMs follow a parabolic trajectory, sometimes climbing to heights of 1,200 km, before descending on the target.

FOBS, on the other hand, are more manoeuvrable and have a flatter trajectory, making them more difficult to track and hit. Simply put, a FOBS has great potential for an atomic stealth attack.

The concern

In theory, China can develop an orbital nuclear weapon that may dodge US’ mainly north-facing strategic radars.

As a report in The Wire explained, the US Space-Based Infrared System can spot an FOBS launch, but the FOBS might be able to evade the country’s Ballistic Missile Defence (BMD) system. That is, one of FOBS’ advantages is that it may be able to beat the BMD and strike targets within mainland US.

The Chinese test – which comes to the knowledge of the world at a time of China’s rising tensions on its borders from Taiwan to India – is also understood to inform the US that it shouldn’t think it can attack China assuming that its BMD will protect it from retaliation.

The very fact that China has been able to test such a weapon is also a matter of concern as the US and many other nations have underestimated the extent of Chinese technology.

Marco Langbroek, an expert on space situational awareness, quoted by The Wire, said the US’ logical course of action now could be to extend the BMD’s coverage and install anti-satellite missiles to counter the FOBS threat.

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A report on the media portal also pointed to a major problem with using FOBS to deploy nuclear weapons: it violates the Outer Space Treaty (OST) that has been operational since October 10, 1967. A functional FOBS, if designed to deliver a nuclear payload, would violate the OST on the ground of placing nuclear weapons in orbit.