On January 17, Japan fired an earth observation satellite into orbit aboard an Epsilon rocket, the workhorse of the country’s civilian space program.

The Epsilon is a Japanese solid-fuel rocket designed to launch scientific satellites. It can place a 1.2 ton payload into low earth orbit.

John Pike, a space security expert, says the peaceful rocket has another possible use, however. He says it can be turned into a nuclear delivery vehicle, providing Japanese defense planners with a ready-made way to drop nuclear warheads on Chinese and North Korean cities.

“It would take Japan less than a year to do this,” Pike told Asia Times. “The Epsilon is a big, solid rocket. All they have to do is take the satellites off the front end and add the warheads.”

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Pike argues this is because the interchangeability of satellite and nuclear warhead launch capability is a well-known fact. “We used to say during in the Cold War that the difference between a missile and a satellite launcher isn’t altitude, but attitude,” Pike told Asia Times.

Case in point: the US, China and the Soviet Union have all used intercontinental ballistic missiles (ICBMs) to loft satellites into orbit. North Korea was only the latest to do so when it launched a satellite on February 7, 2016, in what was widely viewed as a front for a ballistic missile test.

It’s also been known for years that Japan can access ample fissile material from reactor-grade plutonium at its civilian nuclear plants to fashion nuclear warheads and bombs. North Korea, India, Pakistan and others have tapped the same method, using centrifuges and other equipment, to build their nuclear arsenals. Japan’s technological edge would allow it to convert spent nuclear fuel into weapons within months, according to most analysts.

A nuclear power reactor typically produces 250-300 kilograms of plutonium annually, enough to produce 25-30 weapons. (Japan has 54 civilian nuclear reactors, although 43 are now offline due to safety concerns generated by the 2011 Fukushima nuclear disaster.)

A debate on whether Japan should go nuclear because of perceived threats from North Korea and China has also gone public. And Prime Minister Shinzo Abe favors developing new weapons to defend the country in a shifting Asian security environment.

Nukes still a hot potato

But Abe still faces stiff opposition at home in revising the country’s pacifist constitution to develop offensive (as opposed to purely defensive) military weapons. Any move by Japan to perfect such capability might also draw a sharp military reaction from Beijing or Pyongyang.

Daniel C. Sneider, an associate director of research for Stanford University’s Walter H. Shorenstein Asia-Pacific Research, says there’s “no chance” that Japan will develop nuclear weapons anytime soon. “Capability is not the same as reality,” the veteran former Japan correspondent told Asia Times. “Right now a clear majority of Japanese don’t even support constitutional revision. The only way Japan goes nuclear is if the US alliance disappears – and I don’t think even Trump can do that.”

No technical obstacles

But beyond such challenges, Pike stresses there are no technical factors standing in the way of putting nuclear warheads on the Epsilon rocket and otherwise converting it into a serviceable ICBM. “The Japanese have tested re-entry materials” that can be used for nuclear warhead technology,” noted Pike, who runs the military intelligence website globalsecurity.org. The only significant hurdle would be fabricating a nuclear warhead and its accompanying “dispenser” mechanism – something which Pike says Japan could do with ease. The defense analyst also believes Tokyo already has contingency plans for converting the Epsilon into a nuclear missile.

The Epsilon’s big plus as an ICBM is that it relies on solid fuel. Missiles with solid propellants can be preloaded, stored for long periods and launched on short notice. This compares with liquid-fuel rockets whose tanks must be filled with such volatile fuel and need considerable ground preparation before they can be fired.

Pike also notes that Epsilon rockets converted for military use don’t require sophisticated targeting. He predicts that if Japan develops ICBMs, they will be aimed at Chinese or North Korean cities. This won’t require precise targeting capability, as in the case when attacking hardened missile silos and other hardened military sites.

He adds that Japanese defense contractors would have scant trouble producing the modified satellite rockets as weapons. “I think they could be produced, at the very least, at the rate of one per month,” Pike said.

MIRVs too

Moreover, it would be relatively easy for Japan to transition from single nuclear warheads to Multiple Independent Reentry Vehicle (MIRV) delivery. Pike says that’s because the satellite dispersal technology which allows rockets to send more than one satellite into orbit is the same one that allows separately targeted nuclear warheads to hit multiple targets on the ground.

Japan could also make its missiles tougher to hit in preemptive strikes by mounting them on railway cars. “Japan has a very dense rail network. Fixed launch sites are just targets,” Pike said, noting that China and other countries are mulling using high-speed trains as mobile missile launchers.

“The main challenge in this is time and money,” Pike said. “You have to collect all the technology and experts you need and bring it together at one time.”