(News Focus) N. Korea now likely to focus on warheads, rocket precision By Sam Kim

SEOUL, April 5 (Yonhap) -- North Korea will likely push to enhance rocket precision and warhead durability as it tries to complete a delivery system that poses an effective threat to the United States, scientists and analysts said Sunday.

Their warning came after North Korea went ahead with the launch of what it called
a satellite. Neighbors believe the delivery rocket has been made with the same
technology used to produce the Taepodong-2 ballistic missile which can
theoretically hit Alaska.
Weapons experts agree that rocket technology is almost identical to missile
technology, while North Korea watchers say the communist state will be quick to
make military use of its rocket.
But they also doubt the communist country has perfected the technology to mount
nuclear warheads on its long-range missiles even though some analysts believe
there has been noticeable progress.
"It's not just the weight of warheads that makes it difficult to mount them. It's
the heat that poses the greatest challenge for the development of warheads," said
Sohn Myung-hwan, a South Korean rocket scientist heading a private defense
research institute.
An intercontinental ballistic missile undergoes extreme air friction and heat
from the sun as it travels in and out of outer space, he said, adding they
require "protective shielding" until they reach their targets.
"Or the warheads would simply explode during flight," he said.
North Korea conducted its first known atomic test in October 2006 and is believed
to possess plutonium enough to create several nuclear bombs.
Kim Byung-yong, a researcher at the state-funded Korea Institute for Defense
Analysis, said that the North is likely to have increased the rigidity of
warheads while it has also decreased their size.
"They go hand in hand," he said, voicing doubt that North Korea has sufficiently
"coated" its warheads against heat.
Hong Il-hee, chief researcher at the state-run Korea Aerospace Research
Institute, said precision is another key factor in guaranteeing the effectiveness
of a long-range rocket or missile.
"A rocket cannot be considered reliable if it can't reach its intended
destination," he said.
He said the next phase of North Korea's rocket development will almost certainly
involve a "gyroscope", which measures and maintains the orientation of a flying
vehicle.
The embedded device is backed by sophisticated computer algorithms and auxiliary
navigational tools, he said, adding, "precision is determined by how those sets
of devices and computer software work together."
Other areas of improvement involve an internal "spring" that remains contracted
until it catapults a mounted object when a rocket reaches its destination, these
scientists said.
They also said Pyongyang is likely to accelerate its research after the launch,
which offered a valuable chance to test a whole range of equipment the country
has been experimenting with for years.
"Such a launch is a real boost in terms of both confidence and technological
advancement," Kim said. "Research will speed up because the technology used in
the launch can now be applied with a greater sense of security in diverse
scientific areas."
samkim@yna.co.kr
(END