MALMSTROM AIR FORCE BASE — Sgt. Michael Howard stands upon the 110-ton blast door, a living-room-sized slab of concrete and steel sitting over the Minuteman III nuclear missile perched below.

The missile isn’t live. If it were, Howard tells the group of journalists, the hatch over the access tube wouldn’t be left open. This, we’re told, is the missile’s most vulnerable moment — the only opportunity a well-timed infiltrator may have in gaining access to the warhead.

After September 11, 2001, when the 341st Space Wing locked down Montana’s 23,500-acre missile field, security upgrades to the Minuteman III defense system began in earnest. Thicker concrete around the silo, security cameras around the perimeter and a beefed up rapid-response team have been implemented at all 200 missile sites around Montana — the largest ballistic missile field in the U.S.

Changes to the Minuteman defense system run deeper than added security. The missiles, along with the components that make them work, are undergoing an upgrade that will cost the U.S. Air Force $6.2 billion when finished, extending the life of the intercontinental ballistic missile, or ICBM, out to 2030.

At a morning briefing, Col. Paul Gydesen, vice commander of the 341st Space Wing, explains the overall Malmstrom mission, along with the changes his airmen are making to update each Minuteman III missile.

“Before, we were focused on a certain adversary that had overwhelming power to destroy the United States,” Gydesen says, opening his talk with a slide presentation. “That adversary, although we don’t call them an adversary any more, is still there, and still capable of destroying the United States.”

More than 40 years have passed since the Cuban missile crisis prompted President Kennedy to declare that his “aces in the hole” were ready to fire. Those so-called aces, the Minuteman I, became alert-ready at Malmstrom on October 26, 1962.

While the Cold War showdown has ended, nuclear proliferation continues. Attempts by North Korea were recently abandoned, but Iran, defense experts believe, continues to pursue nuclear capabilities despite warnings from the world court to stop.

With that in mind, Gydesen says the “deterrent mission” at Malmstrom must go on. The underground missile, capable of carrying warheads that can strike a target anywhere on the planet in less than one hour, remains the Air Force’s most threatening and prolific weapon.

“Once you launch that missile and it’s on its way to its target, there is no recall,” Gydesen says after showing a politically correct video in which the missile ultimately splashes down in the ocean, not over some strategic foreign target. “It’s a very capable system with great intercontinental range. It can carry three independent, retargeting warheads.”

Gydesen injects frequent reminders into his talk. The Minuteman system is more than 40 years old. It is, he continues, 1960s technology getting a 21st century makeover.

“This is not the system of 1962,” he says, moving through his presentation. “That was the Minuteman I and this is the Minuteman III. It has progressed, and our modernizations continue.”

While Malmstrom crews work to decommission the 564th Missile Squadron and with it, the 50 Montana-based ICBMs it once controlled, more than 150 nuclear warheads will remain in the state when the phase-out is complete.

The remaining ICBMs are part of the Minuteman III defense system, which includes 450 missiles total when Warren and Minot Air Force Bases are included. The defense system, spread across Montana, Wyoming and North Dakota, has undergone several evolutions since the early 1960s, but none as far reaching as the changes now taking place.

“We’ll touch everything from the tip of the rocket down to the nozzles,” Gydesen said. “It doesn’t replace every component, but it does replace most, so they can last to the 2030 time frame.”

Enhancements include modern security upgrades to each missile silo, such as additional concrete, cameras and a rapid rising “B-Plug,” allowing missile crews to open or close underground sites faster than before.

Air Force crews at Malmstrom also continue changing out each missile’s “limited life” components, including a $2.6 billion effort to replace the rocket engines. Other improvements include upgrades to the missile guidance set ($2.4 billion), along with the re-entry vehicle system, or the platform that ultimately delivers the warheads ($551 million).

“You just can’t do 1960s technology any more,” said Gydesen. “Things were breaking. The supply system was running out. We needed to have modern components in there.”

The Peacekeeper system, which was phased out beginning in 2002 at Warren AFB, had a more modern delivery system, capable of carrying three warheads for every one missile.

Until recently, the Minuteman carried just one warhead. But when the Peacekeeper was retired, Gydesen explained, defense engineers set out to modify the Minuteman to carry three warheads.

The various upgrades, however, have not touched the missile’s guidance system. The gyros and accelerometers — the items that drive the missile to its target — are still 1960s technology. Gydesen believes replacing such components will be a key factor in extending the life of the Minuteman III defense system.

“If we want to get the system out to the 2030 time frame, we’ll need another modification program at some point, in my opinion,” he said.

Down inside the silo, the temperature hovers near 71 degrees. Teams skilled in specific areas often scale down the ladder descending the entry hatch.

The hatch is slightly larger than a manhole. It’s covered by a 175-pound door and plugged by a 7-ton steel core. One encrypted code is required to open the hatch. A second code is needed to initiate the jack screw that quickly lowers the steel plug.

Only then, with others watching from remote sites — with alarms and detectors identifying one’s presence — can the site be accessed.

“The entire system is based around no one person having access to the entry,” said Sgt. Jeremy Karr, who, along with Sgt. Howard, will lead the silo tour. “In order for us to get access we have to have two parts, the maintainers who need to do the maintenance, and the security to control the aspects.”

The ladder places one firmly on the first platform about 15 feet underground. A network of pipes and cables cling to the concrete wall. The equipment emits a gentle hum, the noise echoing off walls 3 feet thick.

At the center of the room, the missile points skyward. Here, on the first platform, one is eye level with the final-stage booster and the cone containing the warhead. Under that cone, the warheads would arm with their encrypted mission.

Showing off the newest enhancement, Howard moves to a nearby electric box. It’s a powerful device that provides the crews proprietary power — even when power has been lost — to open and close the entry plug. Doing so successfully locks out any hostile threat, and locks crews in.

“We can raise that door three times with no external power being applied,” Howard says, pointing to the 7-ton plug. “It’s just another way for us to keep it secure, so if somebody did cut a power line, we could lock them out before they were able to get downstairs. We actually have some going in right now.”

This is only the top of the silo. Eyes adjusting to the low light, one gets the feeling that there’s much more sitting below, a fact Howard confirms. The silo itself is 90 feet deep, dropping as a mineshaft to accommodate the length of the missile.

Another ladder. Another 10 feet down. The second platform sits on a giant swing supported by equally giant cables. This swing, crews say, will help absorb a near miss by an incoming missile, thus protecting the Minuteman’s launch-critical equipment; electrical surge arrestors, batteries, medium frequency radios, and the digital data terminal.

“It’s what communicates to the missile and back, and to the capsule crew,” Howard says. “The signals are encrypted. Anything that leaves this site gets encrypted and decrypted over at the missile control site.”

Once the launch crews dispatch their encrypted message and commence the launch sequence, the missile begins to arm. The terminal countdown, Howard says, takes less than one minute.

“It’s ‘Minuteman’ for a reason,” he says. “Once terminal countdown starts, it’s going to go. There’s really no stopping it. The missile lights in the hole and out it goes. I’ve seen first hand what these things can do. They’re pretty fast.”

Nineteen seconds after launch, the Minuteman III is traveling the speed of sound (770 mph). At 40 seconds, it’s moving three times the speed of sound (2,310 mph). One minute into flight, it ejects the first-stage rocket booster.

Maneuvering in near space, the re-entry vehicle will make its final calculations. The thrusters place the warhead into position. Once over its target, it begins a lethal dive, the world’s most catastrophic weapon.

Staging a launch sequence for the edification of the press, Capt. Sarah Wood and Lt. Anthony Surman receive an encrypted message. In a real scenario, the message would travel from the president to U.S. Strategic Command, then on to this team, in a matter of minutes.

Wood and Surman receive the encrypted code separately, but must work in unison to initiate the launch. Seated at the panel, the two officers type in their code. “Enable value — PPPP777,” Surman reads. “Initiate. Unlock enable switch.” Simultaneously, they turn the keys to fire. The screen indicates the launch is in progress.

The only single person with authority over the launch system is the president, Wood says. Even then, the president is assisted by numerous strike advisers and planners. There are eight to 10 checks leading up to a launch.

It’s an efficient system practiced more times than they can count. But like gaining access to the missile silo, it takes more than one person to initiate the launch. Doing it this way, Wood says, adds one more redundancy to the system, ensuring a rogue individual can’t fire the weapon and trigger a nuclear holocaust.

“You need two people with two hands each to talk to the missile,” says Wood. “We have to initiate within one second of each other in order for it to work, or we’d have to go through the process again.”

With the code enabled, the missile aligns itself to the target. In Wood’s own words, it’s cocking the pistol.

“Once the sortie goes LIP (Launch In Progress), there’s no calling it back,” she says. “It’s on its ballistic trajectory.”

Reporter Martin Kidston: 447-4086 or mkidston@helenair.com