If a launch order came over the speakers, the officers were supposed to unlock their locks, open the safe, grab their codes and keys, then return to their consoles. The keys looked unexceptional, like the kind used to unlock millions of American front doors. The codes were hidden inside flat plastic disks called “cookies.” The disks were broken open by hand, like fortune cookies, and the codes were read aloud. And if the codes authenticated the emergency war order from SAC headquarters, the launch checklist went something like this:
SURFACE WARNING CONTROL… Lighted red.
Remove security seals and insert keys into switches.
Launch keys… Inserted.
Circuit breaker 103 on… Set.
BVLC — OPERATE Code Word… Entered.
Simultaneously (within 2 seconds) turn keys for 5 seconds or until sequence starts.
LAUNCH ENABLE… Lighted.
BATTERIES ACTIVATED… Lighted.
APS POWER… Lighted.
SILO SOFT… Lighted.
GUIDANCE GO… Lighted.
FIRE ENGINE… Lighted.
LIFTOFF… Lighted.
Assuming that everything worked as planned, the Titan II would be gone within seconds. Its warhead would strike the target in about half an hour. Once the missile left the silo, the crew’s job was done. They couldn’t destroy a missile midflight or launch another. The complex was designed to be used once.
The Titan II would not launch, however, unless the two keys were turned at the same time; the launch switches were too far apart for one person to activate them both. SAC’s “two-man policy” had been adopted to prevent a deranged or fanatic crew member from starting a nuclear war. The butterfly valve lock on the stage 1 rocket engine offered some additional control over who could launch the missile. Oxidizer wouldn’t flow into that engine until the correct butterfly valve lock code (BVLC) was used during the launch checklist — and without the oxidizer, the missile would stay in the silo. This code wasn’t kept in the safe or anywhere else on the complex. It was transmitted with the emergency war order from SAC. And the valve lock contained a small explosive device. Any attempt to tamper with the lock set off the explosive and sealed the oxidizer line shut.
The SAC two-man rule governed not only how the missile was launched but also how the complex was run. At least two authorized personnel always had to be present and within visual range of each other in the control center. You couldn’t allow the other person out of your sight. The same rule applied in the silo, whenever the missile had a warhead. At entrances to the control center and the silo, a warning stenciled in bold red letters said: “NO LONE ZONE, SAC TWO MAN POLICY MANDATORY.”
The commander and the deputy commander at every Titan II site were issued.38 caliber revolvers, in case an intruder penetrated the underground complex or a crew member disobeyed orders. Transferring the weapons was part of the turnover checklist, when a new crew arrived for duty. In addition to the handguns and their holsters, Mazzaro and Childers received some bad news from the crew preparing to leave 4–7. Pressure in the stage 2 oxidizer tank was low. A PTS team would have to visit the site, and most of the day would have to be devoted to major maintenance. Before the other crew departed, Mazzaro and Childers opened the safe, made sure the cookies and launch keys were inside, shut it, and installed their own locks.
For the next hour or so Mazzaro, Childers, Holder, and Fuller went through the daily shift verification (DSV) checklist in the control center. They checked every piece of equipment on all three levels of the center, every gauge, switch, and warning light. Level 3 was the basement. It housed the DC power supplies and battery backups, switching equipment for the communications systems, the air-conditioning and ventilation systems. Fresh air was pulled into the control center from outdoors, filtered, cooled, and then sent throughout the rest of the complex. The positive air flow helped to protect the crew from toxic vapors that might drift from the silo. The go-to-war safe, the tall steel cabinets, and the launch consoles were on level 2. The top floor, level 1, had a kitchen, a small round table, four chairs, a toilet, and four beds. The complex had enough food to last for a month, but its emergency diesel generator had enough fuel for only two weeks. During wartime, the crew might find itself eating canned and dehydrated military rations in the dark.