National Affairs: Rise of Polaris

In a time when the U.S. must have the power of instant retaliation, the weakness of the U.S.'s growing family of liquid oxygen ("lox") -and-kerosene-fueled missiles is that they cannot retaliate instantly. Time needed to fuel the Air Force's test-ICBM Atlas: a minimum 15 minutes after an hour-long countdown. Time needed to fuel the Air Force's test IRBM Thor, even using a promising but not fully tested method of "force-feeding": eight minutes. The U.S.'s lox missiles could conceivably be knocked out by the enemy before they could be fueled and primed for launching.

One promising answer to the problem is the Navy's 1,500-mile test-missile Polaris. Reason: it is fueled with a solid propellant. The Navy turned to solid fuels because it wants a missile that can be fired from submarines or surface vessels, and liquid-oxygen fueling is too complex for shipboard handling. Since solid-fuel missiles can be fired in the minutes needed to arm their warhead and make the final check on their guidance and control systems. Air Force Missile Boss Major General Ben Schriever is interested in Polaris, has a team of technicians sitting in on the Navy Polaris project. Said Richard Horner. Air Force Assistant Secretary for Research and Development, last week: "There is the possibility of a very clear payoff for both of us."

But solid fuel is by no means a proved item. Solid-charge missiles have less thrust than liquid propellants, cannot carry as heavy a warhead per pound of fuel. Critics of solid fuel argue that it requires a canister that can withstand great pressures, that solid fuel blasts off with a jolt that is rough on the missile's complex guidance systems; the Navy insists that it can control the blastoff, but it has not yet tested its technique on the missile. Another key problem: how to shut off the solid-charge propulsion at the precise point needed to drop the missile on target (in lox missiles this is accomplished by turning off a valve). The Navy says it has solved this problem in the laboratories and on test vehicles, admits it has yet to test it out on a missile.

The Navy is giving top priority to solid-fuel shortcomings, hopes for a flight test of Polaris next summer or fall. Says Chief of Naval Operations Arleigh Burke about Rear Admiral William F. Raborn, officer in charge of Polaris: "He is the only man in the Navy who has a blank check. All he has to do is say 'I want,' and he gets." If the faults can be whipped, even the most loyal Air Force birdmen admit that their lox systems will probably give way to solid fuels in the next round of missile development.