Despite the many obstacles involved, a decades-long quest to develop air-launched ballistic missiles continues.
Right now, officers on duty in hardened capsules near underground missile silos await an order they hope will never come: an inbound emergency action message to launch their intercontinental ballistic missiles. Deep beneath the waves, meanwhile, submarine crews are relieved to see that their latest EAM signals yet another drill rather than an actual attack. As joint custodians of ICBMs, these personnel share a heavy burden of responsibility. But if current plans come to fruition, aircrews could one day be joining them on the front lines of nuclear deterrence. After being put on the back burner decades ago, the concept of deploying air-launched ballistic missiles, or ALBMs, is again gaining currency in a number of nations.
Aircraft have been carrying atomic weapons ever since the B-29 Superfortress Enola Gay dropped the “Little Boy” bomb on Hiroshima. As long as the arming plug is kept separate from the device until it’s actually deployed, transporting these fearsome weapons by air is relatively safe. Sure, in the event of a crash or accidental drop—and that’s happened more than once—there is the danger of radioactive materials spreading. But very specific circumstances are required to start the chain reaction that sets off an atomic explosion, including, of course, the use of an arming mechanism.
Military cargo planes have been hauling ICBMs for decades. What distinguishes the risks inherent in that exercise from the dangers of actually launching ballistic missiles from an aircraft is the thousands of pounds of explosive fuel filling the missile. And that’s just one of many challenges that must be overcome.
U.S. Air Force officials first had the idea to attempt air-launching ICBMs during the 1950s. It seemed like a good idea for several reasons, one of which involved interservice rivalry. At the time, the Air Force and the U.S. Navy were engaged in an often acrimonious contest to see who would be in charge of deploying most of America’s atomic arsenal. In 1959, with the Polaris submarine-launched ballistic missile in development, Air Force chief of staff General Thomas White was quoted as saying, “If the Navy can launch a ballistic missile from a submarine, we can launch one from a bomber.” No doubt many others in the Air Force agreed with General White.
While the debate raged, the U.S. deployed its first ICBM, the Atlas. Though it was an impressive technological achievement, the Atlas had two glaring weaknesses: It had to be raised onto an open pad, and it needed to be fueled in the open. Both requirements meant it was vulnerable. An atomic strike relatively far from the missile battery could destroy an entire complement of missiles, and an incoming first strike could hit before the fueling cycle had been completed.
There were also concerns about the nuclear bomber force. With jet interceptors and anti-aircraft missiles rapidly becoming more sophisticated and effective, it seemed less and less likely that a bomber armed with conventional free-fall nuclear bombs could survive to fly all the way to a well-defended target.
The obvious advantage of deploying ballistic missiles from aircraft was mobility— an enemy couldn’t target the aircraft in a first strike. Unlike an ICBM, the aircraft could be recalled after deployment, much as a conventional atomic bomber could. Among the many difficulties involved were expense and maintenance hours. Instead of maintaining only a missile and a launchpad, it would also require keeping an airplane at peak readiness, plus a significant number of trained crewmen would be needed for each plane. Another problem was security. It’s much easier to secure an Air Force missile launch complex somewhere in rural South Dakota than it is a typical Air Force base. Just one shoulder-launched missile could take down an aircraft on takeoff and block a runway, putting a squadron out of commission. That argument was often used against the proposed scheme.
Guidance and targeting were also challenges. To strike its target, a ballistic missile needs two crucial pieces of information: the exact location it’s being launched from, and where it’s supposed to strike. Preprogramming a target location into the missile was simple enough, but telling the weapon where it was being launched from while the platform was constantly moving presented a problem. Today that problem can be resolved via global positioning satellites, but the first GPS satellites were not launched until 1974, nearly two decades after ALBMs were first considered.
Based on experience gained from earlier ballistic missile research projects, the Air Force proceeded with development of the Skybolt ALBM. Britain, which planned to arm its V-bomber force with the new missile, joined the effort. There were also proposals to arm several other types of aircraft with Skybolts, including the Vickers VC-10 airliner. The British were in fact so confident in the concept that they based their entire nuclear deterrence plan on the Skybolt, canceling all other efforts.
Unfortunately, the Skybolt suffered several failures during testing. With the Polaris missile coming into service at that juncture, the program was canceled in December 1962, leading to bitter recriminations be – tween the British and Americans. That crisis would be resolved when the U.S. shared Polaris missiles and the technology to build ballistic missile subs with Britain.
In 1974, when negotiators in the U.S./ USSR Strategic Arms Limitation Talks (SALT) were looking for additional bargaining chips before their November meeting in Vladivostok, USAF officials proposed reviving the ALBM program and taking it all the way to an actual launch. For this new test program they chose Boeing’s Minuteman ICBM, paired with Lockheed’s C-5A Galaxy cargo plane.
On October 24, 1974, crews carefully loaded an LGM-30B Minuteman I (sans warhead) onto C-5A serial no. 69-0014 at Hill Air Force Base, in Utah, for the last in a series of eight test flights. The Galaxy took off at 8 a.m., heading west to the Pacific. An engineer from Space Vector Corporation, responsible for the missile guidance set, checked his charge. If all went well, in 85 minutes, just over 640 miles away, the cargo plane would make aviation history.
The flight crew consisted of two Lockheed test pilots and an Air Force Flight Test Center pilot, as well as a flight engineer and two flight test engineers. In charge of the cargo were an airdrop test engineer and loadmaster, both from the 6511th Test Group (Parachute), plus Military Airlift Command loadmasters Chief Master Sgts. Elmer W. Hardin and James Sims. A Boeing engineer was also on hand to ensure the missile functioned properly.
Just over an hour after takeoff, the aircraft neared Vandenberg Air Force Base on the California coast. Riding in the rear seat of a Douglas B-66 Destroyer chase plane, a cameraman prepared to film the drop. Another chase plane was ready to film it from farther away, plus there were multiple cameras ready to roll aboard the Galaxy.
At the 10-minute warning, Hardin and Sims removed the safety locks connecting the missile platform to the aircraft and checked to see that the extraction chute was properly hooked up. Sims then removed the red safety plug from the Minuteman and replaced it with a green one: The missile was now ready for launch.
At the eight-minute warning, the rear cargo doors opened, exposing the cargo deck to the howling wind. Sims armed the mechanism that would automatically release the missile platform as soon as the extraction parachutes were dropped from the plane.
By the three-minute warning, the C-5A was over the Pacific, 15 miles west of Vandenberg. Loadmasters armed the rail locks, and the Space Vector engineer turned the missile guidance power switch to internal power. At one minute to launch, the range controller issued clearance to proceed. With 30 seconds to go, the loadmasters armed the extraction parachute mechanism. Then, 10 seconds before the drop, the cage was removed from the missile guidance platform.
The countdown began: five, four, three, two, one…launch!
Extraction parachutes were released through the open rear cargo hatch, smoothly unfurling in the airstream. The missile platform rattled noisily down the ramp, pulled by the parachutes. Four seconds later explosive bolts released the straps connecting the missile to its platform, which was then pulled away by the extraction parachutes. As the Minuteman fell, three stabilization parachutes deployed and inflated, changing the weapon’s orientation to vertical. Standing on the edge of the loading ramp, the loadmasters watched it disappear beneath the thick cloud layer 10,000 feet below them. The stabilization parachutes detached and the missile’s motor ignited as it continued falling to just under 8,000 feet.
At that point the Minuteman started to climb. The crewmen watched it rise through the clouds several miles behind the Galaxy. Once the missile reached the aircraft’s altitude—20,000 feet—its fuel was exhausted and it fell into the Pacific. The mission had been an unqualified success.
When Soviet military planners learned of the American success, they promptly went to work on their own air-launched weaponry. They had some previous experience to build upon. Early ALBM development efforts were led by the Makayev design bureau, builders of most Soviet (and now Russian) submarine-launched ballistic missiles. Among various proposals was a plan to launch ballistic missiles from three tubes mounted vertically through the fuselage of a large transport plane, in a configuration that very much resembled a flying missile submarine. But when the Soviets encountered the same challenges that had dogged early efforts in the U.S., they put the concept on the back burner.
With the 1980s arrived another escalation of the Cold War, and the Soviets decided to try again. The Yuzhnoye design bureau, in cooperation with Tupolev, worked to modify the Tu-160 bomber into the Tu-160K variant, with load-carrying capacity increased by 50 tons. The Tu-160K was designed to carry two Krechet-R ALBMs, one in each of its bomb bays. These new solid-propellant missiles would be armed with six multiple, independently targetable reentry vehicles. Targeting would be accomplished via an inertial guidance system, through satellite positioning data. By December 1984, equipment for transporting and loading the Krechet missiles into the Tu-160K bomb bays had been designed.
Although the Tu-160 was a promising carrier aircraft, the expense and difficulty of developing an entirely new missile proved to be too much of an obstacle for the bureaus. Work was discontinued on the system by the end of 1984. Since the Soviet Union’s fall, there have been a number of projects in Russia and the former Soviet republics aimed at air-launching civilian rockets with satellite payloads, but so far none has managed to secure enough financing to succeed.
Given this laundry list of attempted and abandoned projects, one might assume the ALBM concept would be on the decline by this point, but that’s not the case. In October 2000, Trimbach Turbine Ltd. filed a U.S. patent for an “Aircraft having multiple fuselages.” The patent application described a plane with a central fuselage and “side-saddle” fuselages mounted on both sides. The additional fuselages could each house a launch tube “adapted for transporting and launching a large or oversize missile.”
In 2004 Israel Aircraft Industries filed a patent describing several methods for air-launching large missiles from cargo aircraft. In an interesting twist on the Lockheed method, the missile support platform would have control surfaces that unfold after the assembly is detached from the carrier aircraft, as well as thrusters for correcting its orientation. Among the options envisioned is the familiar missile drop from the cargo bay or attaching the missile platform to the top or bottom of the carrier plane’s fuselage.
In 2004 and 2009, the British defense firm BAE Systems filed two patents for “Air-based vertical launch ballistic missile defense,” though the applications also envisioned missions such as offensive ground attack, mine laying and satellite launch. The documentation lists various configurations of mounting multiple missile tubes vertically through the fuselages of large cargo aircraft, similar to the concept considered by the Soviets. Also described in the applications were solutions for problems such as launching vertically into a rapid airstream.
The U.S. military has also returned to the ALBM concept in recent years. Under the auspices of the DARPA/USAF Falcon Small Launch Vehicle program, in 2006 AirLaunch Corporation conducted three test drops of inert rockets from the rear of a Boeing C-17. The final mission marked the heaviest cargo yet dropped from a C-17. Unlike the drops conducted in 1974, these tests did not deploy the rocket via a pallet; instead, the rocket itself was rolled off the aircraft along a set of rollers installed in the cargo bay, greatly simplifying the process. A single stabilization parachute provided the change of orientation to vertical.
The U.S. Missile Defense Agency has also been air-drop-launching large missiles, as targets for missile defense systems tests. At the time of this writing, 12 air launches had been performed since 1997 with several types of short-, medium- and long-range missiles using propulsion stages repurposed from deactivated Minuteman IIs. The first two launches used a Lockheed C-130 as their platform, and the rest of them have been launched from C-17As. All of the drops save one employed pallet-extraction via parachute.
Most recently, Lockheed’s Extended Medium-Range Ballistic Missile target was air-dropped in dummy form on May 14, 2013, at the Yuma Proving Ground in Ariz. On September 10, a C-17 dropped a live Lockheed target missile over the Pacific that was destroyed by a ground-launched missile from the Army’s 2nd Air Defense Artillery Regiment on Kwajalein Atoll.
The ALBM has intrigued nuclear-armed nations around the world for several decades now. Technological and financial difficulties have repeatedly proved to be only temporary impediments in the development of this concept. The only real deterrent has been political: Treaties limiting strategic arms have included language on ALBMs since SALT I was signed in 1972. However, the new Strategic Arms Reduction Treaty (START) between the United States and Russia, which was signed in Prague on April 8, 2010, classifies each ALBM-armed bomber as one nuclear warhead. Since each aircraft can in fact carry multiple missiles armed with multiple reentry warheads, this could be viewed as a significant opportunity for military planners. Russian advocates of increased nuclear armament have in fact supported exploiting that loophole. We might yet see ALBM-armed aircraft operationally deployed in the not too distant future.
Emil Petrinic wishes to acknowledge Henry J. Hunter, a participant in the 1974 air-drop mission, whose article in the November 2000 issue of The Loader (the Professional Loadmaster Association newsletter) described the mission’s details. He would also like to acknowledge the writers and editors of the Air Mobility Com mand Museum newsletter, Hangar Digest, for their coverage of the 1974 mission. You can view a video of the 1974 drop on YouTube (search “ICBM air drop”).
Originally published in the July 2014 issue of Aviation History. To subscribe, click here.