Atlas F Site 550-2 Missile Silo, Abilene Kansas

The quiet prairie west of Abilene, Kansas, hides one of the more vivid afterlives in the Atlas F story, a Cold War launch complex built for a thermonuclear missile, later stripped of its weapon, watched through environmental cleanup records, and publicly rediscovered as an 11-acre underground bunker offered for sale. Atlas F Site 550-2 was never just a hole in the ground. It was one node in a ring of hardened launch sites around Schilling Air Force Base, each designed to keep a first-generation intercontinental ballistic missile alive long enough to answer a national emergency.

Atlas F Site 550-2, also identified as Schilling AFB Atlas S-02, was an SM-65F Atlas intercontinental ballistic missile launch complex of the 550th Strategic Missile Squadron, 310th Strategic Aerospace Wing, Strategic Air Command. The parent base was Schilling Air Force Base at Salina, Kansas. Site 550-2 was located west of Abilene in Dickinson County, Kansas. The individual Atlas F complex had its own underground launch-control and support facility, so it did not have a separate Minuteman-style parent Launch Control Center.

The site was part of the twelve-site Atlas F deployment assigned to the 550th Strategic Missile Squadron. Air Force unit history lists the 550th Strategic Missile Squadron as organized at Schilling AFB on 1961-04-01, operational on 1962-09-09, and discontinued on 1965-06-25.

Today Site 550-2 is decommissioned and privately held. Public reporting in 2022 described the former complex as a private 11-acre property with its launch and control room, silo, and support buildings still present. There is no confirmed public access, and the site should be treated as private property.

Location, Landscape, and Site Description

Site 550-2 stood in farm country west of Abilene, Kansas, several miles from the city and well away from Schilling Air Force Base at Salina.

The location reflected Atlas F deployment logic, the missile sites were widely dispersed around their support base so that an attack on Schilling AFB or one launch complex would not necessarily destroy the entire squadron. Site 550-2 was one of twelve single-missile hardened sites in the Schilling field. Its rural setting reduced exposure to dense population centers, provided room for security fencing and blast-hardening features, and connected the site to the road network needed for missile transport, liquid-oxygen support, maintenance teams, security response, and routine supplies.

An Atlas F complex was a self-contained vertical-silo launch installation. The missile sat upright underground in a reinforced concrete and steel launch silo. The launch-control center and crew-support area were underground and connected to the silo by a tunnel. Surface features typically included the access road, security fencing, entry-control features, support buildings, utility structures, antenna or communications equipment, and the large silo doors over the launcher. Unlike later Minuteman launch facilities, which were unmanned silos controlled from remote launch-control centers, an Atlas F site normally had its own on-site crew and support personnel.

Public reporting on Site 550-2 in 2022 described the remaining underground complex as including the former launch control center and living quarters about 170 feet below ground, connected to the missile silo by a concrete tunnel. The same reporting described exterior support buildings, including a large Quonset-type building and a smaller office or storage building. The article also noted that the site no longer contained a nuclear-armed missile but still retained the hardened underground spaces that made Atlas F complexes so distinctive.

Strategic and Cold War Context

Atlas F Site 550-2 existed because the United States needed land-based intercontinental ballistic missiles that could survive long enough to deter or answer a Soviet nuclear attack. The Atlas program was a first-generation ICBM system, and the F model represented the last and most hardened operational Atlas variant. Earlier Atlas D and E sites used aboveground or semi-hardened launchers. Atlas F moved the missile into a vertical underground silo, giving the weapon better protection before launch and reducing the vulnerability of the earlier, more exposed layouts.

The 550th Strategic Missile Squadron at Schilling AFB and the 551st Strategic Missile Squadron at Lincoln AFB were among the first Atlas F operational units. The 550th's twelve Kansas silos formed a ring around Salina and placed a single SM-65F Atlas at each independent complex. That layout gave Strategic Air Command dispersal, redundancy, and a more survivable deterrent while the Air Force moved toward the next generation of solid-fueled Minuteman missiles.

The Atlas F was powerful but operationally demanding. It used RP-1 kerosene fuel and liquid oxygen oxidizer. RP-1 could remain aboard the missile during alert, but liquid oxygen was cryogenic and had to be loaded shortly before launch. For Atlas F, an operational launch-ready alert posture did not mean the missile was continuously raised above ground or continuously filled with liquid oxygen. It meant the missile, crew, communications, fueling systems, maintenance support, security force, and command procedures were maintained so that, if a valid launch order came, the site could begin the launch sequence: open the silo doors, raise the missile, load or top off liquid oxygen, maintain pressurization with gaseous nitrogen, and launch after the required preparations. That approach gave Atlas F a rapid response for its era but still left it more vulnerable during the final minutes before launch than later missiles that could launch directly from hardened silos.

Construction and Activation

The 550th Strategic Missile Squadron was organized at Schilling AFB on 1961-04-01, but the physical missile field was already under construction. The contractor and detailed construction timeline for this specific complex were not identified, but the construction of an Atlas F site required excavation for a deep vertical silo, heavy reinforced-concrete placement, blast-resistant doors, an elevator/launcher system, an underground control center, utilities, environmental-control systems, propellant-handling systems, communications equipment, security infrastructure, and surface support buildings.

In June 1962, the first Series F Atlas ICBM operational sites at the 550th Strategic Missile Squadron, Schilling AFB, and the 551st Strategic Missile Squadron, Lincoln AFB, were accepted by Strategic Air Command. Air Force unit history lists turnover to SAC for the 550th on 1962-09-07 and operational status on 1962-09-09.

Site 550-2's assigned missile was Atlas 29F, General Dynamics missile serial number 60-5552, Air Force tail number 552. The missile acceptance date was 1961-11-22, delivery date was 1962-02-19, destination as Schilling Air Force Base, mission as operational ICBM, and site assignment as the 550th Strategic Missile Squadron's Site 2.

Missile System and Technical Role

Site 550-2 housed the SM-65F Atlas, the final operational Atlas ICBM model. Atlas F was stored vertically in a hardened underground silo and was raised to the surface for launch. It was not launched from within the silo. The missile used RP-1 kerosene fuel and liquid oxygen oxidizer. In alert operations, the RP-1 fuel could be kept aboard, while liquid oxygen had to be loaded during the launch sequence. The missile was guided by an inertial guidance system and was part of Strategic Air Command's nuclear deterrent force.

Public museum and Air Force-associated sources identify the Atlas E/F reentry vehicle as the Mark 4, made by Avco Corporation. The Smithsonian National Air and Space Museum describes the Mark 4 as used on U.S. Air Force Titan I and Atlas E/F ICBMs deployed in the early 1960s and states that it carried a W-38 nuclear warhead with a yield of about 3.75 megatons. The 2024 310th Space Wing / DVIDS history video on Atlas F strategic deterrence (see below) describes Atlas F as a former 310th Space Wing-operated system and states that the missile could reach targets across much of the Northern Hemisphere.

The site role was both technical and human. The missile needed propellant systems, power, environmental controls, guidance and checkout equipment, security systems, communications links, and a trained crew. A 2022 public description of the site summarized the underground crew area as a launch control center and living quarters connected to the silo. In the Atlas F system, launch readiness depended on the on-site crew and support systems as well as the wider SAC command-and-control network.

Operational History

From 1962 to 1965, Site 550-2 was one of the twelve Atlas F launch complexes operated by the 550th Strategic Missile Squadron from Schilling AFB. The squadron's Atlas F sites were distributed across central Kansas around Salina: Abilene, Bennington, Chapman, Carlton, McPherson, Mitchell, Kanopolis, Wilson, Beverly, Tescott, Glasco, and Minneapolis were among the locations used to identify the launch sites. The 550th's emblem itself reflected this dispersed system: Air Force unit history states that the twelve stars represented the twelve missile complexes of the squadron.

Site 550-2's operational missile was Atlas 29F / serial 60-5552 / tail number 552. Once Site 550-2 entered the 550th SMS alert system, it contributed a single nuclear-armed Atlas F to SAC's ICBM force. Each site had to sustain readiness around the clock. The sites were manned 24 hours a day, seven days a week, 365 days a year during the active period. That staffing model reflected the Atlas F design, the launch complex combined a missile silo with its own crewed underground control and support spaces.

The Cuban Missile Crisis came only weeks after the 550th was declared operational. During the crisis, all operational 550th sites were at a high level of alert and ready to launch if necessary. For Site 550-2, that would have meant elevated crew, security, communications, maintenance, and propellant-readiness posture at the Abilene complex, not a missile kept permanently above ground or permanently loaded with liquid oxygen. Atlas F readiness was demanding because it required carefully controlled steps before launch, especially liquid-oxygen loading and raising the missile from the silo.

Deactivation and Disposal

Atlas F Site 550-2's active missile career was brief. The Air Force moved rapidly from first-generation liquid-fueled Atlas systems to more survivable and easier-to-maintain solid-fueled Minuteman missiles. Air Force unit history provides 550th Strategic Missile Squadron phaseout milestones: first ICBM off alert on 1965-02-01, last ICBM off alert on 1965-03-05, last ICBM shipped on 1965-03-11, and the squadron discontinued on 1965-06-25.

Those dates represent different steps in the shutdown process. A missile could come off alert before the site was fully decommissioned. A missile could be physically shipped before the unit was formally discontinued. The squadron could remain administratively active after its missiles were no longer in alert service.

Site 550-2 was not part of the later START-era Minuteman and Peacekeeper silo-demolition regime, because it had already left service in the 1960s. Its disposal history is instead a story of Atlas phaseout, missile removal, property reuse, and later environmental tracking. The assigned missile, Atlas 29F, survived long enough to be used in a 1978 space launch rather than being scrapped immediately after operational retirement.

Environmental records identify the former site as SCHILLING AFB ATLAS S-02. The 2015 USACE FUDS inventory lists the property in Dickinson County, city/locality Abilene, property number B07KS0260, site 01, category HTRW. DoD DERP status tables use FFID KS79799F030400 for Schilling AFB Atlas S-02. A 2023 DoD DERP Table 9 entry lists SCHILLING AFB ATLAS S-02 / KS79799F030400 as a Formerly Used Defense Site with one IRP site, no MMRP sites, and costs incurred through FY22 of $1.431 million, among installations/properties achieving final response complete before FY22. ProPublica's older Bombs in Your Backyard table listed Schilling AFB Atlas S-02 at Abilene, Dickinson County, as high risk; the later DERP Table 9 response-complete listing appears to be the more current cleanup-status indicator, but the older risk listing remains useful evidence that the site had been tracked as an environmental concern.

Current Status and Site Use

Site 550-2 is a decommissioned Atlas F launch complex on private property west of Abilene, Kansas. Public reporting in 2022 described the site as an 11-acre former missile complex that retained the underground launch-control space, tunnel, silo, and exterior support buildings. The same report stated that it had been purchased by a Manhattan-based owner on 2022-01-25 and relisted the next day for $380,000. Current ownership and use after that listing were not independently verified.

The site should not be treated as a public museum or public attraction. There is no confirmed public access. Any visit would require permission from the owner.

Chronology

• 1960 Construction began at Site 550-2, with the exact month and day not identified in the reviewed source.
• 1961-04-01 The 550th Strategic Missile Squadron was organized at Schilling AFB, Kansas.
• 1961-11-22 Atlas 29F, General Dynamics serial 60-5552 and Air Force tail number 552, was accepted.
• 1962-02-19 Atlas 29F was delivered for the Schilling AFB / 550th SMS operational ICBM mission.
• 1962-06 The first Series F Atlas ICBM operational sites at the 550th SMS, Schilling AFB, and 551st SMS, Lincoln AFB, were accepted by Strategic Air Command.
• 1962 Site 550-2 was turned over to the Air Force; the exact site-specific month and day were not identified in the reviewed source.
• 1962-09-07 Air Force unit history lists turnover of the 550th Strategic Missile Squadron to SAC.
• 1962-09-09 Headquarters SAC declared the 550th Strategic Missile Squadron operational.
• 1962-10 During the Cuban Missile Crisis, operational 550th SMS sites were held at a high level of alert; for Atlas F this did not mean the missiles were continuously raised or continuously LOX-loaded.
• 1965-02-01 Air Force unit history lists the first 550th SMS ICBM as removed from alert.
• 1965-03-05 Air Force unit history lists the last 550th SMS ICBM as removed from alert.
• 1965-03-11 Air Force unit history lists the last 550th SMS ICBM as shipped.
• 1965-06-25 The 550th Strategic Missile Squadron was discontinued as part of the Atlas phaseout.
• 1978-10-13 Former Site 550-2 missile Atlas 29F was successfully launched from Vandenberg AFB SLC-3W carrying the TIROS-N weather satellite.
• 2015 The USACE FUDS inventory listed SCHILLING AFB ATLAS S-02 / B07KS0260 at Abilene, Dickinson County, Kansas, with one HTRW site.
• 2021 DoD DERP records listed SCHILLING AFB ATLAS S-02 / KS79799F030400 among properties achieving final response complete in FY2021 / before FY2022.
• 2022 Public reporting described the former 550th SMS Site 2 near Abilene as an 11-acre decommissioned Atlas F silo complex listed for sale.

Read about the Atlas at Schilling AFB

All Atlas Missile Silo Locations