SM-65C Atlas

Atlas C (SM-65C)

Atlas C awaiting launch (USAF)
Function	Prototype ICBM
Manufacturer	Convair
Country of origin	United States
Launch history
Status	Retired
Launch sites	LC-12, CCAFS
Total launches	6
Successes	3
Failures	3
First flight	24 December 1958
Last flight	24 August 1959

The SM-65C Atlas, or Atlas C was a prototype of the Atlas missile. First flown on 24 December 1958, the Atlas C was the final development version of the Atlas rocket, prior to the operational Atlas D. It was originally planned to be used as the first stage of the Atlas-Able rocket, but following an explosion during a static test on 24 September 1959, this was abandoned in favor of the Atlas D.

One of the more significant upgrades to the Atlas C was the addition of motion detectors in the gyroscope package to ensure proper operation. This was implemented after the first B-series Atlas had failed in flight due to launch crews neglecting to power on the gyroscopes and would soon become a standard part of all ballistic missile guidance systems.

Missile 9C was designated for the Atlas-Able launch, which would take place in October 1959 from LC-12 at Cape Canaveral. The vehicle used the elongated propellant tanks first seen on Missiles 10B and 13B, but unfortunately this design change did not work as well here.

On September 24, the Atlas was prepared for a planned 12-minute static firing test. The upper stages were unfueled and the satellite was not on the launch vehicle.All went normally for two minutes when a fire erupted in the base of the Atlas. Fed by leaking liquid oxygen, it proved impossible to put out with pad extinguishers and soon a huge inferno was raging on LC-12. 37 seconds after the blaze began, the Atlas toppled over in a massive fireball, the biggest explosion seen at Cape Canaveral up to that point. The pad was severely damaged, with both umbilical towers totally destroyed, the concrete launch stand caved in, and the top portion of the service tower blown off. It would take four months of repairs to get it back online. The blast was estimated to be equivalent to 20,000 pounds of TNT and was particularly violent because of the nature of the failure - the common bulkhead between the RP-1 and LOX tanks collapsed and allowed the propellants to mix and form a gel which then detonated.

Investigators concluded that the disaster was due to the above-mentioned configuration change on the Atlas C. When Missile 9C was assembled at Convair, workmen attached a helium line to the wrong port. The result of this was that pressurization gas got into the sustainer LOX turbopump, leading to cavitation and rupture of the fuel lines. This then caused the fire that led to vehicle destruction.

After this debacle, it was decided instead to use the operational Atlas D for space launches instead of the developmental Atlas C.

Six flights were made. These were all sub-orbital test flights of the Atlas as an Intercontinental Ballistic Missile, with three tests succeeding, and three failing.

All Atlas C launches were conducted from Cape Canaveral Air Force Station, at Launch Complex 12.

Launch history

Date	Time (GMT)	Serial	Apogee	Outcome
1958-12-24	04:45	3C	900 kilometres (560 mi)	Success
1959-01-27	23:34	4C	900 kilometres (560 mi)	Failure. Missile lost thrust 1-1/2 minutes into the flight due to failure of a fuel regulator caused by overheating in the boattail.
1959-02-20	05:38	5C	100 kilometres (62 mi)	Failure. Valve malfunction during staging led to loss of tank pressure and reversal of the intermediate bulkhead. The missile destroyed itself at T+174 seconds.
1959-03-19	00:59	7C	200 kilometres (120 mi)	Partial failure. Premature booster engine shutdown due to an electrical malfunction at T+131 seconds led to an unstable flight trajectory.
1959-07-21	05:22	8C	900 kilometres (560 mi)	Success
1959-08-24	15:53	11C	900 kilometres (560 mi)	Success

See also

• SM-65 Atlas
• Able (rocket stage)

References

• Encyclopedia Astronautica - Atlas C