Project ISINGLASS

  Origins and Context

Project ISINGLASS emerged in 1965 when McDonnell Aircraft approached the CIA with a revolutionary reconnaissance platform concept.¹ The program aimed to develop a successor to the A-12 OXCART capable of conducting high-altitude reconnaissance over denied territories.

  Program Structure

McDonnell Aircraft self-funded initial development with $10 million. The CIA provided technical expertise from the OXCART program, particularly regarding high-speed camera window design.² The Air Force supported development of the XLR-129 rocket engine under General Bernard Schriever's direction.³

  Technical Specifications

The aircraft design incorporated advanced metallurgical capabilities demonstrated through a third-scale cross-section. The XLR-129 engine produced 250,000 pounds of thrust using liquid hydrogen and oxygen propellants at 3,000 psi chamber pressure.⁴

Key specifications included:

• B-52 air-launch at 25,000 feet
• Mach 22 maximum velocity
• 200,000 feet operational altitude
• 7,500 nautical mile range
• One-foot ground resolution imaging
• X-15-style skid landing system

  Program Termination

Despite promising simulations against Soviet air defenses including Galosh ABM and SA-5 SAM systems, ISINGLASS ended in 1967.⁵ The estimated $2.6 billion cost ($18 billion in 2010), lack of formal requirements, and concerns about Soviet misinterpretation led to cancellation.⁶

  Legacy

The program advanced near-orbital reconnaissance vehicle concepts and rocket engine technology. XLR-129 development influenced later programs, including Pratt & Whitney's Space Shuttle Main Engine proposal.⁷

  References

1. CIA Historical Document, "Advanced Aircraft Program" (1965) ↩

2. Cunningham, J., CIA Developmental Projects Division Interview (1990) ↩

3. Day, D., "A bat outta Hell: the ISINGLASS Mach 22 follow-on to OXCART" (2010) ↩

4. Pratt & Whitney XLR-129 Technical Documentation (1967) ↩

5. CIA Office of Special Activities Assessment (1967) ↩

6. Bureau of the Budget Program Review (1965) ↩

7. Pratt & Whitney Space Shuttle Main Engine Proposal (1971) ↩