Advanced Soaring Concepts Apex
High-altitude research sailplane for aerodynamic studies and Mars vehicle design.
The Advanced Soaring Concepts Apex was a remotely piloted research sailplane built for high-altitude flight, a joint effort between Advanced Soaring Concepts and NASA's Dryden Flight Research Center (now Armstrong). Its purpose was to investigate aerodynamic behavior in the upper atmosphere, especially around 100,000 feet (30,480 meters), with the goal of guiding the design of future high-altitude aircraft and even vehicles for Mars exploration.
The design started with a modified Schweizer SGS 1-36 sailplane, which was heavily reworked to handle the demands of extreme altitude. The airframe used graphite/epoxy and boron/epoxy composites to achieve the needed strength without excess weight. A standout feature was the custom wing, which employed the "APEX-16" airfoil created by Dr. Mark Drela at MIT. This airfoil was tailored for stable performance in the thin, low-Reynolds-number conditions found high in the sky. The sailplane was about 22.7 feet (6.9 meters) long, with a wingspan of 41.2 feet (12.6 meters) and a wing aspect ratio of 13.6. It was built for a target gross weight of 600 pounds (272 kilograms) and a 5-g maneuver load factor.
The planned mission involved lifting the Apex to roughly 105,000 feet (32,000 meters) via a high-altitude balloon. After release, it would descend nose-first, then transition to horizontal flight using a small rocket motor. Once stable, it would take aerodynamic measurements during its glide back down. Onboard instruments included a "wake rake" positioned behind the wing to measure drag and other parameters. The data would have helped validate computer models for high-altitude flight and support the development of future aircraft for similar conditions.
Flight tests were initially scheduled for 1998, but the project faced repeated technical delays. By January 1999, the aircraft was still under construction, with delivery to NASA's Dryden expected in March or April. However, the program was mothballed before it could be completed. It saw a brief revival in 2000 but was ultimately canceled. Later high-altitude research goals were met by other NASA projects, such as the Helios solar-powered aircraft, which exceeded 96,000 feet (29,260 meters) in 2001.
Quick Facts
- Manufacturer
- Advanced Soaring Concepts
- First Flight
- Project canceled before flight
- Primary User
- NASA
- Number Built
- 0
Facts from the source article.
Lore & Background
The Apex was based on a modified Schweizer SGS 1-36 sailplane, extensively redesigned to withstand the rigors of high-altitude flight. The airframe incorporated graphite/epoxy and boron/epoxy composites to achieve the necessary strength-to-weight ratio. A distinctive feature was its custom-designed wing, utilizing the 'APEX-16' airfoil developed by Dr. Mark Drela of the Massachusetts Institute of Technology, optimized for stable flight in the low-density, low-Reynolds-number conditions of the upper atmosphere.
The planned mission profile involved lifting the Apex to an altitude of about 105,000 feet (32,000 meters) using a high-altitude balloon. Upon release, the sailplane would descend nose-down, transitioning to horizontal flight with the assistance of a small rocket motor. Once stabilized, it would conduct a series of aerodynamic measurements during its glide back to lower altitudes. Instrumentation included a 'wake rake' mounted behind the wing to measure drag and other aerodynamic parameters.
Initially scheduled for flight tests in 1998, the Apex project faced multiple delays due to technical challenges. By January 1999, the aircraft was under construction, with delivery to NASA's Dryden Flight Research Center anticipated in March or April. However, the project was mothballed before completion. The program saw a brief revival in 2000 but was ultimately canceled.
Reader's Guide
The Advanced Soaring Concepts Apex project was notable for its ambitious goal of studying aerodynamic phenomena at altitudes around 100,000 feet, a regime critical for future high-altitude aircraft and potential Mars exploration vehicles. Although the aircraft was never completed or flown, its design and development contributed to the validation of computational models for high-altitude flight. The data that would have been collected from its wake rake and other instrumentation was intended to inform the design of future aircraft operating in similar low-density, low-Reynolds-number conditions. Subsequent high-altitude research objectives were achieved through other NASA projects, such as the Helios solar-powered aircraft, which reached altitudes exceeding 96,000 feet (29,260 meters) in 2001. The Apex remains a documented example of a collaborative effort between a private company and a NASA research center to push the boundaries of aerodynamic knowledge for both terrestrial and extraterrestrial applications.
Did You Know?
- Its wing used the 'APEX-16' airfoil designed by Dr. Mark Drela of MIT.
- The planned mission involved a high-altitude balloon lift to 105,000 feet.
- The project was mothballed before completion and later canceled after a brief revival in 2000.
Frequently Asked Questions
What is the Advanced Soaring Concepts Apex?
The Apex is a remotely piloted research sailplane created to operate at extreme altitudes, developed jointly by Advanced Soaring Concepts and NASA's Dryden (now Armstrong) Flight Research Center.
What was the Apex designed to accomplish?
Its primary mission was to probe aerodynamic behavior near 100,000–105,000 feet, generating data that could guide the design of future high-altitude aircraft and even vehicles intended for Mars exploration.
What are the Apex's key dimensions and performance targets?
The sailplane is 22.7 feet long with a 41.2-foot wingspan and a 13.6 aspect ratio, targeting a 600-pound gross weight and a 5-g design load factor at its 105,000-foot ceiling.
What airframe served as the starting point for the Apex?
The project began with a Schweizer SGS 1-36 sailplane that was extensively reworked to endure the thin, frigid conditions of the upper atmosphere.
Why does the Apex matter in the history of unmanned flight?
It demonstrated that uncrewed, sailplane-based platforms could be pushed into the upper atmosphere for serious aerodynamic research, creating a direct link between Earth high-altitude testing and the engineering challenges of Martian flight.
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