Editing Advanced Soaring Concepts Apex


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{{Infobox aircraft
| name = Advanced Soaring Concepts Apex
| image = ASC_Apex.jpg
| caption = Computer-generated image of the Apex high-altitude research sailplane
| type = Experimental high-altitude research sailplane
| manufacturer = [[Advanced Soaring Concepts]]
| first flight = Project canceled before flight
| status = Canceled
| primary user = [[NASA]]
| number built = 0
}}

The '''Advanced Soaring Concepts Apex''' was a remotely piloted, high-altitude research [[sailplane]] developed by [[Advanced Soaring Concepts]] in collaboration with [[NASA]]'s Dryden Flight Research Center (now [[Armstrong Flight Research Center]]). The project aimed to study aerodynamic phenomena in the upper atmosphere, particularly at altitudes around 100,000 feet (30,480 meters), to inform the design of future high-altitude aircraft and potential Mars exploration vehicles.<ref name="NASA_Apex">{{cite web |title=Apex Remotely Piloted Sailplane |url=https://www.nasa.gov/reference/apex-sailplane/ |publisher=NASA |access-date=2025-04-16}}</ref><ref>{{cite journal |last= Ianotta |first= Ben |title=Where aircraft fear to go |journal=[[New Scientist]] |date=31 May 1997 |url=https://www.newscientist.com/article/mg15420845.000-where-aircraft-fear-to-go.html |accessdate=2008-07-01}}</ref>

== Design and development ==

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.<ref name="Greer1999">{{cite report |last=Greer |first=Donald |author2=Hamory, Phil |author3=Krake, Keith |author4=Drela, Mark |title=Design and Predictions for a High-Altitude (Low-Reynolds-Number) Aerodynamic Flight Experiment |publisher=NASA Dryden Flight Research Center |date=July 1999 |url=https://ntrs.nasa.gov/api/citations/19990049398/downloads/19990049398.pdf |access-date=2025-04-16}}</ref>

A distinctive feature of the Apex was its custom-designed wing, utilizing the "APEX-16" airfoil developed by Dr. [[Mark Drela]] of the [[Massachusetts Institute of Technology]]. This airfoil was optimized for stable flight in the low-density, low-[[Reynolds number|Reynolds-number]] conditions of the upper atmosphere.<ref name="Greer1999" />

The sailplane measured approximately 22.7 feet (6.9 meters) in length with a wingspan of 41.2 feet (12.6 meters) and a wing aspect ratio of 13.6. It was designed for a target gross weight of 600 pounds (272 kilograms) and a 5-g maneuver load factor.<ref name="Greer1999" />

== Mission profile ==

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.<ref name="NASA_Apex" />

Instrumentation included a "wake rake" mounted behind the wing to measure drag and other aerodynamic parameters. Data collected would have contributed to the validation of computational models for high-altitude flight and the development of future aircraft operating in similar conditions.<ref name="NASA_Apex" />

== Project status ==

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.<ref name="NASA_Apex" />

The program saw a brief revival in 2000 but was ultimately canceled. Subsequent high-altitude research objectives were achieved through other NASA projects, such as the [[AeroVironment Helios Prototype|Helios]] [[solar-powered aircraft]], which reached altitudes exceeding 96,000 feet (29,260 meters) in 2001.<ref name="NASA_Apex" />

== See also ==

* [[Advanced Soaring Concepts]]
* [[NASA Armstrong Flight Research Center]]
* [[High-altitude platform station]]
* [[Mars aircraft]]

==References==
{{reflist}}

==External links==
* [http://www.nasa.gov/centers/dryden/history/pastprojects/Apex/index.html Description of Apex project on NASA Dryden website]
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{{Advanced Soaring Concepts aircraft}}

[[Category:Advanced Soaring Concepts aircraft|Apex]]
[[Category:1990s United States experimental aircraft]]
[[Category:1990s United States sailplanes]]
[[Category:Unmanned aerial vehicles of the United States]]
[[Category:Glider aircraft]]
[[Category:Mid-wing aircraft]]