Pre 70's Vs. post 2000's UAS technology

History of UAS

Lockheed D-21

       The Lockheed D-21 was intended as a high speed, high altitude reconnaissance Unmanned Air System (UAS).  It is based on Lockheed A-12, which was a piloted CIA aircraft.  The UAS operated at a speed in excess of Mach 3 and at an altitude of 90,000 feet and had an operational range of 3,000 nautical miles ("Lockheed D-21B (Article 525) - Flight Test Historical Foundation", 2016).  It was deployed at a high altitude utilizing an A-12 aircraft modification, which was designated M-21 (M for mothership).  The UAS then operated utilizing a ramjet engine. Following an accident, which lead to the crash of an M-21 in 1966, another deployment method underwing of a B-52 was devised and a solid propellant booster was added to the UAS (Merlin, 2016).

            Following a launch, a D-21 will fly a predesignated route set into its navigation system.  The payload consisted of a high-resolution camera, an INS navigation system, an air data computer, and an automatic flight control system.  At the end of a mission, the payload separated and the UAS self-destructed.  A C-130 airplane would then recover the parachuted payload (Goodall & Goodall, 2002).

        The project commenced its test flights on 1964 and lasted until 1969.  Only four operational sorties were conducted over China between 1969 and 1971, the aim was to collect aerial photography of the Lop Nor nuclear site.  The first mission failed to set course back to friendly territory and crashed over the USSR, the second mission failed when the payload failed to detach, the third failure was during the recovery attempt, the final attempt also failed to accomplish a safe return and crashed over China.  The high failure rate and the high mission cost, approximately 5.5 million US, lead to the termination of the project in 1971 ("Lockheed D-21B (Article 525) - Flight Test Historical Foundation", 2016).                 

Boeing X-37

       The Boeing X-37 is a reusable and autonomous unmanned space shuttle.  The shuttle launches utilizing a space rocket before it deploys to orbit. After mission completion, the X-37 returns to base conducting an automatic landing (Halvorson, 2012).  The first mission orbited for 224 days, the last mission stretched the endurance to 674 days in orbit (Smith-Strickland, 2016).

        NASA's collaboration with Boeing to develop the X-37 began in 1999; however, in 2004 DARPA took over the project and then transferred it to the U.S. Air Force in 2006.  The purpose of this project has not been officially declared.  Independent agencies and nations like Russia and China are skeptical about the peaceful intentions behind the project; however, U.S. officials reported that it is a developmental project of new space technology and a testing bed for advanced sensory technologies (Halvorson, 2012).

References

Donald, D. (2003). Black jets. Norwalk, Conn.: AIRtime.

Goodall, J. C. & Goodall N. D. (2002). "Senior Bowl–the Lockeed D-21". International Air Power Review. Norwalk, Connecticut: AIRtime Publishing.

Halvorson, T. (2012). Air Force's mysterious X-37B launched. azcentral.com. Retrieved 27 March 2016, from http://www.azcentral.com/news/articles/20121211air-force-space-plane-launch.html

Lockheed D-21B (Article 525) - Flight Test Historical Foundation. (2016). Flight Test Historical Foundation. Retrieved 22 October 2016, from http://afftcmuseum.org/exhibits/blackbird-airpark-exhibits/lockheed-d21-article-525/

Merlin, P. (2016). Lockheed D-21B (Article 525) - Flight Test Historical Foundation. Flight Test Historical Foundation. Retrieved 22 October  2016, from http://afftcmuseum.org/exhibits/blackbird-airpark-exhibits/lockheed-d21-article-525/

Rogoway, T. (2015). Foxtrotalpha.jalopnik.com. Retrieved 27 March 2016, from http://foxtrotalpha.jalopnik.com/we-finally-know-something-about-what-the-shadowy-x-37b-1700434054

Smith-Strickland, K. (2016). What’s the X-37 Doing Up There?. Air & Space Magazine. Retrieved 22 October 2016, from http://www.airspacemag.com/space/spaceplane-x-37-180957777/?no-ist