The NASA Centurion was the third aircraft developed as part of an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as atmospheric satellites, to perform atmospheric research tasks as well as serve as communications platforms. It was developed from the NASA Pathfinder Plus aircraft and was developed into the NASA Helios.
Centurion
Centurion, originally built for the altitude on solar power milestone specified by the ERAST project, was the third generation aircraft in the NASA Pathfinder series of electrical-powered flying wing unmanned aircraft. The ERAST program managers had determined that an aircraft based on the Pathfinder/Pathfinder Plus concept would be the lowest risk approach of achieving the altitude goal.NASA Centurion fact sheet, archived at archive.org, accessed September 8, 2008
Initially, a quarter-scale model of the Centurion was test flown at El Mirage Dry Lake on March 4, 1997. The full-size Centurion's maiden flight took place at Rogers Dry Lake on November 10, 1998, and lasted a total of 1 hr and 24 minutes. At the time, it weighed in at (including a steel anvil hanging on its centerline to simulate a payload) for its first flight. The flight was nearly flawless and was followed by a second similar performance on November 19, this time before a crowd of VIPs and Media. It lasted 1 hr and 29 minutes. The third and final flight of the low altitude test series took place on December 3. On this flight the vehicle was loaded down to its maximum gross weight of to test its weight carrying capability. Total flight time on this flight was 30 minutes, as it was shortened because high winds were anticipated by mid-morning. All of these flights took place on battery power and verified the design's handling qualities, performance, and structural integrity. Following these three flights, NASA decided to expand the aircraft into the Helios Prototype, with work starting in January, 1999.
Aircraft description The design of Centurion resulted in an aircraft that looked very much like the Pathfinder, but with a much longer wingspan of . Although the Centurion shape resembled the Pathfinder, the structure was designed to be stronger and capable of carrying numerous payloads (up to ) more efficiently. Its wing incorporated a redesigned high-altitude airfoil and the span was increased to . The number of motors was increased to 14 and the number of underwing pods to carry batteries, flight control system components, ballast, and landing gear rose to four.
Specifications
+ SpecificationsNASA Pathfinder fact sheet, archived at archive.orgInvestigation of the Helios Prototype Aircraft Mishap – Volume 1, T.E. Noll et al., January 2004NASA Centurion Fact Sheet archived at archive.org Pathfinder Pathfinder-Plus Centurion Helios HP01 Helios HP03 Length ft(m) 12 (3.6) 12 (3.6) 12 (3.6) 12 (3.6) 16.5 (5.0) Chord ft(m) 8 (2.4) Wingspan ft(m) 98.4 (29.5) 121 (36.3) 206 (61.8) 247 (75.3) Aspect ratio 12 to 1 15 to 1 26 to 1 30.9 to 1 Glide ratio 18 to 1 21 to 1 ? ? ? Airspeed kts(km/h) 15–18 (27–33) 16.5–23.5 (30.6–43.5) ? Max altitude ft(m) 71,530 (21,802) 80,201 (24,445) n/a 96,863 (29,523) 65,000 (19,812) Empty Wt lb(kg) ? ? ? 1,322 (600) ? Max. weight lb(kg) 560 (252) 700 (315) ±1,900 (±862) 2,048 (929) 2,320 (1,052) Payload lb(kg) 100 (45) 150 (67,5) 100–600 (45–270) 726 (329) ? Engines electric, 2 hp (1.5 kW) each No. of engines 6 8 14 14 10 Solar pwr output (kW) 7.5 12.5 31 ? 18.5 Supplemental power batteries batteries batteries Li batteries Li batteries, fuel cell
See also The prehistory of endurance UAVs Electric aircraft Regenerative fuel cell NASA Pathfinder (First flew in June 1983) NASA/AeroVironment Helios Prototype (First flight 8 September 1999) QinetiQ/Airbus Zephyr (First flight in 2008) Facebook Aquila (First flight 28 June 2016) SoftBank/AeroVironment HAPSMobile (First flight 11 September 2019) BAE Systems PHASA-35 (First flight 17 February 2020)
References This article contains material that originally came from the web article by Greg Goebel, which exists in the Public Domain.
"Photovoltaic Finesse: Better Solar Cells—with Wires Where the Sun Don't Shine", an article by Daniel Cho on page thirty-three of the September, 2003 issue of Scientific American
External links
NASA's Helios Project Helios for kids Helios model by DesignsbyALX . "3G Tested at in the stratosphere" 3G news release July 23, 2002 Science Daily article on Pathfinder Plus altitude record Telecom relay achievements at Airport International Space.com article History of solar powered UAVs at The Future of Things Pathfinder Plus at NASM
NASA image collections: NASA Pathfinder NASA Pathfinder Plus NASA Centurion NASA Helios Prototype