MacCready Solar Challenger

{{Infobox aircraft

|name = Solar Challenger

|image = Solar Challenger drawing.jpg

|caption = A drawing of the Solar Challenger

|type = Experimental aircraft

|national_origin = United States

|manufacturer = AeroVironment

|designer = Paul MacCready

|first_flight = 6 November 1980

|introduction =

|retired =

|status = Museum piece

|primary_user =

|more_users =

|produced =

|number_built = 1

|program cost =

|unit cost =

|developed_from = Gossamer Penguin

|variants =

|developed_into =

}}

The Solar Challenger was a solar-powered aircraft designed by Paul MacCready's AeroVironment. The aircraft was designed as an improvement on the Gossamer Penguin, which in turn was a solar-powered variant of the human-powered Gossamer Albatross.{{Citation|last=Goebel |first=Greg |title="Solar-Powered UAVS: HALSOL & Solar HAPP", The Prehistory Of Endurance UAVs |url=http://www.vectorsite.net/twuav_12.html#m3 |access-date=2008-08-13 |url-status=usurped |archive-url=https://web.archive.org/web/20090211170130/http://www.vectorsite.net/twuav_12.html |archive-date=2009-02-11 }} It was powered entirely by the photovoltaic cells on its wing and stabilizer, without even reserve batteries, and was the first such craft capable of long-distance flight.{{Citation | last = Lindsey | first = Robert | title = Physicist's Solar Airplane Set to Challenge the English Channel | newspaper = New York Times | date = June 9, 1981 | url = https://query.nytimes.com/gst/fullpage.html?sec=health&res=9D07EFD61238F93AA35755C0A967948260&scp=1&sq=solar%20challenger&st=cse }} In 1981, it successfully completed a 163-mile (262 km) demonstration flight from France to England.{{Citation | title = Solar-Power Research and Dryden | publisher = Dryden Flight Research Center, NASA | url = http://www.nasa.gov/centers/dryden/news/FactSheets/FS-054-DFRC.html | access-date = 2008-08-13}}

History

The Solar Challenger was designed by a team Ciotti, Paul, (2002) "More With Less", Encounter Books, San Francisco, {{ISBN|1-893554-50-3}} led by Paul MacCready as a more airworthy improvement on the Gossamer Penguin, directly incorporating lessons learned from flight testing the earlier aircraft.[http://library.propdesigner.co.uk/solar_challenger.pdf Solar Challenger - Exclusive first hand report, of Paul MacCready's solar powered aircraft project] {{Webarchive|url=https://web.archive.org/web/20110820012018/http://library.propdesigner.co.uk/solar_challenger.pdf |date=2011-08-20 }} Martyn Cowley, with drawings by Pat Lloyd. Aeromodeller, June 1981 As with the Gossamer Penguin, construction was sponsored by DuPont in exchange for publicity for the company's patented materials incorporated in the design. AstroFlight, Inc. supplied the motors and solar panels, designed by Robert Boucher.Boucher, Robert J, (1984), [http://astrobobb.com/solarhistory.pdf History of Solar Flight] The plane's wings carried 16,128 solar cells yielding a maximum solar power of 3,800 watts. It was flight tested in Western USA in winter 1980–1981.[http://www.donaldmonroe.com/solar_challenger.html "Solar Challenger" by Don Monroe (1981)] ([https://web.archive.org/web/20150221091354/http://donaldmonroe.com/solar_challenger.html Archive])

On July 7, 1981, the aircraft flew 163 miles from Pontoise – Cormeilles Aerodrome, north of Paris, France to Manston Royal Air Force Base in Manston, United Kingdom, staying aloft 5 hours and 23 minutes, with pilot Stephen Ptacek at the controls. Currently the plane is owned by the Smithsonian Institution's Air and Space Museum.{{Citation | title = Solar-Plane Sets Height Record | newspaper = Space Daily | date = August 6, 1998 | url = http://www.spacedaily.com/news/solarcell-98f.html | access-date = 2008-08-13}}.{{cite web |url=http://www.si.edu/Exhibitions/Details/The-Solar-Challenger-3493 |title=The Solar Challenger {{!}} Exhibitions {{!}} Smithsonian |website=www.si.edu |url-status=dead |archive-url=https://web.archive.org/web/20130926184936/http://www.si.edu/Exhibitions/Details/The-Solar-Challenger-3493 |archive-date=2013-09-26}}

Design

The Solar Challenger was designed to be sturdier, more powerful, and more maneuverable than the Gossamer Penguin so as to be able to withstand sustained high-altitude flight and normal turbulence. It was over three times as heavy (without pilot) as the Gossamer Penguin and had a shorter wingspan, but was proportionately more powerful, with electricity supplied by 16,128 solar cells powering two three-horsepower motors. The solar panels were directly affixed to the wing and large horizontal stabilizer, both of which had to be flat on top to accommodate them. The two motors, each 3 inches wide and 17 inches long and incorporating samarium-cobalt permanent magnets, operated in tandem on a common shaft to drive a single, controllable-pitch propeller. The design incorporated advanced synthetic materials with very high strength to weight ratios, including Kevlar, Nomex, Delrin, Teflon, and Mylar, all supplied by the aircraft's sponsor, Dupont.

Specifications

{{Aircraft specs

|ref=

|prime units? = imp

|crew=One

|capacity=One

|length m=8.8

|length ft=29

|length in=0

|span m=14.3

|span ft=47

|span in=0

|empty weight kg=90

|empty weight lb=205

|gross weight kg=159

|gross weight lb=350

|eng1 number=1

|eng1 name=solar-powered electric motor[http://library.propdesigner.co.uk/solar_challenger.pdf Solar Challenger - Exclusive first hand report, of Paul MacCready's solar powered aircraft project] {{Webarchive|url=https://web.archive.org/web/20110820012018/http://library.propdesigner.co.uk/solar_challenger.pdf |date=2011-08-20 }} Martyn Cowley, with drawings by Pat Lloyd. Aeromodeller, June 1981

|eng1 kw=2

|eng1 hp=2.75

|max speed kmh=64

|max speed mph=40

|range km=645

|range miles=400

|range note= (projected)

|endurance=11 hours (projected)

|ceiling m=4,360

|ceiling ft=14,300

|ceiling note=demonstrated, {{cvt|35,000|ft|m}} calculated at summer solstice

|g limits=+6, -3

|climb rate ms=0.765

|climb rate ftmin=150

}}

See also

{{Portal|Renewable energy|Energy}}

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References

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