Editing Jean Piccard (section)

==Cluster balloons==
Developed with John Akerman of the University of Minnesota and piloted by Jean Piccard in 1937 in [[Rochester, Minnesota]], the first multi-celled balloon was called ''The Pleiades'' and was made of 98 [[latex (rubber)|latex rubber]] balloons. In a letter to Robert Gray of the Dewey and Almy Chemical Co. later published in ''Time'' magazine, Piccard describes how he broke balloons with a hunting knife and revolver to control his descent. A TNT charge released the cluster as he expected but sent burning [[excelsior (wood wool)|excelsior]] down that destroyed the first ''Pleiades''. He suggested to Gray that [[mineral wool|rock wool]] in place of excelsior would prevent similar accidents in the future.<ref name=Egg-Shell>{{cite magazine| author= Piccard, Jean via Robert Gray| title= Egg Shell Landing| magazine= Time| date=  August 16, 1937| url= http://www.time.com/time/magazine/article/0,9171,770771,00.html?promoid=googlep| archive-url= https://web.archive.org/web/20121022125122/http://www.time.com/time/magazine/article/0,9171,770771,00.html?promoid=googlep| url-status= dead| archive-date= October 22, 2012| accessdate= 2007-01-27}}</ref>

Balloon research stopped for the most part during [[World War II]].<ref name=Goebel>{{cite web| author= Goebel, Greg| title= A Short History Of Balloons & Ballooning: 3.0 The Stratosphere Expeditions| date= July 1, 2006| url= http://www.vectorsite.net/avbloon_3.html| archive-url= https://web.archive.org/web/20060719011615/http://www.vectorsite.net/avbloon_3.html| url-status= usurped| archive-date= July 19, 2006| accessdate= 2007-02-01}}</ref>

In February 1946 with [[Otto C. Winzen]], Jean Piccard proposed manned flight to the US Navy using clustered balloons made of thin plastic. In June the Office of Naval Research approved ''Project Helios'' and that year [[General Mills]] and the University of Minnesota contracted to build a cluster of 100 [[polyethylene]] balloons for atmospheric research.<ref name=Navy-FAQ>{{cite web| author= US Department of the Navy - Navy Historical Center| title= Navy in Space Chronology, 1945 - 1981| date= July 24, 2003| url= http://www.history.navy.mil/faqs/faq124-1.htm| archive-url= https://archive.today/20121212210948/http://www.history.navy.mil/faqs/faq124-1.htm| url-status= dead| archive-date= December 12, 2012| accessdate= 2007-01-27}}</ref><ref>{{cite web |url=http://www.blog.generalmills.com/2011/08/the-daddy-of-the-balloon-industry/ |last=Goodsell |first=Suzy |title=The "daddy" of the balloon industry |date=August 4, 2011 |website=General Mills blog website |accessdate=2015-03-15}}</ref> ''Helios'' was designed to reach 100,000 feet for ten hours with a payload of instruments.<ref name=Navy-Space>{{cite web| author= Unknown author| title= Manned| publisher= US Department of the Navy - Navy Historical Center| date= n.d.| url= http://www.history.navy.mil/download/space-11.PDF| archive-url= https://web.archive.org/web/20010629190432/http://www.history.navy.mil/download/space-11.PDF| url-status= dead| archive-date= June 29, 2001| accessdate= 2007-01-26}}</ref>

Jean Piccard helped Winzen design the [[Skyhook balloon|Skyhook]] polyethylene balloons that replaced ''Project Helios'' in 1947. Skyhook balloons were used unmanned for atmospheric research by the Navy and for manned flights by the [[United States Air Force|US Air Force]].<ref name=Navy-FAQ /><ref name=BalloonLife>{{cite web|author=Stekel, Peter |publisher=Balloon Life Magazine |title=Don Piccard - 50 Years of Ballooning Memories |date=August 1997 |url=http://www.balloonlife.com/9707/piccard.htm |accessdate=2007-01-26 |url-status=dead |archiveurl=https://web.archive.org/web/20070216155254/http://www.balloonlife.com/9707/piccard.htm |archivedate=2007-02-16 }}</ref> Later Jean Piccard developed electronics for emptying ballast bags.<ref name=CFC/>

Piccard died on January 28, 1963 (his 79th birthday) in Minneapolis.