fer ometry ▁for ▁detection ▁of ▁Gra vity ▁W aves - a ▁Wing lee , ▁Robert : ▁Sample ▁Return ▁Systems ▁for ▁Ext reme ▁En viron ments ▁Z ha , ▁Ge Ch eng : ▁Sil ent ▁and ▁E fficient ▁Sup erson ic ▁Bi - Direction al ▁F lying ▁Wing ▁▁ 2 0 1 3 ▁N I AC ▁Project ▁Se lections ▁In ▁ 2 0 1 3 ▁N I AC ▁conducted ▁a ▁third ▁solic itation ▁for ▁ ▁propos als , ▁with ▁projects ▁to ▁start ▁in ▁the ▁summer ▁of ▁ 2 0 1 3 . ▁ ▁NASA ▁selected ▁ 1 2 ▁phase - I ▁projects ▁with ▁a ▁wide ▁range ▁of ▁imag in ative ▁concepts , ▁including ▁ 3 - D ▁printing ▁of ▁bi om aterial s , ▁such ▁as ▁arrays ▁of ▁cells ; ▁using ▁gal actic ▁ray s ▁to ▁map ▁the ▁ins ides ▁of ▁astero ids ; ▁and ▁an ▁" et ernal ▁flight " ▁platform ▁that ▁could ▁hover ▁in ▁Earth ' s ▁atmosphere , ▁potentially ▁providing ▁better ▁imag ing , ▁Wi - Fi , ▁power ▁generation , ▁and ▁other ▁applications . ▁ ▁They ▁selected ▁ 6 ▁phase ▁II ▁projects , ▁including ▁phot onic ▁las er ▁thrust ers , ▁extreme ▁sample ▁return , ▁and ▁innov ative ▁spher ical ▁rob ots ▁designed ▁for ▁planet ary ▁expl oration . ▁ ▁Ph ase ▁I ▁se lections ▁were : ▁Adams , ▁Rob : ▁ ▁P uls ed ▁F ission - F usion ▁( P u FF ) ▁Prop ulsion ▁System ▁Brad ford , ▁John : ▁Tor por ▁Ind uc ing ▁Transfer ▁Hab