washington head u.s. senate arm service committee wednesday increase pressure pentagon air force demand answer continue use russian rocket engines u.s. satellite launch senator john mccain letter date feb. 10 see reuters ask air force secretary deborah jam pentagon chief arm buyer frank kendall explain u.s. government continue deal npo energomash russian firm build russian rd-180 rocket engines mccain press officials legality business npo energomash give sanction place russian deputy prime minister dmitry rogozin others control company recent reorganization mccain also question air force continue payment large launch support contract unite launch alliance ula joint venture lockheed martin corp boeing co despite presence certify competitor space exploration technologies spacex mccain say want answer question february 22. jam pledge respond question january hear mccain say follow write underscore concern describe subsidies russian leader vladimir putin gang corrupt cronies congress ban use russian rd-180 rocket engines military use russia annex ukraine crimea region 2014. u.s. lawmakers weaken ban late last year worry could drive ula business leave privately-held spacex lift satellite space jam officials urge congress allow use russian engines power ula atlas rocket several years alternatives available several years letter mccain ask u.s. air force explain options penalize ula bid recent launch competition despite receive launch support 800 million billion year since 2006. also ask department examine percentage annual support contract associate ula family rocket delta company plan retire since costly atlas 5. mccain senators argue would worth extra cost end u.s. reliance russian engines mccain press u.s. air force pentagon russian engines