00535cam a2200205 4500 153206664 TxAuBib 20100603120000.0 100603s2010||||||||||||||||||||||||eng|u 9781615300006 1615300007 (OCoLC)406945407 TxAuBib Gregersen, Erik. Manned Spaceflight. Britannica, 2010. 20100603. Astronautics- history. TXJOU