From left, Anders, Collins, and Borman, the prime crew of the cancelled Apollo 503 mission.
NASA, via Joachim Becker/SpaceFacts.de
1960s <div style="display: none;">date QS:P,+1960-00-00T00:00:00Z/8</div>
<a rel="nofollow" class="external text" href="http://www.spacefacts.de/cancelled/photo_hi/apollo-503.jpg">Image</a>, <a rel="nofollow" class="external text" href="http://www.spacefacts.de/cancelled/english/apollo-503.htm">SpaceFacts Page</a>