Editing Atlas II (section)

=== Atlas IIAS ===
Atlas IIAS was largely identical to IIA, but added four [[Castor (rocket stage)|Castor 4A]] solid rocket boosters to increase performance. These boosters were ignited in pairs, with one pair igniting on the ground, and the second igniting in the air shortly after the first pair separated. The "half-stage booster section would then drop off as usual.<ref name=ppg /> IIAS was used between 1993 and 2004, concurrently with IIA.<ref name=astronautixAtlasIIAS>{{cite web|title=Atlas IIAS|url=http://www.astronautix.com/lvs/atlsiias.htm|archive-url=https://web.archive.org/web/20020501080034/http://www.astronautix.com/lvs/atlsiias.htm|url-status=dead|archive-date=May 1, 2002|publisher=Astronautix|access-date=January 9, 2016}}</ref>