Press [Enter] on the numpad and ammo and fuel will be refilled.

 Level codes:

 Level  2 - AURIGA
 Level  3 - CEPHEUS
 Level  4 - APUS
 Level  5 - MUSCA
 Level  6 - PYXIS
 Level  7 - CETUS
 Level  8 - FORNAX
 Level  9 - CAELUM
 Level 10 - CORVUS