When an engine is ignited, it produces thrust and boosts the rocket into the sky. After the propellant is used up, delay is activated, producing tracking smoke and allowing the rocket a brief coast.
infirmary (plural infirmaries) 1  A place where sick or injured people are cared for, especially a small hospital; sickhouse. 2  A clinic or dispensary within another institution.
St. James Infirmary on tenor sax. St. James Infirmary Blues, sometimes known as Gambler's Blues, is an American folksong of anonymous origin, though sometimes credited to the songwriter Joe Primrose (a pseudonym for Irving Mills). Louis Armstrong made it famous in his influential 1928 recording.