Upper Stages
The upper stages of space launch vehicles are designed to operate at high altitude, and thus under little or no atmospheric pressure. This allows them to use lower pressure combustion chambers and still obtain near-optimum nozzle expansion ratios with nozzles of reasonable size. In many low pressure liquid rocket upper stage engines, such as the Aerojet AJ-10, propellants are pressure fed without need for complex turbomachinery. Low chamber pressures also generate lower heat transfer rates, which allow ablative or radiative cooling of the combustion chambers rather than more elaborate regenerative cooling.
Read more about this topic: Multistage Rocket
Famous quotes containing the words upper and/or stages:
“When my old wife lived, upon
This day she was both pantler, butler, cook,
Both dame and servant, welcomed all, served all,
Would sing her song and dance her turn, now here
At upper end o’the table, now i’the middle,
On his shoulder, and his, her face afire
With labor, and the thing she took to quench it
She would to each one sip.”
—William Shakespeare (1564–1616)
“The playing adult steps sideward into another reality; the playing child advances forward to new stages of mastery....Child’s play is the infantile form of the human ability to deal with experience by creating model situations and to master reality by experiment and planning.”
—Erik H. Erikson (20th century)