Orion is a series of

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

solid-fuel rocket A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants ( fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persian ...

stages, developed and manufactured by a joint venture between Hercules Aerospace and Alliant Techsystems (now Northrop Grumman Innovation Systems). They were originally developed for use as all three stages on the Pegasus rocket, first flown in 1990. Orion is available in several configurations for a variety of use scenarios. All stages in this family are fueled by a mixture called QDL-1, which includes

HTPB Hydroxyl-terminated polybutadiene (HTPB) is an oligomer of butadiene terminated at each end with a hydroxyl functional group. It reacts with isocyanates to form polyurethane polymers. HTPB is a translucent liquid with a color similar to wax paper ...

and 19%

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

, with the exception of the yet-unflown Orion 32, which uses QDL-2, containing HTPB and 20% aluminium.

Versions

Orion stages are numbered to indicate their configuration. The first number, either 38 or 50, indicates the diameter of the stage. This is followed by various letters. S indicates a stretched, first stage variant. XL indicates an additional stretch. G indicates a ground-launched stage, with a shorter nozzle. T indicates a strengthened skirt.

References

{{Rocket engines Alliant Techsystems Spaceflight Solid-fuel rockets