NASA's latest assessment of
orbiter ascent and landing weights incorporates currently approved modifications to all vehicle elements, including crew escape provisions, and assumes a maximum Space Shuttle main engine throttle setting of 104 percent. It is noted that the resumption of Space Shuttle flights initially requires more conservative flight design criteria and additional
instrumentation, which reduces the following basic capabilities by approximately 1,600 pounds(725.74 kg):
¥
Kennedy Space Center.Eastern Space and Missile Center (ESMC) satellite deploy missions. The basic cargo-lift capability for a due east (28.5 degrees) launch is 55,000 pounds(24,947.58 kg) to a 110-nautical-mile (126-statute-mile)(203.72 km) orbit using
OV-103 (
Discovery) or
OV-104 (
Atlantis) to support a 4-day satellite deploy mission. This capability will be reduced approximately 100 pounds(45.35 kg) for each additional nautical mile of altitude desired by the customer.
The payload capability for the same satellite deploy mission with a 57-degree inclination is 41,000 pounds(18,597.28 kg).
The performance for intermediate inclinations can be estimated by allowing 500 pounds(266.79 kg) per degree of plane change between 28.5 and 57 degrees.
If
OV-102 (
Columbia) is used, the cargo-lift weight capability must be decreased by approximately 8,400 pounds(3,810.17 kg). This weight difference is attributed to an approximately 7,150-pound(3,243.18 kg) difference in inert weight, 850 pounds(385.55 kg) of
orbiter experiments, 300 pounds(136.07) of additional
thermal protection system and 100 pounds(45.35 kg) to accommodate a fifth cryogenic liquid oxygen and
liquid hydrogen tank set for the
power reactant storage and distribution system.
¥Vandenberg Air Force Base Western Space and Missile Center (WSMC) satellite deploy missions. Using
OV-103 (
Discovery) or
OV-104 (
Atlantis), the cargo-lift weight capability is 29,600 pounds(13,426.33) for a 98-degree launch inclination and 110-nautical-mile (126-statute-mile)(203.72 km) polar orbit. Again, an increase in altitude costs approximately 100 pounds(45.35 kg) per nautical mile(1.85 km). NASA assumes also that the advanced solid rocket motor will replace the filament-wound solid rocket motor case previously used for western test range assessments. The same mission at 68 degrees inclination (minimum western test range inclination based on range safety limitations) is 49,600 pounds(22,498.18 kg). Performance for intermediate inclinations can be estimated by allowing 660 pounds(299.37 kg) for each degree of plane change between inclinations of 68 and 98 degrees.