Inertial Upper Stage
The IUS (Inertial Upper Stage, German as: " inertia navigated high school ," or originally Interim Upper Stage, German about: preliminary upper level) is manufactured by Boeing, two-stage module to satellites from low Earth orbit into a geostationary orbit or interplanetary orbit to bring.
The IUS is stabilized about three axes and has two solid rocket motors, Orbus -21 and Orbus -6, for the two bursts of pulses of a Hohmann orbit.
Originally intended only as an interim solution until the introduction of the Centaur -G stage on the Space Shuttle (hence the original name ), the IUS was after setting the Shuttle Centaur upper stage program to the standard for heavy geostationary payloads and deep space missions.
The IUS was used on both launchers from titanium - 34D -4A titanium, titanium -4B as well as the Space Shuttle. The payload capacities in the geostationary orbit were as follows:
- Shuttle: 2268 kg
- Titan - 34D: 1817 kg
- Titan -4A: 2364 kg
- Titan -4B: 2860 kg
Payloads were next TDRSS communications satellites and military satellites, the NASA missions Magellan, Ulysses, Galileo and Chandra.
At the start of the Ulysses space probe, the IUS has been equipped with an additional PAM -S upper stage to bring Ulysses to a particularly high escape velocity.