The Boeing-developed Inertial Upper Stage (IUS) was an autonomous, upper-stage booster rocket. It could be launched from Titan IV expendable launch vehicles or the Space Shuttle. Its primary payloads were communications satellites, Department of Defense reconnaissance satellites, and interplanetary robotic spacecraft. Interplanetary probes propelled by the IUS include Magellan (Venus, 1989), Galileo (Jupiter, 1989), and Ulysses (Sun, 1990). From 1982 to 2004, a total of 24 IUS missions were launched, of which 21 were considered successful.

For a typical Boeing IUS mission launched from a Titan IVB, the IUS would separate from the Titan second-stage booster approximately nine minutes into the ascent. For the next six hours and 54 minutes, the IUS would autonomously perform all functions to place the spacecraft into the appropriate geosynchronous orbit, approximately 22,000 miles above the Earth. The IUS first stage rocket burn would begin a little over one hour into the IUS booster flight. The IUS second stage motor would ignite at apogee, to circularize the orbit, about six-and-a-half hours into the flight. A coast phase followed, and then separation of the spacecraft. The IUS second stage, after accomplishing its mission, would then fire its reaction control rockets to ensure permanent separation from the payload.

For Space Shuttle-launched interplanetary missions, the IUS would be carried to the desired initial orbit, checked out while still in the Shuttle payload bay, then deployed. After the Shuttle achieved a safe separation distance, the IUS first stage and second stage burns would occur in sequence to achieve maximum velocity.

The Museum's IUS is a full scale mockup of the spacecraft, donated by The Boeing Company in August 1991.

Length:
17ft
Diameter:
10ft
Gross Weight:
32,500lbs
First Stage Thrust:
58,600
Second Stage Thrust:
24,500lbs

The Boeing-developed Inertial Upper Stage (IUS) was an autonomous, upper-stage booster rocket. It could be launched from Titan IV expendable launch vehicles or the Space Shuttle. Its primary payloads were communications satellites, Department of Defense reconnaissance satellites, and interplanetary robotic spacecraft. Interplanetary probes propelled by the IUS include Magellan (Venus, 1989), Galileo (Jupiter, 1989), and Ulysses (Sun, 1990). From 1982 to 2004, a total of 24 IUS missions were launched, of which 21 were considered successful.

For a typical Boeing IUS mission launched from a Titan IVB, the IUS would separate from the Titan second-stage booster approximately nine minutes into the ascent. For the next six hours and 54 minutes, the IUS would autonomously perform all functions to place the spacecraft into the appropriate geosynchronous orbit, approximately 22,000 miles above the Earth. The IUS first stage rocket burn would begin a little over one hour into the IUS booster flight. The IUS second stage motor would ignite at apogee, to circularize the orbit, about six-and-a-half hours into the flight. A coast phase followed, and then separation of the spacecraft. The IUS second stage, after accomplishing its mission, would then fire its reaction control rockets to ensure permanent separation from the payload.

For Space Shuttle-launched interplanetary missions, the IUS would be carried to the desired initial orbit, checked out while still in the Shuttle payload bay, then deployed. After the Shuttle achieved a safe separation distance, the IUS first stage and second stage burns would occur in sequence to achieve maximum velocity.

The Museum's IUS is a full scale mockup of the spacecraft, donated by The Boeing Company in August 1991.

Length:
17ft
Diameter:
10ft
Gross Weight:
32,500lbs
First Stage Thrust:
58,600
Second Stage Thrust:
24,500lbs