NASA Expendable Launch Vehicle Status Report 4 October 2011

Mission: NPP (NPOESS Preparatory Project)
Launch Vehicle: Delta II 7920
Launch Site: Vandenberg Air Force Base, Calif.
Launch Pad: Space Launch Complex 2
Launch Date: Oct. 27, 2011
Launch Window: 2:48:01 – 2:57:11 a.m. PDT
Orbital Altitude: 512 miles

The launch of the NPOESS Preparatory Project (NPP) spacecraft aboard a United Launch Alliance Delta II rocket is rescheduled to Oct. 27.

Two items have resulted in additional work to be performed on the NPP launch vehicle and this has resulted in the 2-day delay in the launch date. During systems testing, a hydraulic system leak was detected and the cause was found to be a small crack in a hydraulic tube. A replacement tube was manufactured, installed, and retested. All other similar tubes have been inspected and confirmed to be free of any defects.

Also, a flexible fabric collar connecting two engine system exhaust ducts was found to be damaged following pressurized leak testing. The damaged fabric collar is being removed and replaced.

Once these tasks are complete, standard launch processing tests will resume on Oct. 6. The NPP spacecraft will be transported to the launch pad for attachment to the Delta II rocket on Oct. 12.

NPP represents a critical first step in building the next-generation of Earth-observing satellites. NPP will carry the first of the new sensors developed for this satellite fleet, now known as the Joint Polar Satellite System (JPSS), to be launched in 2016. NPP is the bridge between NASA’s Earth Observing System (EOS) satellites and the forthcoming series of JPSS satellites. The mission will test key technologies and instruments for the JPSS missions.

Previous status reports are available at: http://www.nasa.gov/centers/kennedy/launchingrockets/status/index.html