The United Launch Alliance (ULA) Delta II launch with the NPP (NPOESS Preparatory Project) satellite has passed through its Flight Readiness Review (FRR) on Friday. The launch from SLC-2W at Vandenberg Air Force Base (VAFB) in California has been set for a launch window which opens at 9:48am GMT on October 28.
NPP – the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project – is the first of a new generation of satellites, carrying 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.
The mission will provide a bridge between NASA’s Earth Observing System (EOS) satellites and the forthcoming series of JPSS satellites, as NPP will test key technologies and instruments for the JPSS missions.
“NPP’s observations of a wide range of interconnected Earth properties and processes will give us the big picture of how our planet changes,” said Jim Gleason, NPP project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.
“That will help us improve our computer models that predict future environmental conditions. Better predictions will let us make better decisions, whether it is as simple as taking an umbrella to work today or as complex as responding to a changing climate.”
The NPP spacecraft is a member of the Ball Configurable Platform (BCP) family of spacecraft designed for cost-effective, remote sensing applications. Its proven design accommodates a wide range of payloads, including optical applications with sub-meter resolutions and synthetic aperture radar.
The spacecraft bus is the eighth of 11 spacecraft built by Ball Aerospace on the same BCP 2000 core architecture. The BCP 2000 was designed to accommodate a wide variety of Earth-observing payloads that require precision pointing control, flexible high-data throughput and downlinks, and controlled re-entry.
The NPP spacecraft incorporates both MIL-STD-1553 and IEEE 1394 (FireWire) data networks to support the payload suite. The spacecraft has a 7-year design life, with a five-year mission life.
The five instruments manifested for flight on the NPP spacecraft trace their heritage to instruments on NASA’s Terra, Aqua and Aura missions, on NOAA’s Polar Operational Environmental Satellite (POES) spacecraft, and on DOD’s Defense Meteorological Satellite Program (DMSP).
Delta II Preparations:
The integration flow at VAFB has proceeded without any major issues, with only slight interruption, such as the 24 hour delay to the NPP transport and mate to the Delta II due to unacceptable winds in the Californian launch site. This process was completed on October 13.
“The SC and can were under the hook by 05:30, (prior to) waiting for ground winds to subside. The can was hoisted at 09:45, and mate was complete by 11:45. There was a ~25 minute interruption in activity due to a pad temperature sensor triggering a false alarm which forced personnel to evacuate the pad,” added L2 notes for October 13’s flow.
Engineers then worked on connecting the GN2 purge to the spacecraft, along with setting up access platforms. Once complete, the spacecraft was then put on air conditioning, while the team worked on the umbilical connections, performed basic tests and “configure for launch” testing – along with charging of the flight battery.
“Ordnance installation and connections, including stage sep ordnance electrical connections, GEM ordnance electrical connections, and SC sep ordnance electrical connections are complete,” added the flow notes.
Technicians then performed a walkdown of the vehicle, ahead of closeouts on the spacecraft, which included the installation of the Payload Fairing (PLF) by ULA engineers.
It was during this point of the flow when a “material review” resulted in a one day slip to the launch date.
“The postponement for at least 24 hours will allow time to complete the necessary engineering review before the payload fairing is installed around the spacecraft,” noted NASA in an update.
With the review passed to the satisfaction of the mission’s stakeholders, Friday’s FRR passed the launch vehicle and spacecraft for launch next Friday.
“The timing of the NPP launch could hardly be more appropriate,” noted Louis W. Uccellini, director of NOAA’s National Centers for Environmental Prediction in Camp Springs, Md. “With the many billion dollar weather disasters in 2011, NPP data is critical for accurate weather forecasts into the future.”
Upcoming milestones include the Launch Management Coordination Meeting and Mission Dress Rehearsal – set to take place over the weekend. This will be followed by Second Stage Oxidizer Load and Second Stage Fuel Load early on the launch vehicle – flying in the 7920-10 configuration – next week.
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