WASHINGTON — Officials with the U.S. National Oceanic and Atmospheric Administration (NOAA) said the agency’s newest geostationary weather satellite will still launch in late June from Cape Canaveral Air Force Station, Fla., despite a minor problem with the rocket that is to deliver the spacecraft to orbit.
Launch of the Geostationary-orbiting Operational Environmental Satellite-N (GOES-N) was pushed back one day to June 24 at Boeing’s request to make repairs to the turbopump on the RS-68 main engine of the company’s Delta 4 rocket.
Pre-launch testing June 12 indicated that the turbopump was providing less pressure to the engine than is normally desired on Delta 4 launches, according to Robert Villanueva, a spokesman for Boeing Expendable Launch Systems of Huntington Beach, Calif. Boeing elected to replace the part as a precaution, Villanueva said.
Built by Boeing Satellite Systems International of El Segundo, Calif., GOES-N is the first of a new series of GOES satellites that monitor weather conditions and track severe storms for NOAA’s National Weather Service. NOAA typically operates two GOES satellites, one each overlooking the East and West coasts of the U.S. mainland.
GOES-N will be launched into orbital storage until it is activated in three to five years as a replacement for one of two GOES satellites currently in operation , NOAA officials said in a June 13 teleconference.
In a June 17 interview, Gary Davis, director of systems development at NOAA’s satellite and information services division, said the decision to launch GOES-N well ahead of its projected need is in keeping with NOAA’s strategy of maintaining a spacecraft on orbit that can be pressed into service quickly should another GOES satellite fail. The current orbital spare is set to be activated next year, he said.
NOAA also plans a longer check-out period for GOES-N because it is the first in a new series, Davis said. GOES-N will have a six-month check-out period, while two satellites that will follow will each have three-month check-out periods, he said.
Like its predecessors, GOES-N features an imager that produces visible and infrared images of the Earth’s surface, oceans, cloud cover and severe storm developments; and a sounder that takes vertical profiles of atmospheric temperature and moisture . Built by ITT Industries Space Systems Division of Rochester, N.Y., the imager and sounder on GOES-N are similar in capability to those the company built for the previous GOES satellite series.
But GOES-N sensors will nonetheless provide more accurate data because of the more precise pointing capability of their host platform, which is based on Boeing’s 601-model satellite frame, according to Steve Kirkner, NOAA’s GOES program manager. The GOES-N satellites are equipped with star trackers that can determine their precise position based on the relative location of up to five stars, Kirkner said June 17. The earlier GOES satellites rely on less-accurate Earth sensors for positioning, he said.
GOES satellites are not just used to monitor weather conditions here on Earth. The most recently launched GOES satellite was equipped with a prototype solar X-ray imager that provides advanced warning of solar flare activity that can disrupt electronic systems on Earth. GOES-N features an operational version of that sensor that has been upgraded for more sensitive readings.
GOES N also is equipped with a brand new instrument dubbed the Extreme Ultraviolet Sensor that will measure the effect of solar energy absorbed in the upper atmosphere, which can cause increased drag on satellites in low orbits.
Boeing’s contract to build the GOES-N, O and P satellites is worth about $713 million, a sum that includes launch but not the instruments . The original value of the contract, awarded in early 1998, was $614 million: $423 million for the first two satellites and $191 million for the option for a third.
Kirkner noted that the original contract included about $100 million in options to cover items including additional study work.
GOES-N originally was expected to launch in 2001, but the date was pushed back due to the on-orbit longevity of the earlier craft . NOAA later chose to delay the launch about a year, from mid-2004 to mid-2005, for similar reasons and to provide Boeing time to switch the spacecraft to the Delta 4 rocket from the discontinued Delta 3, Kirkner said.
GOES-N is expected to be followed by GOES-O and GOES-P in 2007 and 2008, respectively.