COLORADO SPRINGS, Colo. — The first, and likely the second, of a new series of U.S. geostationary weather satellites will not carry a dedicated sensor for taking vertical profiles of atmospheric temperature and humidity, measurements that are key to hurricane forecasting, officials with the U.S. National Oceanic and Atmospheric Administration (NOAA) said.

During a press conference April 11 here at the National Space Symposium 2007, NOAA officials also confirmed plans to run separate procurements for the space and ground segments of the Geostationary-orbiting Operational Environmental Satellite-R (GOES-R) system.

The decision not to include a dedicated sounding instrument aboard the first — and in all likelihood the second — GOES-R satellite follows an earlier move that eliminated a far-more-challenging sensor package known as the Hyperspectral Environmental Suite from the program. The hyperspectral suite was supposed to collect both atmospheric soundings and ocean-color data. After canceling that development effort late last year, NOAA considered adding a less-complex sounder to the GOES-R satellites, but has since opted against the idea.

“It’s not going to have a sounder,” NOAA Administrator Conrad Lautenbacher said emphatically when asked about the first GOES-R satellite, which is scheduled for launch in December 2014. “It’s hard to imagine [a sounder] on the second satellite at this point given what we believe the risk to be in developing an operational instrument.”

Lautenbacher said the agency has a plan to bridge the gap in sounding coverage until the agency is comfortable with the technical risk of including an advanced sounder on future GOES satellites.

NOAA simulations show that data from the GOES-R Advanced Baseline Imager can be combined with temperature and moisture predictions from weather balloons and other sensors to produce sounding data comparable to that from the sounders on today’s GOES satellites, explained a NOAA scientist involved in the effort. “Nobody thinks this is a good idea for the long term, but I think it’s the best idea to fill in the gap between what we have now and what we want to get to in the future,” the scientist said.

GOES-R officials considered and rejected an alternative proposal to build a sounder based on the design now flying on the current generation of GOES satellites. The existing sounder is a 1980s design that would not be compatible with the GOES-R platform, one GOES official said.

NOAA canceled the Hyperspectral Environmental Suite as part of a GOES-R restructuring undertaken after the program’s projected cost ballooned from roughly $6 billion to about $11 billion. The restructuring, which NOAA officials say has gotten the program’s estimated price tag down to about $7 billion, also reduced the number of GOES-R-class spacecraft to be procured from anywhere between three and eight to two.

Lautenbacher said NOAA has not given up on the idea of developing an advanced sounder for future GOES satellites.

The agency is exploring options for demonstrating an advanced sounding instrument in space to build confidence, according to Mary Kicza, NOAA associate administrator for satellite and information services.

“It’s unlikely that we would have an operational advanced sounder before [GOES] T or U,” Kicza said, referring to the satellites that will follow GOES-R and its sister satellite, GOES-S.

Kicza also suggested that NOAA still might buy more than two GOES-R-class satellites. “We’re looking at that possibility,” Kicza said.

Lautenbacher and Kicza also confirmed that NOAA will issue separate requests for proposals for the GOES-R program : one for the ground segment , which includes the hardware and software to receive and process the data; and one for the spacecraft. NOAA and NASA, which traditionally has procured satellites and launch vehicle’s on NOAA’s behalf, previously had planned to issue a single prime contract for GOES-R that would cover the space and ground segment.

Harris Corp. of Melbourne, Fla., and Raytheon Intelligence and Information Systems of Falls Church, Va., have publicly said they would bid for the prime contractor role in the ground segment.

Under the new GOES-R strategy, NASA will manage procurement of the space segment, including the instruments, while NOAA will oversee the ground-segment acquisition, Lautenbacher said.

“We have worked out with NASA a program management strategy that we believe gives us the best chance for lowering risk and lowering cost on this program,” Lautenbacher said. NOAA “will take the lead for the ground system and develop the algorithms for processing the data,” he said.

Kicza said a draft request for proposals would be issued shortly for both the ground- and space-segment contracts, followed by the final solicitations in August or September.