WASHINGTON — Scheduling issues created by a delayed space station resupply mission have postponed the launch of a long-awaited space and Earth sciences satellite by several days, officials said Dec. 29.

The U.S. National Oceanic and Atmospheric Administration announced Dec. 29 that in “coordination with our partners,” it had rescheduled the launch of its Deep Space Climate Observatory (DSCOVR) to no earlier than Jan. 29. The launch, on a Space Exploration Technologies Corp. Falcon 9 rocket from Cape Canaveral Air Force Station, Florida, previously was scheduled for Jan 23.

NOAA did not elaborate on the reasons for the delay, but an official familiar with launch preparations, who was not authorized to speak on the record, told SpaceNews that the delay was to relieve schedule pressure caused by the rescheduling of another Falcon 9 launch from Cape Canaveral. There are no issues with the DSCOVR spacecraft itself or its launch vehicle, the official said.

The Jan. 23 launch date for DSCOVR was set when SpaceX planned to launch a commercial resupply mission to the international space station on Dec. 19. However, SpaceX announced Dec. 18 that it was postponing that launch to perform a second static-fire test of the Falcon 9’s first-stage engines. That additional test and other issues, including lighting conditions at the station, led SpaceX and NASA to reschedule the launch for Jan. 6.

The latest delay for DSCOVR is a minor one in the long and tortured history of the satellite. The mission dates back to 1998, when then-Vice President Al Gore announced plans for a spacecraft called Triana that would provide constant imagery of the full disk of the Earth for scientific and educational purposes. Those original plans called for NASA to build and launch the spacecraft by the year 2000.

Triana ran into opposition from some members of Congress, however, who criticized the mission’s usefulness as well as its White House origins. A 1999 report by NASA’s Office of Inspector General concluded that while Triana’s science was peer reviewed, NASA had not subjected the overall mission to the usual level of scrutiny.

The administration of President George W. Bush elected not to continue Triana, and placed the completed spacecraft in storage in November 2001. NASA, in cooperation with NOAA and the U.S. Air Force, resurrected the spacecraft as DSCOVR in 2009 with a new focus on solar observations.

Like Triana, DSCOVR will operate from the Earth-Sun Lagrange point 1 (L1), about 1.5 million kilometers from the Earth in the direction of the sun. DSCOVR, though, is primarily billed as a solar science mission, making observations of the solar wind and providing early warning of space weather activity. It will replace the Advanced Composition Explorer spacecraft, which has provided similar data from L1 since 1997, long exceeding its five-year design life.

DSCOVR does retain some elements of its initial mission. The spacecraft’s instruments include an Earth-facing camera that will provide full-disk images of the Earth, as well as a radiometer to collect climate science data.

NOAA, the lead agency for DSCOVR, anticipates spending $104.8 million on the mission over its life. The Air Force is providing the launch under a $97 million contract it awarded to SpaceX in 2012.