The NOAA-N Prime spacecraft, a Polar Operational Environmental Satellite (POES), was delivered to Vandenberg Air Force Base, Calif., for a Feb. 4 launch, Lockheed Martin Corp. [LMT] announced.

Lockheed Martin Space Systems Co. built the bird.

NOAA-N Prime is the latest in the Advanced TIROS-N (ATN) satellite series.

All have been designed and built for NASA and the National Oceanic and Atmospheric Administration (NOAA) by Lockheed since the first Television and Infrared Observational Satellite (TIROS) weather satellite launch in April 1960.

Most spacecraft in the series have operated far longer than originally expected, earning them a reputation as the workhorses of the civil space Earth-imaging inventory.

A constellation consists of two polar-orbiting satellites circling the planet in nearly north-south orbits. As the Earth rotates, the entire globe, one swath at a time rolls into view of the satellites’ instruments. The instruments continually sense the entire depth of the atmosphere and report on the following environmental measurements:

• Atmospheric temperatures and moisture soundings
• Sea-surface temperatures
• Land-surface temperatures
• Cloud cover and heights
• Precipitable moisture
• Total ozone
• Clear radiance
• Incoming and radiated heat

Together these data comprise irreplaceable inputs to the numerical weather forecast model and are vital to medium and long-range forecasting. Separately or in combination, the data are utilized to produce sea-surface temperature maps, ice condition charts, snow cover analysis, vegetation maps and other forecasting and management tools.

Additionally, NOAA-N Prime carries an enhanced complement of microwave instruments to generate temperature, moisture, surface, and hydrological products in cloudy regions where visible and infrared instruments have decreased capability.

NOAA-N Prime also carries search and rescue instruments that are used internationally for locating ships, aircraft, and people in distress. The use of satellites in search and rescue has been instrumental in saving more than 24,500 lives since inception of the Search and Rescue Satellite-Aided Tracking (SARSAT) system.

The NOAA-N Prime satellite will operate in a circular, near-polar orbit of 450 nautical miles above the Earth with an inclination angle of 98.7465 degrees to the equator. Its orbital period, which is the time it takes to complete one orbit of the Earth, will be approximately 101.35 minutes.

The NOAA-N Prime orbit is sun-synchronous, rotating eastward about the Earth’s polar axis 0.986 degrees each day, approximately the same rate and direction as the Earth’s average daily rotation about the Sun. The rotation keeps the satellite in a constant position with reference to the Sun for constant scene illumination throughout the year.

Goddard Space Flight Center, in Greenbelt, Md., is responsible for procurement, development, launch services, and verification testing of the spacecraft, instruments, and unique ground equipment.

Following deployment of the spacecraft from the launch vehicle, Goddard is responsible for initial in-orbit satellite checkout and evaluation.

Following the launch and a comprehensive on-orbit verification period that lasts 45 days, NASA will turn operational control of the satellite over to NOAA. NOAA will operate the satellite from the Satellite Operations Control Center in Suitland, Md., along with the nation’s other environmental satellites that it operates.

NOAA’s environmental satellite system is composed of two types of satellites: Geostationary Operational Environmental Satellites (GOES) for national, regional, short-range warning and "now-casting"; and Polar Operational Environmental Satellites (POES) for global, long-term forecasting and environmental monitoring. Both GOES and POES are necessary for providing a complete global weather monitoring system. Both also carry search and rescue instruments to relay signals from people in distress.