The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment.

[4] Primary sensors included: The secondary experiment was a Data Collection and Platform Location System (DCPLS).

[4] The AVHRR/2 was a four-channel scanning radiometer capable of providing global daytime and nighttime sea-surface temperature and information about ice, snow, and clouds.

All three instruments were designed to determine radiances needed to calculate temperature and humidity profiles of the atmosphere from the surface to the stratosphere (approximately 1 mb).

The SSU operated at three 15.0 μm channels using selective absorption, passing the incoming radiation through three pressure-modulated cells containing CO2.

[6] The DCPLS on NOAA-9, also known as Argos, was designed and built in France to meet the meteorological data needs of the United States and to support the Global Atmospheric Research Program (GARP).

The system received low-duty-cycle transmissions of meteorological observations from free-floating balloons, ocean buoys, other satellites, and fixed ground-based sensor platforms distributed around the globe.

[7] The SEM was an extension of the solar proton monitoring experiment flown on the ITOS spacecraft series.

[8] The Earth Radiation Budget Experiment (ERBE) was designed to measure the energy exchange between the Earth-atmosphere system and space.

Real-time data were monitored by local user terminals operated in the United States, Canada, and France.

The 406-MHz data were also processed by the Search and Rescue Processor (SARP) and retransmitted in real time and stored on the spacecraft for later transmittal to the CDA stations in Alaska and Virginia, thus providing full global coverage.

The SBUV/2 instrument measured backscattered solar radiation in an 11.3° field of view in the nadir direction at 12 discrete, 1.1-nm wide, wavelength bands between 252.0 and 339.8 nm.

The solar irradiance was determined at the same 12 wavelength bands by deploying a diffuser which reflected sunlight into the instrument's field of view.

The SBUV/2 had another narrowband filter photometer channel, called the Cloud Cover Radiometer (CCR), which continuously measured the surface of Earth brightness at 380 nm.

The ERBE scanner instrument malfunctioned on 20 January 1987 and the MSU lost one of three channels in February and another in May of the same year.