When the mission finally ended in June 2005 due to funding cuts, 14 years after the satellite's launch, six of its ten instruments were still operational.

Considerable media attention surrounded the event, largely due to NASA's predictions that substantial parts of the satellite might reach the ground, potentially endangering inhabited areas.

[4] CLAES was a spectrometer that determined the concentrations and distributions of nitrogen and chlorine compounds, ozone, water vapor and methane.

[6] In order to differentiate the relatively weak signature of trace gases from the background radiation in the atmosphere, CLAES had to have high resolution and sensitivity.

CLAES produced a 19-month global database showing the vertical distributions of important ozone-layer gases in the stratosphere and their variation with time of day, season, latitude, and longitude.

ISAMS is an infrared radiometer for measuring thermal emission from the Earth's limb (the line of the horizon as seen from UARS), on both sides of the spacecraft.

The CO2 cells also allow measurement of ozone (O3), nitric acid (HNO3) and dinitrogen pentoxide (N2O5)[7] The specific objectives of ISAMS were: (i) To obtain measurements of atmospheric temperature as a function of pressure, from the tropopause to the mesopause, with good accuracy and spatial resolution, and hence to study the structure and dynamics of the region, (ii) To investigate the distribution and variability of water vapour in the middle atmosphere, to determine its role in the atmospheric general circulation, and its sources and sinks in the middle atmosphere, (iii) To measure the global distribution of oxides of nitrogen and hence to investigate their origins and their roles in catalytic cycles which control the amount of ozone in the stratospheric ozone layer.

[8] The MLS detected naturally occurring microwave thermal emissions from Earth's limb to create vertical profiles of atmospheric gases, temperature, pressure and cloud ice.

The 205 GHz radiometer measures ClO, ozone, sulfur dioxide, nitric acid and water vapor.

HALOE uses solar occultation to measure simultaneous vertical profiles of ozone (O3), hydrogen chloride (HCl), hydrogen fluoride (HF), methane (CH4), water vapor (H2O), nitric oxide (NO), nitrogen dioxide (NO2), temperature, aerosol extinction, aerosol composition and size distribution versus atmospheric pressure at the Earth's limb.

The measurements are done at eight different wavelengths of infrared across a 1.6 km (0.99 mi) wide field of view of Earth's limb.

The instrument's input slit was configurable for solar or stellar modes, to accommodate for the vast difference in target brightness.

In addition to stars, SOLSTICE also took occasional measurements of targets of opportunity, including the moon and other objects in the solar system.

[14] The ACRIM1 experiment's results provided the first discoveries of intrinsic variations in the TSI and their relationships to solar magnetic activity phenomena.

[3] On 7 September 2011, NASA announced the impending uncontrolled re-entry of UARS, and noted that there was a small potential risk to the public.

[21] At 07:46 UTC on 24 September 2011, NASA released an updated statement on the UARS website, stating that: "The Joint Space Operations Center at Vandenberg Air Force Base in California said the satellite penetrated the atmosphere over the Pacific Ocean".

"[24] However, the Joint Space Operations Center later announced that the reentry took place at 04:00 UTC on 24 September, at 14°06′S 170°06′W / 14.1°S 170.1°W / -14.1; -170.1, just downrange of American Samoa.