This visualization illustrates how JPSS-1 (now NOAA-20) orbit phasing and raising works relative to Suomi NPP, the notional way can be maneuvered a quarter-orbit along-track separation from NOAA-20 prior to launch of NOAA-21 (JPSS-2), and how a three-satellite constellation operates on a Sun-synchronous orbit node-crossing including sensor-swath footprints as the world turns below.
NOAA-20, designated JPSS-1 prior to launch, is the first of the United States National Oceanic and Atmospheric Administration's latest generation of U.S. polar-orbiting, non-geosynchronous, environmental satellites called the Joint Polar Satellite System. NOAA-20 was launched on 18 November 2017 and joined the Suomi National Polar-orbiting Partnership satellite in the same orbit. NOAA-20 operates about 50 minutes behind Suomi NPP, allowing important overlap in observational coverage. Circling the Earth from pole-to-pole, it crosses the equator about 14 times daily, providing full global coverage twice a day. This gives meteorologists information on "atmospheric temperature and moisture, clouds, sea-surface temperature, ocean color, sea ice cover, volcanic ash, and fire detection" so as to enhance weather forecasting including hurricane tracking, post-hurricane recovery by detailing storm damage and mapping of power outages.[2][3]
The project incorporates five instruments, and these are substantially upgraded since previous satellite equipment. The project's greater-detailed observations provide better predictions and emphasize climate behavior in cases like El Niño and La Niña.[2]
The NOAA-20 launch was delayed several times. When the contract was awarded in 2010, launch was scheduled for 2014.[4] By 2011, launch had slipped to 2016, and by 2012 that had slipped to 2017.[5][6] In August 2016, following environmental testing, launch slipped from 20 January 2017 to 16 March 2017 due to problems with ATMS and the ground system.[7] In January 2017, launch was delayed from March 2017 to the fourth quarter of fiscal year 2017, or July to September 2017 for the same reasons.[8] The launch was delayed from September 2017 to 10 November 2017 to provide extra time for engineers to complete testing of the spacecraft and electronics as well as ATMS.[9]
It also experienced several brief launch delays in the final weeks before launch. Originally scheduled to launch on 10 November 2017, it was delayed to the 14 November 2017 following the discovery of a faulty battery on the Delta IIlaunch vehicle.[10] The launch was then delayed to 15 November 2017 due to boats being in the launch safety zone minutes before the launch and due to a bad reading on the first stage of the launch vehicle.[11] It was delayed a third time to 18 November 2017 due to high winds.[12]
NOAA-20 successfully launched on 18 November 2017 at 09:47:36 UTC.[2] It represented the penultimate, and 99th consecutive successful launch of the Delta II launch vehicle. It was launched along with 5 CubeSats that conducted research in "3D-printed polymers for in-space manufacturing, weather data collection, bit flip memory testing, radar calibration and the effects of space radiation on electronic components".[13]
The Cross-track Infrared Sounder (CrIS) produces high-resolution, three-dimensional temperature, pressure, and moisture profiles. These profiles are used to enhance weather forecasting models, and facilitate both short- and long-term weather forecasting. Over longer timescales, they help improve understanding of climate phenomena such as El Niño and La Niña. This is a brand-new instrument with breakthrough performance.[15] CrIS represents a significant enhancement over NOAA's legacy infrared sounder — High Resolution Infrared Radiation Sounders (HIRS) and is meant to be a counterpart to the Infrared Atmospheric Sounding Interferometer (IASI).
Advanced Technology Microwave Sounder (ATMS)
The Advanced Technology Microwave Sounder (ATMS) is a cross-track scanner with 22 channels, provides sounding observations needed to retrieve atmospheric temperature and moisture profiles for civilian operational weather forecasting as well as continuity of these measurements for climate monitoring purposes. It is a lighter-weight version of the previous Advanced Microwave Sounding Unit (AMSU) and Microwave Humidity Sounder (MHS) instruments flown on previous NOAA and NASA satellites with no new performance capabilities.[16]
Ozone Mapping and Profiler Suite (OMPS)
The Ozone Mapping and Profiler Suite (OMPS) is an advanced suite of three hyperspectral instruments, extends the 25-plus year total-ozone and ozone-profile records. These records are used by ozone-assessment researchers and policy makers to track the health of the ozone layer. The improved vertical resolution of OMPS data products allows for better testing and monitoring of the complex chemistry involved in ozone destruction near the troposphere. OMPS products, when combined with cloud predictions, also help produce better ultraviolet index forecasts.[17] OMPS carries on a long tradition of space borne measurements of ozone beginning in 1970 with the Nimbus 4 satellite and continuing with the Solar Backscatter Ultraviolet (SBUV and SBUV/2), Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) instruments on various NASA, NOAA, and international satellites. Over the more than 30-year period in which these instruments have been operating, they have provided a very detailed and important long-term record of the global distribution of ozone.
Clouds and the Earth's Radiant Energy System (CERES)
The Clouds and the Earth's Radiant Energy System (CERES), senses both solar-reflected and Earth-emitted radiation from the top of the atmosphere to the surface of Earth. Cloud properties are determined using simultaneous measurements by other JPSS instruments such as the VIIRS and will lead to a better understanding of the role of clouds and the energy cycle in global climate change.[18]
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Cubesats are smaller. Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).
