Katana VentraIP

Soil Moisture Active Passive

Soil Moisture Active Passive (SMAP) is a NASA environmental monitoring satellite that measures soil moisture across the planet. It is designed to collect a global 'snapshot' of soil moisture every 2 to 3 days. With this frequency, changes from specific storms can be measured while also assessing impacts across seasons of the year.[5] SMAP was launched on 31 January 2015.[2] It was one of the first Earth observation satellites developed by NASA in response to the National Research Council's Decadal Survey.[6][7]

Mission type

Earth observation

NASA

2015-003A

40376

smap.jpl.nasa.gov

3 years (nominal) [1]
Elapsed: 9 years, 4 months, 27 days

Jet Propulsion Laboratory

944 kg

79 kg

1.5 x 0.9 x 0.9 m

1450 watts

31 January 2015, 14:22 (2015-01-31UTC14:22) UTC [2]

Delta II 7320-10C [3]

Vandenberg, SLC-2W

United Launch Alliance

August 2015

Geocentric

Sun-synchronous

680.9 km

683.5 km

98.12°

98.5 minutes

15 October 2019, 23:39:39 UTC[4]

NASA invested US$916 million in the design, development, launch, and operations of the program.[8]


An early fault in a radar power supply limited the resolution of the radar data collected from 2015 onwards.

Status[edit]

In August 2015, scientists completed their initial calibration of the two instruments on board, however, SMAP's radar stopped transmitting 7 July due to an anomaly that was investigated by a team at JPL.[9] The team identified the anomaly to the power supply for the radar's high-power amplifier.[10][11] On 2 September 2015, NASA announced that the amplifier failure meant that the radar could no longer return data. The science mission continues with data being returned only by the radiometer instrument.[12] SMAP's prime mission ended in June 2018. The 2017 Earth Science senior review endorsed the SMAP mission for continued operations through 2020, and preliminarily, through 2023.[13]

Measurement concept[edit]

The SMAP observatory includes a dedicated spacecraft and instrument suite in a near-polar, Sun-synchronous orbit. The SMAP measurement system consists of a radiometer (passive) instrument and a synthetic-aperture radar (active) instrument operating with multiple polarizations in the L-band range. The combined active and passive measurement approach takes advantage of the spatial resolution of the radar and the sensing accuracy of the radiometer.[14]


The active and passive sensors provide coincident measurements of the surface-emission and backscatter. The instruments sense conditions in the top 5 cm of soil through moderate vegetation cover to yield globally mapped estimates of soil moisture and its freeze-thaw state.


The spacecraft orbits Earth once every 98.5 minutes and repeats the same ground track every eight days.[8]

ExoCube, a space weather satellite developed by California Polytechnic State University, and sponsored by the National Science Foundation. Cal Poly designed the core-satellite bus, while the scientific payload is supplied by NASA's Goddard Space Flight Center. The University of Wisconsin, at Madison, and Scientific Solutions, Inc. (SSI) are developing the scientific objectives and providing guidance for instrument development. ExoCube measures the density of hydrogen, oxygen, helium, and nitrogen in Earth's upper atmosphere (exosphere and thermosphere) using direct mass spectroscopy measurements. The size of ExoCube is three CubeSat units, or 30 x 10 x 10 cm.

[8]

GRIFEX, the Geo-cape Roic In-Flight performance Experiment, developed by the University of Michigan's Michigan Exploration Laboratory in partnership with NASA's Earth Science Technology Office and NASA's Jet Propulsion Laboratory. This is a technology validation mission that performs an engineering assessment of a JPL-developed all digital high-performance focal plane array consisting of an innovative in-pixel analog-to-digital readout integrated circuit. Its high throughput capacity enables the proposed Geostationary Coastal and Air Pollution Events (GEO-CAPE) satellite mission concept to make hourly high spatial and spectral resolution measurements of rapidly changing atmospheric chemistry and pollution with the Panchromatic Fourier Transform Spectrometer (PanFTS) instrument in development. GRIFEX advances the technology required for future space-borne measurements of atmospheric composition from geostationary orbit that are relevant to climate change, as well as future missions that require advanced detectors in support of the . The size of GRIFEX is three CubeSat units, or 30 x 10 x 10 cm.[8]

Earth Science Decadal Survey

FIREBIRD-II (A and B), developed by the University of New Hampshire, Montana State University, Los Alamos National Laboratory, and the Aerospace Corporation. FIREBIRD-II is a two-CubeSat space weather project to resolve the spatial scale, size, and energy dependence of electron microbursts in the Van Allen radiation belts. Relativistic electron microbursts appear as short periods of intense electron precipitation measured by particle detectors on low-altitude spacecraft, seen when their orbits cross magnetic field lines that thread the outer radiation belt. FIREBIRD-II provides dual point radiation belt measurements that offer insight into electron acceleration and loss processes in the outer Van Allen radiation belt. Each of the FIREBIRD CubeSats is 1.5 CubeSat units in size, or 15 x 10 x 10 cm.

[8]

Program description[edit]

SMAP is a directed mission of the National Aeronautics and Space Administration. The SMAP project is managed for NASA by the Jet Propulsion Laboratory, with participation by the Goddard Space Flight Center. SMAP builds on the heritage and risk reduction activities of NASA's cancelled ESSP Hydros Mission.[15]

satellite

Soil Moisture and Ocean Salinity

at NASA/JPL

SMAP website

at the National Snow and Ice Data Center

SMAP data

article at NASA.gov

"Technology Innovations Spin NASA's SMAP into Space"

Archived 2020-06-06 at the Wayback Machine, article at NASA.gov

"NASA's New Studies of Earth's Seas, Skies and Soils"