International Space Station Agricultural Camera (ISSAC) - 07.29.14
ISS Science for Everyone
Science Objectives for Everyone
The International Space Station Agricultural Camera (ISSAC) takes frequent infrared and visible-light images of the North American Great Plains, with an emphasis on forests, grasslands and agricultural fields. Farmers and ranchers are able to use the images within one or two days of their collection in space, helping them make changes to agricultural management decisions, such as drainage and irrigation planning, fertilizer and pesticide application, or livestock forage/grazing plans. Along with capturing images of a significant crop production region of the nation, ISSAC also collects imagery of changing environmental processes around the planet, from melting glaciers to deforestation, and helps monitor natural disasters around the globe.
Science Results for Everyone
A special camera on the ISS makes it possible to watch from space how crops grow and livestock grazing on grass. The International Space Station Agricultural Camera, or ISSAC, collects data from the red and near-infrared bands of the light spectrum to reveal changes in vegetation on the northern Great Plains far below. ISSAC imagery is made available via the web (http://dngp.umac.org/newdngp372/index.php) so farmers, ranchers, and land managers can use the data to make land use decisions. With the decommissioning of Landsat 5 in June 2013, ISSAC will serve as a partial gap-filler for Landsat services for the Great Plains region.
University of North Dakota, Grand Forks, ND, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
National Laboratory (NL)
ISS Expedition Duration
March 2011 - March 2013
Previous ISS Missions
AgCam, the precursor to ISSAC was performed on ISS Expedition 19/20.
- Existing Earth remote sensing system applicable to vegetative studies each have individual shortcomings that reduce their effectiveness for in-season agriculture applications research and operational decision support. Existing sensor platforms typically collect data too infrequently for rapidly changing short-season northern crops that often are under cloud cover, or deliver data with too much latency for effective in-season decision support; those that can meet the preceding needs have spatial resolutions that are too coarse for evaluation of in-field variability.
- End user research partners (farmers, ranchers) and collaborating research scientists will be able to select specific geographical areas of interest and request collection of ISSAC imagery. The ISSAC sensor will collect multi-spectral (green, red, and near-infrared) images at medium spatial resolution (about 15-20 meter pixels), and can point up to 30 degrees off-nadir, enabling frequent (multi-week to multi-day) imaging of a requested area, dramatically improving chances of obtaining cloud-free images. Collected images will be downlinked, processed on the ground, and delivered to the requesting end users within 1-2 days of image collection.
- Farmers using variable-rate application and other precision agriculture techniques will be able to dynamically delineate management zones as the crop vegetation canopy changes during the growing season; this can result in more effective use of fertilizer and other chemical inputs and reduce negative environmental effects. Ranchers will be better able to determine livestock carrying capacity of rangelands; this can help avoid ecosystem damage due to overgrazing and erosion. Scientists will gain new knowledge of rapidly-changing phenomena, ranging from mass-balance changes to glaciers, to observing phonological response to daily changing conditions. Geographic locations around the globe that are frequently under cloud cover during overflights of existing sensors will be able to be observed at times more conducive to cloud-free imaging.
ISSAC is a multi-spectral camera destined for use on the ISS as a sub-rack payload of the Window Observational Research Facility (WORF). Primary ISSAC system components include an ISSAC Sensor Assembly (ISA), a Base Mounting Assembly, a Slide/Pointing Assembly, a Power/Data Controller, associated cabling and support items, and a NASA-supplied T61p Laptop, including power supply, and interconnecting power and data cables. The Base Mounting Assembly provides a solid mounting to the internal WORF payload support shelf. The Slide/Pointing Assembly has a slide mechanism to facilitate crew setup and activation within the WORF, and incorporates an integral gearbox and controller to point the lens assembly up to 30 degrees cross-track. The Power/Data Controller individually powers on the gearbox/controller and the ISA. Within the ISSAC Sensor Assembly, a vibration isolation and absorption system helps prevent excessive jitter in the ISSAC images. A single 150 mm lens and optical beam splitter supply light to three digital framing cameras, each with its own filter; green, red (630-690 nm) and near infrared (780-890 nm).
Nominally all payload operations are commanded via ground uplink. Commands are stored in an on-board command queue and executed based on system time supplied by the ISS. Imagery collected is downlinked via the medium-rate payload LAN. The onboard command queue capability can allow autonomous 24-hour operations, enabling routine worldwide target accessibility.
Being able to quickly bring space imagery down to Earth directly benefits farmers and ranchers. This helps all International Space Station experiments by making them more relevant to the general public. The system also enhances the nation’s suite of remote sensing satellites by focusing on the parts of the light spectrum that are most sensitive to vegetation. In addition, students at the University of North Dakota work with ISSAC data, which helps train the next generation of space scientists and engineers.
While many satellites already contain instruments for studying vegetation, they either take pictures too infrequently or take too long to deliver the data, limiting their value for farmers and ranchers. ISSAC captures anywhere from four to sixteen images of different areas per day, focusing on specific locations requested by farmers, ranchers and researchers in the northern Great Plains. The region has a shorter growing season than other areas in the United States and can be affected by cloud cover, drought and other climate variations. ISSAC’s fast response time and frequent image collection helps farmers and ranchers understand the health of crops and grasslands, and act more quickly when necessary. The experiment also studies global deforestation, plant behavior throughout the seasons, and other environmental phenomena.
To be able to image the Earth, ISSAC requires the ISS to be in Local-Vertical-Local-Horizontal (LVLH) attitude control mode, and preferably with the ISS X-axis in the direction of the Velocity Vector (+XVV), though imaging is still possible in other velocity orientations (i.e., -XVV, etc.). In addition, the US Laboratory Window external shutter must also be open (within shutter Flight Rule constraints).
Once in operation, nominal imaging plans call for acquiring 2-4 images per orbit, 2-4 orbits per day. Contraints on maximum imaging performance are principally data dowlink and operational staffing; a practical upper limit is about 40-50 images per 24 hour period, on an episodic basis. Specific science investigations and application results may be achievable with only one or a few images of a target; others, such as agricultural uses, may require multiple images closely spaced in time, several times during a growing season, and repeated over 2-3 growing seasons.
Crew members have installed ISSAC components, including a T61p Laptop and related Government Furnished Equipment (GFE). No more crew support is needed for nominal operations, other than manual opening and closing of the Lab Window external shutter per standard flight rules, and a once-per-increment cleaning of an air inlet screen.
From within the ISSAC Science Operations Center (SOC) at the University of North Dakota, operators will receive ISSAC imagery requests from an extensive network of end-user participants and research scientists, and will convert these requests into specific sets of commands for uplink to ISSAC. Through coordination with NASA for WORF rack operations, image acquisition and other ISSAC operational commands will be uplinked to the ISSAC payload software, which will take images over specific areas of the Earth. Resultant imagery data will be downlinked and transferred to the University of North Dakota for processing and quick delivery to image requestors.
ISSAC was installed into the WORF on May 13, 2011.
Kim HJ, Olsen D, Laguette S. International Space Station Agricultural Camera (ISSAC) Sensor Onboard the International Space Station (ISS) and Its Potential Use on the Earth Observation. American Society for Photogrammetry and Remote Sensing, Sacramento, CA; 2012 Mar 19-23
Ground Based Results Publications
Upper Midwest Aerospace Consortium
NASA Image: ISS019E007157 Astronaut Michael Barratt,Expedition 19/20 flight engineer,working at the Destiny laboratory module window during the Agricultural Camera (AgCam) Setup and Activation. AgCam was the presursor to ISSAC.
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NASA Image: ISS027E023644 - NASA astronaut Ron Garan, Expedition 27 flight engineer, works with ISS Agricultural Camera (ISSAC) hardware in the Destiny laboratory of the International Space Station. ISSAC, a successor of the earlier AgCam, will operate in conjunction with EarthKAM, both instruments to conduct simultaneous but independent operations in the WORF rack in Destiny.
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Florida west coastal region. ISSAC image courtesy UND UMAC
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