ISS Experiments
Last checked 6 hours ago.
Experiments listed in NASA's ISS research explorer workbook.
Showing 2801–2820 of 3004 records
The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Vizual (Uragan - Vizual) (Uragan-Vizual (Hurricane-Visual))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 33/34, 35/36, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Vizual (Uragan - Vizual) (Uragan-Vizual (Hurricane-Visual)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Electrostantsia (Uragan - Electrostantsia ) (Uragan-Electrostantsia (Hurricane-Electric Power Station))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Electrostantsia (Uragan - Electrostantsia ) (Uragan-Electrostantsia (Hurricane-Electric Power Station)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - GC (Uragan-GC) (Uragan-GC (Hurricane-GC))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - GC (Uragan-GC) (Uragan-GC (Hurricane-GC)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Katastrofa (Uragan - Katastrofa) (Uragan-Katastrofa (Hurricane-Disaster))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 33/34, 35/36, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Katastrofa (Uragan - Katastrofa) (Uragan-Katastrofa (Hurricane-Disaster)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Kolka (Uragan - Kolka) (Uragan-Kolka (Hurricane-Kolka))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Kolka (Uragan - Kolka) (Uragan-Kolka (Hurricane-Kolka)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Okruzhayuschaya Sreda (Uragan - Okruzhayuschaya Sreda ) (Uragan-Okruzhayuschaya Sreda (Hurricane - Environment))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Okruzhayuschaya Sreda (Uragan - Okruzhayuschaya Sreda ) (Uragan-Okruzhayuschaya Sreda (Hurricane - Environment)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Pamir (Uragan - Pamir) (Uragan-Pamir (Hurricane-Pamir))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Pamir (Uragan - Pamir) (Uragan-Pamir (Hurricane-Pamir)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Pochva (Uragan - Pochva) (Uragan-Pochva (Hurricane-Soil))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Pochva (Uragan - Pochva) (Uragan-Pochva (Hurricane-Soil)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Prikaspy (Uragan - Prikaspy) (Uragan-Prikaspy (Hurricane-Prikaspy))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Prikaspy (Uragan - Prikaspy) (Uragan-Prikaspy (Hurricane-Prikaspy)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Sel (Uragan - Sel) (Uragan-Sel (Hurricane-Mudflow))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Sel (Uragan - Sel) (Uragan-Sel (Hurricane-Mudflow)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Stikhiynoe Bedstvie (Uragan - Stikhiynoe Bedstvie) (Uragan-Stikhiynoe Bedstvie (Hurricane-Natural Disaster))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Stikhiynoe Bedstvie (Uragan - Stikhiynoe Bedstvie) (Uragan-Stikhiynoe Bedstvie (Hurricane-Natural Disaster)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Voda (Uragan - Voda) (Uragan-Voda (Hurricane-Water))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Voda (Uragan - Voda) (Uragan-Voda (Hurricane-Water)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Volga (Uragan - Volga) (Uragan-Volga (Hurricane-Volga))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Volga (Uragan - Volga) (Uragan-Volga (Hurricane-Volga)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Yug (Uragan - Yug) (Uragan-Yug (Hurricane-South))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Yug (Uragan - Yug) (Uragan-Yug (Hurricane-South)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Zapovednik (Uragan - Zapovednik) (Uragan-Zapovednik (Hurricane-Nature Reserve))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Zapovednik (Uragan - Zapovednik) (Uragan-Zapovednik (Hurricane-Nature Reserve)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Zemlya (Uragan - Zemlya) (Uragan-Zemlya (Hurricane-Earth))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters - Zemlya (Uragan - Zemlya) (Uragan-Zemlya (Hurricane-Earth)) (opens in a new tab)The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters- Ural (Uragan- Ural) (Uragan-Ural (Hurricane-Ural))
- Research category
- Earth and Space Science
- Sponsoring space agency
- State Space Corporation ROSCOSMOS (ROSCOSMOS)
- Principal investigators
- Lev Desinov, Institute of Geography of the Russian Academy of Sciences (IG RAS)
- Expeditions
- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19/20, 21/22, 23/24, 25/26, 27/28, 29/30, 37/38, 39/40, 41/42, 43/44
- Category
- Earth and Space Science
ISS experiment: Earth and Space Science; sponsored by State Space Corporation ROSCOSMOS (ROSCOSMOS); expeditions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ….
View source for The Experimental Testing of an Earth-Space System for Monitoring and Predicting the Development of Natural and Man-Made Disasters- Ural (Uragan- Ural) (Uragan-Ural (Hurricane-Ural)) (opens in a new tab)The Fourth Rhodium Scientific Bioprospecting Program Investigation Targets Novel Bioproducts in Space for Biotech, Biopharma Industries (Rhodium Microgravity Bioprospecting-4)
- Research category
- Biology and Biotechnology
- Sponsoring space agency
- National Aeronautics and Space Administration (NASA)
- Principal investigators
- Olivia Holzhaus, M.S., Rhodium Scientific, LLC, Houston
- Developers
- Rhodium Scientific, LLC, Houston, TX, United States
- Expeditions
- 73
- Category
- Biology and Biotechnology
ISS experiment: Biology and Biotechnology; sponsored by National Aeronautics and Space Administration (NASA); expeditions 73.
View source for The Fourth Rhodium Scientific Bioprospecting Program Investigation Targets Novel Bioproducts in Space for Biotech, Biopharma Industries (Rhodium Microgravity Bioprospecting-4) (opens in a new tab)The Impact of Microgravity on the Physical Properties of <em>Boswellia Carterii</em> (BC Frankincense)
- Research category
- Educational and Cultural Activities
- Sponsoring space agency
- National Aeronautics and Space Administration (NASA)
- Principal investigators
- Sylvia Beckham, Seventy First Classical Middle School, Fayetteville, Jacob Regensburger, Seventy First Classical Middle School, Fayetteville
- Developers
- Nanoracks LLC, Webster, TX, United States, Cumberland County Schools, Fayetteville, NC, United States
- Expeditions
- 70
- Category
- Educational and Cultural Activities
ISS experiment: Educational and Cultural Activities; sponsored by National Aeronautics and Space Administration (NASA); expeditions 70.
View source for The Impact of Microgravity on the Physical Properties of <em>Boswellia Carterii</em> (BC Frankincense) (opens in a new tab)The Impact of Staying on the Space Station in Low Earth Orbit (LEO) on the Human Gut Microbiota Analysed Through Targeted Sequencing of the 16S rRNA Gene Amplicons (Human Gut Microbiota)
- Research category
- Human Research
- Sponsoring space agency
- European Space Agency (ESA)
- Principal investigators
- Elzbieta Trafny, Military Univeristy of Technology, Warsaw
- Developers
- Military University Technology, Warsaw, Poland
- Expeditions
- 73
- Category
- Human Research
ISS experiment: Human Research; sponsored by European Space Agency (ESA); expeditions 73.
View source for The Impact of Staying on the Space Station in Low Earth Orbit (LEO) on the Human Gut Microbiota Analysed Through Targeted Sequencing of the 16S rRNA Gene Amplicons (Human Gut Microbiota) (opens in a new tab)
About this data
ISS Experiments
Source: NASA, International Space Station research explorer. Last successful refresh: 19 Oct 2026, 04:24 EDT.
- The workbook has no identifier column, so each experiment is identified by its Short Name (case and spacing normalised); two rows with the same name are held for review.
- Activity status is not stated by the workbook and is not inferred.
- The workbook does not name the facilities an experiment used, so experiments are not linked to facilities.
Acronyms and Terminology
- ABS
- for Acrylonitrile Butadiene Styrene
- ADCs
- Antibody-Drug Conjugates
- AFC
- Alternate Fecal Container
- AMF
- Additive Manufacturing Facility
- APM
- Airborne Particulate Monitor
- ARES
- Active Radiation Environment Sensor
- ASIM
- Atmosphere-Space Interactions Monitor
- AWE
- Atmospheric Waves Experiment
- BBND
- Bonner Ball Neutron Detector
- BEAM
- Bigelow Expandable Activity Module
- BEST
- Biomolecule Extraction and Sequencing Technology
- CRISPR
- Clustered Regularly Interspaced Short Palindromic Repeats
- CSA
- Canadian Space Agency
- ESA
- European Space Agency
- ISS
- International Space Station
- JAXA
- Japan Aerospace Exploration Agency
- MOF
- of Metal-Organic Framework
- NASA
- National Aeronautics and Space Administration
- REACCH
- Responsive Engaging Arms for Captive Care and Handling