HICO and RAIDS Experiment Payload - Remote Atmospheric and Ionospheric Detection System (RAIDS) (HREP-RAIDS) - 05.13.15
The Remote Atmospheric and Ionospheric Detection System studies the highest layers of Earth’s atmosphere. This region includes the ionosphere and the thermosphere. The ionosphere gets its name from interactions with solar rays, and it influences the way radio waves move around the Earth. The thermosphere, a region just below the edge of the atmosphere and the beginning of space, is home to the International Space Station. The density of the thermosphere affects the space station’s orbit. RAIDS contains eight instruments that can study the atmosphere’s structure, density and temperature in great detail.
Science Results for Everyone
Work on the ISS is leading to new techniques for remote sensing of Earth’s atmosphere on future space missions. HREP-Remote Atmospheric and Ionospheric Detection System, or HREP-RAIDS, is an ultraviolet (UV) and remote sensing instrument that documents the density, composition, and temperature of the thermosphere and ionosphere, two upper layers of Earth's atmosphere. It was used on a long-duration ISS experiment to test new remote sensing techniques. Experiment Details
Scott A. Budzien, Naval Research Laboratory, Washington, DC, United States
The Aerospace Corporation, El Segundo, CA, United States
United States Department of Defense Space Test Program, Johnson Space Center, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
National Laboratory - Department of Defense (NL-DoD)
ISS Expedition Duration
March 2009 - Ongoing
Previous ISS Missions
HREP-RAIDS is a unique investigation that has not been performed on spacecraft before.
- The HICO and RAIDS Experiment Payload - Remote Atmospheric and Ionospheric Detection System (HREP-RAIDS) combines two experiment sensors into one payload.
- HREP-RAIDS is an ultraviolet (UV) and visible remote sensing instrument that views the limb (edge) of the Earth to measure vertical composition and temperature of the atmosphere above 95 km.
The Hyperspectral Imager for the Coastal Ocean (HICO) and Remote Atmospheric and Ionospheric Detection System (RAIDS) Experiment Payload (HREP) consists of two instruments. The HREP-RAIDS is an experiment designed to perform a comprehensive study of naturally occurring airglow emissions in the upper atmosphere. HREP-RAIDS observations are used to develop and test techniques for remote sensing of the neutral atmosphere and ionosphere on a global scale. HREP-RAIDS is an array of eight optical instruments covering the wavelength region 55 - 870 nanometers and measures the vertical structure of the atmosphere. The experiment scans or images the limb of the Earth to measure profiles of airglow from major ionospheric and neutral atmospheric species in the upper atmosphere. HREP-RAIDS measurements are used to determine the composition and temperature of the thermosphere and ionosphere. HREP-RAIDS tests new techniques for atmospheric remote sensing and looks for signs of global change.
HREP-RAIDS performs a comprehensive study of naturally occurring airglow in the upper atmosphere, where the International Space Station is in a stable orbit. Its instruments measure the vertical structure of the atmosphere, which can be used to study the effects of atmospheric drag and charged subatomic particles. RAIDS is part of a larger experiment called HICO and RAIDS Experiment Payload, or HREP, which combines RAIDS with the Hyperspectral Imager for the Coastal Ocean.
RAIDS measures the density, temperature, and composition of the atmosphere at altitudes between 59 and 186 miles, which is generally a poorly studied region. It tests techniques for measuring the atmosphere, especially the ionosphere, on a global scale. Data from RAIDS may lead to improved understanding of how the atmosphere works, and how it can affect satellites and space debris in low-Earth orbit.
HREP-RAIDS is mounted to the ISS exterior on JEM-EF at position number six. It requires power provided by the International Space Station (ISS), and uses the ISS for commanding and data downlink. All interaction is via the POIC and no crew interaction is planned other than installation and removal via extravehicular robotics (EVR).
HREP-RAIDS launches to the ISS as a part of the HTV-1 mission. EVR mounts HREP to the JEM-EF and removes it for disposal on a later HTV flight.
RAIDS was installed on ISS September 24, 2009, and began science operations one month later. RAIDS measured airglow emissions, specifically the 61.7 and 83.4 nanometer (nm) singly ionized oxygen (oxygen that has lost one electron) emission bands. Airglow is the weak atmospheric light generated from the reaction between solar radiation and atoms or molecules in the upper atmosphere. The singly ionized oxygen (O II) 61.7 nm emission band can be used to monitor photoionization (the process in which one or more electrons are ejected from an atom after it absorbs energy) of atomic oxygen in the lower atmosphere. The O II 61.7 nm emission altitude profile, measured for the first time by RAIDS, will be used to adjust current airglow models. The O II 83.4 nm emission band responds to changes in ionospheric density and so can be used to monitor global changes in the ionosphere. RAIDS data were used to improve models of the daytime O2 atmospheric band, or A-band, emission, which is one of the brightest emission features observed in the visible and near infrared region of the airglow spectrum. RAIDS also measured the temperature profile of the O2 A-band, which, while in rough agreement with model predictions, was warmer than predicted values above 100 kilometers in altitude.^ back to top
Stephan AW, Picone M, Budzien SA, Bishop RL, Christensen AB, Hecht JH. Measurement and application of the O II 61.7 nm dayglow. Journal of Geophysical Research. 2012 Jan 25; 117: A01316. DOI: 10.1029/2011JA016897.
Stephan AW, Christensen AB, Minschwaner K, Budzien SA, Bishop RL, Hecht JH. Characterization of sensitivity degradation seen from the UV to NIR by RAIDS on the International Space Station. Solar Physics and Space Weather Instrumentation IV; 2011 814804.
Budzien SA, Bishop RL, Stephan AW, Christensen AB, McMullin DR. Atmospheric Remote Sensing on the International Space Station. Eos, Transactions American Geophysical Union. 2010 October 19; 91(42): 381-382. DOI: 10.1029/2010EO420002.
Douglas ES, Smith SM, Stephan AW, Cashman L, Bishop RL, Budzien SA, Christensen AB, Hecht JH, Chakrabarti S. Evaluation of ionospheric densities using coincident OII 83.4 nm airglow and the Millstone Hill Radar. Journal of Geophysical Research. 2012 May 31; 117: A05331. DOI: 10.1029/2012JA017574.
Christensen AB, Yee J, Bishop RL, Budzien SA, Hecht JH, Sivjee G, Stephan AW. Observations of molecular oxygen Atmospheric band emission in the thermosphere using the near infrared spectrometer on the ISS/RAIDS experiment. Journal of Geophysical Research. 2012 Apr 24; 117: A04315. DOI: 10.1029/2011JA016838.
Ground Based Results Publications
Budzien SA, Bishop RL, Stephan AW, Straus PR, Christensen AB, Hecht JH. The Remote Atmospheric and Ionospheric Detection System experiment on the ISS: Mission Overview. Proceedings of SPIE 7438, Solar Physics and Space Instrumentation III, San Diego, CA; 2009 0X1-0X12.
Remote Atmospheric and Ionospheric Detection System
Unlatched HREP-RAIDS configuration fully rotated (on-orbit the instrument is rotated 180 degrees). Image courtesy of the Naval Research Laboratory.
+ View Larger Image
NASA Image: S129E009592 - View of the Hyperspectral Imager for Coastal Oceans (HICO) and Remote Atmospheric and Ionospheric Detection System (RAIDS) Experiment Payload (HREP) installed on the Japanese Experiment Module - Exposed Facility and the port side Solar Array Wings. Photo taken from a JEM Pressurized Module window.
+ View Larger Image
NASA Image: ISS033E018906 - Image through the JEM window during Expedition 33 showing the side of the HREP hardware mounted at EFU slot 6
+ View Larger Image