A small glass disk designed and manufactured by the National Institute of Standards and Technology soon will be orbiting the Earth aboard a satellite that will provide unusually detailed data about the chemical composition and properties of the planet.
Standard Reference Material 2035, believed to be the first SRM to be used in space, is a wavelength standard for transmission measurements in the ultraviolet, visible, and near infrared regions of the electromagnetic spectrum – the portions closely associated with chemical changes. It will be used to help monitor and validate the performance of spectral imaging equipment aboard OrbView-4, scheduled for launch this month. The project is a joint venture of the Air Force Research Laboratory Space Vehicles Directorate and Orbital Sciences Corp. of Dulles, Va. The satellite will be operated by an Orbital affiliate, ORBIMAGE.
Natural and manmade materials on the Earth's surface each exhibit unique signatures of reflected light from the sun, much of which cannot be captured with either a conventional camera or the human eye. Using detectors that transform the reflected light into electronic signals, OrbView-4 will measure the signatures and identify materials ranging from plant species to minerals to inland and coastal water features. The resulting imagery has many applications, including mineral, oil and gas exploration; forestry, farming and environmental monitoring; and military activities.
SRM 2035 was originally developed for Earth-bound chemical applications in a narrower spectral range but is well suited for the space application because of its small size, light weight, broad spectral coverage, and well-characterized temperature dependence.