TRACE
Transition Region and Coronal Explorer (TRACE)
Mission Descriptions
Overview
TRACE (Transition Region and Coronal Explorer) is a NASA solar observation satellite designed to observe the Sun's corona and transition region in detail. Launched on April 2, 1998, TRACE concluded its observations on June 21, 2010. The primary objective of TRACE was to understand solar activity and its impacts by observing various physical phenomena occurring in the Sun's corona and transition region. The mission provided a wealth of high-resolution images and data, enhancing our understanding of solar dynamics.
TRACE is a small satellite, measuring approximately 1.6 meters in length and weighing around 250 kg. It was placed in a sun-synchronous polar orbit with a periapsis altitude of 600 km, an apoapsis altitude of 650 km, and an inclination of 97.8 degrees, orbiting the Earth every 96 minutes. The mission was primarily managed by NASA's Goddard Space Flight Center and Lockheed Martin's Solar and Astrophysics Laboratory.
Observation Instruments
TRACE Telescope
The main observational instrument on TRACE is its telescope, which is a 1.6-meter long Cassegrain reflector with a 30 cm aperture. The telescope has a field of view of 8.5 x 8.5 arcminutes and a spatial resolution of 1 arcsecond. Light is focused onto a 1024 x 1024 pixel CCD detector (0.5 arcseconds per pixel), with exposure times ranging from 2 milliseconds to 260 seconds.
The telescope observes wavelengths from visible light to extreme ultraviolet (17.1 nm, 19.5 nm, 28.4 nm, and white light: 500 nm). The system uses a combination of an imaging CCD camera and specialized filters, allowing high-resolution imaging of the corona and chromosphere structures. The camera system can take short-exposure images to observe dynamic phenomena such as solar flares in detail.
Achievements
The TRACE mission achieved several important milestones, including:
- Understanding Coronal Heating: TRACE provided detailed data on the heating mechanisms of the solar corona, offering new insights into why the corona's temperature suddenly increases.
- Magnetic Reconnection Observations: The mission collected specific observational data on the role of magnetic reconnection in solar flares and the formation of coronal loops.
- High-resolution Images of Solar Dynamics: TRACE's high-resolution images established a new standard for observing the fine structure of the Sun's surface and upper atmosphere, serving as a valuable resource for researchers.
The TRACE mission played a crucial role in the field of solar physics, offering a foundation for numerous new discoveries and further research.