# THEMIS-D > satellite in the THEMIS constellation **Wikidata**: [Q111497118](https://www.wikidata.org/wiki/Q111497118) **Source**: https://4ort.xyz/entity/themis-d ## Summary THEMIS-D is a geomagnetic satellite launched as part of NASA's THEMIS constellation in 2007. It was designed to study Earth's magnetosphere and related regions, contributing to our understanding of space weather and its effects on Earth's magnetic field. ## Key Facts - **Class**: Geomagnetic satellite (designed to monitor Earth's magnetosphere and related regions) - **Launch Date**: February 17, 2007, at 23:01:00 UTC - **Launch Vehicle**: Delta II (D-323 configuration) - **Launch Site**: Cape Canaveral Space Launch Complex 17B - **Operator**: National Aeronautics and Space Administration (NASA) - **Manufacturer**: Swales Aerospace (general contractor), University of California, Berkeley (subcontractor for instruments and system integration) - **Mass**: 77 kg (dry weight), 126 kg (launch weight) - **Dimensions**: 51 cm height, 84 cm diameter - **Power System**: Spacecraft solar array (37 watts), reaction control system (hydrazine, 4 thrusters) - **Part of**: THEMIS constellation (a group of satellites studying space weather) - **Aliases**: Explorer 88, THEMIS-P3, MIDEX-5D, Эксплорер-88 - **COSPAR ID**: 2007-004D - **NSSDCA ID**: 2007-004D ## FAQs ### Q: What was the purpose of THEMIS-D? A: THEMIS-D was part of NASA's THEMIS mission to study Earth's magnetosphere and related regions, particularly focusing on space weather phenomena like substorms and auroras. ### Q: Who built THEMIS-D? A: THEMIS-D was built by Swales Aerospace as the general contractor, with the University of California, Berkeley contributing as a subcontractor for the spacecraft's instruments and system integration. ### Q: What launch vehicle was used for THEMIS-D? A: THEMIS-D was launched using a Delta II rocket in the D-323 configuration, operated by United Launch Alliance. ### Q: How much did THEMIS-D weigh? A: THEMIS-D had a dry weight of 77 kg and a launch weight of 126 kg. ### Q: What is the significance of THEMIS-D's launch date? A: THEMIS-D was launched on February 17, 2007, at 23:01:00 UTC, marking the beginning of NASA's THEMIS mission to study space weather. ## Why It Matters THEMIS-D played a crucial role in NASA's THEMIS mission, which aimed to unravel the mysteries of space weather and its impact on Earth's magnetic field. By studying substorms and auroras, the mission provided valuable insights into how solar activity influences Earth's magnetosphere. The data collected by THEMIS-D and its sister satellites helped scientists better understand the dynamics of space weather, which can affect satellite operations, power grids, and communication systems. The mission's findings contributed to improved space weather forecasting and enhanced our understanding of Earth's complex relationship with the Sun. ## Notable For - **Part of a Constellation**: THEMIS-D was one of five satellites launched as part of NASA's THEMIS mission, working together to study space weather. - **Geomagnetic Focus**: Unlike many satellites, THEMIS-D was specifically designed to monitor Earth's magnetosphere and related regions. - **Collaborative Development**: THEMIS-D was developed through a partnership between Swales Aerospace and the University of California, Berkeley, showcasing interdisciplinary collaboration in space exploration. - **Precise Launch Timing**: THEMIS-D's launch at 23:01:00 UTC on February 17, 2007, was carefully coordinated to achieve optimal scientific observations. - **Legacy in Space Weather Research**: THEMIS-D's data contributed to significant advancements in understanding space weather and its effects on Earth's magnetic environment. ## Body ### Mission Overview THEMIS-D was launched as part of NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, which aimed to study the auroral substorms and their effects on Earth's magnetosphere. The mission involved a constellation of five identical satellites, each equipped with advanced instruments to measure magnetic fields, plasma waves, and energetic particles. ### Technical Specifications THEMIS-D had a dry mass of 77 kg and a launch mass of 126 kg, with dimensions of 51 cm in height and 84 cm in diameter. The spacecraft was powered by a solar array capable of generating 37 watts, supplemented by a reaction control system using hydrazine fuel and four thrusters for attitude control. ### Launch and Deployment THEMIS-D was launched aboard a Delta II rocket in the D-323 configuration, operated by United Launch Alliance. The launch took place from Cape Canaveral Space Launch Complex 17B on February 17, 2007, at 23:01:00 UTC. The satellite was deployed into a highly elliptical orbit to facilitate its scientific observations. ### Scientific Contributions THEMIS-D's primary instruments included magnetic field sensors, electric field antennas, and particle detectors, which allowed it to gather data on the interactions between the solar wind and Earth's magnetosphere. The satellite's observations contributed to a deeper understanding of space weather phenomena, including substorms and auroras, which can disrupt satellite communications and power grids on Earth. ### Legacy and Impact THEMIS-D's data, along with that from its sister satellites, provided critical insights into the dynamics of space weather and its effects on Earth's magnetic environment. The mission's findings have been instrumental in improving space weather forecasting and enhancing our understanding of the Sun-Earth connection. THEMIS-D's legacy continues to influence ongoing research in heliophysics and space weather monitoring. ## References 1. [Source](http://www.swales.com/spacecraft/themis.html) 2. [Source](https://www.nasaspaceflight.com/2007/02/ulas-delta-ii-launches-with-themis/) 3. Jonathan's Space Report 4. [Source](https://directory.eoportal.org/web/eoportal/satellite-missions/t/themis#spacecraft) 5. [Source](https://directory.eoportal.org/web/eoportal/satellite-missions/t/themis)