# Dawn

> NASA space probe exploring Vesta and Ceres

**Wikidata**: [Q48558](https://www.wikidata.org/wiki/Q48558)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Dawn_(spacecraft))  
**Source**: https://4ort.xyz/entity/dawn

## Summary
Dawn is a NASA space probe designed to explore the celestial bodies Vesta and Ceres. Launched on September 27, 2007, it holds the distinction of being the first spacecraft to orbit two distinct extraterrestrial bodies. The mission concluded on October 30, 2018, following the loss of signal, after spending years gathering data from the asteroid belt.

## Key Facts
- **Entity Type:** Space Probe (unmanned robotic spacecraft).
- **Launch Date:** September 27, 2007.
- **Launch Site:** Cape Canaveral Space Launch Complex 17B.
- **Launch Vehicle:** Delta II (retired expendable launch system).
- **Primary Targets:** Vesta (orbital activity from July 16, 2011, to September 5, 2012) and Ceres (orbital activity from March 6, 2015, to October 30, 2018).
- **Operators:** National Aeronautics and Space Administration (NASA) and Jet Propulsion Laboratory (JPL).
- **Manufacturers:** Orbital Sciences Corporation, Jet Propulsion Laboratory, and University of California, Los Angeles.
- **Mass:** 1,217.7 kg at launch; 747.1 kg zero-fuel weight.
- **Power Source:** Spacecraft solar arrays (2 units) and nickel-hydrogen battery.
- **Mission End:** Loss of signal occurred on October 30, 2018; predicted atmospheric entry is December 30, 2044.

## FAQs
### Q: What celestial bodies did the Dawn spacecraft explore?
A: Dawn explored Vesta and Ceres. It entered orbit around Vesta in July 2011 and later orbited Ceres starting in March 2015.

### Q: When was the Dawn spacecraft launched and by whom?
A: Dawn was launched on September 27, 2007, using a Delta II rocket from Cape Canaveral. It was operated by NASA and the Jet Propulsion Laboratory.

### Q: Is the Dawn spacecraft still active?
A: No, Dawn is no longer active. The mission ended on October 30, 2018, when NASA lost contact with the probe after it depleted its propellant.

## Why It Matters
The Dawn mission represents a significant achievement in space exploration due to its technical capability to orbit two separate celestial bodies, Vesta and Ceres, within the asteroid belt. By successfully entering and leaving orbit around Vesta to travel to Ceres, the probe provided scientists with a comparative dataset on two distinct protoplanets that formed early in the solar system's history.

This mission enhanced the understanding of the solar system's evolution by characterizing the geology, composition, and evolution of these bodies. The data collected helps explain the processes that dominated the formation of terrestrial planets. The mission's longevity—operating for over a decade—demonstrated the robustness of ion propulsion and solar power in deep space environments, setting a precedent for future extended missions.

## Notable For
- **First Dual-Orbit Mission:** The only spacecraft to have orbited two separate extraterrestrial bodies (Vesta and Ceres).
- **Exploration of the Asteroid Belt:** The first mission to specifically target and orbit two of the largest bodies in the asteroid belt.
- **Extended Duration:** Operated for over 11 years, far exceeding its original mission timeline.
- **Academic Partnership:** A unique collaboration involving NASA's Jet Propulsion Laboratory, Orbital Sciences Corporation, and the University of California, Los Angeles.

## Body

### Mission Profile
Dawn was launched as part of NASA's Discovery Program to study two of the largest bodies in the asteroid belt: the giant asteroid Vesta and the dwarf planet Ceres.

**Timeline of Significant Events:**
- **September 27, 2007:** Rocket launch from Cape Canaveral Space Launch Complex 17B.
- **February 18, 2009:** Planetary flyby of Mars.
- **July 16, 2011:** Arrival and start of orbital activity at Vesta.
- **September 5, 2012:** End of orbital activity at Vesta.
- **March 6, 2015:** Arrival and start of orbital activity at Ceres.
- **October 30, 2018:** Mission end due to loss of signal.
- **December 30, 2044:** Predicted date of atmospheric entry.

### Technical Specifications
The spacecraft was designed to operate deep in the solar system without orbiting Earth.

**Physical Dimensions:**
- **Width:** 19.7 meters (spacecraft solar array) and 1.27 meters (bus width).
- **Height:** 1.77 meters.
- **Length:** 1.64 meters.

**Mass and Power:**
- **Launch Mass:** 1,217.7 kilograms.
- **Zero-Fuel Weight:** 747.1 kilograms.
- **Power Systems:** Powered by two spacecraft solar arrays and a nickel–hydrogen battery.

### Program Context
Dawn was part of the Discovery Program, which focuses on highly focused scientific missions. In the sequence of these missions:
- **Preceded by:** Deep Impact.
- **Succeeded by:** Kepler Space Telescope.

### Administration and Manufacturing
The mission was managed and operated by the Jet Propulsion Laboratory (JPL) and NASA. Manufacturing and scientific partnership involved:
- **Orbital Sciences Corporation**
- **Jet Propulsion Laboratory**
- **University of California, Los Angeles** (a public university founded in 1919).

## Schema Markup
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  "@type": "Thing",
  "name": "Dawn",
  "description": "NASA space probe exploring Vesta and Ceres.",
  "url": "http://dawn.jpl.nasa.gov/",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q32249",
    "https://en.wikipedia.org/wiki/Dawn_(spacecraft)"
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## References

1. Jonathan's Space Report
2. [Source](https://www.jpl.nasa.gov/news/press_kits/dawnatCeres2015.pdf)
3. Freebase Data Dumps. 2013
4. [Source](https://www.nytimes.com/2018/11/01/science/nasa-dawn-ceres-vesta-asteroids-end.html)
5. [Source](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html)