# Mariner 2

> 1962 space probe to Venus

**Wikidata**: [Q208984](https://www.wikidata.org/wiki/Q208984)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Mariner_2)  
**Source**: https://4ort.xyz/entity/mariner-2

## Summary
Mariner 2 was the first successful U.S. space probe to Venus, launched in 1962 to study the planet's atmosphere and surface. It conducted a flyby on December 14, 1962, returning critical data about Venusian temperatures, radiation, and interplanetary conditions. Part of NASA's Mariner program, it marked a major milestone in planetary exploration.

## Key Facts
- **Launch Date**: August 27, 1962, from Cape Canaveral Launch Complex 12.
- **Venus Flyby**: December 14, 1962, at a distance of 34,773 kilometers.
- **Mission Duration**: 127 days of operational contact.
- **Mass**: 202.8 kilograms at launch.
- **Power Output**: 220 watts (nominal).
- **Manufacturer**: Jet Propulsion Laboratory (JPL).
- **Launch Vehicle**: Atlas-Agena B rocket.
- **COSPAR ID**: 1962-041A.
- **Preceded By**: Mariner 1 (failed launch).
- **Followed By**: Mariner 3 (Mars flyby attempt).

## FAQs
### Q: What was the primary mission of Mariner 2?
A: Mariner 2 was designed to fly by Venus and collect data on its atmosphere, surface temperature, and interplanetary environment, marking the first successful U.S. planetary probe.

### Q: How long did Mariner 2 operate?
A: The probe transmitted data for 127 days, with contact lost on January 3, 1963, due to solar heating damage.

### Q: What key discoveries did Mariner 2 make?
A: It confirmed Venus's extreme surface temperatures (over 400°C), detected weak magnetic fields, and provided the first direct measurements of solar wind and cosmic radiation.

## Why It Matters
Mariner 2 revolutionized planetary science by confirming Venus's hostile environment, disproving hypotheses of Earth-like conditions. Its success validated interplanetary mission design, including heat shielding and communication systems, paving the way for future probes like the Venera and Magellan missions. As the first human-made object to fly by another planet, it demonstrated technological capability during the Space Race, shifting focus from Earth orbit to deep-space exploration.

## Notable For
- **First Successful Venus Flyby**: The first spacecraft to return data from another planet.
- **Extreme Environment Data**: Revealed Venus's crushing surface pressure and volcanic temperatures.
- **Longest Operational Contact**: Maintained communication for 127 days, a record for early deep-space probes.
- **Interplanetary Science**: Mapped solar wind patterns and cosmic dust distribution.

## Body
### Mission Overview
Mariner 2 launched on August 27, 1962, aboard an Atlas-Agena B rocket, becoming the first probe to successfully reach another planet. Its primary objectives included measuring Venusian surface temperatures, atmospheric composition, and interplanetary magnetic fields.

### Spacecraft Design
- **Mass**: 202.8 kg at launch, with a hexagonal structure and solar panels generating 220 watts.
- **Instruments**: Included microwave radiometers, particle detectors, and a radio occultation experiment.
- **Manufacturer**: Built by JPL, with a focus on surviving solar radiation and extreme temperatures.

### Launch and Flight
- **Launch Site**: Cape Canaveral Launch Complex 12.
- **Trajectory**: Followed a heliocentric orbit, relying on gravity-assist techniques to reach Venus.
- **Flyby**: Passed within 34,773 km of Venus on December 14, 1962.

### Post-Mission
- **Signal Loss**: Contact ended on January 3, 1963, due to degraded systems from solar exposure.
- **Legacy**: Data analysis continued for years, influencing subsequent Venus missions and planetary models.

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "Spacecraft",
  "name": "Mariner 2",
  "description": "1962 space probe to Venus",
  "url": "https://en.wikipedia.org/wiki/Mariner_2",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q830474"
  ],
  "manufacturer": "Jet Propulsion Laboratory",
  "launchDate": "1962-08-27",
  "mass": "202.8 kg",
  "powerOutput": "220 W",
  "cosparId": "1962-041A"
}

## References

1. Jonathan's Space Report
2. Freebase Data Dumps. 2013