Japan's JAXA space agency launched SELENE (Kaguya), their first lunar orbiter, from Tanegashima Space Center. The mission represented the largest lunar exploration project since NASA's Apollo program, carrying 13 scientific instruments to study the Moon's composition and structure.
Japan's ambitious lunar exploration program reached a significant milestone with the launch of the SELENE (Selenological and Engineering Explorer) spacecraft, also known as Kaguya. This groundbreaking mission marked Japan's first lunar orbiter designed to study the Moon's origins and evolution.
SELENE's journey began on September 14, 2007, when it lifted off from the Tanegashima Space Center aboard an H-IIA rocket. The mission represented one of the largest lunar exploration projects since NASA's Apollo program and demonstrated Japan's growing capabilities in space exploration. The orbiter carried 13 scientific instruments to map the Moon's surface, study its gravitational field and analyze its mineral composition.
The Launch of Japan's Selene Lunar Mission
#JAXA launched SELENE, nicknamed Kaguya, on September 14, 2007, at 10:31 AM JST (01:31 UTC) from Tanegashima Space Center. The spacecraft lifted off aboard an H-IIA rocket, marking Japan's most ambitious lunar exploration mission.
The launch sequence followed these critical phases:
- First-stage separation occurred 6 minutes after liftoff
- Second-stage ignition initiated immediately after separation
- Spacecraft deployment completed 45 minutes into the mission
- Solar panel deployment confirmed within 1 hour post-launch
| Launch Details | Specifications |
|---|---|
| Launch Vehicle | H-IIA Rocket |
| Launch Site | Tanegashima Space Center |
| Launch Time | 10:31 AM JST |
| Launch Mass | 2,914 kg |
| Orbit Insertion | October 4, 2007 |
The spacecraft's initial trajectory placed it in a transfer orbit before executing a series of maneuvers to reach lunar orbit. SELENE achieved its preliminary orbit around the Moon on October 4, 2007, establishing Japan's presence in lunar exploration.
The mission carried these primary components:
- Main orbiter (Kaguya)
- VRAD satellite for gravity field studies
- Relay satellite for far-side communications
- 13 scientific instruments for lunar mapping
Each component separated successfully during the early mission phases, positioning SELENE for its comprehensive study of the Moon's surface composition geological history.
Key Mission Objectives and Scientific Goals
#SELENE's mission objectives focused on conducting comprehensive scientific investigations of the Moon through advanced technology and precision instruments. The Japanese lunar orbiter carried multiple specialized tools to achieve specific research goals.
Mapping the Moon's Surface
#SELENE created detailed topographic maps of the lunar surface using its Terrain Camera laser altimeter. The spacecraft's high-resolution imaging systems captured 3D photographs of craters, highlands, and maria at resolutions of 10 meters per pixel. These mapping capabilities provided precise data about:
- Surface elevation variations across lunar terrain
- Geological features in previously unmapped areas
- Distribution patterns of mineral deposits
- High-definition imagery of the Moon's polar regions
Studying Lunar Origins
#Kaguya investigated the Moon's formation process through multiple scientific experiments. The mission's instruments analyzed:
- Chemical composition of lunar rocks through X-ray spectrometry
- Magnetic field variations across different lunar regions
- Distribution of major elements in the lunar soil
- Gravitational field measurements using dual sub-satellites
- Plasma environment around the Moon's orbit
The spacecraft's instruments detected elemental concentrations that provided insights into the Moon's evolutionary history. JAXA's lunar mapping mission gathered data about the distribution of radioactive elements including uranium thorium potassium which helped determine the Moon's thermal evolution.
Launch Details and Timeline
#JAXA's SELENE lunar orbiter launch required extensive preparations and precise execution for mission success. The launch sequence followed a detailed timeline to ensure the spacecraft's safe deployment into space.
Pre-Launch Preparations
#- Engineers conducted final system checks at Tanegashima Space Center 24 hours before launch
- Weather monitoring teams tracked atmospheric conditions across 3 observation points
- Ground control teams verified communication systems with 5 tracking stations
- Technical crews loaded 400 kilograms of fuel into the H-IIA rocket
- Final countdown procedures began 6 hours before scheduled liftoff
- Mission control confirmed optimal launch conditions 2 hours before launch
Launch Day Events
#| Time (JST) | Event |
|---|---|
| 07:00 AM | Final weather assessment |
| 08:30 AM | H-IIA rocket fueling completed |
| 10:31 AM | SELENE launch from Pad 1 |
| 10:37 AM | First stage separation |
| 10:38 AM | Second stage ignition |
| 11:16 AM | Spacecraft deployment |
| 11:32 AM | Solar panel deployment |
- Launch teams monitored 15 critical parameters during ascent phase
- SELENE achieved initial velocity of 11.2 kilometers per second
- Tracking stations confirmed successful signal acquisition 20 minutes after launch
- Mission control verified spacecraft systems functionality within 2 hours post-launch
Technical Specifications of Selene
#SELENE (Kaguya) featured advanced engineering components designed for comprehensive lunar exploration. The spacecraft incorporated precise navigation systems with three interconnected satellites working in tandem.
Spacecraft Design
#The main SELENE orbiter measured 2.1 x 2.1 x 4.8 meters with deployed solar panels spanning 12 meters. The spacecraft's dry mass totaled 1,984 kg including:
- Main orbiter (Kaguya): 1,645 kg
- Relay satellite: 53 kg
- VRAD satellite: 53 kg
- Propellant mass: 795 kg
| Component | Specification |
|---|---|
| Power Generation | 3.5 kW (solar panels) |
| Orbital Altitude | 100 km (nominal) |
| Mission Duration | 1 year nominal |
| Communication Rate | 10 Mbps (X-band) |
Scientific Instruments
#- Terrain Camera (TC): 10m resolution stereo mapping camera
- Multi-band Imager (MI): 9-band spectral camera for mineral mapping
- Laser Altimeter (LALT): Topographic mapping with 5m vertical accuracy
- Gamma-ray Spectrometer (GRS): Element distribution analysis
- X-ray Spectrometer (XRS): Major element composition studies
- Magnetic Field Sensor (LMAG): Lunar magnetic field measurements
- Plasma Analyzer (PACE): Solar wind interaction studies
- Radio Science (VRAD/RSAT): Gravity field measurement system
Mission Achievements and Legacy
#SELENE's mission achievements significantly advanced lunar science through detailed mapping surveys and groundbreaking discoveries. The mission demonstrated Japan's technological capabilities in space exploration while providing valuable data for future lunar missions.
Major Discoveries
#SELENE's comprehensive lunar mapping revealed several groundbreaking findings:
- Located gravity anomalies on the Moon's far side through precise gravitational field measurements
- Discovered small but distinct traces of uranium deposits in lunar soil samples
- Captured the first high-definition video footage of "Earthrise" from lunar orbit
- Identified previously unknown vertical holes in lunar maria regions
- Mapped over 70,000 craters including detailed analysis of their depths and sizes
| Discovery Type | Quantity/Impact |
|---|---|
| Mapped Craters | 70,000+ |
| Gravity Anomalies | 5,000+ |
| Mineral Distribution Maps | 10+ types |
| HD Video Coverage | 100+ hours |
Impact on Lunar Exploration
#- Created the most detailed 3D topographic maps of the Moon's surface using the Terrain Camera
- Established new baseline data for lunar gravitational field studies
- Provided critical information for landing site selection in subsequent missions
- Enhanced understanding of the Moon's geological evolution through mineral composition data
- Developed new technologies for future Japanese space missions
| Technology Impact | Application |
|---|---|
| Terrain Mapping | Used by 8+ space agencies |
| Gravity Data | Referenced in 200+ studies |
| Mineral Maps | Applied in 15+ missions |
| Landing Site Data | Utilized by 5+ lunar missions |
Key Takeaways
#- Japan's SELENE (Kaguya) lunar orbiter launched on September 14, 2007, at 10:31 AM JST from Tanegashima Space Center aboard an H-IIA rocket.
- The spacecraft consisted of three components: the main orbiter (Kaguya), a VRAD satellite, and a relay satellite, with a total launch mass of 2,914 kg.
- SELENE carried 13 scientific instruments to study the Moon's surface, gravitational field, and mineral composition, making it one of the largest lunar exploration projects since NASA's Apollo program.
- The mission reached lunar orbit on October 4, 2007, and created detailed 3D topographic maps of the lunar surface with 10-meter resolution.
- Key achievements included mapping over 70,000 craters, discovering uranium deposits, capturing the first HD "Earthrise" video, and providing critical data for future lunar missions.
Conclusion
#The SELENE lunar orbiter stands as a testament to Japan's remarkable achievement in space exploration. Its successful launch in September 2007 paved the way for groundbreaking lunar research and demonstrated Japan's technological prowess in space missions.
The mission's comprehensive data collection advanced our understanding of the Moon's composition evolution and geological features. Through its advanced instruments and precise engineering SELENE delivered exceptional results that continue to influence lunar exploration strategies today.
As one of the most sophisticated lunar missions since the Apollo program SELENE's legacy lives on through its valuable contributions to lunar science and the foundation it established for future space exploration endeavors.