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Video
HAYABUSA's seven-year journey in space

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The probe's name was "Hayabusa". Courtesy of NEC Corporation

An asteroid probe departed Earth on a round-trip journey that spanned billions of kilometers to search for secrets behind the birth of our solar system.
The probe's name was "Hayabusa".

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Under the direction of JAXA, the Japan Aerospace Exploration Agency, NEC was involved in the project as a system integrator. The journey was a miraculous achievement made possible by leading-edge technologies and teamwork between human beings and machines.

The asteroid Itokawa Courtesy of NEC Corporation

Hayabusa's target was Itokawa, an asteroid located between the orbits of Earth and Mars.
To enter the asteroid orbit, Hayabusa employed an Earth swing-by navigation technique developed by JAXA and NEC over many years.

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(Mr. Kominato)
"Usually, spacecrafts use a powerful engine for propulsion, but, Hayabusa uses a combination of ion engines and Earth swing-by for its orbit control.
First, Hayabusa traveled all the way around Earth along approximately the same orbit as Earth, which took a year. The ion engines provided continuous thrust during this time. When the probe got close to Earth again, it performed a swing-by to use the gravity of Earth so as to increase the probe's acceleration.

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Hayabusa's Earth swing-by required extremely precise adjustments and other calculations. These requirements included an altitude of 3,700 km, a positional error of 1 km or less, and a velocity error of 1 cm/s or less when the probe got close to Earth again. Hayabusa succeeded in meeting these requirements.

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An orbit control engineer at NASA sent us an email to say "congratulations," on an "outstanding job". We were happy about that. Getting an email from NASA made us feel like we really accomplished something."

In this way, Hayabusa changed its orbit to that of the asteroid Itokawa.

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As Itokawa has almost no gravitational pull, landing on it is not possible, so Hayabusa had to collect a sample by simply touching down on the asteroid.

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(Mr. Hagino)
"When looking from Earth, Itokawa is behind the sun and twice as far away from the Earth as the sun. At this distance, we could only control Hayabusa about once every hour. Therefore, once it approached the asteroid surface, Hayabusa had to look at the terrain on its own, determine which way to tilt, and decide how Itokawa's rotation affected the probe position."

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Hayabusa successfully touched down by using various new methods and technologies, including a laser altimeter, a target marker, and a high sensitivity camera.

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Unfortunately, after the successful touchdown and asteroid takeoff, terrible events awaited: Hayabusa lost its attitude control due to fuel leakage from its chemical engine, and communication with the probe was lost.
However, those on Earth maintained their faith that Hayabusa would respond.

Seven silent weeks passed.

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(Mr. Hagino)
"We believed that, once sunlight could strike the solar arrays, a command would reach Hayabusa and we would hear back from it. However, although we were happy to hear from the probe, our first thought was that we needed to figure out how to fix it."

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By this time, it was no longer possible to use the chemical engine, which had lost its fuel, to control the attitude, so Hayabusa used its ion engines and solar power to start its return.

(Mr. Shirakawa)
"At that time, Hayabusa was returning with most of its attitude control capabilities lost, and our only available option was to use the neutralizers attached to the ion engines to generate a weak force, so we continuously used this force for a while to control and maintain the attitude.

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We used this extremely weak force, the force of solar radiation, and other forces that could gradually change the attitude over time. This was a continuous process. If we tried to tilt the probe right, for example, we wouldn't know the results until the next day, so we would have come back the next day, check whether the probe was moving as we expected, and then apply force in the opposite direction if it wasn't.

I sometimes felt it was our duty to keep the light of Hayabusa from going out."

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After a seven-year journey, Hayabusa returned to Earth, and its mission came to an end.

NEC provided total support for the Hayabusa project, including the development of the ion engines and various other devices, orbit design, and space navigation operations.
The know-how obtained through the many challenges overcome during this project will be extremely valuable in taking the next step in space development.

The achievements of Hayabusa continue to inspire us, guiding us into the future.

NEC Satellite Systems

Name
HALCA (MUSES-B)

Date of launch
February 1997

Courtesy of NEC Corporation and JAXA

Major objectives
Study of large-scale precision deployment structure and mechanism, tests of phase synchronization required for VLBI, etc.

Remarks
Radio telescope satellite performing the world’s first space VLBI observation with resolution 300 times that of the Hubble Space Telescope



Name
NOZOMI (PLANET-B)

Date of launch
July 1998

Courtesy of NEC Corporation and JAXA

Major objectives
Study of the composition, movement and in particular mutual action of solar winds in the upper atmosphere of Mars

Remarks
Japan's first space probe, approaching Mars in December 2003 with the names of 270,000 people aboard


Name
HAYABUSA (MUSES-C)

Date of launch
May 2003

Courtesy of NEC Corporation and JAXA

Major objectives Scientific
observation of Asteroid ITOKAWA

Remarks
The world’s first space probe to succeed in landing on and taking off from an extraterrestrial celestial body, at present undertaking full-scale cruising for its return trip to Earth in June 2010



Name
SUZAKU (ASTRO-E2)

Date of launch
July 2005

Courtesy of NEC Corporation and JAXA

Major objectives
X-ray astronomy satellite

Remarks
Equipped with instruments for observing high energy cosmic phenomena such as black holes and galaxy clusters



Name
AKARI (ASTRO-F)

Date of launch
February 2006

Courtesy of NEC Corporation and JAXA

Major objectives
Observation for creating an all-sky map in infrared light, taking over from the first global infrared astronomy satellite "IRAS"


http://www.nec.com/global/solutions/space/satellite_systems/sa-tellite004.html#s007

NEC Remote Sensing Applications

NEC Disaster Monitoring Solutions

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Solutions Overview


Flood Monitor and Alarm System


Through a combination of SAR observation and ground sensors, We can monitor the water levels of rivers in real time.

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Through integration and analysis of various observation data, accurate evaluation of flood risk becomes possible.


Environment Solutions


SAR observation provides more accurate elevation data than optical observation and can be used for mapping.

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Additionally, it is suitable for natural resource management purposes such as monitoring for illegal logging through periodic observation.


Agricultural Solutions


In the future, the SAR satellite can be utilized for many ways and bring various benefits to our lives.

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For example, SAR observation can be used to estimate rice-field acreage and contributes to improving agricultural productivity.


SAR Observation System


NEC comprehensively supports all aspects of the SAR observation system, including not only the development and manufacturing of the satellite itself, but also ground stations, data processing and analysis facilities, application systems, and training on using data.

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Today, we can proactively detect and prevent disasters by observing the earth from space.

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Even when the weather is bad or at night. The NEC SAR satellite can clearly observe the terrain and geological features.

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SAR is a Synthetic Aperture Radar that observes the terrain and geology through the received reflection of microwaves irradiated from a satellite to the ground surface.


http://www.nec.com/global/solutions/space/remote_sensing/index.html  

NEXTAR

NEC advanced small satellite provides world-class remote sensing capabilities using newly developed standard bus system, which ensures High Reliability, Low Cost, Quick Delivery.

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NEC revised the system architecture in order to achieve highly integrated and open system with adopting advanced COTS technology.

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NEXTAR ：　NEC Next　Generation　Star


Advanced High Resolution Earth Observation Satellite Series

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High Flexibility adaptable for various mission requirement


Technical Data

Core Bus Features

- Bus dry mass : 200 kg
- Payload mass capability : 200 kg max.
- Payload power supply : 600 w max.
- Life : 5 years

Telemetry and Command

- Communication frequency : S-band

Mission Data Handling

- Data bus I/F : Space Wire （IEEE 1355）
- Data rate & storage : 200 Mbps, 4GB

Attitude Control

- Control method : 3-axis, zero momentum
- Control capability : ±6.6x10-2 deg

Power

- Bus voltage : 50 V
- Battery : Li-ion
- Solar Array : TJ-GaAs cell

Propulsion (option)

Structure

- Bus module dimension : 1 m x 1 m x 0.8 m
- Module : Bus / Mission separation


System Block Diagram

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NEC Original Advanced Small Satellite Simulation Data

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NEC Heritage of SAR Technology

Night view around Shizuoka-city by the PALSAR

Courtesy of NEC Corporation and JAXA

Advanced Land Observing Satellite "Daichi"(ALOS)

Courtesy of NEC Corporation and JAXA

http://www.nec.com/global/solutions/space/satellite_systems/nextar.html