(launch photo by Mitsubishi Heavy Industries)

Launch sequence
JAXA's countdown page
Piggyback payloads

(background: artwork of Sotatsu Tawaraya, 17th century)

SPRITE-SAT (RISING) on the rocket booster (before separation)

All the spacecrafts including GOSAT (main payload) and SPRITE-SAT (one of the sub-payloads) were encapsulated in a rocket fairing. The fairing is a cover for the payloads to protect from air resistance, friction heat, and acoustic vibrations in the atmosphere during the liftoff. In the picture, SPRITE-SAT is seen on the right bottom of the payload mounting base. ((C) JAXA)

[TOP] SPRITE-SAT was lifted up and attached on the rocket interface assembly. ((c) JAXA)
[Bottom left] Arrangement of sub-payload assembly. ((C) JAXA)
[Bottom right] SPRITE-SAT was firmly connected. ((C) JAXA)

SPRITE-SAT safely arrived at JAXA's Tanegashima Space Center (TNSC), in Kagoshima prefecture, on December 16th. Then the final checkout was conducted by the SPRITE-SAT development team until 19th. Passing through a safety review on December 23th, the spacecraft was transported into the Spacecraft and Fairing Assembly Building (SFA) on 24th.

[Top left] Safe arrival at TNSC ((C) JAXA)
[Top right] Final check of observation cameras（Dec.19th）
[Bottom] Tohoku SPRITE-SAT team members（Dec.19th）

SPRITE-SAT had completed final touches of its assembling and testing processes. On December 12th, SPRITE-SAT was shipped out to the launch site, JAXA's Tanegashima Space Center (TNSC).
On the same day, a press conference was held in Tohoku University, and the result of the qualification tests and the schedule of launch campaign at TNSC were announced by Prof. Yukihiro Takahashi (Principal Investigator) and Prof. Kazuya Yoshida (Project Manager).

[Left] Shipping out of the SPRITE-SAT in a dedicated container
[Right] Press conference in a class room

The qualification tests were conducted from the beginning of September to the end of November in JAXA's facilities in Tsukuba and Higashi-Osaka. The tests included the measurements of exterior dimensions, mass and inertia properties, shock and vibrations, out-gas evaluation, thermal and vacuum, and function of electronic assemblies in all different condisions.
A review meeting was held on December 1st and SPRITE-SAT was qualified to "GO" for the launch!

SPRITE-SAT is a micro satellite in the size of 50 cm cube and weighing less than 50-kg, under the development by Tohoku University. The satellite will conduct scientific observation of atmospheric luminous emissions called "sprites".
The specific mission objectives are the following two points:

(1)The "sprites" are a type of Transient Luminous Events (TLE) observed in the middle atmosphere (typically 40-90 km altitude, from upper Stratosphere to Mesosphere),
which were first discovered in 1989. It is considered that large scale thunderstorms are capable of producing such luminous events over the clouds, but a true mechanism is still under the veil.
Although extensive studies have been carried out in these years, no clear model has yet established for their horizontal structure, because it is difficult to observe from the ground based instruments.
SPRITE-SAT will look down the sprites from orbit then identify the horizontal structure and physical relationships of the sprites and the cloud-to-ground lightnings. It will also provide a clear figure of the global distribution of the events.
SPRITE-SAT will reveal the mechanism of such mysterious luminous events.　

(2)Brief bursts of gamma-rays coming from space have been observed since the 1960s,
but recent observations suggest that shorter bursts of gamma-rays occur in the earth's atmosphere. Such bursts are called the Terrestrial Gamma-ray Flashes (TGF).
The flashes are considered generated by high-energy photons in the atmosphere
and a strong relationship is inferred with the thunderstorms and the transient luminous events, such as sprites.
SPRITE-SAT also equips dedicated sensors to observe the TGF. Simultaneous observation of TLE and TGF, particularly with high precision on the timing of these events, will reveal a new model to describe the relationship of these phenomena.

SPRITE-SAT is being developed in the Science and Engineering departments of Tohoku University. It will be launched as a piggyback payload of an H-IIA rocket for the JAXA's Greenhouse Gas Observation Satellite (GOSAT). The launch is scheduled in January 2009. The orbit will be a sun-synchronous polar orbit with 660 km altitude form the earth's surface.


Advantages of SPRITE-SAT

Conventional, or large scale, satellite programs conducted by a national space agency take
a large amount of budget (typically some hundred million dollars) and long period of development time (typically ten years).
In contrast to them, novel challenges using small (micro, nano, or pico) satellites are proposed and successfully conducted by universities in these years.　
Advantages of such small satellites are found in low-cost and short-term development, and well-focused mission objectives.

SPRITE-SAT is one of university-based small satellites in the size of 50 kg, yet it aims to achieve remarkable scientific discovery. As mentioned above, Transient Luminous Events (TLE) and Terrestrial Gamma-ray Flashes (TGF) are newly discovered phenomena,
and a lot more of significant observations are needed from space. Making the most of advantages in low-cost and short-term development, SPRITE-SAT challenges to achieve a world first observation to determine a clear model on the TLE and TGF phenomena.

SPRITE-SAT is being developed by the faculty and student members of Tohoku University,
with technical supports from mentors (well-experienced experts) of the satellite development. Students play leading roles in the assembling and testing processes.
Through this project, the students are gaining precious experience in various aspects of a space flight mission, such as quality verification and trouble shooting. This program is therefore considered a unique opportunity for hands-on education (or project-based learning) in space science and space engineering.

more photos