Data Relay Test Satellite "KODAMA" (DRTS) Topics

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Aug. 7, 2017 Updated
KODAMA Ends Operations

At 2:45 p.m. (Japan Standard Time), August 5, 2017, JAXA sent a set of commands to shut down the operations of KODAMA, JAXA’s data relay test satellite.
Since launch on September 10, 2002, KODAMA was in use for about fifteen years, long after its operations phase. The time lapse took its toll on the satellite. On July 31, JAXA started the procedure to end the KODAMA operations to prevent interference with other spacecraft. On August 5, KODAMA received signals for controlled deorbit. The satellite sent its last transmission to Earth, ceasing its operations.

KODAMA Ends Operations

Sep. 10, 2012 Updated
KODAMA on-orbit operations mark 10 years

The KODAMA, which was launched on Sept. 10, 2002, has marked its 10-year anniversary. The KODAMA succeeded in a data relay experiment with the world's fastest speed of 278 Mbps using the Advanced Land Observing Satellite "DAICHI," and has been contributing to global land observations and disaster monitoring with the DAICHI by utilizing KODAMA’s broad view area and real-time and large-volume data relay capacity. Some 95% of DAICHI's 6.54 million scenes (or almost one PB of observation data) were received on earth through KODAMA's relays.
Also, in these 10 years, the KODAMA successfully conducted data relay tests with six different spacecraft including the International Space Station (ISS) Japanese Experiment Module “Kibo,” and its operating rate for experiments has reached as high as 99%.
As we expect more data relay satellite utilization plans in the future, we continue to operate the KODAMA while preparing to maintain our country's satellite data relay capability.

KODAMA on-orbit operations mark 10 years

Oct. 7, 2009 Updated
KODAMA completes regular operation phase

The KODAMA, launched in September 2002, completed its six-and-half-year regular operation phase, and entered the post operation phase.
The KODAMA successfully performed inter-satellite communication experiments with the Advanced Land Observing Satellite "DAICHI" at a global-leading speed of 278 Mbps, and contributed to DAICHI's earth observation activities by relaying a huge volume of data acquired and transmitted by the DAICHI. The KODAMA achieved its scheduled goals as it also successfully carried out inter-satellite communication experiments with the Optical Inter-orbit Communications Engineering Test Satellite "KODAMA," the Small Demonstration Satellite-1 "SDS-1," the Japanese Experiment Module "Kibo," and the earth observation satellite "Envisat" of the European Space Agency.
In the post-operation phase, the KODAMA will continue its relay operations mainly with the DAICHI and Kibo.

Photo: Test image taken by Kibo and relayed via KODAMA

Dec. 1, 2006 Updated
Data relay experiments with ESA satellite

The Data Relay Test Satellite "Kodama" successfully carried out data relay experiments with the earth observation satellite "Envisat" of the European Space Agency (ESA). The experiments were performed in April and September, 2006, by coordinating the regular operation schedules of the two satellites.

In April, we confirmed that the "Envisat" at 800 km altitude, and the "Kodama" at 36,000 km altitude, were able to accurately face each other. In September, data was sent from the "Envisat" to the Tsukuba Space Center via the "Kodama", then it was further transmitted to the European Space Research Institute of the ESA in Italy. The quality of the data was verified to be high there.

The "Envisat" usually carries out operations using the ESA data relay satellite "Artemis" in a geostationary orbit at 21.5 degrees east longitude over the equator. We have already successfully performed communication experiments with the "Artemis" using two of our satellites, the "Midori II (S-band and Ka-band)" and the "Kirari (S-band and laser beams)". We have been making big progress in one of the challenges facing space agencies around the globe, namely "Interoperability and mutual support".

Mt. Fuji taken by the ASAR
(Advanced Synthetic
Aperture Radar)
Hokkaido taken
by the MERIS
(MEdium Resolution Image

Experiments details and background
(in Japanese and English / PDF:45.3KB)

- Envisat
- Consolidated Space Tracking and Data Acquisition Department

Jan. 9, 2003 Updated
Kodama moved to the normal operation phase.

Kodama is expected to accumulate inter-satellite communication technology data by relaying communications between ground stations and satellites in low to middle altitude orbits (about 300 to 1,000 km), including Midori-II and Kibo, which will be launched in the future, during the 7-year operation phase of Kodama.

Sep. 17, 2002 Updated
"Kodama" completed its preparatory phase for initial functional verification

On Sep. 13 (Fri), the Data Relay Test Satellite "Kodama" launched at 5:20 p.m. on Sep. 10 (Japan Standard Time) was maneuvered to go into the drift orbit* whose altitude is approximately the same as the geostationary orbit by firing the apogee engine (the third apogee firing). The altitude of the satellite after the third firing, however, was lower than expected, thus it was further controlled on the 14th (Sat), and, consequently, "Kodama" was successfully placed into the scheduled orbit.
After being injected into the proper orbit, two antennas, the feeder link antenna for data communication with the ground stations, and the inter-satellite communication antenna for communication with spacecraft, were deployed and verified with data from a satellite on the 15th. The three-axis attitude stabilization** was also established on the 15th, and the satellite is now stabilized.

Photo : "Kodama"(DRTS) communication test (image)

Sep. 10, 2002 Updated
Nickname is "Kodama" (meaning an echo)

The National Space Development Agency of Japan (NASDA) launched the H-IIA Launch Vehicle No.3 (H-IIA F3) at 5:20 p.m. on September 10, 2002 (Japan Standard Time) from the Tanegashima Space Center. The H-IIA F3 was loaded with two payloads, the Data Relay Test Satellite (DRTS) and Unmanned Space Experiment Recovery System (USERS) Spacecraft. The launch vehicle was lifted off with its initial flight azimuth of 90 degrees.
Being released from the launch vehicle in 29 minutes and 36 seconds after liftoff, the Data Relay Test Satellite (DRTS) continued stable flight, and at 5:59 p.m. (Japan Standard Time), the Santiago Station at Chile University acquired the signal of DRTS. By the signal, it was confirmed that solar array paddles deployment and sun acquisition were successfully carried out as scheduled. At the Tsukuba Space Center, DRTS was officially named "Kodama" (meaning an echo) as it was confirmed that power supply for DRTS was secured through the solar array paddles.

Sep. 4, 2002 Updated
Data relay station in the space

DRTS of NASDA will become a data relay station in the space. It will relay real-time data transmission between the ground and satellites that cannot directly send data to the ground. This relay technology will allow to extend the time of real-time data transmission dramatically.
DRTS will be separated from the H-IIA Launch Vehicle No.3 (H-IIA F3) in about 30 minutes after the liftoff from the Tanegashima Space Center (TNSC) to be injected into the long elliptic orbit whose apogee height is about 36,000km and perigee height is about 450km. After being separated, DRTS will deploy its solar array paddles and repeatedly control the attitude and shift its orbit for about four days to go into the circular orbit at the altitude of 36,000km that is almost the geostationary orbit. Then DRTS will deploy its stowed "inter-satellite communication antenna" (about 3.6m in diameter) for communication with other spacecraft and the "feeder link antenna" (about 1.8m in diameter) for communication with the ground stations. At the same time, the attitude control mode will be switched to the normal operation mode to fix its on-orbit configuration.

The DRTS is being unloaded from a ship at Nishinoomote Port in Tanegashima Island.

Sep. 2, 2002 Updated
Loaded on top of the launch vehicle

The fairing that encapsulates payload of H-IIA Launch Vehicle No.3 was transported from the Spacecraft and Fairing Assembly Building (SFA) to the Vehicle Assembly Building to be loaded on top of the launch vehicle.
After loaded, two satellites, Data Relay Test Satellite (DRTS) and Unmanned Space Experiment Recovery System (USERS) Spacecraft are being electrically connected with H-IIA F3. The batteries of the payloads need to be continuously charged until the launch day. Their environment, such as temperature and humidity, is also monitored all times.

Photo : Payloads and fairing Loaded onto H-IIA F3

The DRTS is being unloaded from a ship at Nishinoomote Port in Tanegashima Island.

Aug. 22, 2002 Updated
DRTS and PAF mating

On Aug. 20 (Tue) and 21 (Wed), the Data Relay Test Satellite (DRTS) was mated with the Payload Attach Fitting (PAF) in the Spacecraft and Fairing Assembly Building (SFA) at the Tanegashima Space Center. The PAF is a mount to be loaded onto the launch vehicle, thus the mating operations were part of the fairing encapsulation and loading operation of the payload on top of the launch vehicle.
DRTS is 2.2m x 2.4m (width) x 2.2m (height) (main body only with antennas stowed) and 2,650kg in weight. For mating, DRTS was carefully and slowly hung by the special sling equipment on the ceiling and mated with the PAF. On the 22nd, the Data Relay Test Satellite (DRTS) attached was being covered by the lower fairing.

Photo : Lower fairing encapsulation for DRTS

Lower fairing encapsulation for DRTS

Jul. 27, 2002 Updated
DRTS Press release

DRTS, which is the first data relay satellite in Japan, is currently under launch preparation operations in the Spacecraft and Fairing Assembly Building (SFA) at the Tanegashima Space Center (TNSC).

Photo : DRTS Press release

DRTS Press release

Jun. 14, 2002 Updated

The DRTS is shipped to TNSC and preparation for launch starts.The DRTS (Data Relay Test Satellite) was carried into the Spacecraft Test and Assembly Building No.2 in Tanegashima Space Center on May 2, 2002. From now on, the launch site work proceeds to final checkout and launch configuration setup for the launch in this summer.

Photo : The DRTS is being unloaded from a ship at Nishinoomote Port in Tanegashima Island.

The DRTS is being unloaded from a ship at Nishinoomote Port in Tanegashima Island.

Feb. 13, 2002 Updated

The Proto Flight Test (PFT) for the Data Relay Test Satellite (DRTS) was completed as scheduled at the Tsukuba Space Center and the remaining tests are being conducted prior to delivery to the launch pad.
The delivery to the launch pad at Tanegashima Space Center is scheduled for early 2002.

Apr. 24, 2001 Updated
DRTS System Proto-flight Test

System Proto-Flight Test (PFT) for DRTS is continuously progressing. The Shock Test has finished so far, and quasi-propellant is currently discharged and dried. After finishing the coming alignment measurement, final electrical performance test, UPS (Unified Propulsion Subsystem) functional test and mass properties test will start.

Photo : Cherry Trees in Full Blossom of April 10 at Tsukuba Space Center

Mar. 27, 2001 Updated
System Proto-flight Test for DRTS Goes Well

In the series of the system proto-flight tests for DRTS, the system vibration test conducted from January to February 2001 has completed, and the shock test, which is to evaluate the endurance against the shock by pyrotechnics to separate the satellite from the rocket or to deploy the solar array paddles and antennas, is currently in operation.
Upon completion of the vibration test, the alignment measurement after mechanical environment test and the final electrical performance test will be the next phase.

Photo : Snow-clad Tsukuba Space Center of March 9, 2001

Nov. 17, 2000 Updated

We are now conducting Alignment measurement work from this month. The purpose of Alignment measurement is to confirm whether attitude system sensor that must meets precise requirements in its installment position and angle, and propulsive system thruster are installed correctly as required. After this work had finished, we will move on to mechanical environment tests such as acoustic test, vibration test, and shock test.

Photo : DRTS-W (PFM) halfway through the assembly

Aug. 25, 2000 Updated
Test Schedule for This Month

System Thermal Vaccum Test
System Thermal Vaccum Test is a test to confirm environment-resistant in vacuum or heat environment in outer space. We will conduct Heat Equilibrium Test during spring and autumn, and Electrical Performance Test for approximately one month, 24 hours non-stopping. The photo is beginning of the test, putting the satellite into 13m in diameter space chamber, and we watched the big door closing together.

Jul. 21, 2000 Updated
System Thermal Vacuum Test Began

System Thermal Vacuum Test has began from this month. We now are going to conduct several tests in vacuum environment that simulates launch/on-orbit environment for approximately one month and prepare for a launch.

Apr. 21, 2000 Updated

We have investigated Tanegashima Launch Site. In this month, DRTS project team conducted the research on facilities at Tanegashima Space Center, which the rocket to be launched and condition of these facilities. The research was conducted with an investigation committee of the satellite maker who is responsible for launch site operation, both going to Tanegashima Space Center to confirm facilities.
We confirm whether there would be any problem when the satellite actually carried in to Tanegashima Space Center by this research in advance.

Photo : H-IIA launch site. Taken at "Rocket Hill Observation Spot" in TNSC

Jan. 31, 2000 Updated
Main Tests Expected in January

Initial Electrical Performance Test
DRTS project had conducted the confirmation tests on EPS(Electric Power Subsystem), ACS(Attitude Control Subsystem), and UPS(Unified Propulsion Subsystem) etc. until last month.
From this month, we are going to continue to conduct the confirmation tests on ICE(Inter-orbit Communication Equipment), TTC(Telemetry Tracking and Command ), and others.

Dec. 17, 1999 Updated
DRTS - Main tests scheduled for December -

Initial electrical performance test
Unified Propulsion Subsystem function test
Apogee kick engine long duration Firing test
*From Jan. 2000, we will begin to prepare for thermal vacuum test.

Nov. 19, 1999 Updated
Our Main Tests Scheduled This Month

Initial Electrical Performance Test
Initial Electrical Performance Test is a test on the actual satellite as it assembled. The tests have been conducted on each parts (component or sub-system) until the last month, and tests on satellite (not on parts already) have been started on this month.

Photo : Scale Model (1:25)

Oct. 15, 1999 Updated
Our Main Tests Scheduled This Month

Telemetry Tracking and Command Subsystem Test
Inter-Satellite Communication Equipment (PFM) Bit Error Rate Evaluation Test
Solar Array Paddle Vibration/Deployment Test (Continuation)
We will conduct Initial Electrical Performance Test next month.

Sep. 24, 1999 Updated
Proto-flight test is underway!

Our main tests scheduled this month are as follows.
Solar Array Paddle Thermal Vacuum Test
Solar Array Paddle Deployment Test
Solar Array Paddle Vibration Test
Solar Array Paddle Mass Characteristic Test
Inter-Orbit Link Antenna Range Test
Others are also in progress smoothly.
(Photograph illustrates deployment condition of Solar Array Paddle)

Jul. 26, 1999 Updated
The Proto-flight Test Has Finally Begun

CDR (Critical Design Review) for the Data Relay Test Satellite (DRTS) is now finished and the system test is about to begin at the Tsukuba Space Center.
Now, we are almost there, till a date it to be launched. We will present various information regarding to DRTS from now on. Enjoy!
(Note: Picture is Structure & Thermal Model (STM))