ETS-VII
Encyclopedia
The ETS-VII, or Engineering Test Satellite No. 7, was a satellite
developed and launched by the National Space Development Agency of Japan
(NASDA). It is also known as KIKU-7. It was launched aboard an H-II rocket
from Tanegashima Space Center
, on 28 November 1997. The ETS-VII was equipped with a 2 metre long robotic arm
, which was used to carry out several experiments related to rendezvous docking
and space robotics. It was the world’s first satellite to be equipped with a robotic arm, and also the first unmanned spacecraft
to conduct autonomous rendezvous docking operations successfully. Although it was originally intended to be used for 1.5 years, the satellite was functional for a period of almost five years.
. A 2 m long robotic arm was attached to this part. The smaller target satellite was named Orihime. The box shaped, complete satellite system weighed 2,860 kg. The ETS-VII was equipped with three solar panels, with two on the chaser satellite and one on the target satellite. The satellite was assisted by relative global positioning system
(RGPS) navigation.
on 28 November 1997. The launching took place at the Tanegashima Space Centre in Japan. The orbit of the ETS-VII was at an altitude of 550 km, with an inclination of 35 degrees.
The ETS-VII was built with an intended mission life of 1.5 years, with the mission to be ended in May 1999. However, in March 1999, it was decided to carry out operations for an additional six months because the satellite was in good condition. The last experiment carried out with the ETS-VII was ended on 16 December 1999. All the planned experiments had been carried out by this time, but the satellite was monitored to evaluate its durability. On 30 October 2002, the operating of the ETS-VII was terminated.
NASDA had invited research institutes in Japan and other countries to conduct joint experiments with the ETS-VII. As a result, joint experiments were conducted with organizations such as the European Space Agency
(ESA).
operations were carried out with the ETS-VII, which involved placing the target satellite 200 mm away from the chaser and using the robot arm to retrieve and hold it in place. Several other experiments were also carried out with the satellite’s robotic components. Most of the robot experiments were successfully completed by March 1999, and target satellite handling experiments were carried out in May 1999.
An error occurred during the second rendezvous docking operation which was carried out in August 1998. The troubleshooting
to identify this error was done in early March 1999. All previously planned robot experiments were completed by the end of March. Additional experiments were planned and carried out later.
The final rendezvous docking operation was successfully completed on 27 October 1999. The satellite’s final robot experiment was carried out on 29 November. Satellite checkout was conducted as the last experimental operation on 15 and 16 December, concluding all operations carried out by the ETS-VII project team.
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
developed and launched by the National Space Development Agency of Japan
National Space Development Agency of Japan
of Japan, or NASDA, was a Japanese national space agency established on October 1, 1969 under the National Space Development Agency Law only for peaceful purposes...
(NASDA). It is also known as KIKU-7. It was launched aboard an H-II rocket
H-II
The H-II rocket was a Japanese satellite launch system, which flew seven times between 1994 and 1999, with five successes. It was developed by NASDA in order to give Japan a capability to launch larger satellites in the 1990s. It was the first two-stage liquid-fuelled rocket Japan made using only...
from Tanegashima Space Center
Tanegashima Space Center
The is one of Japan's space development facilities. It is located on Tanegashima, an island located 115 km south of Kyūshū. It was established in 1969 when the National Space Development Agency of Japan was formed...
, on 28 November 1997. The ETS-VII was equipped with a 2 metre long robotic arm
Robotic arm
A mechanical arm is a robotic, usually programmable, with similar functions to a human arm. The links of such a manipulator are connected by joints allowing either rotational motion or translational displacement. The links of the manipulator can be considered to form a kinematic chain...
, which was used to carry out several experiments related to rendezvous docking
Space rendezvous
A space rendezvous is an orbital maneuver during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance . Rendezvous requires a precise match of the orbital velocities of the two spacecraft, allowing them to remain at a constant...
and space robotics. It was the world’s first satellite to be equipped with a robotic arm, and also the first unmanned spacecraft
Unmanned spacecraft
Unmanned spacecraft are spacecraft without people on board, and probably includes unmanned resupply spacecraft, space probes, and most space observatories. A difference between robotic spacecraft and unmanned spacecraft, is that unmanned spacecraft is inclusive to non-robotic unmanned spacecraft,...
to conduct autonomous rendezvous docking operations successfully. Although it was originally intended to be used for 1.5 years, the satellite was functional for a period of almost five years.
Features
The ETS-VII consists of two main parts; the chaser satellite and the target satellite. The chaser satellite is the main satellite body, and was named HikoboshiHikoboshi
is the Japanese name for the star Altair, also known as or in Japanese.It also refers to:* the cowherd celebrated in the Chinese star festival, Qi Xi.* the cowherd celebrated in the Japanese star festival, Tanabata influenced by Qi Xi...
. A 2 m long robotic arm was attached to this part. The smaller target satellite was named Orihime. The box shaped, complete satellite system weighed 2,860 kg. The ETS-VII was equipped with three solar panels, with two on the chaser satellite and one on the target satellite. The satellite was assisted by relative global positioning system
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
(RGPS) navigation.
Functioning
The satellite was launched using an H-II rocketH-II
The H-II rocket was a Japanese satellite launch system, which flew seven times between 1994 and 1999, with five successes. It was developed by NASDA in order to give Japan a capability to launch larger satellites in the 1990s. It was the first two-stage liquid-fuelled rocket Japan made using only...
on 28 November 1997. The launching took place at the Tanegashima Space Centre in Japan. The orbit of the ETS-VII was at an altitude of 550 km, with an inclination of 35 degrees.
The ETS-VII was built with an intended mission life of 1.5 years, with the mission to be ended in May 1999. However, in March 1999, it was decided to carry out operations for an additional six months because the satellite was in good condition. The last experiment carried out with the ETS-VII was ended on 16 December 1999. All the planned experiments had been carried out by this time, but the satellite was monitored to evaluate its durability. On 30 October 2002, the operating of the ETS-VII was terminated.
NASDA had invited research institutes in Japan and other countries to conduct joint experiments with the ETS-VII. As a result, joint experiments were conducted with organizations such as the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...
(ESA).
Experiments
Three rendezvous dockingSpace rendezvous
A space rendezvous is an orbital maneuver during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance . Rendezvous requires a precise match of the orbital velocities of the two spacecraft, allowing them to remain at a constant...
operations were carried out with the ETS-VII, which involved placing the target satellite 200 mm away from the chaser and using the robot arm to retrieve and hold it in place. Several other experiments were also carried out with the satellite’s robotic components. Most of the robot experiments were successfully completed by March 1999, and target satellite handling experiments were carried out in May 1999.
An error occurred during the second rendezvous docking operation which was carried out in August 1998. The troubleshooting
Troubleshooting
Troubleshooting is a form of problem solving, often applied to repair failed products or processes. It is a logical, systematic search for the source of a problem so that it can be solved, and so the product or process can be made operational again. Troubleshooting is needed to develop and...
to identify this error was done in early March 1999. All previously planned robot experiments were completed by the end of March. Additional experiments were planned and carried out later.
The final rendezvous docking operation was successfully completed on 27 October 1999. The satellite’s final robot experiment was carried out on 29 November. Satellite checkout was conducted as the last experimental operation on 15 and 16 December, concluding all operations carried out by the ETS-VII project team.