STSAT-2B
Encyclopedia
STSAT-2B, or Science and Technology Satellite 2B, was a South Korea
n satellite
which was lost in the failure of the second flight of the Naro-1 carrier rocket
. It was to have been operated by the Korea Aerospace Research Institute
, and was intended to demonstrate technology for future spacecraft. The satellite had a mass of 100 kilograms (220.5 lb), and was expected to operate for at least two years.
STSAT-2B was originally intended to operate alongside a second spacecraft, STSAT-2A
; however STSAT-2A was lost in 2009 after the payload fairing of its carrier rocket failed to separate, leaving the rocket unable to achieve orbit.
of the Earth at 23.8 GHz and 37 GHz. The secondary payload, the Laser Retroreflector Array or LRA was to have been used for the Satellite Laser Ranging experiment, which was intended to determine the parameters of the satellite's orbit with a greater degree of precision. Data collected by the secondary payload would have been used to calibrate DREAM, to conduct geodetic
research, and to evaluate the performance of the carrier rocket. Due to lower manufacturing tolerance, the retroreflectors on STSAT-2B would have provided greater precision than those intended on STSAT-2A.
A series of technological experiments were also to have been conducted; investigating attitude control systems, and testing pulsed plasma thruster
s, star trackers, a Sun sensor, as well as an experimental onboard computer, and data relay at rates of up to 10 megabits per second.
The launch was initially scheduled to occur on 9 June 2010, during a two hour launch window
opening at 07:30 GMT (16:30 local time). Further launch attempts were available at the same time each day until 19 June 2010. The launch attempt on 9 June 2010 was scrubbed after the launch pad's fire suppression system activated for no apparent reason.
Following the scrub, the launch was rescheduled for the next day, and took place at 08:01 GMT (17:01 local time) on 10 June 2010. During the first stage burn, around 137 seconds into the flight, contact with the rocket was lost. South Korean science minister Ahn Byung-man later told reporters that the rocket was believed to have exploded. If the launch had been successful, STSAT-2B would have been deployed into an orbit with a perigee
of approximately 300 kilometres (186.4 mi), an apogee
of approximately 1500 kilometres (932.1 mi), and around 80 degrees of inclination
.
South Korea
The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...
n satellite
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....
which was lost in the failure of the second flight of the Naro-1 carrier rocket
Launch vehicle
In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....
. It was to have been operated by the Korea Aerospace Research Institute
Korea Aerospace Research Institute
The Korea Aerospace Research Institute is the aeronautics and space agency of South Korea. Its main laboratories are located in Daejeon, in the Daedeok Science Town. Current projects include the KSLV launcher. Past projects include the 1999 Arirang-1 satellite. The agency was founded in 1989...
, and was intended to demonstrate technology for future spacecraft. The satellite had a mass of 100 kilograms (220.5 lb), and was expected to operate for at least two years.
STSAT-2B was originally intended to operate alongside a second spacecraft, STSAT-2A
STSAT-2A
STSAT-2A was a satellite launched by the Korea Aerospace Research Institute , the national space agency of South Korea, from the Naro Space Center in Goheung County, South Jeolla using the Naro-1 rocket.The satellite carried a Lyman- alpha Imaging Solar Telescope as well as Satellite laser...
; however STSAT-2A was lost in 2009 after the payload fairing of its carrier rocket failed to separate, leaving the rocket unable to achieve orbit.
Instruments
The primary instrument aboard STSAT-2B was the Dual-channel Radiometer for Earth and Atmosphere Monitoring, or DREAM, which would have measured the brightness temperatureBrightness temperature
Brightness temperature is the temperature a black body in thermal equilibrium with its surroundings would have to be to duplicate the observed intensity of a grey body object at a frequency \nu....
of the Earth at 23.8 GHz and 37 GHz. The secondary payload, the Laser Retroreflector Array or LRA was to have been used for the Satellite Laser Ranging experiment, which was intended to determine the parameters of the satellite's orbit with a greater degree of precision. Data collected by the secondary payload would have been used to calibrate DREAM, to conduct geodetic
Geodesy
Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...
research, and to evaluate the performance of the carrier rocket. Due to lower manufacturing tolerance, the retroreflectors on STSAT-2B would have provided greater precision than those intended on STSAT-2A.
A series of technological experiments were also to have been conducted; investigating attitude control systems, and testing pulsed plasma thruster
Pulsed plasma thruster
Pulsed plasma thrusters are a method of spacecraft propulsion also known as Plasma Jet Engines in general. They use an arc of electric current adjacent to a solid propellant, to produce a quick and repeatable burst of impulse...
s, star trackers, a Sun sensor, as well as an experimental onboard computer, and data relay at rates of up to 10 megabits per second.
Launch
STSAT-2B was launched by a Naro-1 rocket, flying from the Naro Space Centre. The launch was the second flight of the Naro-1, which consisted of a modified Angara first stage manufactured by Khrunichev, and a South Korean solid-fuelled upper stage. The previous Naro-1 launch was that of STSAT-2A, which occurred in August 2009 and ended in failure.The launch was initially scheduled to occur on 9 June 2010, during a two hour launch window
Launch window
Launch window is a term used in spaceflight to describe a time period in which a particular launch vehicle must be launched. If the rocket does not launch within the "window", it has to wait for the next window....
opening at 07:30 GMT (16:30 local time). Further launch attempts were available at the same time each day until 19 June 2010. The launch attempt on 9 June 2010 was scrubbed after the launch pad's fire suppression system activated for no apparent reason.
Following the scrub, the launch was rescheduled for the next day, and took place at 08:01 GMT (17:01 local time) on 10 June 2010. During the first stage burn, around 137 seconds into the flight, contact with the rocket was lost. South Korean science minister Ahn Byung-man later told reporters that the rocket was believed to have exploded. If the launch had been successful, STSAT-2B would have been deployed into an orbit with a perigee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of approximately 300 kilometres (186.4 mi), an apogee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of approximately 1500 kilometres (932.1 mi), and around 80 degrees of inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
.