GSAT-4
Encyclopedia
GSAT-4, also known as HealthSat, was an experimental communication and navigation satellite
launched in April 2010 by the Indian Space Research Organisation
on the maiden flight of the Geosynchronous Satellite Launch Vehicle
Mk.II rocket. It failed to reach orbit after the rocket's third stage malfunctioned. The third stage was the first Indian-built cryogenic-fuelled
upper stage, and was making its first flight. The ISRO suspects that the failure was caused by the third stage not igniting.
, and a navigation payload in the C, L1, and L5 bands. Designed to guide civil and military aircraft, GSAT-4 was to have employed several new technologies such as a bus management unit, miniaturised dynamically tuned gyros, lithium-ion battery, 70 volt bus for Ka-band travelling-wave tube amplifiers, and electric propulsion. GSAT-4 also incorporated technological experiments like on-board structural dynamic experiment, thermal control coating experiment and vibration beam accelerometer. With a lift-off mass of about 2180 kilograms (4,806.1 lb), the spacecraft was to have generated a maximum of 2,760 W of power.
GSAT-4 was also to have been the first Indian spacecraft to employ ion propulsion. Four Hall effect thruster
s would have been used for north–south station keeping operations. Two types of Hall effect thrusters are developed by ISRO Satellite Centre (ISAC) and Liquid Propulsion Systems Centre (LPSC).
, or GAGAN, navigation payload. GSAT-4 was also intended to carry to the Israel
i TAUVEX-2
space telescope array. Due to concerns that the new upper stage may have reduced the rocket's payload capacity, ISRO decided to remove TAUVEX in order to decrease the mass of the payload. GAGAN was still flown.
GAGAN consisted of a Ka band bent pipe transponder and a regenerative transponder.
at the Satish Dhawan Space Centre
. Its third stage was fitted with a new Indian-built cryogenic engine, which was intended to make the GSLV reliant on only Indian technology, since earlier launches had used Russia
n engines. GSLV D3 was the sixth flight of the Geosynchronous Satellite Launch Vehicle
across all variants/
The rocket was 40.39 metres (132.5 ft) in length minus its payload fairing, and consisted of a solid-fuelled S139 first stage augmented by four L40 hypergolically-fuelled strapons, burning UH25 and N2O4 as fuel and oxidiser respectively. The second stage used the same hypergolic propellants, whilst the third stage was the new Cryogenic Upper Stage (CUS), burning liquid hydrogen
oxidised by liquid oxygen
.
The rocket's first and second stages performed normally, and at the time controllers reported that third stage ignition had occurred. However, shortly afterwards the rocket began to under-perform, tumbling out of control, and deviating from its planned trajectory. Around 300 seconds into the flight, contact with the rocket was lost. Initial analysis of the data suggested that the vernier thruster
s, used to provide attitude control
, had failed to ignite due to engineering problems. On 17 April, ISRO announced that further analysis of the data indicated that the third stage main engine had not ignited either. According to ISRO mission failed after the fuel turbo pump that supplied fuel to the cryogenic engine had stopped working a second after ignition.
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....
launched in April 2010 by the Indian Space Research Organisation
Indian Space Research Organisation
The Indian Space Research Organisation is an independent Indian governmental agency established in 1969 for the research and development of vehicles and activities for the exploration of space within and outside of Earth’s atmosphere. Headquartered in Bangalore...
on the maiden flight of the Geosynchronous Satellite Launch Vehicle
Geosynchronous Satellite Launch Vehicle
The Geosynchronous Satellite Launch Vehicle is an expendable launch system operated by the Indian Space Research Organisation...
Mk.II rocket. It failed to reach orbit after the rocket's third stage malfunctioned. The third stage was the first Indian-built cryogenic-fuelled
Cryogenic fuel
Cryogenic fuels are fuels that require storage at extremely low temperatures in order to maintain them in a liquid state. Cryogenic fuels most often constitute liquefied gases such as liquid hydrogen....
upper stage, and was making its first flight. The ISRO suspects that the failure was caused by the third stage not igniting.
Satellite
Weighing around two tons, GSAT-4 carried a multi-channel, Ka-band, bent pipe and regenerative transponderTransponder
In telecommunication, the term transponder has the following meanings:...
, and a navigation payload in the C, L1, and L5 bands. Designed to guide civil and military aircraft, GSAT-4 was to have employed several new technologies such as a bus management unit, miniaturised dynamically tuned gyros, lithium-ion battery, 70 volt bus for Ka-band travelling-wave tube amplifiers, and electric propulsion. GSAT-4 also incorporated technological experiments like on-board structural dynamic experiment, thermal control coating experiment and vibration beam accelerometer. With a lift-off mass of about 2180 kilograms (4,806.1 lb), the spacecraft was to have generated a maximum of 2,760 W of power.
GSAT-4 was also to have been the first Indian spacecraft to employ ion propulsion. Four Hall effect thruster
Hall effect thruster
In spacecraft propulsion, a Hall thruster is a type of ion thruster in which the propellant is accelerated by an electric field. Hall thrusters trap electrons in a magnetic field and then use the electrons to ionize propellant, efficiently accelerate the ions to produce thrust, and neutralize the...
s would have been used for north–south station keeping operations. Two types of Hall effect thrusters are developed by ISRO Satellite Centre (ISAC) and Liquid Propulsion Systems Centre (LPSC).
Secondary payloads
GSAT-4 carried the first GPS Aided Geo Augmented NavigationGPS Aided Geo Augmented Navigation
The GPS aided geo augmented navigation or GPS and geo-augmented navigation system is a planned implementation of a regional satellite-based augmentation system by the Indian government. It is a system to improve the accuracy of a GNSS receiver by providing reference signals.The Rs...
, or GAGAN, navigation payload. GSAT-4 was also intended to carry to the Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
i TAUVEX-2
TAUVEX
The Tel Aviv University Ultraviolet Explorer, or TAUVEX, is a space telescope array designed and constructed in Israel for Tel Aviv University by El-Op, Electro-Optical Industries, Ltd. acting as Prime Contractor, for the exploration of the ultraviolet sky...
space telescope array. Due to concerns that the new upper stage may have reduced the rocket's payload capacity, ISRO decided to remove TAUVEX in order to decrease the mass of the payload. GAGAN was still flown.
GAGAN consisted of a Ka band bent pipe transponder and a regenerative transponder.
Launch
GSAT-4 was launched on the maiden flight of the GSLV Mk.II rocket, GSLV D3, flying from the Second Launch PadSatish Dhawan Space Centre Second Launch Pad
The Second Launch Pad of the Satish Dhawan Space Centre is a rocket launch site in Sriharikota, India. It is the second of two launch pads at the centre, the other being the First Launch Pad...
at the Satish Dhawan Space Centre
Satish Dhawan Space Centre
The Satish Dhawan Space Centre is the launch centre for the Indian Space Research Organisation . It is located in Sriharikota, Andhra Pradesh, India, north of Chennai in South India. It was originally called Sriharikota High Altitude Range , and was sometime known as Sriharikota Launching Range...
. Its third stage was fitted with a new Indian-built cryogenic engine, which was intended to make the GSLV reliant on only Indian technology, since earlier launches had used Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n engines. GSLV D3 was the sixth flight of the Geosynchronous Satellite Launch Vehicle
Geosynchronous Satellite Launch Vehicle
The Geosynchronous Satellite Launch Vehicle is an expendable launch system operated by the Indian Space Research Organisation...
across all variants/
The rocket was 40.39 metres (132.5 ft) in length minus its payload fairing, and consisted of a solid-fuelled S139 first stage augmented by four L40 hypergolically-fuelled strapons, burning UH25 and N2O4 as fuel and oxidiser respectively. The second stage used the same hypergolic propellants, whilst the third stage was the new Cryogenic Upper Stage (CUS), burning liquid hydrogen
Liquid hydrogen
Liquid hydrogen is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecular H2 form.To exist as a liquid, H2 must be pressurized above and cooled below hydrogen's Critical point. However, for hydrogen to be in a full liquid state without boiling off, it needs to be...
oxidised by liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
.
The rocket's first and second stages performed normally, and at the time controllers reported that third stage ignition had occurred. However, shortly afterwards the rocket began to under-perform, tumbling out of control, and deviating from its planned trajectory. Around 300 seconds into the flight, contact with the rocket was lost. Initial analysis of the data suggested that the vernier thruster
Vernier thruster
A vernier thruster is a thruster used on a spacecraft for attitude control. It is a smaller thrust motor than main attitude control motors and is used for fine adjustments to the attitude or velocity of a spacecraft...
s, used to provide attitude control
Attitude dynamics and control
Spacecraft flight dynamics is the science of space vehicle performance, stability, and control. It requires analysis of the six degrees of freedom of the vehicle's flight, which are similar to those of aircraft: translation in three dimensional axes; and its orientation about the vehicle's center...
, had failed to ignite due to engineering problems. On 17 April, ISRO announced that further analysis of the data indicated that the third stage main engine had not ignited either. According to ISRO mission failed after the fuel turbo pump that supplied fuel to the cryogenic engine had stopped working a second after ignition.
External links
- "GSLV-D3". Indian Space Research Organisation. Retrieved 22 October 2011.