India’s GSLV Mark III rocket successfully made its first all-up launch and first attempt to reach orbit Monday in a late afternoon liftoff from the Satish Dhawan Space Centre. The launch was on schedule at 17:28 local time (11:58 UTC), with the mission tasked with lofting the GSAT-19 satellite.
The first orbital launch of India’s Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk.III) marked a milestone in India’s space program, with the more powerful rocket allowing the Indian Space Research Organisation (ISRO) to begin launching heavier payloads aboard its own vehicles – both for spaceflight applications such as communications and in support of the country’s nascent manned space program.
Monday’s launch came two and a half years after the GSLV Mark III’s maiden flight, a successful suborbital test for which only the rocket’s lower stages were live. The test flight, conducted on 18 December 2014, carried a prototype crew capsule and also served to validate the rocket’s design and demonstrate the stage performance and operation of the rocket’s solid-fuel first stage and liquid-fuelled second stage.
As a result of the test flight, ISRO has refined the GSLV Mk.III’s design. The nose cones of the vehicle’s two large solid rocket motors now taper towards the core and the rocket will fly with an ogive-shaped payload fairing instead of the more cylindrical fairing that was used on the 2014 launch.
GSLV Mk.III, which ISRO has also previously referred to as LVM3 – although that name now seems to have been phased out – marks the beginning of a third generation of rockets for India’s orbital launch capabilities.
India made its first orbital launch in July 1980, with a four-stage Satellite Launch Vehicle (SLV) rocket orbiting the Rohini, or RS-1, satellite. This was India’s second launch attempt – a previous launch in August 1979 failed after the thrust vectoring system on the second stage malfunctioned. Following the RS-1 launch, SLV made two further launches, with one failure and one success.
The SLV was a small vehicle, with a relatively low payload capacity of around 40 kilograms (90 lb). In order to allow heavier payloads to be launched, ISRO developed the SLV into the five-stage Augmented Satellite Launch Vehicle (ASLV). This added two solid rocket motors – based on the SLV’s first stage – to the sides of the rocket, burning as the first stage of the new vehicle. The modified SLV served as the second to fifth stages of the ASLV.
In four launches between March 1987 and May 1994, the ASLV achieved two failures, one partial failure and completed one mission successfully.
Instead of continuing to invest in the ASLV, India opted to develop a new generation of larger rockets. The new Polar Satellite Launch Vehicle (PSLV) first flew in September 1993. Despite the failure of its maiden flight, and a partial failure on its first operational launch four years later, the PSLV has become the workhorse of India’s space program. It has made thirty-nine launches to date, including the deployments of the Chandrayaan 1 lunar probe and the Mars Orbiter Mission.
The PSLV forms the basis for ISRO’s Geosynchronous Satellite Launch Vehicle, in its Mark I and Mark II configurations. GSLV replaces the PSLV’s solid rocket boosters with larger liquid boosters, and the PSLV’s third and fourth stages with a single cryogenic upper stage. The Mark I GSLV used a stage developed between India and Russia, powered by a Russian KVD-1M engine. The Mark II vehicle replaced this with an all-Indian stage and engine.
First flown in April 2001, the GSLV initially struggled for reliability. The rocket’s maiden flight failed, although the second and third launches successfully deployed their payloads. Beginning with its fourth launch, in July 2006, the rocket entered a run of four consecutive launches without success – with one delivering its payload to a lower-than-planned orbit and three falling short of orbit altogether. Since January 2014 the GSLV Mk.II has posted four consecutive successful launches.
Despite sharing a name with its predecessors, the GSLV Mk.III is a completely new vehicle to the Mk.I and Mk.II. The Mark III is a three-stage rocket, with a first stage comprised of two solid rocket motors mounted on either side of a liquid-fuelled core, containing two stages.
GSLV Mark III launches take place from the Second Launch Pad (SLP) at the Satish Dhawan Space Centre – a launch complex which is shared with the PSLV and the GSLV Mark II. In preparation for Monday’s launch the rocket, designated GSLV Mk.III D1, was stacked atop a mobile launch pedestal in the complex’s Vehicle Assembly Building. The assembled rocket was then rolled out to the launch pad a few days in advance of liftoff.
The Second Launch Pad, along with the nearby First Launch Pad (FLP) have been used for all of India’s orbital launches since the ASLV was retired. SLV and ASLV launches took place from older pads, to the South of the active launch complexes. The First Launch Pad is used mostly for PSLV launches. Since the Second Launch Pad was completed in 2005, it has been used for all GSLV launches.
Monday’s launch was the twenty-first from the Second pad.
The Satish Dhawan Space Centre is named after former ISRO chairman Satish Dhawan. Prior to Dhawan’s death in 2002, the facility was named the Sriharikota High Altitude Range (SHAR). The launch site – located on the island of Sriharikota on India’s east coast, just north of Chennai – has been used for all of India’s orbital launches.
The two S200 motors that make up GSLV Mk.III’s first stage are 26.2 meters (86.0 feet) long with a diameter of 3.2 meters (10 feet).
Each S200 contains 205 tons (202 imperial tons, 226 US tons) of solid propellant, which is composed of ammonium perchlorate, aluminum and hydroxyl-terminated polybutadiene (HTPB).
First stage ignition occurred at liftoff, beginning a 140-second burn. After lifting off, GSLV flew downrange along an azimuth of 107 degrees.
About 114 seconds after liftoff, the rocket’s second stage – the lower stage of the core vehicle – ignited. This is an L110, powered by a pair of Vikas engines. The Vikas is a license-built version of the French Viking rocket engine, which powered Europe’s Ariane 1, 2, 3 and 4 rockets between 1979 and 2004.
India has previously used Vikas aboard PSLV and GSLV rockets. The second stage burns unsymmetrical dimethylhydrazine (UDMH) propellant, oxidized by dinitrogen tetroxide. First stage burnout and separation occurred twenty-six seconds after second stage ignition.
At staging, GSLV Mk.III D1 was at an altitude of around 62 kilometers (39 miles, 33 nautical miles), traveling downrange at a speed of 1.95 kilometers per second (4,360 mph). At around three minutes and 45 seconds mission elapsed time, with the rocket at an altitude of about 116 kilometers (72 miles, 63 nautical miles), the payload fairing separated from around GSAT-19 at the nose of the rocket.
The second stage burned for three minutes and twenty-three seconds, shutting down five minutes and 17 seconds after liftoff. The spent stage was jettisoned three seconds later, with third stage ignition two seconds after separation. This began a ten-minute, 43-second burn for the C25 second stage. Powered by an Indian CE20 cryogenic rocket engine, the C25 burns liquid hydrogen oxidized by liquid oxygen.
When the third stage shut down sixteen minutes and five seconds after liftoff, GSLV Mk.III D1 was in a geosynchronous transfer orbit with a perigee of 170 kilometers (106 miles, 91.8 nautical miles), an apogee of 35,975 kilometers (22,354 miles, 19,425 nautical miles) and inclination of 21.5 degrees. GSAT-19 will separate from the rocket fifteen seconds after cutoff.
The 3,136-kilogram (6,914 lb) GSAT-19 is the heaviest satellite India has ever launched, to any orbit, using its own rockets. More than half of the satellite’s mass is propellant, much of which will be expended during initial orbit-raising, when the satellite will maneuver from its initial transfer orbit into an operational geostationary orbit. A liquid apogee motor, generating 440 Newtons (99 pounds-force) of thrust, will be used for this purpose. The satellite has a dry mass of 1,394 kilograms (3,073 lb).
GSAT-19 was built by ISRO and is based on the three-axis-stabilised I-3K satellite bus. It carries four Ku/Ka band forward link transponders and four return link transponders.
The spacecraft’s mission is primarily technology demonstration, serving to test new systems in geostationary orbit for use on future Indian communications satellites. Technologies to be tested include more miniaturized forms of heat pipe intended to provide better thermal control, micro electromechanical (MEMS) accelerometers and fiber optic gyroscopes to help determine the attitude of the satellite.
Also aboard GSAT-19 is the Geostationary Radiation Spectrometer (GRASP), which will detect and study charged particles in the satellite’s environment. This will help to characterize the effect of these particles on the satellite and its electrical systems. GSAT-19 will initially be stationed at a longitude of 74 degrees East.
The GSAT-19 spacecraft has a design life of ten years. The satellite is powered by a pair of solar arrays capable of generating 4.5 kilowatts of electrical power, and is also equipped with an Indian-manufactured lithium-ion battery which can store 100 amp-hours of energy for subsequent use.
Monday’s launch was the third of the year for India, following a PSLV launch in February which deployed the Cartosat-2D military imaging satellite along with 103 other spacecraft, and May’s GSLV Mk.II flight with the GSAT-9 satellite aboard. India’s next launch is expected around the end of this month, with a PSLV carrying another Cartosat spacecraft into orbit. The GSLV Mk.III’s next launch will carry India’s GSAT-20 communications satellite – this is currently scheduled for no earlier than December, or more likely early 2018.
(Images via ISRO).