Spaceport of India - ISRO’s Rocket Launching Facility at Sriharikota

An important road trip that we undertook from Chennai was to the Satish Dhawan Space Center (SDSC) where the Indian Space Research Organization (ISRO) has the Sriharikota High Altitude Range (SHAR) rocket launching center. This was an exciting trip where we traveled out of this world, literally, as we glanced past the amazing set-up where space vehicles are assembled and launched for their journey into outer space. We left our home at about 8 in the morning of December 23rd, 2015. What excited us was not only this rare opportunity to observe the rocket launching facility from close quarters but also the scenic journey to the SHAR campus.

The Journey to ISRO's Rocket Launching Center

SHAR campus is situated on an island in the Bay of Bengal with strategic purposes of avoiding civilian contact, securing the facilities, and exploiting supportive weather conditions. The island is connected to the mainland by a narrow long road that takes you through the Pulicat Lake and Bird Sanctuary on the way. This sanctuary is famous as the habitat of cranes during the season we visited. The Pulicat sanctuary is drained by the Arni River while the Buckingham Canal brings in the city’s drainage water. At the southern end is an opening onto the Bay of Bengal through a shallow mouth of 200 m in width. The rest of the lake is closed by a sand bar running parallel to the Bay of Bengal in the form of Sriharikota Island. 

Marsh Lands on Way to ISRO Facility

Cranes Visiting the Region

We were at the entry of this narrow road after about 3 hours of a drive during which we passed through the dam on Red Hills and crossed the Kalinga River on the National Highway connecting Chennai with Kolkata. It was only after crossing the Sriharikota town that we found ourselves cruising on a road, long and narrow, with water bodies on both sides. The water at times would get along with land to create marshlands where specific vegetation thrived. 

It was not long after the town that we saw birds of various forms and nature. Among the most spectacular was the flamingo, a tall gaunt, white-colored bird with a touch of pink on the wings, pink beak, and legs, seen feeding in shallow water. The squat, large-billed gray pelican with a gular pouch was another interesting attraction. Flocks of seagulls and terns circling in the sky or bobbing up and down on the water added to the beauty of the scene. We spent some time there admiring the rich fauna and beauty of the entire set-up. After about another hour of the journey, we were there at the entry checkpost of the elite ISRO facility – Satish Dhawan Space Center, or what we call ISRO's rocket Launching Center.

The Drive to ISRO's Rocket Launching Center

An Introduction to the Launching Center

The Entrance to ISRO's Rocket Launching Center

SDSC is a strategically important establishment of ISRO where PSLV and GSLV-based launch vehicles are assembled and launched. The center also caters to the preparation of solid propellant stage for the launch vehicles. The center has two launch pads to cater to rocket launching operations supported by a world-class mission control center. It has the necessary infrastructure for launching satellites into the low earth, polar, and geostationary transfer orbits. The launch complexes provide complete support for vehicle assembly, fueling, checkout, and launch operations. Apart from these, it also has facilities for launching sounding rockets meant for studying the earth's atmosphere. 

The center has gained importance in recent times as ISRO has started providing services to other countries. ISRO has until now launched over 50 satellites into space, both for domestic and international clients. The success of this center is elucidated by the heavy demand that this facility has witnessed. The launch frequency has doubled up in 4-5 years from one in 40 days to one in 20 days. The facility is launching one vehicle every month on average. This has led to pressure on resources and the two launch pads are now almost always under operation with limited downtime available post-launch. The demand is so high that the operation cannot even rest during rain and a specially designed system allows super-quick drainage of water. 

The facility has its own metrological department to monitor weather conditions. The campus houses many observation decks to monitor launch operations. There is also the deepest penetrating radar in India called Mobile Object Tracking Radar – MOTR. This has over 100 kilometers of range and ensures that the path of the launch vehicle is clear from disturbances.

Taking you on a Journey to the Rocket Launching Center

The Map of the Rocket Launching Center

The First Launch Pad - Building That Moves Out

Immediately after breakfast, we proceeded to our first point of interest – The First Launch Pad. The design of this launchpad is based on the concept of a Mobile Service Tower (MST) where the assembly building is a movable tower that travels on special rails and places itself next to the launch vehicle during its assembly. Heavy motors are used for the movement of MST over the 200-meter track. The 3450-ton building moves at a speed of about 7 meters per minute using four 8-wheeled bogies. 

It was a Family Trip to ISRO

The integration and assembly of the launch vehicle are a time-consuming affair and hence, the MST is designed to protect the launch vehicle during the entire process. The design, made in 1980, provides this 76-meter building with 16 fixed platforms and large protective doors allowing it to cover the launch vehicle during assembly. We visited the launch pedestal which has a centrally located angular structure used to hold the rocket. The steel structure is refurbished with silicon-based rubber insulation as bare steel with a melting temperature of 1500 Degrees Celsius cannot withstand a launch flame of 3000 Degrees Celsius. The insulation has been designed in-house by ISRO’s chemical engineers.

As soon as the launch is complete, water jets are used to cool the platform to prevent any long-term damage to the structure. All the equipment used within the MST is flameproof including a landline phone device which costs over 1.5 Lakh. The entire assembly crew is required to wear special clothing, when on work. Additionally, there are four 120-meter-high lightning towers to protect the vehicle from any damage during thunderstorms. 

Keys to Rocket Launcher ....Ha Ha No Way!

There is a mobile tower located about 100 meters from the MST to facilitate communication during assembly. This is an ambulatory tower and is relocated during launches. During a launch, 4 hours prior to actual launch time (T-4), complete evacuation from the launch pad (LP) area is ensured to prevent any loss of life. This launch pad is specially designed for four-stage PSLV launches. The design of a stage PSLV includes a satellite on top with a solid propellant stage below it, which takes 105 seconds to burn. 

The satellites are manufactured/assembled at ISRO’s Bangalore facility while the first stage is prepared at the SHAR facility itself. The next stage is liquid propellant, filled in after assembly during the countdown because of its hazardous nature. There is a mechanism that separates each stage once the fuel of the stage is exhausted, based on the height achieved by the vehicle. The liquid stage comes from Mahendragiri in Tamil Nadu, a small city near Kanyakumari.

The Second Launch Pad - The Rocket Moves Out

After covering the First Launch Pad, we proceeded towards the Second Launch Pad which is an engineering marvel in itself. This launch pad was dedicated to the nation by the Missile Man – Dr. APJ Abdul Kalam himself. It is different from the first one in its basic design itself. At the first launch pad, the vehicle assembly building moves to the assembly and umbilical tower where the vehicle remains fixed. However, at the second launch pad, the assembly building is fixed and the vehicle moves on a mobile platform.

Posing at the ISRO Campus

We had the pleasure of witnessing a live assembly during our trip. There are specially designed bogies where the assembly of the entire launch vehicle takes place. The base structure is placed on the bogie and it is then moved into the assembly building through huge gates. Here, the entire assembly of the vehicle takes place where the fuel units and other components are put together to complete the vehicle. The assembly building is about 100 m high and is capable of assembling a launch vehicle of about 40 m height. 

All the assembly takes place while the vehicle is mounted on the bogie. There are platforms at various levels in the assembly building that can be moved (vertically) to adjust according to the requirements of the launch vehicle and mission objectives. This is another difference from the first launch pad where the platform levels were fixed. Once the assembly is completed, the bogie takes the vehicle to the umbilical tower or UL where it is readied for launch. 

While we were there, the crew was busy preparing a PSLV for launch. This particular vehicle was developed by Mencken for ISRO and was designed to place the fifth IRNSS satellite in space. This would strengthen the capability of our in-house GPS system – Read More at IRNSS Programme. Once the entire assembly is completed the vehicle is moved to the launch area and set up within the umbilical tower. The Mobile Launch Pad or MLP is used for this purpose.

The Launch Facility for the Second Launch Pad

Once we completed our tour of the assembly building for the 2nd Launch Pad, we went ahead to explore the launch facility. The platform is capable of launching both GSLV and PSLV-based vehicles. An elevator takes you to a height of 18 meters where metaled platforms provide an exciting site to base on. The entire view consists of machinery, wires, and tubes. There are four umbilical towers that run in to feed the vehicle with necessary inputs – Propellant (which includes fuel and oxidizer), Gas (through motor turbine operations to generate pressure for ignition), cooling agent, and electronic connections. There is a special water storage to support the acoustic suppression mechanism. Another ride in the elevator takes you to 70 meters height, which is the crane level – a 10-ton crane is based on this level.

Facilities at the SHAR Campus

The Nerve Center or Launch Control Center

The next spot on our tour of this marvelous ISRO facility was a plant-shaped building built strategically to allow a clear line-of-sight view of the launch pads, which are about 5 kilometers from here. This building is a nerve center of operations related to any satellite launch and is connected to both the launch pads through communication links which are protected by heavy concrete structures, designed to withstand launch impact. It houses the Launch Control Center (LCC) and Mission Control Center (MCC). 

LCC handles the initial preparation and facilitation of launch and controls fueling, testing, and verification of the launch vehicle. Once the vehicle is ready for launch and has been fueled in, control is transferred to the MCC. MCC is responsible for managing the launch and flight path until 25 minutes post-launch. Directors sit in the last row of the center with the exception of the TTC director who sits a row ahead and is charged with the responsibility of monitoring weather and telemetry.

A Glimpse of Space Museum

ISRO has established multiple monitoring stations around the world to capture real-time weather and other relevant parameters and avoid communication delays. The SHAR center also has its own metrological unit which gives real-time weather updates. Prelaunch special balloons with sensors are sent into the atmosphere to gather temperature, wind speed, and other weather parameters to assess if weather conditions are apt for a launch.

The Count Down - 10...9...8...7...

The countdown starts 50 hours before a launch (T-50hr). This is the time when LCC springs into action and begins the preparation of the vehicle for launch. An hour before the launch (T-1hr) the control of the vehicle is transferred to the MCC where a well-choreographed process manages the launch operations. A half hour before the launch (T-1/2 hour), a readiness signal is given out by 6 radars spread throughout the campus. 

Once everything is apt for the launch, final launch authorization is given at T-17 minutes post which an automated sequence of events takes place. Post authorization, the entire module is handled by computers powered by artificial intelligence. Once the launch is successful and the vehicle maintains the correct path for 25 minutes, the control is transferred to the Satellite Control Center (SCC) in Bangalore where the satellite is monitored continuously. 

Once the launch is over the launch area is kept out of bounds based on the launch platform. For GSLVs, the crew is allowed in the launch arm only after a day while for PSLVs, the security team analyzes the pollution level from one hour after launch, and the crew is only allowed in once the pollution dips past the acceptable levels.

Space Museum Entrance

The Top Notch Security 

One would assume that this definitely is a critical facility for the strategic interests of India and hence security provisions for the SHAR center need to be top-notch. CISF has the responsibility of securing the campus from the very start. The current strength of security personnel is 1000 and there are over 12 watch towers across campus for CISF to monitor the area. Night and day-specific binoculars and goggles are used by the personnel.

Security personnel for the establishment are sourced from across the country to prevent collusion and sabotage. Special surveillance equipment to monitor any breach through surrounding waterbodies has been set up. The location itself has been chosen strategically as an island is dedicated to ISRO operations and no unauthorized person is allowed. Shores are easier to monitor than land and hence the island.

At the end of the visit, we also visited the Space Museum maintained by ISRO. It brings together interesting memorabilia from the past, various spacecraft designs, and a gamut of useful information. After covering this last spot we bid goodbye to the staff at the center and left the campus for our way back towards home. We were back in the nest by 5 in the evening and readied for our train later in the night to proceed to the next destination – Queen of Hills: Ooty !!

Few Additional Glimpses

Posing in the Space Museum