Chandrayaan 2: The mission has entered its last leg, with the countdown for the mission is scheduled to start at 6.51am Sunday (July 14) after the full dress rehearsal (FDR) of the spacecraft and launch rehearsals that have been completed.
Chandrayaan 2 Launch: India has its eyes set on the moon, yet again. This time it is Chandrayaan 2. The Rs 978-crore Chandrayaan-2 mission is India’s first attempt to soft-land on the Moon. The mission has entered its last leg, with the countdown for the mission is scheduled to start at 6.51am Sunday (July 14) after the full dress rehearsal (FDR) of the spacecraft and launch rehearsals that have been completed.
Understandably there is excitement and nervousness writ large on the faces. For scientists at the Indian Space Research Organisation (ISRO) Telemetry, Tracking and Command (ISTRAC) are spending tense moments preparing for the launch soon.
The full dress rehearsal (FDR) of the spacecraft has already taken place this week when all the links from the Lander (Vikram) and the Orbiter was checked.
What followed were preparations by ISRO for the launch rehearsals—simulations at the launch pad in Sriharikota—which involved ‘dummy’ commands sent to see how the systems respond. All the signals and communication links were tested during the rehearsal.
Now, the sequence of events will include a series of tests, including checks on the health of the Orbiter and Vikram, the launch vehicle (Geosynchronous Satellite Launch Vehicle-MkIII) systems, and others.
In the earlier two big missions before this included —the Chandrayaan-1 and Mars Orbiter Mission (MOM) and ISRO had launched using the Polar Satellite Launch Vehicle (PSLV) class of launch vehicles, however, for this launch it will be using India’s heaviest rocket so far.
Though the launch of Chandrayaan-2 is going to be on the heaviest rockets, the scientists at ISRO have their fingers crossed as this is the only the second operational launch of GSLV-MkIII.
The PSLV is the go-to launch vehicle and has proven itself over the years and has a great track record. Despite the rehearsals the scientists at ISRO are on tenterhooks as the GSLV programme, has had a chequered past and a lot will depend on how this launch vehicle behaves.
ISRO Chairman K Sivan and other senior scientists from the space agency have been reiterating the capabilities of GSLV during various interactions with the media.
However, this is going to be a huge test for GSLV as it is scheduled to carry India’s first crew to space as part of Gaganyaan.
What is the difference between PSLV and GSLV?
Both PSLV (Polar Satellite Launch Vehicle) and GSLV (Geosynchronous Satellite Launch Vehicle) are satellite-launch vehicles –rockets and have been developed by ISRO.
The PSLV is designed mainly to deliver the “earth-observation” or “remote-sensing” satellites.
And orbits the earth from pole-to-pole.
These orbits are often referred to as “Low Earth Orbit (LEO)”. This enables the onboard camera to take images of the earth.
This is also used to launch the satellites of lower lift-off mass of up to about 1400 Kg to the elliptical Geosynchronous Transfer Orbit (GTO).
This is a four-staged launch vehicle with first and third stage using solid rocket motors and second and fourth stages using liquid rocket engines.
It also uses strap-on motors which help in augmenting the thrust provided by the first stage.
Depending on the number of these strap-on boosters, the PSLV is classified into its various versions like core-alone version (PSLV-CA), PSLV-G or PSLV-XL variants.
According to the design of the GSLV, it is meant to mainly deliver the communication-satellites to the highly elliptical (typically 250 x 36000 Km) GTO.
Two versions of the GSLV have been developed by ISRO.
The GSLV Mk-II has the capability to launch satellites of lift-off mass of up to 2,500 kg to the GTO.
And can launch satellites of up to 5,000 kg lift-off mass to the LEO.
It is a three-stage vehicle.
The first stage uses solid rocket motor; the second stage uses Liquid fuel and the third stage, called Cryogenic Upper Stage uses cryogenic engine.
GSLV Mk III is a three-stage heavy-lift launch vehicle.
It has two solid strap-ons, a core liquid booster and a cryogenic upper stage.
It is designed such that it carries 4 ton class of satellites into GTO or about 10 tons to LEO.
It has double the capability of GSLV Mk II.