ISRO is working on upgrading its heavy-lifter GSLV Mk III where the upper stage of the rocket will have highly refined form of kerosene as fuel in order to increase its payload capability. The advantage of using Kerolox is that it is 10 times dense — meaning the same volume of Kerolox will generate more thrust than the same volume of Hydrolox. The advanced GSLV MKIII will help ISRO cut expenses and save time

NEW DELHI: Indian Space Research Organisation (ISRO) is working on upgrading its heavy-lifter GSLV Mk III where the upper stage of the rocket will have highly refined form of kerosene as fuel in order to increase its payload capability.

Talking to TOI, ISRO chairman K Sivan said, “To increase the payload capability of GSLV Mk III + from 4 tonnes to 6 tonnes, we are in the process of making some improvements in rocket stages. First, we are working on enhancing the cryogenic stage fuel loading from 25 tonnes to 30 tonnes. Second, we are also working on changing the core stage L110 — which has 110 tons of unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (N2O4). We want to replace L110 stage with semi-cryogenic engine that will carry liquefied oxygen and highly refined kerosene called Kerolox (aka RP-1) instead of liquefied hydrogen.”

Sivan said, “The first test of the advanced version of Mk III will take place in December 2020. With upgrade in Mk III, we will also have to upgrade the launchpad facility at Sriharikota. We have therefore issued a tender notice recently inviting quotations for infrastructure upgrades at the second launchpad.”

However, the chairman clarified the rocket with the semi-cryogenic stage won't be used for the Gaganyaan mission. The current GSLV Mk III with L110 stage will only be used for the manned mission with some modifications.