Indian Space Research Organisation (ISRO) Chairman V Narayanan said on Friday that the space agency was in the process of building its heaviest rocket ever, and had named it Lunar Module Launch Vehicle (LMLV). He also said the LMLV would be ready by 2035, and would be used for the lunar missions, including the first human mission to the Moon, planned by 2040. The new rocket would be capable of carrying about 27 tonnes to the Moon and 80 tonnes to low Earth orbits, which are between 200 and 2,000 km from the planet’s surface. Here is a brief history of ISRO’s launch vehicles. The origin India had been thinking of rockets even before ISRO was established. On November 21, 1963, it launched the US Nike Apache ‘sounding rocket’ from Thumba, near Thiruvananthapuram. The rocket was taken to the launch site on a bullock cart. Sounding rockets are suborbital rockets that carry experiments to the upper atmosphere of the Earth. They aren’t capable of exiting the planet’s gravity or reaching into space. The first Indian launch vehicle to arrive there was the SLV-3 in 1980. The mission was led by A P J Abdul Kalam, who had joined ISRO in 1969, and was responsible for designing, developing and launching the vehicle. But the success didn’t come instantly, as the first attempt to send the SLV-3 into space on August 10, 1979, failed. Scientist Ramabhadran Aravamudan in his book, ISRO: A Personal History, writes about the incident as follows: “The burning of the first stage seemed normal. I was watching Kalam for some sign. Had the rocket performed well? After some time, I saw a blank and fixed expression on his face, followed by disappointment. He turned around and made a thumbs down gesture. Something had gone wrong.” SLV-3 had gone out of control and splashed into the Bay of Bengal at a distance of 560 km from the coast, about five minutes after take-off from the Sriharikota launch pad. Kalam and his team learnt quickly from the mistakes. The second attempt for the launch was scheduled for just a year later, on July 18, 1980. There was some tension because Sanjay Gandhi, the Prime Minister’s son, had died in a plane crash about three weeks ago. “Delhi was in chaos as Indira Gandhi tried to come to terms with the loss. In Trivandrum and SHAR this had a trickledown effect, but we were determined to go ahead with our launch,” Ramabhadran wrote. SLV-3 took off without any glitches, and placed its payload, Rohini 1, a 40 kg experimental satellite, in space. This made India the sixth member of the exclusive club of space-faring nations, and boosted ISRO’s morale to new heights. The rise of PSLV SLV-3’s payload capability wasn’t significant. But it provided a learning platform to ISRO, and led to the development of the Augmented Satellite Launch Vehicle (ASLV). This was essentially the SLV-3 rocket, but with additional strap-on boosters, which enabled it to carry a payload of more than 100 kg. However, ASLV didn’t prove very successful. Its first two launches ended in failure and by the time its first glitch-free take-off came in 1992, a new generation of launch vehicles had made its entry. It was the Polar Satellite Launch Vehicle (PSLV). PSLV’s development started in 1982, and its maiden successful launch took place in October 1994. Most significantly, it marked India’s entry into the Big Rockets league, as it could carry a payload of up to 1,000 kg. In the years that followed, PSLV emerged as one of the most reliable and versatile workhorse launch vehicles, sending numerous Indian and foreign customer satellites into space. Some of India’s most ambitious space missions have been launched using this rocket — Chandrayaan-1 rode a PSLV rocket in 2008, as did Mangalyaan, the Mars Orbiter mission, in 2013. PSLV also helped India enter the arena of satellite navigation, which is considered crucial for both civilian and defence applications. “Today, PSLV is available in three configurations: the generic PSLV with six strap-ons, the core alone (PSLV-CA) configuration with no strap-ons and the most powerful one designated as PSLV-XL, with extended strapons,” scientist N Narayanamoorthy, who was associated with the PSLV project from the beginning, wrote in From Fishing Hamlet to Red Planet: India’s Space Journey. The latest generation of vehicles The next and latest class of rockets is the Geosynchronous Satellite Launch Vehicle (GSLV). The new launch vehicle primarily aimed to solve two of the biggest limitations of PSLV: it can deliver a payload of about 1,750 kg to a lower Earth orbit, up to an altitude of 600 km from the Earth’s surface; and it can go a few hundred kilometres higher in Geostationary Transfer Orbit (GTO), though only with a reduced payload. Unlike their predecessor vehicles, GSLVs use cryogenic engines — they consist of liquid hydrogen and liquid oxygen — that provide far greater thrust than the engines used in the older launch vehicles. ISRO developed these cryogenic engines indigenously after the US refused to transfer the technology to India in the 1990s. The big success came in December 2014, with the experimental flight of the third generation (Mk-III) GSLV, now known as Launch Vehicle Mark-3, containing an indigenous cryogenic engine. The rocket can put a 4,000 kg payload into geostationary orbits that are over 30,000 km from Earth — it is ISRO’s heaviest launch vehicle right now. LVM-3’s first successful mission was in 2017, when it carried the GSAT-19 satellite, a communication spacecraft, into space. Subsequently, the same launch vehicle put the Chandrayaan-2, weighing 3,850 kg, outside the Earth’s atmosphere in 2019, and took Chandrayaan-3 into space in 2023.
