The long haul

ISRO began studies to develop a cryogenic engine 40 years ago, but it fatefully decided to import technology at a high cost.

Published : Jan 22, 2014 12:30 IST

Former ISRO Chairman Satish Dhawan flanked by U.R.Rao (left) and K. Kasturirangan. In December 1982, Dhawan revived studies on cryogenic technology. After his retirement in 1984, it was left to Rao to decide how ISRO would develop the cryogenic engine and the GSLV based on that technology.

Former ISRO Chairman Satish Dhawan flanked by U.R.Rao (left) and K. Kasturirangan. In December 1982, Dhawan revived studies on cryogenic technology. After his retirement in 1984, it was left to Rao to decide how ISRO would develop the cryogenic engine and the GSLV based on that technology.

THE Indian Space Research Organisation’s (ISRO) quest for cryogenic technology is over four decades old. The first studies began within a decade of the beginning of the Indian foray into space, which was well before ISRO’s first satellite launch vehicle, SLV-3, flew and a good 20 years before Glavkosmos and Russian technology came into the picture. In 1971, a team of seven people constituted what was called the Cryogenics Techniques Project (CTP). Interestingly, this was at the initiative of Vasant Gowarikar, whose chief responsibility was actually to develop solid propellants. As a first step towards developing a fully cryogenic engine, Gowarikar’s idea was to develop a 60-tonne-thrust semi-cryogenic engine.

In a cryogenic engine, the propellants, both the fuel (usually hydrogen) and the oxidiser (usually oxygen), which are gases at room temperatures and liquefy only at extremely low (cryogenic) temperatures, are used in their liquid state. In a semi-cryogenic engine, however, only oxygen is in the cryogenic liquid form. The fuel, usually kerosene of a particular grade, is a liquid at ordinary temperatures.

Vikram Sarabhai, the founder of the Indian space programme and the first Chairman of ISRO, approved the project immediately and also sanctioned money to establish a liquid oxygen (LOX) plant ( Frontline , April 6, 2007). But he passed away shortly thereafter and, sadly, the project was abandoned. Nevertheless, Gowarikar’s team built a small-scale and somewhat primitive 500-kilogram LOX-kerosene engine. But in 1974, the CTP was transferred from Gowariker to the Liquid Propulsion Division headed by A.E. Muthunayagam. Following this, the CTP was closed and ISRO carried out no further work on cryogenics. It must, however, be mentioned that it was the CTP that provided inputs for a 7.5-tonne-thrust fully cryogenic engine and stage to the Vasagam Committee, which was set up in 1973 to look into ISRO’s options for launch vehicle configurations after SLV, and recommended such an engine. (A rocket stage includes the engine, the propellants and the associated components.)

In fact, subsequent to the development of the Vikas engine, based on the Viking liquid engine technology obtained from France, a committee set up in the late 1970s under M.R. Kurup had also recommended the feasible option of clustering four 7.5–tonne-thrust LOX-kerosene engines in lieu of Vikas. The Vikas engine uses earth-storable liquid propellants—unsymmetric dimethyl hydrazine (UDMH) and dinitrogen tetroxide (N2O4)—and powers the second stage of ISRO’s workhorse, the Polar Satellite Launch Vehicle (PSLV). This would have also given ISRO the necessary experience in handling cryogenic fluids to building a fully cryogenic engine. It can be safely stated that ISRO would have achieved cryogenic capability much earlier had this semi-cryo project been nurtured and sustained.

But having committed money and 100 man-years of work by about 35 ISRO engineers in France towards the development of the Viking engine, the ISRO leadership felt it was prudent to focus on building the PSLV based on a much surer Viking technology rather than diverting manpower and money towards an uncertain outcome. “This import culture in the liquid propulsion group,” writes Gopal Raj, the science correspondent of The Hindu , in his book Reaching for the Stars (2000), “greatly influenced ISRO’s fateful decisions when cryogenic technology became necessary for its Geosynchronous Satellite Launch Vehicle (GSLV)”.

Even as the final four-stage configuration of the PSLV was being finalised around 1982, it had become clear that to put Indian National Satellite (INSAT) class of communication satellites (weighing about two tonnes) in the circular 36,000 kilometre x 36,000 km geostationary equatorial orbit (GEO) the simplest and the lowest-cost option was to replace the last two stages of the PSLV with a single cryogenic stage of appropriate thrust and capacity with LOX and liquid hydrogen (LH2) as propellants. Today, even with its improved versions, the PSLV, which began with a payload capacity of about 1,100 kg, can deliver only 1,600 kg in the low-earth polar orbit (LEO) or about 1,060 kg in the Geostationary Transfer Orbit (GTO) or about 1,400 kg in the sub-GTO. All the two-tonne class INSAT satellites have until now been launched through procured launch services of foreign agencies.

Therefore, in December 1982, six months after the government sanctioned the PSLV project, Satish Dhawan, the then ISRO Chairman, revived studies on cryogenic technology. He set up the Cryogenic Study Team (CST) to evolve an appropriate configuration for the cryogenic upper stage and to recommend a road map for developing the technology. The CST report, which ran into 15 volumes and was submitted a year later, recommended the development a 10-tonne-thrust cryogenic engine, which could be upgraded to 12 tonnes. After Dhawan’s retirement in 1984, it was left to his successor U.R. Rao to decide how ISRO would develop the cryogenic engine and the GSLV based on that technology.

The CST report also recommended the development of a one-tonne-thrust sub-scale engine to gather relevant data for an up-scaled version. The first pre-project funding for this indigenous development came only in 1986 to set up a Cryogenic Engineering Laboratory and fabrication cum testing facility for the sub-scale one-tonne version. The heat-sink and water-cooled versions of the sub-scale engine were tested around 1987-88. But it was around this time that the crucial decision to import the technology was taken even though by then the project report for a 12-tonne thrust cryogenic engine and stage was ready. The apparent reason for this decision was the assessment by ISRO, on the basis of the experience of other space-faring nations, that ab initio indigenous development of a cryogenic engine would take about 15 years. Importing the technology was seen as the way to reduce this time frame to six years.

ISRO approached the United States, Japan and France to get the technology. Japan apparently refused to part with its LE-5 engine technology that was being used in its H-1 series of launch vehicles. Negotiations with the U.S. over its RL-10 engine did not succeed either. Developed by Pratt & Whitney, RL-10 was the world’s first LOX-LH2 cryogenic engine. ISRO hoped that France, which had licensed its Centaure sounding rocket to India, helped India establish solid motor test facilities, and transferred the Viking liquid engine technology, would not disappoint it. France offered to sell its HM-7 engine, which was used in the Ariane launcher, but at a hefty price of Rs.1,000 crore. Also, France apparently put restrictions on its use in commercial launches by ISRO. Despite the price and the conditions, ISRO was, according to ISRO sources, inclined to accept the offer. However, the Finance Ministry rejected the proposal given the high cost.

According to the book A Brief History of Rocketry in ISRO by former ISRO officials P.V. Manoranjan Rao and P. Radhakrishnan, towards the end of the Viking engine technology acquisition negotiations with Societe Europeenne Propulsion (SEP), France, the company had also offered to transfer its HM-7 technology for just Rs.1 crore, a thousand times less than what it wanted a decade later. But, inexplicably, ISRO declined the offer. According to the authors, the decision was made to ensure that available energies within ISRO at that time were focussed on developing the Vikas engine and building the PSLV, and no manpower was diverted to cryogenic technology acquisition. Having put indigenous development on the back burner earlier, if ISRO had at least accepted SEP’s offer, perhaps cryogenic engine development and the GSLV would have followed close on the heels of Vikas and the PSLV. “At this point,” remark the authors, “one cannot help wondering how a perceptive and far-sighted mind like Dhawan’s slipped up on what seemed an irresistible offer in the mid-1970s.”

Contract with Soviet Union Once it became clear that the technology could not be obtained from Japan, the U.S. and France, ISRO turned to the Soviet Union. It was only in 1987, after the U.S., Japan and China, that the Soviet Union had its first launch with a cryogenic engine. ISRO had also kept its ongoing studies on indigenous development alive in case the Russian option too failed to materialise. In fact, in November 1990, the indigenous GSLV project, which included the development of a 12-tonne-thrust cryogenic engine (called C-12) carrying 14 tonnes of propellant (LOX+LH2) and the corresponding stage, had been approved by the government at a sanctioned cost of Rs.756 crore. The GSLV launch target was 1995-96.

However, the Soviet Union agreed to sign a commercial contract with ISRO. In January 1991, Glavkosmos, the Soviet commercial space agency, signed a Rs.235-crore contract with ISRO, which covered two flight-worthy cryogenic stages and technology transfer. It also provided an option to buy three more stages. The Soviet engine (called KVD-1M) was contracted to deliver 7.5-tonne-thrust and carry 12 tonnes of propellant. The stage to be supplied was designated 12KRB, where 12 meant the amount of propellant being carried, and was to be specially made for ISRO.

It was reasoned, as is evident from a reading of ISRO’s 1992-93 Performance Budget, that the Soviet stage was found to be compatible with the ISRO boosters and could be used in the GSLV instead of the C12 under development. Later, this 12KRB stage would be replaced by an identical indigenised stage based on Soviet technology. And this GSLV, like the one envisaged with the C12 stage, would be able to put into GTO a satellite of 2.5 tonnes.

But there were international politico-strategic developments with regard to missile proliferation, which ISRO chose to ignore despite warnings from within that these could impinge on the proposed Indo-Soviet deal. The multilateral Missile Technology Control Regime (MTCR) had come into being in April 1987 as an informal arrangement between the U.S. and its six major trading allies (the Group of Seven). (Today, 34 countries are members of the MTCR, which does not include India.) The objective of the MTCR is “to restrict the proliferation of missiles, complete rocket systems, unmanned aerial vehicles, and related technology for those systems capable of carrying a 500-kg payload at least 300 km, as well as systems intended for the delivery of weapons of mass destruction (WMD)”.

The guidelines of the MTCR, which the members are required to adhere to, set out technologies, systems and their specifications whose export is sought to be controlled. Though there is no outright ban on their export, partner countries are expected to exercise restraint in the transfer of such items by considering them on a case-by-case basis, but with a strong presumption of denial for items/technologies of greater proliferation sensitivity known as “Category I” items. Accordingly, the MTCR guidelines are implemented by each country in accordance with its domestic export control laws and regulations.

Specifically, the guidelines restrict the transfer of the following Category I items:

a) “Complete rocket systems (including ballistic missile systems, space launch vehicles, and sounding rockets) capable of carrying a 500-kg payload to a range of at least 300 km.”, “individual rocket stages usable in the [above] systems”, and associated technologies;

b) “Solid propellant rocket motors, hybrid rocket motors or liquid propellant rocket engines, usable in the [above] systems…having a total impulse capacity equal to or greater than 1,100 kilonewton-seconds.”

It is clear that the proposed sale of the cryogenic engine (which is a liquid propellant engine) and the stage violated these guidelines. Specifically, the limiting impulse value given in the guidelines is about 50 times less than that of the 12-tonne thrust engine being sold to ISRO. While it is known that cryogenic engines are not used in ballistic missiles, the rationale for the restrictions on these is that the technology of integration of rocket stages would be useful for long-range ballistic missile systems as well.

A geopolitical development that affected the deal was the break-up of the Union of Soviet Socialist Republics in December 1991. In fact, the process of the break-up had begun even as the ISRO-Glavkosmos deal was being signed. As a result, the contractual obligations of the ISRO deal fell upon Russia. Also, shortly before the ISRO-Glavkosmos contract was signed, in November 1990, the U.S. amended its export control laws to include provisions for trade sanctions against entities that violated the MTCR. Accordingly, the U.S. began to put pressure on Russia and India to terminate the contract. Resistance by both was of no avail. Sanctions were imposed on ISRO and Glavkosmos in May 1992, which banned exports to and imports from these two entities and government contracts to the two entities for two years.

According to a report of the then Office of Technology Assessment (OTA), the main concern of the U.S. was the potential military uses of the technology that was being transferred rather than the sale of the cryogenic engines themselves. So, the U.S. dangled the commercial carrots before Russia in the form of allowing its participation in the International Space Station (ISS) and access to commercial launch market in exchange for the cancellation of the cryogenic technology transfer.

The Al Gore-Viktor Chernomyrdin talks kicked off in April 1993 and one of the agreements signed by the U.S. and Russia as part of them pertained to a $400-million contract (over a four-year period) to buy Russian goods and services for the ISS as well as a launch service agreement that allowed Russia to launch nine geostationary satellites through 2000 at prices within 7.5 per cent of what Western agencies charged. Russia, faced with a worsening economic situation, could hardly resist the offer. The agreements were inked in September 1993 and formalised in December 1993. Besides, the two countries also entered into a memorandum of understanding that committed Russia to MTCR guidelines. In fact, faced with the prospect of sanctions, Russia, though not a partner of the MTCR then, put in place export controls in line with the MTCR guidelines in January 1993.

Following the Russia-U.S. agreement, Russia sought to renegotiate the contract with ISRO without technology transfer. ISRO agreed to that and the terms of the 1991 contract were revised. Why ISRO did so is not clear but it is learnt that the government did not want ISRO to annul the contract totally given that Russia was India’s major arms supplier. The new agreement included two more flight-worthy stages and two mock-up stages for ground-based studies for the same contract value of Rs.235 crore ($128 million at 1991 rates). Besides, Glavkosmos could supply three more flight-worthy stages at $3 million a piece. The contract was renegotiated a year later in dollar terms following the dismantling of the earlier rupee trading system with Russia. This meant a near-doubling of the cost (including the cost of the three additional stages, which the ISRO decided to procure) in rupee terms denominated at 1995 rupee-dollar rates. Seven flight-worthy stages were thus delivered to ISRO “not without some delay by Glavkosmos”, note Manoranjan Rao and Radhakrishnan. The first development flight of the GSLV, using the Russian stage, took place on April 18, 2001.

However, it was a suboptimal launch, with the Russian engine underperforming. Since then, six of the seven stages supplied by Glavkosmos have been used in the GSLV’s developmental (GSLV-D1 and D2) and operational flights (F01, F02, F04 and F06). Of these, there have been only two successful launches. Of the four failures, two were due to outright failures of the Russian engine/stage and the remaining two were due to failures in ISRO’s liquid strap-on motors. Whether the Russian stages would have worked as expected if the strap-ons had fired properly in these is anybody’s guess.

Now, following the successful launch of the indigenous cryogenic engine/stage on January 5, the same will be used in all subsequent launches of the GSLV as well. What will happen to the seventh Russian stage? No one knows. “That’s a good question. Maybe it will be used for training purposes,” says K. Radhakrishnan, Chairman, ISRO.


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