1.Down but not out (The Hindu, The Indian Express)
2.Sabre-rattling (The Hindu)
3.Biofuel breakthrough (Down to Earth)
1.Down but not out (The Hindu, The Indian Express)
Synoptic line: It throws light on the issue of the failed PSLV attempt to launch navigation satellite is unlikely to affect future missions. (GS paper III)
- An attempt by the Indian Space Research Organisation (ISRO) to launch an Indian navigation satellite IRNSS-1H to “augment’’ navigation services in the subcontinent failed after a heat shield, protecting the satellite on board the PSLV-C39 rocket, did not detach.
- The PSLV-C39 rocket carrying the eighth satellite of the Indian Regional Navigation Satellite System (IRNSS) had a normal lift-off and flight events but ended in an unsuccessful mission.
- The IRNSS-1H was launched from the Satish Dhawan Space Centre the Sriharikota High Altitude Range (SHAR) in Andhra Pradesh, was on board ISRO workhorse PSLV but the rocket lost velocity after the heat shield failed to separate at the requisite height. This is just the second instance when the PSLV has had an unsuccessful mission in all of its 41 launches; the first setback was back in 1993.
- With such an enviable track record of launching 104 satellites in one go, the failure of the mission this time almost comes as a surprise. The spacecraft is in a low orbit and there will be natural decay. Going by its falling pattern it will fall back to Earth may be between four and eight weeks. Most of its parts of the 1425-kg will burn up as it re-enters the atmosphere.
- The huge quantity of propellants on it is also a worry. ISRO is part of the IADC and will also get inputs of the North American debris watch body, NORAD.
- In comparison, the heat-shield separation is a relatively minor operation which takes place once the rocket crosses an altitude of 100-110 km, and the temperature in the absence of the heat-shield will no longer damage the satellite.
- The failure of the mission is particularly disheartening as the IRNSS-1H satellite was jointly assembled and tested by ISRO and a Bengaluru-based private company, the first time a single private company, rather than a consortium, was involved in building a satellite.
- The space organisation has thrown open its doors to private companies to build as many as 18 spacecraft a year beginning mid or end-2018. The IRNSS-1H satellite was launched as a replacement for the IRNSS-1A satellite, which became inoperational in terms of surveillance following the failure of all three atomic clocks.
What is a heat shield?
- The heat shield is a protective cover provided around the satellite to help it withstand the adverse temperatures felt when a rocket is launched into space. Separation of the heat shield occurs mid-flight when the rocket leaves Earth’s atmosphere.
- IRNSS-1H was the eighth in a series of IRNSS (Indian Regional Navigation Satellite Systems) satellites launched by ISRO since July 2013. This was to create a constellation to provide satellite-based navigation services over the Indian subcontinent on the lines of the global positioning system (GPS) created by the United States.
- The Indian navigation satellite constellation, called NavIC, essentially comprises seven satellites. IRNSS-1H was intended to replace IRNSS-1A, which developed problems last year. IRNSS-1H would have augmented “the existing seven satellites of NavIC constellation”. It was supposed to sit in a sub-Geosynchronous Transfer Orbit (sub-GTO).
- IRNSS is intended to provide two services – Standard Positioning Service for general users and a Restricted Service, which is an encrypted service only for authorised users like the defence forces. NavIC is designed to provide accurate position information services to users in India as well as the region, up to 1,500 km from the boundary. For NavIC to become ubiquitous in the subcontinent, ISRO will sell its capabilities to general positioning service providers like mobile phone manufacturers, vehicle manufacturers etc.
- IRNSS-1H had a navigation payload and a ranging payload. The ranging payload of IRNSS satellites has a C-band transponder to determine the range of the satellite. The navigation payload is meant to transmit navigation service signals to users on earth while operating in the L5-band and S-band. Part of the navigation payload is high-accuracy RAFS clocks.
- India will have to wait for some more time before the next mission to send a replacement for the IRNSS-1A satellite is ready. The IRNSS was created so that the country would not need to rely on American-based GPS data -the encrypted, accurate positioning and navigation information provided by the system will make Indian military operations self-reliant.
Question– Explain the implications of failed PSLV attempt on upcoming space exploration missions?
2.Sabre-rattling (The Hindu)
Synoptic line: It throws light on the issue to need to the de-escalate the crisis in the Korean peninsula. (GS paper II)
- North Korea mentioned that it set off a hydrogen bomb in its sixth nuclear test, which judging by the earthquake it set off appeared to be its most powerful explosion yet.
- South Korea’s weather agency estimated the nuclear blast yield of the presumed test was between 50 and 60 kilotons, or five to six times stronger than North Korea’s fifth test in September 2016. That would mark a significant step forward in the North’s quest for a viable nuclear missile capable of striking anywhere in the United States.
- Pyongyang claimed its leader had inspected a hydrogen bomb meant for a new intercontinental ballistic missile.
North Korea missile launch
- North Korea conducted two nuclear tests last year and has since maintained a torrid pace in weapons tests, including flight-testing developmental intercontinental ballistic missiles and flying a powerful midrange missile over Japan.
- Trump’s response to Sunday’s development was to ratchet up threats, besides calling out U.S. ally South Korea for “appeasement” and threatening to cut trade ties with countries that conduct any form of business with the North Koreans. It is only pushing North Korea’s totalitarian regime to take even more provocative steps in a quest to attain the status of a de facto nuclear power.
- In response to the exacerbated tensions in the region, South Korea and Japan have significantly enhanced their defence capabilities, including spending on missile defence. South Korea’s new President has now accepted the U.S.’s missile defence system, THAAD, which is opposed locally by many South Koreans.
- The unpalatable prospect of the escalation of a possible military conflict into a nuclear war is also a way to stave off any external intervention against the dictatorship, the likes of which were seen in Iraq and Libya.
- The Chinese, however, seem to be willing to live with a nuclear North Korea as opposed to applying drastic trade sanctions that could lead to a crippled economy and a refugee crisis besides other unpredictable responses by a beleaguered regime.
Hydrogen bombs are more powerful
- Atomic or “A-bombs” work on the principle of nuclear fission, where energy is released by splitting atoms of enriched uranium or plutonium encased in the warhead.
- Hydrogen or H-bombs, also known as thermonuclear weapons, work on fusion and are far more powerful, with a nuclear blast taking place first to create the intense temperatures required.
- The North Korean leadership says a credible nuclear deterrent is critical to the nation’s survival, claiming it is under constant threat from an aggressive US. The North said in its statement that it’s H-bomb “is a multi-functional thermonuclear nuke with great destructive power which can be detonated even at high altitudes for super-powerful EMP (electromagnetic pulse) attack according to strategic goals.”
Question– Korean peninsula crisis are adversarial for the tranquillity of the region as a whole. What should be the role of India in this regard?
3.Biofuel breakthrough (Down to Earth)
Synoptic line: It throws light on potential of biofuels to replace the conventional fuels. (GS paper III)
- The use of biofuels helps reduce human greenhouse gas emissions. That’s one reason why some petroleum companies offer petrol containing up to 10% ethanol (a biofuel).
- But if we are to have any real chance of avoiding catastrophic climate change, it is not enough to reduce our emissions. We must aim for “negative emissions”.
Negative emissions and biofuels
- Negative emissions mean removing carbon dioxide from the atmosphere, and ideally returning to pre-industrial atmospheric CO₂ levels. This is a daunting task: the present atmospheric concentration is 410 parts per million (ppm), compared with around 280ppm before the Industrial Revolution.
- For years the petroleum industry has been producing biofuels, using food crops such as sugar cane, corn and soybeans, which are transformed by fermentation or other chemical processes into ethanol or biodiesel. This has been controversial, in part because of the negative consequences of large-scale monoculture farming of these crops.
- Accordingly, petroleum companies are now funding research programs on so-called second-generation biofuel crops – particularly algae, which can be grown in water rather than on land. This will circumvent many of the criticisms of first-generation biofuels.
- Algae come in many forms. Seaweed is a well-known form of macro-algae and there are also many micro-algae, such as the algal blooms that occur from time to time in polluted rivers and lakes. Algae are relatively inefficient at photosynthesising CO₂. But recent discoveries go some way towards solving this problem.
- Exxon-funded researchers have succeeded in genetically modifying algae so as to double the rate of carbon drawdown. Independently, a group of has just discovered how to grow algae in days, rather than weeks, paving the way for more efficient biofuel production.
- If we can grow the right kind of algae, in sufficient quantities, the next step will be to convert it to biofuel. First-generation biofuel crops were rich in sugars and starch that could be transformed into fuels by processes such as fermentation.
- Algae cannot be transformed in this way. There is, however, another process that can be used: pyrolysis.
- If you heat biomass such as algae in the presence of oxygen, it burns, meaning that the carbon combines with oxygen from the air to form CO₂. However, if it is heated in the absence of oxygen, it cannot burn. What happens instead is that various oils and gases are driven off, leaving a relatively pure form of carbon, known as char or biochar. The process is known as pyrolysis and has been practised for thousands of years to turn wood to charcoal.
- Charcoal burns with particular intensity and historically was valued wherever very high temperatures were required, as in metal manufacture. The gas, when burned, produces far more heat than is necessary to run the pyrolyser, and the excess can be used to generate electricity. Most importantly for the petroleum industry, the oils produced are easily refined into transport fuels. For this reason, petroleum companies are funding research on pyrolysis.
- Apart from burning with an intense heat, biochar has two other very important characteristics. First, it is a valued soil additive, and in fact is sold to agricultural users for this purpose.
- Second, when mixed into the soil it will survive for hundreds of years, perhaps even a millennium. Producing char and sequestering it in soil is therefore a semi-permanent way of capturing carbon.
- In contrast, forests are rather less permanent, because trees eventually die and rot, returning methane and carbon dioxide to the atmosphere; or burn, returning CO₂ to the atmosphere. Pyrolysis, then, offers the possibility long-term carbon sequestration – it is a route to negative emissions.
- The last thing to note about pyrolysis is that by varying the parameters of the process such as the temperature and the type of algae, one can vary the relative proportions of outputs. In particular, one can maximise production of char, or alternatively, the production of oils to be used for transport fuels. Biofuel researchers are of course interested in maximising the latter, with char being to some extent an unwanted byproduct.
- However, if the pyrolysis of algae becomes a commercially viable way of producing biofuel, the char can be sold for soil enrichment. The result would be a steady stream – perhaps more realistically a trickle – of carbon returned to the soil.
- All this brings us tantalisingly close to large-scale char production, for its own sake. The very same research that delivers commercially viable second generation biofuels could presumably be redirected to maximise the yield of char. Biofuel would then be a byproduct, rather than the primary goal.
- The market for char is not yet sufficiently developed to make this a commercial proposition. A significant price on carbon could change all this. If we are serious about achieving negative emissions, that may be the price we need to pay. And who knows, once the benefits of char as a soil additive becomes better established, the commercial value of char may be such that the a price on carbon will no longer be necessary.
- Could char production on a massive scale have unwanted side effects? We know that fresh biochar in the soil can deactivate herbicides rapidly leading to poor weed control. These results suggest that biochar use will need to be carefully managed in agricultural situations that rely on herbicides applied to the soil. The net agricultural benefits appear, however, to be overwhelming.
Question– What do you mean by biofuels? How they are threat to food security? What can be done in this regard?