by Gurbir Singh
[694]. Metosat-2 was one of ESA’s earliest weather satellites operating from GEO. CAT-3 was one of a series of spacecraft designed to help ESA gather characteristics about the atmosphere that the launch vehicle Ariane had to support. It contained sensors for acceleration, noise, pollution and vibrations. Metosat-2, like APPLE, got to GEO with their internal rockets, but CAT-3 was designed to remain in GTO. It provided telemetry data using onboard batteries, which limited the mission duration to 60 days.
[695]. Harvey, Brian, Henk H. F. Smid and Theo Pirard. 2011. Emerging Space Powers: The New Space Programs of Asia, the Middle East and South-America. Springer Science & Business Media.
[696]. Specifically, APPLE was put through the following “A pitch rotation manoeuvre was designed to rotate the spacecraft like rotisserie manoeuvre for 4 hours every day in the night time and to re-acquire Earth lock after 4 hours and continue normal operations for the rest of the day”. ISRO. 2016. From Fishing Hamlet to Red Planet: India’s Space Journey. Noida, Uttar Pradesh: HarperCollins India. P219.
[697]. Rao, U. R. 2013. India’s Rise as a Space Power. First edition. Delhi: Cambridge University Press India Private Limited, 2014. P70.
[698]. Ibid. P64.
[699]. A communication satellite has a unique orbit located 36,000 km, directly above the equator, a Geostationary Orbit (GEO). Any satellite at this distance takes 24 hours to orbit the Earth and remains in the same place in the sky at all times. An ideal launch site on the Equator provides a free 1.5 km acceleration of the required 4 km/s (GEO) or 7 km/s velocity (for LEO) required for orbit.
[700]. Sarabhai, Vikram. 1970. Atomic Energy and Space Research. A Profile for the Decade 1970-80. Mumbai: Atomic Energy Commission, Government of India. P29. Retrieved from http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/02/006/2006423.pdf
[701]. Agrawal, Binod C. and Arbind K. Sinha (Eds). SITE to INSAT: Challenges of Production and Research for Women and Children. New Delhi: Concept Publishing Co. P13.
[702]. Raman, Srinivasan. 1997. No Free Launch: Designing the Indian National Satellite. In Butrica, Andrew J. (Ed.) Beyond the Ionosphere: Fifty Years of Satellite Communication. NASA. P12. Retrieved from http://history.nasa.gov/SP-4217/ch16.htm. Pramod Kale has interesting details in his chapter entitled Origins of INSAT-1 in ISRO. 2016. From Fishing Hamlet to Red Planet: India’s Space Journey. Noida, Uttar Pradesh, India: HarperCollins India. P224
[703]. Rao, U. R. 2013. India’s Rise as a Space Power. Delhi: Cambridge University Press India Pvt Ltd. P92.
[704]. Writing for NASA in 1997, S. Raman captures the complex consideration that must have dominated the meetings during the design phase. Raman, Srinivasan. 1997. No Free Launch: Designing the Indian National Satellite. In Butrica, Andrew J. (Ed.) Beyond The Ionosphere: Fifty Years of Satellite Communication. NASA. Retrieved from http://history.nasa.gov/SP-4217/ch16.htm.
[705]. This case was championed by P. R. Pisharoty. ISRO. 2016. From Fishing Hamlet to Red Planet: India’s Space Journey. Noida, Uttar Pradesh, India: Harper Collins India. P228.
[706]. This payload description comes from the INSAT-1A Project Director Pramod Kale, who had served as the Project Manager for SITE. ISRO. 2016. From Fishing Hamlet to Red Planet: India's Space Journey. Noida, Uttar Pradesh: HarperCollins India. P229.
[707]. Rao, U. R. 2013. India’s Rise as a Space Power. Delhi: Cambridge University Press India Pvt Ltd. P95.
[708]. Ibid, P98.
[709]. This source indicates that ISRO recovered $70 million. Evans, Ben. 2012. Tragedy and Triumph in Orbit: The Eighties and Early Nineties. Springer Science & Business Media. P116.
[710]. Lunney, Glynn S. 2000. NASA Johnson Space Center Oral History Project. Edited Oral History Transcript. Retrieved from http://www.jsc.nasa.gov/history/oral_histories/LunneyGS/LunneyGS_1-28-99.htm. Incidentally, INSAT-1B was deployed from the Space Shuttle cargo bay by mission specialists Dale A. Gardner and Dr Guion S. Bluford, Jr. Bluford was NASA's first African-American astronaut in space.
[711]. This is a digest of some of the services initiated by INSAT-1B as listed by RAO and other sources. Rao, U. R. 2013. India’s Rise as a Space Power. Delhi: Cambridge University Press India Pvt Ltd. P146.
[712].The declassified SECRET report states that India’s 160 ground station using S-band (2.5 GHz) would need to be modified to either S-band (6/4 GHz) or Ku-band (14/11 GHz) at a cost of at least $50 million. CIA Report “India: Space Satellite Options), 23 July 1986, https://www.cia.gov/library/readingroom/docs/CIA-RDP86T01017R000302820001-5.pdf P4
[713]. Email exchange with the author in July 2016. Dr David Baker, who worked as Managing Director for Space Consultants International during the 1980s, came to this conclusion on the basis of the information made available to him during his consultancy.
[714]. All five of the INSAT-2 satellites were equipped with a Satellite Assisted Search and Rescue (SASAR), which is part of the international satellite-aided search and rescue programme. India has signed an agreement with the International COSPAS–SARSAT Council for the use and operation of Local User Terminals (LUTs) and an INMCC in Bangalore and Lucknow. The LUTs provide substantial coverage of the Indian Ocean region, as well as other countries: Bangladesh, Bhutan, Maldives, Nepal, Sri Lanka, Seychelles and Tanzania. Retrieved from https://directory.eoportal.org/web/eoportal/satellite-missions/i/insat-2
[715]. INSAT-2D was launched in July 1997 and was terminated in October 1997 following a problem with an electrical power system. To plug the gap, ISRO procured Arabsat-1C (that had been in orbit since 1992) in November 1997.
[716]. Ibid. P247 and 257.
[717]. These are some of the innovations described by K. Kasturirangan, who at the time of writing this paper in 1988 was the ISRO Chairman. Kasturirangan, K. and Sridharamurthy K. March 1988. ISRO Spacecraft Technology Evolution. Sadhana 12 (3): 251–88. See also ISRO. 2016. From Fishing Hamlet to Red Planet: India’s Space Journey. Noida, Uttar Pradesh: HarperCollins India. P244.
[718]. ISRO. 2016. From Fishing Hamlet to Red Planet: India’s Space Journey. Noida, Uttar Pradesh: HarperCollins India. P365.
[719]. The satellite capacity to deliver tele-education remains low. ISRO. 2016. From Fishing Hamlet to Red Planet: India’s Space Journey. Noida, Uttar Pradesh: HarperCollins India. P367.
[720]. Dr Prem Shanker Goel, writing about Operational Satellites of ISRO, relates the spirit of ISRO engineers building TES to that of the European scientists during World War II. ISRO. 2016. From Fishing Hamlet to Red Planet: India's Space Journey. Noida, Uttar Pradesh: HarperCollins India. P263. Also, see P258. “It was a near-miracle to build and launch TES in 2 years, incorporating 11 new technologies like phased-array antenna, step and stare mode for apparent velocity reduction by a factor of 5.8”.
[721]. The six GEO slots referred to in the reference below have now increased with the advent of the IRNSS programme. By mid-2016, two slots, in particular, were becoming congested, 74ºE had five operational satellites and 55ºE had 4. These numbers will change over time. Kasturirangan, K. and Sridharamurthy K. March 1988. ISRO Spacecraft Technology Evolution. Sadhana 12 (3): 251–88. See also ISRO. 2016. From Fishing Hamlet to Red Planet: India's Space Journey. Noida, Uttar Pradesh: HarperCollins India. P306.
[722]. The beacon transmits its unique identification, along with its coordinates, which can be used during the search and rescue operation. These are three types of beacons: (i) EPIRB, Emergency Position Indicating Radio Beacon used in maritime applications. It emits a 5-watt burst about every 52 seconds at 406 MHz; (ii) ELT, Emergency Locator Transmitter for aviation use. Older versions transmit only on 121.5 MHz, but latest models use both 121.5 and 406 MHz; (iii) PLB, Personal Locator Beacon. These are small handheld devices for personal use and not associated with an aircraft or a ship. In October 2000, the International Council of COSPAS–SARSAT ceased processing the 121.5 MHz signal via satellite due to the extremely high level of false alarms.
[723]. ISRO. 2016. From Fishing Hamlet to Red Planet
: India’s Space Journey. Noida, Uttar Pradesh: HarperCollins India. P302.
[724]. As reported by the end of 2015. COSPAS–SARSAT Information Bulletin. Issue 26. 2015. Retrieved from https://www.cospas-sarsat.int/images/stories/SystemDocs/Current/Bul26-FINAL-v-091015.pdf
[725]. India had been participating since 1983 with a ground-based Mission Control Centre, along with Australia, Norway and the UK. Barnes, Richard J. H. and Jennifer Clapp. November 1995. COSPAS–SARSAT: A Quiet Success Story. Space Policy 11 (4): 261–68: 263. The Indian Department of Space makes a passing reference on page 58 in its Annual Report 2014-2015. Government of India, Department of Space. Retrieved from http://www.isro.gov.in/sites/default/files/article-files/right-to-information/AR2014-15.pdf
[726]. Although India is responsible for registering user details for each COSPAS–SARSAT beacon, it can detect signals from any compatible transmitter. The frequency of 121.5 MHz used by all seafarers and aviators as the emergency frequency was not a frequency best suited for a space-based system, which required the signal to leave and then return through the Earth's atmosphere, a round-trip potentially of almost 80,000 km.
[727]. The global population of the 406 MHz distress beacon was estimated at 600,000 as of December 2007. Retrieved from https://inmcc.istrac.org/brochurehtml/page1.htm
[728]. ISRO. 18 March 2002. United Nations, India Workshop on Satellite Aided Search and Rescue (SASAR) Inaugurated. Retrieved from http://www.isro.gov.in/update/18-mar-2002/united-nations-india-workshop-satellite-aided-search-and-rescue-sasar-inaugurated.
Chapter 13
[729]. Pace, Scott, Gerald Frost, Irving Lachow et al. 1995. The Global Positioning System: Assessing National Policies. Santa Monica, CA: RAND. P238.
[730]. See http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1960-003B
[731]. In September 1993, the US announced at the Annual Conference of the International Civil Aviation Organization that the Global Positioning System established by the US for use by its military would be available for civilian use for free worldwide. See Pace, Scott, Gerald Frost, Irving Lachow et al. 1995. The Global Positioning System: Assessing National Policies. Santa Monica, CA: RAND. P248. This was in part triggered by the USSR shooting down a civilian airline KAL007 when it entered the USSR airspace as a result of a navigational error. Degani, A. 2001. Korean Airlines Flight 007: Lessons from the Past and Insights for the Future. Retrieved from ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020043310.pdf
[732]. ISRO. 28 April 2016. PSLV-C33 Successfully Launches India’s Seventh Navigation Satellite IRNSS-1G. Retrieved from http://www.isro.gov.in/update/28-apr-2016/pslv-c33-successfully-launches-indias-seventh-navigation-satellite-irnss-1g
[733]. ISRO Chairman speaking on January 2014. Jagannathan, Venkatachari. 4 April 2014. ISRO Examining Business Model for Industries in Satellite and Rocket Production. Two Circles. Retrieved from http://twocircles.net/2014apr04/isro_examining_business_model_industries_satellite_rocket_production.html#.VPOv4FNlKBY.
[734]. A comprehensive description of the IRNSS program on Earth Observation Portal. https://eoportal.org/web/eoportal/satellite-missions/i/irnss
[735]. Sometimes, the 35,786-km distance to GSO is reported as 42,164 km. The difference of 6,378 km is equal to the radius of the Earth. Orbital dynamics assume that the Earth is a single point with the mass of the Earth concentrated at that point. The distance of 42,164 km is the distance between the centre of the Earth and the satellite's orbit, and 35,678 km is the distance from the surface of the Earth to the orbit. In addition, all seven of the IRNSS satellites are located at GSO/GEO from where they can remain over India at all times. GPS systems for China, Europe, Russia and the US all use medium Earth orbit, GPS 20,180 km, GLONASS 19,130 km, Beidou 21,150 km and Galileo 23,222 km.
[736]. Saikiran, Byroju and Vippula Vikram. 2013. IRNSS Architecture and Applications. KIET International Journal of Communications and Electronics 1 (3): 25.
[737].The report entitled “Economic impact to the UK of a disruption to GNSS”, was published in April 2017 in London. Retrieved from http://www.insidegnss.com/node/5520
[738]. Founders of the space programme of India insisted that its primary objective was societal development. These are just three examples of how the IRNSS service will be exploited: Satellite Mapping to Boost Diary Farming (http://www.business-standard.com/article/current-affairs/satellite-mapping-to-boost-dairy-farming-116033000465_1.html), ISRO Conducts 1st Satellite-based Warning System Trial for Railways (http://indianexpress.com/article/cities/ahmedabad/isro-conducts-1st-satellite-based-warning-system-trial-for-railways/) and ISRO to Map and Provide Management Plans for Heritage Sites and Monuments of National Importance (http://www.isro.gov.in/isro-to-map-and-provide-management-plans-heritage-sites-and-monuments-of-national-importance).
[739]. The scope of the IRNSS appears to be fluid. The number of spare satellites appears to have increased from two to four, and the expected lifetime of the satellites is somewhere between 5 and 12 years. ISRO Works on 4 Back-up Satellites for IRNSS. 8 January 2016. The Indian Express. Retrieved from http://indianexpress.com/article/india/india-news-india/isro-works-on-4-back-up-satellites-for-irnss/. Initially, ISRO had published a lifetime period of 10 years, but the 12-year figure has now become more established. By the time, the system became operational, one of the seven satellites would have been in orbit for three years and another two for at least a year. http://ilrs.gsfc.nasa.gov/docs/2015/ilrsmsr_1106_org_Version1withsignature_for_IRNSS-1D-final.pdf
[740] The clock failures are attributed to faulty components. Rubidium clocks in future NavIC satellites will be checked for quality assurance prior to launch. Retrieved from http://www.india.com/news/agencies/navigation-satellite-clocks-ticking-system-to-be-expanded-isro-2221095/. The Galileo satellites have 4 (2 rubidium and 2 hydrogen maser) clocks onboard each satellite. See https://phys.org/news/2017-07-europe-galileo-satnav-problems-clocks.html
[741]. ISRO. ISRO Annual Report 2014-2015. Government of India, Department of Space. P29. Retrieved from http://www.isro.gov.in/sites/default/files/pdf/AR2014-15.pdf
[742]. Products are now commercially available where a single device can interface simultaneously with IRNSS, GPS, GLONASS and GAGAN. See http://www.accord-soft.com/IRNSS_systems.html
[743]. Seventh BRICS Summit. 9 July 2015. Ufa Declaration. Ufa, the Russian Federation. P16. http://brics2016.gov.in/upload/files/document/5763c20a72f2d7thDeclarationeng.pdf
[744]. A time source designated Stratum 0 generates the most accurate time signal possible. A stratum zero time source is not synchronised with any other time source. A stratum-1 time source is synchronised with a stratum-0 time source. Stratum 2 is synchronised with stratum-1 and so on. This hierarchy is the backbone of the Network Time Protocol and drives the time value around the world. For more, see http://www.ntp.org/ntpfaq/NTP-s-algo.htm#Q-ACCURATE-CLOCK
[745]. To compensate, the IRNSS onboard clocks are not tuned to the nominal frequency of 10.23 MHz but reduced by the so-called ‘factory offset’ of 10.229999994484488852 MHz. For more details, see Babu, R., T. Rethika and S. C. Rathnakara. 2012. Onboard Atomic Clock Frequency Offset for Indian Regional Navigation Satellite System. International Journal of Applied Physics and Mathematics 2 (4): 270–272. Retrieved from http://www.ijapm.org/papers/109-P20007.pdf
[746]. Corner cubes were delivered to the Moon by Apollo 11, 14 and 15, as well as USSR’s Lunakhood 2 spacecraft. These passive devices continue to operate decades after they landed. The distance between the Earth and the Moon is frequently measured with an accuracy of 3 cm. See http://www.lpi.usra.edu/lunar/missions/apollo/apollo_11/experiments/lrr/
[747]. Retroreflector Array (RRA) Characteristics. ILRS. Retrieved from http://ilrs.gsfc.nasa.gov/missions/satellite_missions/future_missions/irns_reflector.html.
[748]. Ganeshan, A.S. et al. First Position Fix with IRNSS. July/August 2015. Inside GNSS. Retrieved from http://www.insidegnss.com/auto/julyaug15-IRNSS.pdf. P50
[749]. Laser ranging is a
critical element of the IRNSS infrastructure, India is not new to laser ranging. https://cddis.nasa.gov/lw20/docs/2016/posters/P62-Elango_poster.pdf.
[750]. Interference is the inability of a satnav receiver to receive a usable signal continuously. This can be the (deliberate or unintentional) consequence of a nearby transmitter. Jamming is interference introduced by a device designed to interfere and prevent reception of the intended signal. Spoofing is also a deliberate action but intended to mislead. It does not prevent the reception of a signal, but a local transmitter generates a false signal posing as the satnav signal. See https://www.newscientist.com/article/dn20202-gps-chaos-how-a-30-box-can-jam-your-life/
[751]. In early 2017, ISRO reported faults with all three of the rubidium atomic clocks on IRNSS-1A. 3 Atomic Clocks Fail on 1 Indian Satellite, Replacement Prepped. 30 January 2017. GPS World. Retrieved from http://gpsworld.com/3-atomic-clocks-fail-on-1-indian-satellite-replacement-prepped/ ESA’s Galileo programme also reported similar problems (ten failures on five satellites), but the built-in redundancy has ensured that all satellites in the Galileo constellation continue to operate.