The fi­asco of GSAT-6A

SP's MAI - - AEROSPACE VIEWPOINT - The views ex­pressed herein are the per­sonal views of the au­thor.

On March 29, 2018, In­dian Space Re­search Or­gan­i­sa­tion (ISRO) launched GSLV Mk-II (GSLV-F08); car­ry­ing the 2,140 kg communication GSAT-6A, it took off from Sri­harikota and some 17 min­utes later the three-stage rocket in­jected the satel­lite into a geosyn­chronous trans­fer or­bit. This was the Geosyn­chronous Satel­lite Launch Ve­hi­cle’s 12th flight and sixth with indige­nous cryo­genic up­per stage. In com­ing days, ISRO sci­en­tists were to fire the on­board thrusters to ma­noeu­vre it to a geo­sta­tion­ary or­bit at an al­ti­tude of 36,000 km from earth.

In this launch, ISRO used the high thrust indige­nous cryo­genic ‘ Vikas’ en­gine that has in­creased thrust by 6 per cent, con­se­quently en­hanc­ing the pay­load ca­pac­ity by 50 per cent – 2.5 tonnes in this case. The sec­ond stage planned also had electro­mechan­i­cal ac­tu­a­tion sys­tem re­plac­ing elec­tro-hy­draulic ac­tu­a­tion to en­hance re­li­a­bil­ity of the rocket. Th­ese im­prove­ments and more are to be in­cor­po­rated into GSLV’s fu­ture mis­sions, in­clud­ing Chan­drayaan-2 planned for Oc­to­ber 2018. How­ever, af­ter the suc­cess­ful long du­ra­tion fir­ings, when the satel­lite was on course to nor­mal op­er­at­ing con­fig­u­ra­tion for the third and the fi­nal fir­ing, sched­uled for April 1, 2018, communication from the satel­lite was lost at 9.30 a.m. on March 31. This is def­i­nitely a ma­jor set­back but ISRO is mak­ing ef­forts to re-es­tab­lish the communication link. Only af­ter the communication link is re-es­tab­lished with the satel­lite can it be placed in its in­tended or­bit. This may be a dif­fi­cult propo­si­tion even if it is a case of me­chan­i­cal/tech­ni­cal fail­ure. On the other hand, if it has been caused by sab­o­tage, then the satel­lite may be con­sid­ered lost.

The fact is that the space is fast be­com­ing an am­bigu­ous bat­tle­ground. China’s space lab may be out of con­trol and hurtling to­wards earth, but not only has it lived its life, its point of im­pact on earth may be fixed by China, though pro­claimed out of con­trol. China would al­ready have con­sid­er­able space ca­pa­bil­i­ties and R&D in space would have been ac­cel­er­ated af­ter Tian­jin Port was stuck by a space weapon in Au­gust 2015. With China fix­ated with lim­it­ing In­dia’s strate­gic space and curb­ing our econ­omy, wouldn’t she love to sab­o­tage ISRO’s satel­lite that would boost mo­bile com­mu­ni­ca­tions in In­dia, in­clud­ing of In­dian Armed Forces? The un­der­ly­ing fact is that such pos­si­bil­ity can­not be dis­counted.

Cause for the down­ing of an In­dian Air Force (IAF) Sukhoi close to the LAC in May 2017 was sus­pected by for­eign an­a­lysts as a cy­ber­at­tack by China. Pos­si­bly same was the rea­son for down­ing of a UAV dur­ing the Dok­lam stand­off, so why not a satel­lite? GSAT-6A, sim­i­lar to its pre­de­ces­sor GSAT-6, is a high power S-band communication satel­lite with a mis­sion life of some 10 years. It has a has a six-me­tre wide an­tenna that is meant for S-band communication; three times broader than those gen­er­ally in ISRO satel­lites, which will en­able the satel­lite to pro­vide mo­bile communication for the coun­try through hand­held ground ter­mi­nals, whereas, smaller an­tenna in other communication satel­lites re­quire larger ground sta­tions. This will also ben­e­fit Armed Forces in use of hand-held mo­bile ter­mi­nals. GSAT-6A will com­ple­ment GSAT-6, which has been pro­vid­ing satel­lite communication ser­vices since its launch on Au­gust 27, 2015. ISRO is pre­par­ing for three launch cam­paigns in­clud­ing PSLV-C41 car­ry­ing IRNSS-1I, to be launched shortly fol­lowed by GSLV Mk-III.

In­dia has plenty catch­ing up to do in terms of mo­bile in­ter­net speed and broad­band speed around the world. In­dia was ranked 109 out of 122 in the Speedtest Global In­dex in Novem­ber 2017, as also 76 rank out of 133 coun­tries in broad­band speed. For this, ISRO is plan­ning to launch heavy-duty communication satel­lites. GSAT11 is planned to be launched in April-May this year, with the 5,725kg satel­lite car­ry­ing 40 transpon­ders in the Ku-band and Ka-band fre­quen­cies aimed at pro­vid­ing high band­width con­nec­tiv­ity with up to 14 gi­ga­bit per sec­ond (Gbps) data trans­fer speed.

On June 5, 2017, ISRO had launched GSAT-19, which too car­ried Ka/Ku-band high through­put communication transpon­ders. Si­mul­ta­ne­ous to GSAT-11 planned to be launched from the Euro­pean space­port in April-May, ISRO will launch GSAT-29 through GSLV Mk III rocket from Sri­harikota. There­after, GSAT20 is planned to be launched in 2019. All th­ese satel­lites to­gether will pro­vide high band­width con­nec­tiv­ity of up to 100 gi­ga­bit per sec­ond; pro­vide high-speed in­ter­net con­nec­tiv­ity in ru­ral ar­eas as well and help bridge the dig­i­tal di­vide. Th­ese satel­lites use mul­ti­ple spot beams through a spe­cial transpon­der op­er­at­ing on high fre­quency, which in­creases in­ter­net speed and con­nec­tiv­ity; spot beam be­ing a satel­lite sig­nal spe­cially con­cen­trated in power to cover lim­ited ge­o­graph­i­cal area on the earth. The nar­rower the beam more is the power. More­over, th­ese satel­lites will re­use the beams sev­eral times in or­der to cover en­tire In­dia. GSAT-19 uses 16 beams and is able to trans­fer data at the rate of 13 Gbps. GSAT-20 will use 40 beams. Each beam will have two po­lar­i­sa­tions, which will ef­fec­tively make them 80 beams. This satel­lite will have data trans­fer rate of 60-70 Gbps.

Many may not know that ISRO is help­ing 125 govern­ment projects work ef­fec­tively and ef­fi­ciently by op­ti­mis­ing space tech­nol­ogy, mainly for so­cial-wel­fare and de­vel­op­ment projects in­clud­ing MGNREGA, nav­i­ga­tion sys­tem and land de­mar­ca­tion plans. ISRO has re­peat­edly proved to be one of the most ef­fi­cient and ded­i­cated or­gan­i­sa­tion in the coun­try with re­cur­ring achieve­ments that have made In­dia proud. If it has set its sight on mak­ing mo­bile in­ter­net speed and broad­band speed in In­dia world class, there is no rea­son it will not achieve it. This year is also launch of Chan­drayaan-2 mis­sion. In case GSAT-6A is re­quired to be re-launched, Chan­drayan-2 may be de­layed. But In­di­ans will be look­ing for­ward to fu­ture ISRO mis­sions.

LT GEN­ERAL P.C. KA­TOCH (RETD)

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