Small satel­lites are pro­vid­ing cost-effective and re­li­able means of space ex­plo­ration

Down to Earth - - CONTENTS - MANUPRIYA

For­get bulky space­craft. Small satel­lites are a cheaper and re­li­able means to ex­plore space

ON JUNE 30, Satish Dhawan Space Cen­tre in Sri­harikota launched a rocket. On board were five satel­lites.The main pas­sen­ger was a French Earth ob­ser­va­tion satel­lite, weigh­ing 700 kg.It was ac­com­pa­nied by four tiny ones: two from Canada and one each from Ger­many and Sin­ga­pore.None of th­ese weighed more than 15 kg.

This is a “global en­dorse­ment of In­dia’s space ca­pa­bil­ity”, de­clared Prime Min­is­ter Naren­dra Modi soon af­ter the suc­cess­ful launch of the rocket, Po­lar Satel­lite Launch Ve­hi­cle (pslv)-c23. Once in space, the Ger­man satel­lite will mon­i­tor sea-traf­fic,the Canadain satel­lites will test for­ma­tion fly­ing of space­craft and the one from Sin­ga­pore will es­tab­lish in­ter-satel­lite link.

Small satel­lites are cheaper and minia­ture ver­sions of the be­he­moth that weigh in tonnes. Th­ese can be cat­e­gorised as pi­cosatel­lites (un­der 1 kg), nanosatel­lites (1 kg to 10 kg) or mi­crosatel­lites (10 kg to 100 kg).

The world’s first small satel­lite was launched on Oc­to­ber 4, 1957, by the Soviet Union. It was called Sput­nik1 and weighed 84 kg. Rid­ing high on the Cold War sen­ti­ment, the US’s first small satel­lite— Ex­plorer 1—fol­lowed soon in Jan­uary 1958. In the 55 years since then, the sec­tor is rev­o­lu­tionised through sus­tained re­search and is no longer a gov­ern­ment-exclusive do­main. At least 170 small satel­lites now or­bit the Earth and are en­gaged in var­i­ous ac­tiv­i­ties,from track­ing wildlife,mon­i­tor­ing sites rav­aged by nat­u­ral dis­as­ters and look­ing for crashed planes like the re­cent MH370 to con­duct­ing space-based ex­per­i­ments, like search­ing for Earth-like plan­ets out­side the so­lar sys­tem. Their util­ity is limited only by the ex­per­i­menter’s imag­i­na­tion.

In the past, the In­dian Space Re­search Or­gan­i­sa­tion (isro) has launched small satel­lites like ims1 and ham­sat. ims1, also called Third World satel­lite, was an Earth ob­ser­va­tion satel­lite and is past its life. ham­sat still caters to the am­a­teur ra­dio com­mu­nity.At present,most small satel­lites launched by isro are built ei­ther by stu­dents at In­dian uni­ver­si­ties or by other coun­tries.

While isro of­fers ser­vice to for­eign agen­cies for a price, it of­fers free rides to the ones de­signed by stu­dents (see in­ter­view).

Pro­mot­ing in­no­va­tions

In­dia’s first stu­dent satel­lite was anusat. Weigh­ing 40 kg,the mi­crosatel­lite was built by Anna Univer­sity in Tamil Nadu and was launched in 2009. A year-and-a-half later, stu­dents from seven en­gi­neer­ing col­leges in Kar­nataka and Andhra Pradesh launched a pi­cosatel­lite,studsat,which weighed 950 g. A pro­lif­er­a­tive year for In­dian small satel­lites, 2011 saw the launch of three stu­dent satel­lites: 92 kg youth­sat, de­vel­oped un­der an In­dia-Rus­sia col­lab­o­ra­tive project; 10.9 kg srmsat de­vel­oped by srm Univer­sity, Chen­nai,and 3 kg Jugnu by iit Kan­pur.

“Cre­at­ing Jugnu was ed­uca­tive and in­ter­est­ing,” says Shashank Chin­tal­giri, the then stu­dent leader of the team. “As a tech­nol­ogy demon­stra­tion mis­sion, where the pri­mary ob­jec­tive was to de­velop nec­es­sary tech­nol­ogy and skills,the Jugnu team was able to show that devel­op­ment of a com­plete, ro­bust, field-de­ploy­able tech­nol­ogy was pos­si­ble in the set­ting of an In­dian univer­sity,” he adds.Among other ob­jec­tives,Jugnu hoped to gen­er­ate imag­ing data for agri­cul­ture. As per for­mal mis­sion suc­cess pa­ram­e­ters, Chin­tal­giri pegs Jugnu’s suc­cess rate at some­where between 60 and 70 per cent.

While isro has not launched any stu­dent satel­lite af­ter 2011, many are be­ing de­vel­oped across the coun­try.

One such at­tempt is by stu­dents at Ma­ni­pal Univer­sity in Kar­nataka. Their small satel­lite, Parik­shit, aims to gen­er­ate a ther­mal map of the In­dian sub­con­ti­nent that will help iden­tify ur­ban heat is­lands. It will also demon­strate the satel­lite de-or­bit­ing tech­nol­ogy, de­vel­oped by Aus­tralia’s Saber Astro­nau­tics. “Con­ven­tion­ally, a satel­lite re­mains in or­bit,even af­ter mis­sion life.This adds to the amount of space de­bris. We are us­ing a tech­nol­ogy to pull the satel­lite down and burn it up as it re-en­ters the at­mos­phere,” says Chan­dra Shekhar,team mem­ber of the project and a BTech fi­nal year stu­dent in com­puter sci­ence. Be­fore de­ploy­ing the tech­nol­ogy on Parik­shit, stu­dent leader of the team, Ad­heesh Bo­ratkar, trav­elled to nasa to test its ef­fi­cacy in zero-grav­ity


Newspapers in English

Newspapers from India

© PressReader. All rights reserved.