The Indian space programme has attained new heights in recent consecutive space expeditions undertaken. Now, when ISRO’s PSLV C-34 establishes a record of launching 20 satellites in a single go, it has added one more feather to ISRO’s cap. Earlier, India had launched 10 satellites together way back in 2008!
The PSLV C-34 consists of 20 satellites out which the largest is Cartosat 2, two student satellites and 17 foreign satellites. The unique feature of this space mission is testing the manoeuvre of India’s space capabilities of launching different satellites in different orbits in one attempt.
India’s Earth Observation spacecraft ‘Cartosat 2’ is a remote sensing satellite and a part of Cartosat series which will be useful for cartographic applications, urban and rural applications, coastal land use and regulation, utility management like road network monitoring, water distribution, creation of land use maps, precision study, disaster management, change detection to bring out geographical and manmade features and various other Land Information System (LIS) and Geographical Information System (GIS) applications. The resolution is 25 cms. It means, it will be able to image objects as small as 25 cms. So, specially near the border areas, it will be able to track the movement, thus keep vigil on border.
PSLV- why unique?
Its previous 33 flights have been successfully launched (Total 36 flights, 1 failure, 1 partial success)
It is most reliable launching vehicle of ISRO. A Time tested design.
Various versions of PSLV have been used for numerous launches, especially critical ones like maiden moon mission (Chandrayaan-I) and Mars mission (MOM).
Cost effective to private space organisations
Hence, while India is making inroads into the elite group of space experts and showing its capability with numerous indigenous space missions as well as affordable commercial services, No doubt it is called ‘workhorse of ISRO’.
Interesting à USA and Russia had powerful rockets to send the spacecraft straightaway to moon and mars. But ISRO had to use PSLV as it didn’t have powerful rocket. Using PSLV, innovative arrangement was made to reach the moon and mars by having a very large orbit and boosting it by firing booster rocket every time it came near to earth. So, without using powerful rocket, ISRO was able to send probe to moon and mars. Cost of MOM was 1/10th the of USA’s Mars Mission.
Major features of PSLV C-34
Launched 20 satellites together
Developing strong foothold amongst global space powers.
Big clientele= Private space companies of USA have also availed ISRO’s service for two reasons. One, a capable and reliable launch system. Two, most cost effective option.
Two Student satellites= shows increased interests of students, which is highly encouraging for space sector
SATYABHAMASAT– to collect data on greenhouse gases
SWAYAM– to provide point to point messaging service to HAM (amateur radio) community
Other student satellites previously launched include Youthsat, Jugnu, Studsat etc.
Uniqueness of flight
At the 4th stage of launch, after satellites are placed into orbit, its engine will be re-ignited for 5 seconds. Then it will be shut down for 50 minutes and re-ignited for another five seconds.
During this time period, after each satellite is injected into orbit, the vehicle will be re-oriented if required and the next satellite will be put into orbit with a varying velocity so that the distance between the satellites grows monotonically. This will be done to ensure that there is no collision of satellites.
Difference from the past: In 2008, all the 10 satellites were placed in same orbit at same height with small time differences.
Thus, this is crucial test of ISRO’s capability and future complex experiments
The past decade has been progressive for ISRO. Increased indigenous space missions and commercial launches have tremendously contributed to conducting new experiments for future space programmes (Aditya, Chandrayaan-II). Launches in lower orbit are continuously taking place for commercial as well as socio- economic reasons like Cartosat or others. Thus, for past decade, it can be said that ISRO is progressing as per plan.
PSLV C-34 comes within a month of another remarkable breakthrough by ISRO when first Reusable Launch Vehicle (RLV) technology-Demonstrator was launched and then recovered. RLV is in nascent stage as it will take another 10 years to have full-fledged space shuttle which will go to space and land back as an aircraft. For now, a good beginning is encouraging.
IRNSS has put all seven satellites in orbit (Operational name NAVIC- NAVigation with Indian Constellation). It is India’s big achievement to have indigenous system for navigation to provide accurate real-time positioning and timing services over India and region extending to 1500 km around India. The NAVIC would provide two services, with the Standard Positioning Service open for civilian use, and the Restricted Service (an encrypted one) for authorized users (including the military). Thus, a big boost to Indian military system due to better navigation facility through own satellites.
In another unique initiative, various government departments have been collaborating with ISRO to assess the use of space technologies or applications. Themes of Agriculture, Energy and Environment, Infrastructure, Water, Development Planning, Communication and Navigation, Weather and Disaster Management, Health and Education are expected to have space application interventions for more useful effect in governance and development activities.
3-5 years ago, ISRO was able to conduct 1-2 launches in the entire year. Now, it plans to conduct one launch per month in future. This points out to increased proficiency and additional launching facilities made at same launch site available. The pressure of commercial launches is simultaneously building up. Thus, ISRO has to make progress in rapid fashion in the space market to establish itself as reliable, affordable launch vehicle provider.
ISRO is yet to develop capabilities to launch satellites of INSAT class (They are heavy satellites of more than 2tonnes to be placed in GTOs which is possible only through GSLV). INSAT (Communication satellite) is used for telecommunications, broadcasting, meteorology, and search and rescue operations. However, it has been launched with help of foreign launch vehicles only. To holistically develop India’s space programme, India has to successfully create GSLV’s advanced versions. GSLV MkIII programme of ISRO is slated to be a game changer when it establishes mammoth capacity to launch 4-6 tonnes payload into space.
GSLV MkIII is most powerful rocket in design. It features an Indian cryogenic third stage and a higher payload capacity than the current GSLV. GSLV MkIII replaces the solid core stage with a large liquid-fuelled core stage and twin Solid Rocket Boosters with a large cryogenic upper stage stacked on top.
PSLV: Polar Satellite Launch Vehicle
Mainly to deliver ‘earth-observation’ or ‘remote sensing’ satellites
Lift off mass of about 1750kg to sun synchronous circular polar orbit of 600-900 km
An orbit is called sun-synchronous when the angle between the line joining the centre of the Earth and the satellite and the Sun is constant throughout the orbit. (Also called Low Earth Orbit)
A four staged launch vehicle. Can launch payload upto 1.5 tonnes
PSLV is classified into its various versions like core-alone version (PSLV-CA), PSLV-G or PSLV-XL variants (C-34 is XL variant)
GSLV: Geosynchronous Satellite Launch Vehicle
GSLV was primarily developed to launch INSAT class of satellites into Geosynchronous Transfer Orbits.
A three stage launcher that uses one solid rocket motor stage, one Earth storable liquid stage and one cryogenic stage.
The satellite in GTO is raised to its final destination, the Geo-synchronous Earth Orbit (GEO) of about 36,000 km altitude.
It can launch upto 2500kg in GTO and 5000kg in LEO
EDUSAT launched through GSLV MkI is India’s first satellite built exclusively to serve the educational sector through satellite based distance education.
Cryogenic fuels are the fuels that are to be stored at low temperature to maintain their liquid state.
They are used in space as in human-explorable space, there is absence of environment to support combustion (oxygen is non-existent).
liquefied gases such as liquid hydrogen, Liquid natural gas, liquid methane are options, but best combination of liquefied hydrogen and liquefied oxygen used in space engines
The thrust comes from the rapid expansion from liquid to gas with the gas emerging from the motor at very high speed. The energy needed to heat the fuels comes from burning them, once they are gasses. Cryogenic engines are the highest performing rocket motors.
Using cryogenic in GSLV MKIII makes India one of the 6 countries which are capable of producing cryogenic engines. (In Feb 2016, ISRO successfully tested indigenous High Thrust Cryogenic Engine)