GS-3, Science & Tech, Uncategorized

What is the difference between GSLV and PSLV?

Both PSLV (Polar Satellite Launch Vehicle) and GSLV (Geosynchronous Satellite Launch Vehicle) are the satellite-launch vehicles (rockets) developed by ISRO. PSLV is designed mainly to deliver the “earth-observation” or “remote-sensing” satellites with lift-off mass of up to about 1750 Kg to Sun-Synchronous circular polar orbits of 600-900 Km altitude.

The remote sensing satellites orbit the earth from pole-to-pole (at about 98 deg orbital-plane inclination). 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.

Due to their sun-synchronism nature, these orbits are also referred to as “Low Earth Orbit (LEO)” which enables the on-board camera to take images of the earth under the same sun-illumination conditions during each of the repeated visits, the satellite makes over the same area on ground thus making the satellite useful for earth resources monitoring.

Apart from launching the remote sensing satellites to Sun-synchronous polar orbits, the PSLV is also used to launch the satellites of lower lift-off mass of up to about 1400 Kg to the elliptical Geosynchronous Transfer Orbit (GTO).

PSLV is a four-staged launch vehicle with first and third stage using solid rocket motors and second and fourth stages using liquid rocket engines. It also uses strap-on motors to augment the thrust provided by the first stage, and depending on the number of these strap-on boosters, the PSLV is classified into its various versions like core-alone version (PSLV-CA), PSLV-G or PSLV-XL variants.

The GSLV is designed mainly to deliver the communication-satellites to the highly elliptical (typically 250 x 36000 Km) Geosynchronous Transfer Orbit (GTO). The satellite in GTO is further raised to its final destination, viz., Geo-synchronous Earth orbit (GEO) of about 36000 Km altitude (and zero deg inclination on equatorial plane) by firing its in-built on-board engines.

Due to their geo-synchronous nature, the satellites in these orbits appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth, thus avoiding the need of a tracking ground antenna and hence are useful for the communication applications.

Two versions of the GSLV are being developed by ISRO. The first version, GSLV Mk-II, has the capability to launch satellites of lift-off mass of up to 2,500 kg to the GTO and satellites of up to 5,000 kg lift-off mass to the LEO. GSLV MK-II is a three-staged vehicle with first stage using solid rocket motor, second stage using Liquid fuel and the third stage, called Cryogenic Upper Stage, using cryogenic engine.

GS-3, Science & Tech, Uncategorized

10 facts you about ISRO’s GSLV-Mk III

The Geosynchronous Satellite Launch Vehicle-Mark III (GSLV-Mk III), the heaviest rocket ever made by India and capable of carrying large payloads, is set for launch from the Satish Dhawan Space Centre in Sriharikota on June 5, 2017.

Here are a few facts you need to know about the rocket.

1. GSKV-Mk III is capable of launching four-tonne satellites in the Geosynchronous Transfer Orbit (GTO).

2. The rocket is also capable of placing up to eight tonnes in a Low Earth Orbit (LEO), enough to carry a manned module.

3. GSLV-Mk III’s first developmental flight, D1, will carry on June 5 the GSAT-19 satellite — developed to help improve telecommunication and broadcasting areas.

4. This is India’s first fully functional rocket to be tested with a cryogenic engine that uses liquid propellants — liquid oxygen and liquid hydrogen.

5. It took about 25 years, 11 flights and over 200 tests on different components of the rocket for it to be fully realised.

6. The 640-tonne rocket, equal to the weight of 200 fully-grown Asian elephants, is the country’s heaviest but shortest rocket with a height of 43 metre.

7. GSLV-Mk III is a three-stage vehicle with two solid motor strap-ons (S200), a liquid propellant core stage (L110) and a cryogenic stage (C-25).

8. ISRO successfully conducted the static test of its largest solid booster S200 at the Satish Dhawan Space Centre (SDSC), Sriharikota on January 24, 2010. The successful test of S200, which forms the strap-on stage for the GSLV, makes it the third largest solid booster in the world. The static test of liquid core stage (L110) of GSLV-Mk III launch vehicle was done at ISRO’s Liquid Propulsion Systems Centre test facility as early as March 2010.

9. C-25, the large cryogenic upper stage of the GSLV, is the most difficult component of the launch vehicle to be developed. ISRO successfully ground-tested the indigenously developed C-25 on February 18, 2017.

10. If successful, the GSLV-Mk III — earlier named as Launch Vehicle Mark-3 or LVM-3 — could be India’s vehicle of choice to launch people into space.

Today's news

Today’s important articles/news in various newspapers (13th June)

Dear aspirants, following are the links of various articles taken from various newspapers. Click the link to read further. To get notification, follow the blog. Thank you!

1- The road from St. Petersburg

There has been a certain depressing pattern in India-Russia relations over the past decade. Annual summit-level meetings have been marked by expressions of nostalgia for the glory days of Indo-Soviet friendship , declarations of solemn intent to take contemporary relations to new heights and highlighting common perspectives even as the two countries mostly go their respective ways.

Q- In a rapidly evolving geopolitical landscape, India and Russia find a more realistic basis and more compelling reasons to work together. Discuss

Link it with GS Paper 2 (Indo-Russia Relationship)

2- More to it than MSP

The rot in farming

Agricultural distress is often viewed as a short-term phenomenon in which farmers look for support from various quarters on account of being unable to get a gainful return due to price crash, poor marketing facilities, rising credit burden, increasing cost of inputs and frequent occurrence of natural calamities.

Q- Agricultural distress has become a permanent feature due to the failure of not only policymakers but also local institutions such as community or social networks which are supposedly weakening because of increasing individualisation. Explain

3- CPI inflation slows to lowest since 2012

Retail inflation in May, at 2.18%, eased to its lowest level since the Centre began measuring it on a nationwide basis in 2012, driven in large part by cooling food prices, according to a latest government release. Separate data showed industrial output expanded by 3.1% in April.

Q- What is inflation? What is the difference between CPI and WPI inflation measurement?

4- ‘CRMs, the true future of ATMs’

Q- What is cash recycling machines (CRMs) and why are they considered futures of ATMs?

Link it with GS Paper 3 (Science and Tech)

5- Raja Mandala: Engaging an inward looking US

Q- The quest for a multipolar world has been one of the central themes of India’s foreign policy since the end of the Cold War. Comment

6- Should Constitution be amended to make Freedom of Speech a direct Fundamental Right?

Q- India should amend its Constitution and include the Freedom of Press as a direct right in the chapter on Fundamental Rights, rather than a derivative freedom of the Right to Speech and Expression . Critically Examine.

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