Context
SpaceX launches ISRO’s GSAT-N2 communication satellite (India’s first collaboration with SpaceX)
About GSAT 20 Satellite:
- India’s newest communications satellite.
- Weight and Capacity: Weighing 4,700 kg, it has a high throughput capacity of 48 GBPS.
- Spot Beams: 32 spot beams, designed to cover all of India, with special emphasis on Northeastern India.
- Ownership and Operation: It will be owned and operated by ISRO’s commercial arm, New Space India Ltd. (NSIL).
- Launch Provider: SpaceX was chosen to launch GSAT 20 as India’s Launch Vehicle Mark 3 cannot lift such a heavy satellite.
New Space India Ltd. (NSIL):
- Incorporation: NSIL was incorporated in March 2019 as a wholly owned Government Company under the administrative control of the Department of Space.
- Capital Details: NSIL has an authorized share capital of ₹7,500 Crore and paid-up capital of ₹5,607.60 Crore.
- Role and Responsibilities:
- Commercial arm of ISRO, with a focus on enabling Indian industries to undertake high-tech space activities.
- Responsible for promoting and commercializing the products and services of India’s space programme.
| Aspect | Antrix Corporation Limited | NewSpace India Limited (NSIL) |
| Incorporation Year | 1992 | 2019 |
| Primary Role | Marketing and commercial exploitation of ISRO’s space products and services to international clients. | Promotion and commercialization of ISRO’s products and services, focusing on domestic industry participation. |
| Key Functions | – Promotion of space products and services globally. – Transfer of ISRO-developed technologies. – Facilitation of development of space-related industrial capabilities in India. | – Enabling Indian industries to undertake high-technology space activities. – Production of launch vehicles and satellites through industry. – Marketing of space-based services like transponder leasing and remote sensing. – Transfer of ISRO-developed technologies to Indian industries. |
| Target Market | International clients and markets. | Domestic Indian industries and markets. |
| Focus Area | Global commercialization of ISRO’s offerings. | Domestic capacity building and industrial participation in space activities. |
Geosynchronous Transfer Orbit (GTO):
- Definition: GTO is an elliptical orbit used to transfer satellites from lower Earth orbits to a geosynchronous orbit.
- Usage: It is the orbit that rockets use to launch satellites into geostationary orbits. The satellite is then boosted to a circular orbit at the geostationary altitude using an onboard engine.
- Key Feature: After reaching GTO, the satellite uses its onboard propulsion system to circularize its orbit and achieve geosynchronous or geostationary orbit.
Other Types of Orbits
Low Earth Orbit (LEO):
- Altitude: Typically between 160 km to 2,000 km above Earth’s surface.
- Characteristics:
- Fast orbit with high speed.
- Short orbital period (typically 90 minutes).
- Common for communication satellites, Earth observation satellites, and space stations like the International Space Station (ISS).
- Use Cases: Earth monitoring, telecommunications, and scientific missions.
Medium Earth Orbit (MEO):
- Altitude: Between 2,000 km and 35,786 km above Earth’s surface.
- Characteristics:
- Used for navigation satellites like the GPS system.
- Longer orbital periods than LEO (typically 2-24 hours).
- Use Cases: Navigation, timing, and communication services.
Geostationary Orbit (GEO):
- Altitude: Approximately 35,786 km above Earth’s equator.
- Characteristics:
- Satellites in this orbit appear stationary from the Earth’s surface because their orbital period matches the Earth’s rotation (24 hours).
- Circular orbit above the equator.
- Use Cases: Communication satellites, weather observation satellites, and broadcasting services.
Polar Orbit:
- Altitude: Typically 200 km to 1,000 km above Earth’s surface.
- Characteristics:
- Passes over Earth’s poles, allowing the satellite to observe the entire surface of the Earth over time.
- Orbiting in a north-south direction.
- Use Cases: Earth observation, reconnaissance satellites, and scientific missions.
Highly Elliptical Orbit (HEO):
- Altitude: Varies, with the apogee (farthest point) well above 35,786 km and perigee near LEO altitudes.
- Characteristics:
- Highly elliptical with an elongated shape.
- Long periods at the apogee and rapid movement at perigee.
- Use Cases: Communication satellites, especially for regions with polar coverage or limited ground access.
Sun-Synchronous Orbit (SSO):
- Altitude: Varies, typically between 600 km and 800 km.
- Characteristics:
- A near-polar orbit where the satellite passes over the same point on Earth at the same local solar time.
- The orbit precesses (rotates) in sync with Earth’s position around the Sun, ensuring consistent lighting conditions for the satellite’s sensors.
- Use Cases: Earth observation, environmental monitoring, and scientific imaging.
Source: IE
Previous Year Question
With reference to India’s satellite launch vehicles, consider the following statements:
1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors, and the second and fourth stages using liquid rocket engines.
Which of the statements given above is/are correct?
[UPSC Civil Services Exam – 2018 Prelims]
(a) 1 only
(b) 2 only
(c) 1 and 2
(d) 2 and 3
Answer: (d)
