The Short Answer: Two things can happen to old satellites: For the closer satellites, engineers will use its last bit of fuel to slow it down so it will fall out of orbit and burn up in the atmosphere. Further satellites are instead sent even farther away from Earth.
PSLV is designed mainly to deliver the earth observation or remote sensing satellites, whereas, GSLV has been designed for launching communication satellites. PSLV can carry satellites up to a total weight of 2000 kgs into space and reach up to an altitude of 600-900 km.
A new era in space flight began on April 12, 1981, when Space Shuttle Columbia, or STS-1, soared into orbit from NASA's Kennedy Space Center in Florida.
Vikram Sarabhai was an award-winning physicist, industrialist, and innovator who established ISRO. Chandrayaan 2's Vikram Lander has been named after him. Vikram Sarabhai established Indian Space Research Organisation in 1962.
NASA's Parker Solar Probe will be the first-ever mission to "touch" the Sun. The spacecraft, about the size of a small car, will travel directly into the Sun's atmosphere about 4 million miles from the surface. Parker Solar Probe launched aboard a Delta IV-Heavy rocket from Cape Canaveral, Aug.
US space agency Nasa has launched its mission to send a satellite closer to the Sun than any before. The Parker Solar Probe rocket lifted off from Cape Canaveral, Florida. The probe is set to become the fastest-moving manmade object in history.
Scientists study the Sun number in a number of ways including ground based telescopes and satellites to obtain as much information as possible. The atmosphere of the Sun varies in temperature so a whole range of wavelengths are needed to make complete observations.
Since they are twelve in number, they are referred as DvadashĀdityás.
A Lagrange point is a location in space where the combined gravitational forces of two large bodies, such as Earth and the sun or Earth and the moon, equal the centrifugal force felt by a much smaller third body.
The size of these islands varies. Each planet in the solar system has its own Lagrangian points. The islands of stability get bigger farther from the Sun and also for more massive planets. The ones associated with Earth are roughly 500,000 miles (800,000 kilometers) wide.
In the Earth-Sun system the first (L1) and second (L2) Lagrangian points, which occur some 1,500,000 km (900,000 miles) from Earth toward and away from the Sun, respectively, are home to satellites. The Solar and Heliospheric Observatory is at L1, because that point allows continuous study of the Sun.
L2 is located 1.5 million kilometres directly 'behind' the Earth as viewed from the Sun. It is about four times further away from the Earth than the Moon ever gets and orbits the Sun at the same rate as the Earth. It is a great place from which to observe the larger Universe.
Earth–MoonThe only two stable Lagrange points are L4 and L5. Lagrange points are stable if the mass of the larger body is at least 25 times the mass of the secondary body. The Earth is over 81 times the mass of the Moon.
Although a Lagrange point is just a point in empty space, its peculiar characteristic is that it can be orbited. Because halo orbits tend to be unstable, stationkeeping is required to keep a satellite on the orbit.
An unstable periodic orbit (UPO) is simply a periodic orbit which is dynamically unstable.
It is at the L3point that the combined pull of Earth and Sun causes the object to orbit with the same period as Earth, in effect orbiting an Earth+Sun mass with the Earth-Sun barycenter at one focus of its orbit.
NASA is one of the most successful space agency on the earth with a higher number of successful space missions. ISRO is more efficient and leading space agency on earth. The biggest difference is the annual budget for space missions. NASA has more budget for space missions as compared to ISRO.
Planned missions
| Mission name | Expected launch | |
|---|
| Lunar Polar Exploration Mission | 2024 | Lunar lander, rover |
| Aditya-L1 | 2022 | Solar observation |
| RISAT-1A | 2020 | Radar imaging satellite |
| NISAR | 2022 | SAR satellite |
The first of ISRO's upcoming missions will be the Radar Imaging Satellite 1A, or RISAT-1A. Chandrayaan-3, expected to be launched in early 2021, will retain the heritage of its predecessor. ISRO will then launch the Indian Human Spaceflight Programme through its Gaganyaan mission.
Chandrayaan-2 was the most complex mission ever attempted by India's space agency, Isro. Its chairman K Sivan - who had earlier described the final descent as "15 minutes of terror" - has since said the mission was "98% successful", based on the findings of an official committee.
Launch statisticsAs of 12 December 2019, there have been a total of 75 launches, including 62 successful launches, 4 partial successes, and 9 failed launches.
Pakistan, which already had five satellites in space, lacks heavy duty launchers and satellite fabrication facilities. Scientists said it would also help Pakistan keep watch on India. India is way ahead of Pakistan in space technology, with 43 operational satellites in space.
ISRO Scientist Engineer Salary Structure
| Parameter | ISRO Scientist/Engineer Salary |
|---|
| Professional update allowances | 1,875 |
| Transport Allowance (TA) | 3,600 – 7,200 |
| NPS Contribution by Employer | 8,800 |
| Net Salary | Rs. 95,059 – 1,07,635/- |
Another important reason that has attributed to their success is the fact that specialists in the field and technocrats — starting with Mr Vikram Sarabhai himself . For instance, ISRO's current chairman, Mr A.S. Kiran Kumar, is also chairman of the Space Commission and secretary of DOS.
