science

INSAT-1B

INSAT-1B is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand INSAT-1B rather than just read about it. In short: INSAT-1B was an Indian communications satellite which formed part of the Indian National Satellite System. Launched in 1983, it was operated in geostationary orbit at a longitude of 74 degrees east.

Key takeaways

INSAT-1B belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect INSAT-1B to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of INSAT-1B from memory before moving on to harder problems.

Reference excerpt

INSAT-1B was an Indian communications satellite which formed part of the Indian National Satellite System. Launched in 1983, it was operated in geostationary orbit at a longitude of 74 degrees east. At the end of its seven-year design life it was replaced by the newly launched INSAT-1D, dropping to backup status. In 1992, it was relocated to 93° east, before being decommissioned in August 1993. Built by Ford Aerospace and operated by the Indian National Satellite System, INSAT-1B was based upon a custom satellite bus developed for the INSAT-1 series of satellites. It had a mass at launch of 1,152 kilograms (2,540 lb), and was expected to operate for seven years. The spacecraft carried twelve C and three S band transponders, powered by a single solar array. A stabilisation boom was used to counterbalance radiation torques from the satellite's asymmetrical design. The spacecraft was propelled by an R-4D-11 apogee motor. INSAT-1B was deployed by Space Shuttle Challenger during the STS-8 mission. Challenger lifted off from Launch Complex 39A at the Kennedy Space Center at 06:32:00 UTC on 30 August 1983. INSAT-1B was deployed from the orbiter's payload bay at 07:48 UTC on 31 August, with a PAM-D upper stage firing shortly afterwards to place it into geosynchronous transfer orbit. The spacecraft used its own propulsion system to raise itself into geostationary orbit. It received the International Designator 1983-089B and Satellite Catalog Number 14318.

After some initial problems deploying its solar array, INSAT-1B became operational in October 1983. It was located at 74° east for most of its operational life, before being moved to 93° east in 1992. In August 1993 it was decommissioned and raised to a graveyard orbit slightly above geosynchronous altitude. As of 14 November 2013, it is in an orbit with a perigee of 35,741 kilometres (22,208 mi), an apogee of 35,846 kilometres (22,274 mi), inclination of 14.69 degrees and an orbital period of 23.93 hours.

References

Illustrations

Worked examples

Example 1 — a first encounter with INSAT-1B

Start with the simplest possible case. Write down what INSAT-1B claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to INSAT-1B before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about INSAT-1B ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of INSAT-1B

In research: INSAT-1B appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses INSAT-1B in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: INSAT-1B is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1983 in India, 1983 in spaceflight, INSAT satellites, so understanding it makes those chapters shorter.
In everyday life: Look for INSAT-1B outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study INSAT-1B in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what INSAT-1B means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain INSAT-1B out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is INSAT-1B in simple terms?

INSAT-1B was an Indian communications satellite which formed part of the Indian National Satellite System. Launched in 1983, it was operated in geostationary orbit at a longitude of 74 degrees east.

Why does INSAT-1B matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study INSAT-1B?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on INSAT-1B.