astronomy

Intelsat I

Intelsat I is a astronomy 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 Intelsat I rather than just read about it. In short: Intelsat I (nicknamed Early Bird for the proverb "The early bird catches the worm") was the first commercial communications satellite to be placed in geosynchronous orbit, on April 6, 1965. It was built by the Space and Communications Group of Hughes Aircraft Company (later Hughes Space and Communications Company, and now Boeing Satellite Systems) for COMSAT, which activated it on June 28, 1965.

Key takeaways

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

Reference excerpt

Intelsat I (nicknamed Early Bird for the proverb "The early bird catches the worm") was the first commercial communications satellite to be placed in geosynchronous orbit, on April 6, 1965. It was built by the Space and Communications Group of Hughes Aircraft Company (later Hughes Space and Communications Company, and now Boeing Satellite Systems) for COMSAT, which activated it on June 28, 1965. It was based on the Syncom series of satellites that Hughes had previously built for NASA to demonstrate that communications via synchronous-orbit satellite were feasible. Its booster was a Thrust Augmented Delta (Delta D). After a series of maneuvers, it reached its geosynchronous orbital position over the Atlantic Ocean at 28° West longitude, where it was put into service. It helped provide the first live TV coverage of a spacecraft splashdown, that of Gemini 6 in December 1965. Originally slated to operate for 18 months, Early Bird was in active service for 4 years and 4 months, being deactivated in January 1969, although it was briefly activated in June of that year to serve the Apollo 11 flight when the Atlantic Intelsat satellite failed. It was deactivated again in August 1969 and has been inactive since that time (except for a brief reactivation in 1990 to commemorate its 25th launch anniversary), although it remains in orbit. The Early Bird satellite was the first to provide direct and nearly instantaneous contact between Europe and North America, handling television, telephone, and telefacsimile transmissions. It was fairly small, measuring nearly 76 cm × 61 cm (2.5 ft × 2.0 ft) and weighing 34.5 kg (76 lb). Early Bird was one of the satellites used in the then record-breaking broadcast of Our World.

Model A full-scale model, or a flight test model, hung in the main lobby of the Intelsat headquarters building, Washington, D.C. before moving to McLean, VA in 2014. It was donated to the National Air and Space Museum in 2022.

Illustrations

Worked examples

Example 1 — a first encounter with Intelsat I

Start with the simplest possible case. Write down what Intelsat I claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 Intelsat I 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 Intelsat I 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 Intelsat I

In research: Intelsat I appears in astronomy 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 Intelsat I 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: Intelsat I is common in secondary-school and first-year university syllabi. It links to neighbouring topics Derelict satellites orbiting Earth, Hughes aircraft, Intelsat satellites, so understanding it makes those chapters shorter.
In everyday life: Look for Intelsat I 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Intelsat I in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Intelsat I 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 Intelsat I out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Intelsat I in simple terms?

Why does Intelsat I matter?

Because it connects several astronomy 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 Intelsat I?

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 Intelsat I.