astronomy

Galaxy 17

Galaxy 17 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 Galaxy 17 rather than just read about it. In short: Galaxy 17 is a communications satellite owned by Intelsat to be located at 91° West longitude, serving the North American market. Galaxy 17 was intended to replace SBS6.

Key takeaways

Galaxy 17 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Galaxy 17 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Galaxy 17 from memory before moving on to harder problems.

Reference excerpt

Galaxy 17 is a communications satellite owned by Intelsat to be located at 91° West longitude, serving the North American market. Galaxy 17 was intended to replace SBS6. It was built by Alcatel Alenia Space (which is now Thales Alenia Space), in its Cannes Mandelieu Space Center, France. Galaxy 17 was launched by Arianespace from Kourou, French Guiana on an Ariane 5 rocket along with Astra 1L. It became operational at 74° West longitude in the geostationary orbit and replaced SBS-6 which was moved out of the geostationary orbit to a parking orbit in the Graveyard orbit. This took place on July 7, 2007. Galaxy 17 began its move to 91° West longitude when Horizons-2 was launched and placed in the 74° West longitude slot. Horizons-2 was originally slated to replace SBS-6 but the launch was delayed, possibly due to the delayed repairs of the Sea Launch vessel. Galaxy 17 is the first primarily European satellite to cover the U.S. Built by a French/Italian manufacturer, it was launched on a French rocket from a French spaceport. Galaxy 17 became operational again in mid July, 2008, when it took over traffic of Galaxy 11. As Galaxy 11 has effectively been replaced, any references to Galaxy 11 can now be considered references to Galaxy 17.

See also Classic Arts Showcase – a non-profit fine arts channel broadcast from Galaxy 17

References

External links

Galaxy 17 footprint(s) at SatBeams

Worked examples

Example 1 — a first encounter with Galaxy 17

Start with the simplest possible case. Write down what Galaxy 17 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 Galaxy 17 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 Galaxy 17 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 Galaxy 17

In research: Galaxy 17 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 Galaxy 17 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: Galaxy 17 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Communications satellites in geostationary orbit, Satellite television, Satellites using the Spacebus bus, so understanding it makes those chapters shorter.
In everyday life: Look for Galaxy 17 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 Galaxy 17 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Galaxy 17 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 Galaxy 17 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Galaxy 17 in simple terms?

Galaxy 17 is a communications satellite owned by Intelsat to be located at 91° West longitude, serving the North American market. Galaxy 17 was intended to replace SBS6.

Why does Galaxy 17 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 Galaxy 17?

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 Galaxy 17.