astronomy

Spaceway-2

Spaceway-2 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 Spaceway-2 rather than just read about it. In short: Spaceway-2 is part of DirecTV's constellation of direct broadcast satellites. The satellite was launched via an Arianespace Ariane 5 ECA rocket from Kourou, French Guiana on 16 November 2005.

Key takeaways

Spaceway-2 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Spaceway-2 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Spaceway-2 from memory before moving on to harder problems.

Reference excerpt

Spaceway-2 is part of DirecTV's constellation of direct broadcast satellites. The satellite was launched via an Arianespace Ariane 5 ECA rocket from Kourou, French Guiana on 16 November 2005. Its operational position is in geosynchronous orbit 35,800 kilometres (22,200 mi) above the equator at 99.2° West longitude. Spaceway-2 is a Boeing 702-model satellite with a 12-year life expectancy. It is expected to support high-definition television to DirecTV customers with its Ka-band communications payload. Although Spaceway-2 was originally built by Boeing to be used for broadband Internet access via Hughes Network Systems, it has been retrofitted to deliver HD local channels (NBC, ABC, CBS, and Fox) to numerous markets nationwide. On 19 April 2006, the satellite was delivered to DirecTV's control after successful on-orbit testing. Spaceway-2 immediately started broadcasting HD locals to DirecTV customers in eight more markets: Minneapolis, Minnesota; Sacramento and San Diego, California; Pittsburgh, Pennsylvania; Nashville, Tennessee; Kansas City, Missouri; Columbus, Ohio; and Birmingham, Alabama. Satellites named T10 (launched in 2007) and T11 (launched in 2008), constructed by Boeing, also for use in high-definition television, are bent-pipe Ka-band satellites instead of regenerative satellites, and are being used to continue the expansion of DirecTV's HD services. Spaceway-2 was originally envisioned as a global Ka-band communications system. Boeing retrofitted the Spaceway-2 satellite for bent-pipe Ka-band communications for use in high-definition television and disabled the regenerative on-board processing of the original system that was to be used for the Spaceway broadband satellite communications. T11 is co-located with Spaceway-2 satellites in order to use the 500 MHz of unused spectrum for HDTV broadcasting. This spectrum was originally intended for the broadband internet capabilities of the two Spaceway satellites which were disabled by Hughes Network Systems at the request of DirecTV.

Worked examples

Example 1 — a first encounter with Spaceway-2

Start with the simplest possible case. Write down what Spaceway-2 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 Spaceway-2 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 Spaceway-2 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 Spaceway-2

In research: Spaceway-2 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 Spaceway-2 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: Spaceway-2 is common in secondary-school and first-year university syllabi. It links to neighbouring topics American spacecraft stubs, Communications satellite stubs, Communications satellites in geostationary orbit, so understanding it makes those chapters shorter.
In everyday life: Look for Spaceway-2 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 Spaceway-2 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Spaceway-2 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 Spaceway-2 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Spaceway-2 in simple terms?

Spaceway-2 is part of DirecTV's constellation of direct broadcast satellites. The satellite was launched via an Arianespace Ariane 5 ECA rocket from Kourou, French Guiana on 16 November 2005.

Why does Spaceway-2 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 Spaceway-2?

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 Spaceway-2.