science

Horizons Satellite

Horizons Satellite 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 Horizons Satellite rather than just read about it. In short: Horizons Satellite is a joint venture between Intelsat and SKY Perfect JSAT Group. Originally formed in 2001, pursuant to a memorandum of understanding between JSAT Corporation and PanAmSat for the launch of Horizons-1, it was renewed for Horizons-2.

Key takeaways

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

Reference excerpt

Horizons Satellite is a joint venture between Intelsat and SKY Perfect JSAT Group. Originally formed in 2001, pursuant to a memorandum of understanding between JSAT Corporation and PanAmSat for the launch of Horizons-1, it was renewed for Horizons-2. JSAT later merged into the SKY Perfect JSAT Group and PanAmSat was acquired by Intelsat, but the companies continued with the relationship, with the order for Horizons-3e. Both companies also launched a joint satellite, Intelsat 15/JCSAT-85, but instead of the equal share agreement of this joint venture, JSAT owns a specific payload of 5 transponders out of the 22 Ku band transponders of the spacecraft.

History On August 1, 2001, JSAT Corporation announced an equal share joint venture with PanAmSat, called Horizons Satellite. On September 4, 2001, it ordered from Boeing its first satellite, Horizons-1/Galaxy 13. It was a 4 t (4.4 tons) spacecraft with 24 C band and 24 Ku band transponders. It had a 10 kW power generation capacity and 15 years of expected life. On the same day of the satellite order, Boeing disclosed that it had received a parallel contract from PanAmSat, where the latter had exercised an existing option to launch Horizons-1 from its Sea Launch subsidiary. On October 22, 2002, JSAT and PanAmSat announced a joint sales agreement where JSAT's clients would gain access to PAS 2 and PAS 8, while PanAmSat's would get JCSAT-2A and JCSAT-3. A week later, on October 28, Horizons Satellites obtained permission to operate in Japan. Horizons-1 was successfully launched on October 1, 2003 aboard a Zenit-3SL rocket from the Ocean Odyssey platform in the Pacific. On June 27, 2005, JSAT and PanAmSat announced that they were renewing the partnership by ordering a second satellite, Horizons-2. This Ku band satellite would be positioned on the 74°West that belonged to PanAmSat. On August 30, 2005, Orbital Sciences announced that Horizons Satellite had ordered a small satellite based on the STAR-2 platform, Horizons-2, for the PanAmSat licensed orbital slot at 74°West. It would carry 20 Ku band transponders, generate 3.5 kW of power, weight around 2.3 t (2.5 tons) and was expected to be launched in 2007. The August 2005 take over of PanAmSat by Intelsat, did not diminished the relationship and, in fact, strengthened the alliance. On December 21, 2007, Horizons Satellite used an Ariane 5 rocket to launch Horizons-2. And, outside of the Horizons Satellite, JCSAT and Intelsat launched the joint satellite Intelsat 15/JCSAT-85 on November 30, 2009 aboard a Zenit-3SLB. On November 4, 2015, JSAT and Intelsat made a joined statement that they would add a new member to their Horizons joint venture. The satellite, called Horizons 3e, would be based on the Intelsat EpicNG platform, featuring an optimized C band and high throughput Ku band payload it would offer mobility and broadband connectivity services in the Asia-Pacific region. It was expected to use the 169°East orbital slot and launch by the second half of 2018. This would be the fourth joint satellite, along with the other two Horizons Satellite spacecraft, Horizons-1 and Horizons-2 and the separately co-owned JCSAT-85/Intelsat 15. Since this would be an investment within Horizons Satellite, it would not be considered a capital expenditure of the parent companies.

Horizons Fleet It has two satellites on-orbit Horizons-1 and Horizons-2, with a third, Horizons-3e planned for 2018.

See also JSAT (satellite constellation) - One of the two constellations under which the Horizons satellite series are managed. List of Intelsat satellites – The other constellation under which Horizons satellites are managed.

References

Worked examples

Example 1 — a first encounter with Horizons Satellite

Start with the simplest possible case. Write down what Horizons Satellite 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 Horizons Satellite 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 Horizons Satellite 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 Horizons Satellite

In research: Horizons Satellite 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 Horizons Satellite 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: Horizons Satellite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Communications satellite operators, Communications satellites of Japan, Horizons satellites, so understanding it makes those chapters shorter.
In everyday life: Look for Horizons Satellite 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 Horizons Satellite in 20 minutes

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

Frequently asked questions

What is Horizons Satellite in simple terms?

Why does Horizons Satellite 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 Horizons Satellite?

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 Horizons Satellite.