science

OPS 5113

OPS 5113 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 OPS 5113 rather than just read about it. In short: OPS 5113, also known as Navstar 3, GPS I-3 and GPS SVN-3, was an American navigation satellite launched in 1978 as part of the Global Positioning System development programme. It was the third of eleven Block I GPS satellites to be launched.

Key takeaways

OPS 5113 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect OPS 5113 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of OPS 5113 from memory before moving on to harder problems.

Reference excerpt

OPS 5113, also known as Navstar 3, GPS I-3 and GPS SVN-3, was an American navigation satellite launched in 1978 as part of the Global Positioning System development programme. It was the third of eleven Block I GPS satellites to be launched.

Background Global Positioning System (GPS) was developed by the U.S. Department of Defense to provide all-weather round-the-clock navigation capabilities for military ground, sea, and air forces. Since its implementation, GPS has also become an integral asset in numerous civilian applications and industries around the globe, including recreational used (e.g., boating, aircraft, hiking), corporate vehicle fleet tracking, and surveying. GPS employs 24 spacecraft in 20,200 km circular orbits inclined at 55°. These vehicles are placed in 6 orbit planes with four operational satellites in each plane.

Spacecraft The first eleven spacecraft (GPS Block 1) were used to demonstrate the feasibility of the GPS system. They were 3-axis stabilized, nadir pointing using reaction wheels. Dual solar arrays supplied over 400 watts. They had S-band communications for control and telemetry and Ultra high frequency (UHF) cross-link between spacecraft. They were manufactured by Rockwell Space Systems, were 5.3 m across with solar panels deployed, and had a design life expectancy of 5 years. Unlike the later operational satellites, GPS Block 1 spacecraft were inclined at 63°.

Launch OPS 5113 was launched at 00:28 UTC on 7 October 1978, atop an Atlas F launch vehicle with an SGS-1 upper stage. The Atlas used had the serial number 47F, and was originally built as an Atlas F. The launch took place from Space Launch Complex 3E at Vandenberg Air Force Base, and placed OPS 5113 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-27 apogee motor.

Mission By 13 November 1978, OPS 5113 was in an orbit with a perigee of 20,285 km (12,605 mi), an apogee of 20,312 km (12,621 mi), a period of 722.60 minutes, and 62.80° of inclination to the equator. The satellite had a design life of 5 years and a mass of 758 kg (1,671 lb). It broadcast the PRN 06 signal in the GPS demonstration constellation, and was retired from service on 18 May 1992.

Worked examples

Example 1 — a first encounter with OPS 5113

Start with the simplest possible case. Write down what OPS 5113 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 OPS 5113 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 OPS 5113 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 OPS 5113

In research: OPS 5113 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 OPS 5113 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: OPS 5113 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1978 in spaceflight, GPS satellites, Spacecraft launched in 1978, so understanding it makes those chapters shorter.
In everyday life: Look for OPS 5113 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 OPS 5113 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what OPS 5113 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 OPS 5113 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is OPS 5113 in simple terms?

Why does OPS 5113 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 OPS 5113?

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 OPS 5113.