astronomy

PoSAT-1

PoSAT-1 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 PoSAT-1 rather than just read about it. In short: PoSAT-1 (OSAT-OSCAR 28, OSCAR 28, PO 28, 1993-061G), the first Portuguese satellite, was launched into orbit on 26 September 1993, on the 59th flight of the Ariane 4 launch vehicle. The launch took place in the Centre Spatial Guyanais, French Guiana.

Key takeaways

PoSAT-1 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PoSAT-1 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PoSAT-1 from memory before moving on to harder problems.

Reference excerpt

PoSAT-1 (OSAT-OSCAR 28, OSCAR 28, PO 28, 1993-061G), the first Portuguese satellite, was launched into orbit on 26 September 1993, on the 59th flight of the Ariane 4 launch vehicle. The launch took place in the Centre Spatial Guyanais, French Guiana. About 20 minutes and 35 seconds after launch, at an altitude of 807 km, PoSAT-1 separated itself from the launch vehicle. The PoSAT-1 weighs about 12 kg and belongs to the class of microsatellites, which are between 10 and 100 kg. The entire project was developed by a consortium of universities and companies in Portugal and was built at the University of Surrey, United Kingdom. The total cost was around €5 million, about €3 million paid by the Portuguese Government and €2 million by the Portuguese companies involved (Po-SAT consortium: Instituto Nacional de Engenharia, Tecnologia e Inovação (INETI), EFACEC, ALCATEL, Marconi Company, OGMA, Instituto Superior Técnico (IST), University of Beira Interior (UBI) and CEDINTEC). The responsible for the project was Fernando Carvalho Rodrigues, known as the father of the first Portuguese satellite.

Mission The mission was called Flight 59, which launched several satellites: PoSAT-1 from Portugal, Eyesat-1 and ItamSat from Italy, KITSAT-2 from South Korea, HealthSat-2 (an international medical satellite) and Stella and SPOT-3 from France, the latter one a large satellite for Earth imaging photography.

Spacecraft The PoSAT-1 is a box of aluminum, in the form of a parallelepiped, 58 cm long, 35 cm wide, 35 cm depth and weighs 12 kg. Over a first drawer that contains the batteries and the remote detection module are stacked 10 other drawers full of electronic cards. At the top of the satellite there are sensors for attitude and the stabilization mast, essential tools for PoSAT-1 to maintain correct orbit. Four solar panels are mounted on the lateral sides of the structure of the satellite, forming a parallelepiped, which are the source of energy for all on-board systems. Each panel contains 1344 cells of Gallium arsenide (GaAs).

Numbers Speed: 7.3 km per second. Orbit: 822 x 800 km, inclination of 98.6°, Sun-synchronous orbit, lasts 101 minutes, revolves around the Earth around 14 times per day.

End of mission PoSAT-1 stopped transmitting information to Earth in 2006. Its re-entry is expected to be happen in 2043.

Illustrations

Worked examples

Example 1 — a first encounter with PoSAT-1

Start with the simplest possible case. Write down what PoSAT-1 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 PoSAT-1 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 PoSAT-1 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 PoSAT-1

In research: PoSAT-1 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 PoSAT-1 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: PoSAT-1 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Amateur radio satellites, Derelict satellites orbiting Earth, First artificial satellites of a country, so understanding it makes those chapters shorter.
In everyday life: Look for PoSAT-1 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “PoSAT-1” →

Affiliate

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

How to study PoSAT-1 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PoSAT-1 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 PoSAT-1 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PoSAT-1 in simple terms?

Why does PoSAT-1 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 PoSAT-1?

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 PoSAT-1.