science

PW-Sat

PW-Sat 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 PW-Sat rather than just read about it. In short: PW-Sat is a series of Polish CubeSats designed and built by students at the Warsaw University of Technology in conjunction with the Faculty of Power and Aeronautical Engineering of Warsaw University of Technology, the Space Research Centre of Polish Academy of Sciences, and the European Space Agency. As of 1 January 2024, there have been 2 PW-Sats with a third in development.

Key takeaways

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

Reference excerpt

PW-Sat is a series of Polish CubeSats designed and built by students at the Warsaw University of Technology in conjunction with the Faculty of Power and Aeronautical Engineering of Warsaw University of Technology, the Space Research Centre of Polish Academy of Sciences, and the European Space Agency. As of 1 January 2024, there have been 2 PW-Sats with a third in development. The first PW-Sat was the first Polish artificial satellite which was launched 13 February 2012 from ELA-1 at Guiana Space Centre aboard Italian-built Vega launch vehicle during its maiden voyage. After their graduation, the team that developed the original PW-Sat have also worked to develop the subsequent missions, establishing a private company named PW-Sat to design and manufacturer the PW-Sats, all of which test novel deorbiting methods, with the overall goal of the program to develop solutions to space debris.

PW-Sat1

Development The PW-Sat project was created in 2004 when group of students from Warsaw University of Technology decided to build satellite compatible with CubeSat 1U standard. Initially planned for a 2007 launch, delays in the development of the Vega caused the mission to be postponed until 2012. The cost of the project was estimated to be 200,000 Polish zloty (63,205 USD), with funding coming from the university's budget, as well as from an agreement between Poland and the European Space Agency.

Hardware PW-Sat1 was a 10x10x10 cm cube with a mass of 1 kg. It is equipped with the following hardware:

EPS: power module ANTS: antenna management system COM: communication compartment PLD: elastic solar cells management sub-system OBC: main computer Access port Elastic solar cells (part of primary mission) Atmospheric drag device (part of primary mission) AX.25 transceiver CW beacon transmitting on 145.901 MHz for tracking by radio amateurs

Mission PW-Sat1 was launched on 13 February 2012, 10:00 UTC from ELA-1 at Guiana Space Centre (Kourou, French Guiana) aboard the maiden flight of the Vega rocket, together with LARES and ALMASat-1 satellites and 6 other CubeSats built by various European universities. It was deployed 1 hour 10 minutes into the flight from the P-POD-2 container, along with the ROBUSTA and MaSat-1 CubeSats. First signals from satellite were received around 12:10 UTC by radio amateurs. The first Polish reception of PW-Sat1's signals came at 12:15 UTC by CAMK in Warsaw. PW-Sat1 was planned stay in orbit until 2013, when it was planned to perform a destructive atmospheric reentry. The satellite used a large amount of the batteries' stored energy while performing tasks early in the mission. This battery depletion, combined with orbital maneuvers designed so the satellite would fly over Poland, delayed deployment of the tail. Commands of tail deployment were sent from Earth on April and May 2012, but PW-Sat did not respond to the commands. Due to a hardware issue with the communication module (that was discovered on a few other CubeSats using the same model) communication with the satellite was problematic and the tail couldn't be extended. PW-Sat1 reentered the atmosphere on 28 October 2014. Development of a successor, PW-Sat2, begun in September 2013 and was launched in December 2018.

PW-Sat2

Development PW-Sat1's successor, PW-Sat2 was also developed by students at the Warsaw University of Technology immediately after the launch of PW-Sat1. The cubesat's primary payload was a 2 m by 2 m solar sail technology demonstration, meant to de orbit PW-Sat2 as a proof of concept for the technology. However, PW-Sat2 would only deploy its sail after a 40-day window so that its secondary payload, an experimental sun sensor, can perform its tests.

Mission PW-Sat2 was launched aboard the Falcon 9 SSO-A's SERPA flight on 3 December 2018. It performed experiments with its secondary payloads and after the allotted 40 day window deployed its primary payload. The sail deployed successfully, however, pictures taken with the on-board camera showed damage to the foil. Although the exact cause of the sail's failure is not known, the PW-Sat2 team's "leading hypothesis is that temperature gradient between sail foil and arms leads to tension and breaking the foil." Despite the damage, the sail successfully shortened the time in orbit from 25 years down to around 2 years. PW-Sat2 deorbited on 23 February 2021.

PW-Sat3

Development A third cubesat, the PW-Sat3 is currently under development by students at the Warsaw University of Technology. This rendition of the satellite is expected for launch aboard an RFA One on the launch vehicle's second ever launch. PW-Sat3 will be controlled by a KP Labs Antelope on-board computer running Oryx modular flight software. The PW-Sat3's mission requires a change in altitude and as such required the design of an onboard thruster. The cold gas thruster uses butane as a propellant and will perform station-keeping maneuvers and at the end of the mission will perform the deorbiting maneuver. The satellite's launch has been significantly delayed to no earlier than late 2025 due to delays in the development of the RFA One.

Hardware Besides the aforementioned butane thruster, the 3U CubeSat will also carry the following hardware:

AOCS system: The primary payload, a custom AOCS system that will be used during propulsion maneuvers to align the satellite in the optimal orientation. EHS sensors: The secondary experiment, a series of Earth Horizon Sensors made from industrial IR matrixes. Camera module: Similarly to PW-Sat2, PW-Sat3 will have an onboard camera to document the probe and its experiments. The development team is planning on having an onboard transponder that would allow amateur radio enthusiasts to broadcast radio packets and to possibly download on-demand low-resolution images from the camera. After the completion of its scientific payloads, PW-Sat3's radio will emit a series of commemorative radio beacons before final deorbiting. The development team has also promised that all telemetry frame formats will be thoroughly described and made publicly available on the project website, as well as decoders and the accompanying software application.

Illustrations

Worked examples

Example 1 — a first encounter with PW-Sat

Start with the simplest possible case. Write down what PW-Sat 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 PW-Sat 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 PW-Sat 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 PW-Sat

In research: PW-Sat 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 PW-Sat 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: PW-Sat is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2012 in Poland, 2012 in spaceflight, 2018 in Poland, so understanding it makes those chapters shorter.
In everyday life: Look for PW-Sat 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 PW-Sat in 20 minutes

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

Frequently asked questions

What is PW-Sat in simple terms?

Why does PW-Sat 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 PW-Sat?

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 PW-Sat.