The latest experiment of the Polish PW-Sat2 satellite
The deorbitation sail of the PW-Sat2 satellite will be opened earlier than originally planned. It was originally assumed that the satellite’s deorbit system would be launched on the 40th day in orbit at the latest, but a number of factors influenced the decision to speed up its opening. The first attempt to transmit a signal for its deployment will take place on the morning of December 29, 2018.
Teamoł of the PW-Sat2 satellite decided to accelerate the opening of the deorbit sail. The decision is hastened by fear of cosmic radiation damage to the satellite. Proba sail opening will take place on December 29, 2018. Official confirmation will not be possible until January 2, 2019 at the earliest.
During the four weeks of operation since December 3, 2018, PW-Sat2 completed all scheduled tasks, exceeded expectations many times, and successfully carried out about 150 communication sessions with the satellite. The opening of the sail will occur on signal and will be supervised by ground stations. The course of the experiment will be recorded by an array of sensorsow, and the onboard camera will take a picture of an open sail.
The process of unfurling the deorbit sail is very dynamic, and in its wake the satellite is likely to fall into uncontrolled rotation, whichore will significantly hinder the reception of data (including images) from the device.
– To supportoln the course of listening, we invite radio amateursow, thanks to whichorym we hope to receive more data than would be possible through our two ground stations located at Warsaw University of Technology and Future Processing’s headquarters in Gliwice,” said Dominik Roszkowski, deputy coordinator of the PW-Sat2 project.
The decisive announcement is planned for the morning communication session, however, experience so far indicates that the stable connection necessary for the entire procedure will only be established during one of the subsequent communication sessions that day.
The satellite’s mission is not without problemsow. During the more than 20 days of the mission, the satellite’s operators recorded at least 3 short circuits (ang. latch-up) most likely resulting from a flyby of the South Atlantic anomaly – a region above Earth with elevated levels of cosmic radiation. They caused m.in. A significant increase in electricity consumption and an increase in the temperature of someorych elementow. Happily, each time it has succeeded in restoring theoto keep the satellite operating smoothly, but the risk of permanent damage to the satellite increases with time.
It is also not insignificant that the operators of PW-Sat2 received a warning from the U.S. space junk tracking office (CSpOC) about an object threatening the PW-Sat2 satellite. – Over the past few days, we have been tracking estimates of the distance at which the object, designated SCC #39841, was expected to pass our satellite on December 27 at 9:03 a.m. Universal Time with a speed of approx. 3.6 km/s. First this distance was estimated at 147 m, then at 95 m, and finally it was about 79 m. Such situations happen relatively often in orbit, but we did not think that the first warning, whichore we get will concern such a short distance,” said Roszkowski.
This event perfectly demonstrates why the mission of the PW-Sat2 satellite is important, and the problem of space junk so topical. In the course of just 20 days, PW-Sat2, which is just a nanosatellite, was already at risk of collision. This type of situation for larger satellitesow occur much more frequently.
The problem of space junk has been growing in importance for several years. According to estimatesoThe European Space Agency had nearly 20,000 left in orbit around the Earth at the end of 2017. Garbage with a total weight of more than 8,000. tons, over whichorhino has no control. They threaten not only other satellites, but also astronauts on the International Space Station.
The deorbitation sail is a device that allows skroThe price of a satellite’s time in orbit. The structure so far enclosed in a tray with a diameter of approx. 8 cm will be released after Dyneema line burns through on signal from Earth. Within approx. poł seconds will extend to a distance of approx. 20 cm and will expand to the size ofow 2×2 m. This will dramatically increase wspohe aerodynamic drag factor of the satellite, and thus will reduce its speed in orbit. Over time, the satellite will be lower and lower until it finally burns up in the Earth’s atmosphere. According to analyses, this should happen within 12 months. A satellite without a deorbit sail would have spent up to 20 years in orbit.
