Roy Orbach, one of the students participating in the development of the Dokifat 2 satellite tells the story of the first student satellites in Israel * Dokifat 2 will be part of a network of 50 2U nanosatellites built by universities and research institutes from all over the world. The second task will be done by the satellites that will be built - each satellite will be given a research task in one of the fields: measuring plasma density, a multi-satellite communication experiment, and an experiment in space debris removal.
The story of the first student satellites
Some of you must have heard when exactly about a year ago the satellite "Dokifat 1" was launched which was launched a year ago, on June 19, 2014. Something that appeared in newspapers, on the internet and on television. About this satellite, which received the titles "the first European student satellite" and "the first Israeli tiny satellite", there is much more information than what was written in the various articles that were written about it during and after its launch. In this article I will summarize the information about Dokifat 1, Dokifat 2 and the project itself, as a student in the project.
Dokifat is a satellite of the cube satellite type (CubeSat), a type of small cube-shaped satellites, where the size of Dokifat is 10x10x10 cm, or U1 in terms of cube satellites. Dokifat has several purposes: an educational purpose, to act as a satellite for radio amateurs, to test the possibility of building the satellites by students and use as a search and rescue satellite, tasks to which I will detail later.
The idea to build the first student satellite Dukifat 1 began in 2003, when Dr. Anna Heller, who saw children and youth as the future generation, initiated a project during which the students would design and build a satellite. After obtaining a job and funding, work began on the satellite components and practical research.
As part of the project, which is considered for the students as a final project in engineering sciences, the students were divided into work teams, according to the areas of responsibility in the satellite - communication, the electrical system, direction control, software, heat control, system engineering and more, when each group was assigned a professional guide who led the student team with the help of Providing tasks and help when needed.
As I wrote, to condense several tasks: the educational task of the satellite is to teach students about building a satellite and communicating with satellites. The next task is his activity as a radio amateur satellite - a hobby in which people all over the world talk with the help of radio connections, when Dokifat will help them establish contact with each other. Dokifat picks up frequencies of radio amateurs who tune in to it, and directs them on, thereby enabling better connections between radio amateurs in other parts of the world. The third mission, which is quite self-explanatory, is to try the issue of building a satellite by students, and the last mission of the satellite is the main mission - Dokifat will be used as a search and rescue satellite for lost travelers and to test the experimental communication protocol
APRS (Automatic Packet Reporting System), a protocol by which location and messages can be transmitted over the radio waves.
Duchifat's orbit, which is adapted to its mission, passes between the poles of the Earth in the range of altitudes that are considered a low satellite orbit, an altitude of about 600 kilometers. Due to the characteristics of its orbit, Duchifat passes anywhere on Earth twice a day with a difference of about an hour and a half between the first pass and the second. For his mission, dochipat Oger from any point in his reception area together with the points of interest from which he was received The signal keeps the information for one day and when it passes over a ground station it sends the signal and the station personnel transmit the information to the rescue services of the area in question, thus helping to save the life of the lost traveler. If the satellite does not pass over a station within twenty-four hours, it will delete the The signal means that he will soon pass through the area where the signal was received and he will be able to get more updated information about the traveler's location Mobile, a device that does not require cellular reception and therefore enables rescue even in areas where it is weak or missing.
During the ten years after the start of the project, a dedicated space laboratory for the design and development of the Dokifat 1 satellite was built at the Science Center in Herzliya, managed by Dr. Meir Ariel, who helped and supported decisions related to the satellite, with the help of the Israeli Radio Amateurs Association. In the laboratory, the project students worked on several things, among other things they prepared a "clean room" - a room with a pressure system that takes care of a minimal amount of dust and moisture, something that took a lot of work to meet the standards so that during assembly the satellite components would not be damaged. The students also worked on preparing a ground station for communication with satellites, with the help of the radio enthusiasts. A ground station is actually a room that includes radio receivers (receiver and transmitter) and devices that enable tracking and communication with satellites in space with the help of antennas. At the ground station, they also tested the communication system of the Incline satellite, a satellite of the Israeli Association for Small Satellites, and the station is also used for the hobby of radio enthusiasts, a hobby During which people from all over the world talk to each other with the help of radio frequencies when they use antennas and satellites to improve the connection between them at the ground station, The students of the project receive the satellite twice a day and store the information collected.In addition, the satellite was recently opened for communication with radio amateurs in order to test its function.
After completing the construction and assembly of the laboratory, the project students worked on software that facilitated communication with the future satellite from the ground and worked on its function and management. In addition, in the built station, the students communicated with satellites in order to learn about satellite communication, when during these operations they communicated with satellites for radio, weather and research enthusiasts, and even renewed the connection with the Technion satellite, which is considered inactive, techsat-1.
In October 2013, work began on actually assembling the satellite, when at the end of the assembly the software was burned into the satellite and its tests began. When all the software tests were done, the satellite was sent for additional tests - vacuum, antenna layout, vibration, temperature changes and more. Finally, it was sent to the Netherlands for final tests and placement in the chamber from which it would be ejected into space from the rocket - when it was accompanied by project representatives for the launch.
After successfully launching Dokifat 1 on July 19.7.14, 36, in a launch that broke the launch record with the largest number of satellites - along with XNUMX other satellites from all over the world, it took its place as the second student satellite in the world - and the first European student satellite. It was an exciting moment, which summed up more than a decade of hard work and unceasing work by the founder of the project, Dr. Anna Heller, the head of the Science Center, Dr. Meir Ariel, and many other people who contributed along the way, including past and present students of the project, some of whom did not get to see the Launching the satellite.
Already during the construction of Dokipat 1, his team prepared and sent forms in order to participate in a European project called "QB50", forms which passed the screening and gave the project the green light to start the construction of Dokipat 2, which I will detail now.
Duchifat 2 is part of the "QB50" project, a project that has several goals. One goal is to test the possibility of launching a network of 50 2U nanosatellites built by universities and research institutes from all over the world. The second task will be done by the satellites that will be built - each satellite will be given one task out of four research tasks in the lower layer of the thermosphere, the ionosphere, a layer that is approximately 300 kilometers high. This layer is too high for research balloons, which do not reach these heights, but satellites that orbit the Earth in this layer are constantly lowered until they crash after a few months, and therefore it has not been studied before. Recently, with the advancement and miniaturization of technology and the technology of tiny satellites and cubesats in particular, the agency decided the European space that instead of sending a large satellite that costs a lot to assemble, plan and launch they will send 50 For tiny satellites that will also explore more space together, both cost less and are easier to launch compared to a large satellite - this is how the "QB50" project began.
After checking the details of the candidates, nearly 50 research institutes and universities were selected, with only one Israeli representative, which also took its place as the only group where the engineers are high school students - the Science Center group. The group of Dokifat 2 consists of several smaller groups, which were added after Dokifat 1 in order to bring science closer to groups from the periphery. These groups work on different parts of the satellite - building a control center, direction control, system engineering and more.
Along with all the changes and the start of work, even after the launch of Dokifat 1 there was no time to rest and we started working on the challenge - to build a high-level scientific and research satellite in a period of less than a year.
The mission chosen for Hoopoe 2 (or "Hoopoe" in English, after the translation of Hoopoe in English) is the investigation of the plasma density in the lower thermosphere layer. It will start from an altitude of about 380 kilometers and descend, when after about nine months it will reach a low altitude and decay in the atmosphere. Another task of the team, which was given to all the teams participating in the project, is to collect information from several satellites, including her satellite, and send it to the European Space Agency.
There are many differences between Duchift 1 and Duchift 2. The most notable difference is the size - Dokift 2, a 2u cube satellite, is twice as large as Dokift 1, so it requires a heat control system, unlike Dokift 1. In addition, unlike Dokift 1 it moves without control in a spin motion, because of the sensors that carry out its research
(Multi-Needle Langmuir Probe) Duchift 2 satellite is required to maintain the direction of the sensors with the direction of movement, in order for the dedicated payload to perform the tests in the best way - something that requires the direction control system. The problem with the aiming system is that there are no motors for satellites of this size, therefore devices are used that align the satellite according to the magnetic field of the Earth and with the help of this rotate the satellite - something that requires complicated physical calculations and a lot of work.
The satellite is planned to be launched in February 2016, along with the other satellites of the European project. Work on Dokifat 2 is already underway - the ground station team is already working on communication software with the satellite, the clean room team is preparing the clean room for the arrival of the components and purifying it and the other teams such as heat control, electrical control, direction control and software are already working on the science behind the satellite and solving the problems that arise during its construction.
Director of the Herzliya Science Center: 16-year-old children are able to carry out advanced research and development
By Avi Blizovsky
Dr. Meir Ariel, Director of the Science Center in Herzliya. He presented the Dokifat 2 project about two weeks ago at the Herzliya conference.
Initially, he described the students' self-screening process and added that the most talented among them become members of the Satellite and Space Laboratory and actually participate in the construction of a satellite. The essence of the project is research and development processes, analyses, simulations, tests and even business development and public relations in a very similar way to what is carried out in the industry.
What is interesting about space and makes it exciting is that it is multidisciplinary and brings together many fields of knowledge - physics and astrophysics, communication, mechanics and control, thermodynamics, electrical engineering and computer science. The variety of fields allows each student to choose a topic that is close to their heart, to focus on it, to study it on its own merits and to do significant research work in this field. The students do not do general research. They choose for themselves some subsystem in the satellite and focus on it. A child who started the project in the 16th grade usually reaches its peak in the XNUMXth grade. Young and talented children do not need more than six months to a year to reach their peak. There are a lot of power control algorithms, airborne logic, satellite communication protocols that are part of the satellite airborne system and XNUMX year olds developed it.
The project arrived and matured to launch a satellite - Dokifat 1 - the first Israeli tiny satellite and the first European satellite designed and built by high school students.
Dokifat 1 is a search and rescue satellite from space and a unique pedagogical platform for the promotion of scientific education in Israel. It was launched on June 19, 2014 from Russia. This tiny satellite (holds up his copy) orbits the earth every 90 minutes, all systems work like an orderly and there is no erosion in performance. And for those who need proof - this is proof of the quality research and development work that 15-16 year olds can produce.
As a demonstration of the differences in the order of magnitude between the satellites built by the Aerospace Industry and the tiny satellite - it was swallowed both in the vacuum chamber and on the vibration test surface and these are the smallest possible facilities - it was necessary to adapt a system that usually performs vibration tests for satellites weighing several tons in order to test an 860 gram satellite.
This illustrates the fact that there is no civil infrastructure in Israel designed to support the academy, the education system, scientific centers and also small companies.
To enable an educational project, the aerospace industry had to disable half of the clean room.
Dokifat 2 is a small scientific satellite for near space exploration. It will be a more sophisticated scientific satellite, it is part of a European-wide program that includes: measuring plasma density, a multi-satellite communication experiment, and an experiment in space debris removal. It will be launched by the European Space Agency.
Since the issue is so challenging, we thought in the municipality of Herzliya, together with the Ministry of Science, to take it out of the Tspanovan bubble and give an opportunity to the students of the periphery who are no less talented than the children of Herzliya. To this end, we have opened five research and development centers in the periphery: a center in Ofakim that will deal with the development of the system, a center in Yeruham that will deal with the mechanical design, a school for girls from the settlement of Ofra (control of the direction), the science school of the Bedouin diaspora in Ahad - control and control, and of course the center for sciences in Tselia that will be responsible for a system The operation, communication and ICT.
Now a hundred gifted students are working together on the project, most of them girls, some Olafna girls from religious education and Bedouins - Muslim, religious and secular Jews, all working together in one team in harmony for a common goal. It creates pride for students, parents, teachers, in the sense of achievement.
Photo Gallery
More of the topic in Hayadan:
The student satellite Dokifat 1 was successfully launched from Russia
The administrator of the students' satellite Dokifat 1 Mead Parinta: the satellite works perfectly * Yonatan Weintraub, SpaceIL: projects like this encourage science and engineering studies
The new space is taking off: space engineering in the NEW SPACE era, Prof. Haim Ashad
17 תגובות
Yuri, thanks for your interest.
It's even more complicated than you think. In order for the patent to work, the signal differences from satellites 30,000 km away need to be measured at 50 nanoseconds (Duchift is much closer). The deviations in the devices can easily disrupt the measurements, but I may have found a solution for this.
Roy, thanks for the response, I sent you an email.
Israel
I asked several people and it turns out that your question, which seems simple, is actually a very complex question. No one could answer. This week I will receive another answer from another source, but I guess he too will have difficulty answering.
By and large, I understood that this was possible. But it probably involves factors that are (very) complex.
I would appreciate it if you could update us on the answers you received from all the sources you contacted.
Shalom Israel ,
I have forwarded your question to the person responsible for the satellite communications team. Could you write a message to the following email so that I can contact you when a solution is found?
Royorbach@gmail.com
Astronzo
I have been receiving signals from satellites, weather satellites, communication and radio stations (SIRIUS XM) for a long time. The problem is not coding but the opposite: displaying the raw frequency, the subject, on an oscilloscope.
The problem is the background noise and the built-in delay that exists in the receivers, which causes instability in the received signal. What's more FM modulation is not very useful because it is almost impossible to detect the modulating frequency, unlike AM or SSB where it can be directly viewed.
I've posed the question on several blogs, hopefully I'll get some helpful responses.
Israel
You with your projects will end up being the first person to contact extraterrestrials 🙂
Anyway, the signals from satellites are not coded or something like that? Maybe the problem is not receiving the signal but that the device will be able to decode it right? If you had said from the beginning that you were trying to receive a signal from the satellite...
I will ask for you some people I know who understand this, maybe they will have an answer.
Hello Roy
Question: Do you or anyone have experience in radio amateurs? I need help with a certain project that requires receiving radio signals from satellites.
Thanks.
Reply to someone:
Since radio amateurism is a worldwide hobby, there would be no way he wouldn't pass over a station for a day - especially considering that he passes over our station twice a day.
Response to Yossi:
You are welcome to see this project as "unrealistic", but it exists and knowing many people is a success. Regarding the knowledge of physics and mathematics, I can reassure you that every student in the project does 5 units in mathematics, with some also in physics, and that the students are not extras who are there to raise money. I am sure that if you had personally met the students of the project your opinion would have changed.
In one of the comments on Facebook, teacher Anna Heller wrote:
A few add-ons: Duchifat2 was accepted for the QB50 project already 3 years ago. The satellites are from 27 countries. The launch was recently postponed to 2017. Duchifat2 is the only Israeli satellite in the project. In the picture Prof Haim Eshed presenting the 2 satellites.
Doesn't sound realistic to me and maybe I'm old fashioned. I was at Sharet Netanya High School at an introductory evening for parents and children and there they also talked about a master class. They have no knowledge of physics, mathematics and no maturity. These are more PR projects of an industrially developed satellite and tied crowns to children. The kids there rush to use concepts they don't understand like black holes, before they understand physics 5 units. The managers are excited to present it as research, I haven't seen too much.
Hope there is time left for my core studies.
"Dokifat Oger from any point in his area of receiving distress signals together with the landmarks from which the signal was received, saves the information for one day and when he passes over a ground station, he sends the signal and the station personnel pass the information to the rescue services of the area in question, thus helping to save the traveler's life Lost. If the satellite does not pass over a station within twenty-four hours, it will delete the signal because it will soon pass the area where the signal was received. And he will be able to get more up-to-date information about the location of the traveler"
It doesn't sound very smart... and what if they don't pick up signals at the second crossing? Maybe a malfunction in the device that transmits the distress signals will not allow it to continue transmitting? Why rush to delete the important signals that were received and could save human lives before first making sure that new signals were received?