Back on the 1st of December 2023, Ireland’s first satellite, EIRSAT-1 was launched onboard a SpaceX Falcon 9 rocket. The EIRSAT-1 control team revealed recently that the satellite was almost lost.
Shortly after launch, the satellite was rotating at 5 degrees per second taking 72 seconds to do a full rotation which was in line with expectations. However, that rotation speed increased and it was soon doing 30 degrees per second taking 12 seconds to do a full rotation. By the time the control station in Dublin had established contact with it, it was spinning at 50 degrees per second and getting faster.
In an interview, Eirstat-1 engineering manager Prof David McKeown said... “If it keeps spinning faster and faster, you won’t be able to communicate with it and you’ll lose the mission. The faster it gets, the harder it is to make it slow down again. Once it gets to a certain speed you can’t even send the commands to it to slow it down. This was very worrying. If it went on, that would have been curtains for us.”
To get a handle on what was going on, the control team had to do simulations on the ground and came up with a solution to slow down the rotation.
Prof McKeown continues... “It is so much work, so much time over so many years. You get a mixture of relief and happiness. It is absolutely a technical success. We took no shortcuts. It was years of testing and it’s years of work that has paid off. We couldn’t be happier with the way things are working. All the critical systems are healthy. We have got data back from one of our payloads.”
The cubesat is going to be launched with 24 other satellites on a SpaceX Falcon 9 rocket from the Vandenberg Space Force Base in California at 18:19 UTC on Friday 1st December 2023.
Other satellites on board include KOREA's 425, Space BD’s ISL48, SITAEL’s uHETSat, D-Orbit’s ION SCV Daring Diego, York Space Systems’ Bane, and PlanetIQ’s GNOMES-4. This is also the 17th flight of the first stage booster supporting this mission, which previously launched Crew-1, Crew-2, SXM-8, CRS-23, IXPE, Transporter-4, Transporter-5, Globalstar FM15, ISI EROS C-3, and seven Starlink missions. Following stage separation, the first stage will land on Landing Zone 4 (LZ-4) at Vandenberg Space Force Base.
Sequence of events... Here is a timeline of what is expected to happen...
18:19 UTC - T=0 - Launch of Falcon 9 from California.
19:49 UTC - T+90 mins - EIRSAT-1 injected into a 520-km Sun-Synchronous Orbit somewhere over Norway.
20:34 UTC* - T+135 mins - Satellite’s antenna deployment somewhere over the South Pacific.
20:45 UTC* - T+146 mins - EIRSAT-1 will pass to the south of New Zealand & Australia. Is it in range? If it is, it's likely to be very low in the southern sky.
20:58 UTC* - T+159mins - EIRSAT-1 will pass over South Africa.
21:18 UTC* - T+180 mins - EIRSAT-1 over Europe
*Approx
Frequencies...
EIRSAT-1 is not a communications satellite and does not relay signals. It has a number of experiments on board and it will transmit telemetry back to earth on the 70cms UHF band, at a frequency of 437.100 MHz.
The downlink is GMSK modulated at a data rate of 9600 bps. Instructions for decoding the EIRSAT-1 beacon are available on the EIRSAT-1 instruction page.
Doppler Shift... As EIRSAT-1 will be traveling at about 27,000kms per hour, there will be a significant amount of doppler shift on the signal at 437 MHz. The amount of doppler and how fast it changes will depend on whether the satellite is going directly overhead or is passing to the east or west and not too far above the horizon.
As a guide, you should tune to 437.110 MHz to first hear the satellite. As you track it, it will move down in frequency and it should be down around 437.090 MHz as it moves out of range.
QSL Card from the European Space Agency... The first confirmed recording of EIRSAT-1 from each continent (Europe, Africa, Asia, North America, South America, and Oceania) within a week of launch will be rewarded with a QSL card from ESA. These “special postcards” confirm that radio contact was made, and will include acknowledgement of the help given by the winners to ESA and the EIRSAT-1 team in acquiring the first signals from EIRSAT-1.
To enter this competition, please send in your recording, timestamp of passage over your ground station, and the location of your ground station to cubesats AT esa DOT int. Be sure to include “EIRSAT-1 competition” in the subject of the e-mail.
EIRSAT-1 Control Room in Dublin
EIRSAT-1 Experiments... EIRSAT-1 is Ireland’s first satellite, and was designed, built, and operated by students with the support of ESA Education’s Fly Your Satellite! programme. In addition to the radio transmitter, EIRSAT-1 houses three main experiment payloads, which were built from scratch by the student team:
GMOD is a detector to study gamma ray bursts, which are the most luminous explosions in the universe and occur when a massive star dies or two stars collide.
EMOD is an experiment to see how a thermal treatment protects the surface of a satellite when in space.
WBC will test a new method of using Earth’s magnetic field to change a satellite’s orientation in space.
Video... This non-technical 22-min video intended for the general public gives an overview of how EIRSAT-1 was conceived and built.
'EIRSAT-1' stands for 'Educational Irish Research Satellite' and it will be Ireland's first satellite. It is a 2U CubeSat being developed as part of the European Space Agency's Fly Your Satellite programme.
The satellite which cost €1.5 million to develop will carry three science experiments and the downlink frequency for the data will be in the 145 MHz amateur radio band. It is expected to launch in 2023.
The British Interplanetary Society have an article about the new Irish satellite in their quarterly Space Chronicle journal. The January 2023 edition is available to members of the British Interplanetary Society... info HERE
EIRSAT-1 stands for the Educational Irish Research Satellite 1. It is a satellite about the size of a shoe box, called a CubeSat. It is a small-scale satellite but still needs the same functionality as a large mission.
The satellite must be able to power itself, orientate itself in space, communicate to the ground station being built on the roof of the UCD School of Physics and collect data from the three science experiments on-board.
EIRSAT-1 in the lab
The first experiment is a novel gamma-ray detector, GMOD, which is being developed in UCD. GMOD will detect gamma-rays from both cosmic and atmospheric phenomena.
The second experiment, EMOD, consists of a payload developed with Irish company, ENBIO Ltd., to monitor the in-flight performance of their thermal spacecraft treatments, SolarWhite and SolarBlack.
The third experiment, Wave Based Control (WBC), is a novel attitude control algorithm, developed in the UCD School of Mechanical and Materials Engineering, which will be tested for the first time in space on EIRSAT-1.
In February 2022, the payloads, GMOD and EMOD, and the antenna deployment module were qualified for space flight. In the last year, the payloads have been subject to environmental testing at the ESA CubeSat Support Facilities in Belgium.
During the lockdown and Covid-19 restrictions, the team has been operating the satellite remotely. The satellite hardware must be kept in a ISO Level 8 cleanroom in a lab in the UCD School of Physics. Hairnets, gloves and anti-static coats have to be worn to prevent dust and contaminants landing on the satellite components.
A private YouTube stream is used to monitor the hardware in the cleanroom and Discord is used for operators to converse during satellite testing and share screens to see the outputs of the on-board computer.
Hopefully all going well a launch date for next year (2023) is a go.
I have been talking to the team in UCD, and they would love to get feedback from radio amateurs on signals reports from the new satellite after its launch's next year.
They will provide the frequencies after launch.
I wish them the best of luck and look forward to giving signal reports.
Lez, EI4GEB
Some RF info...
On-board Communications: The on-board CMC (Common Mode Current) transceiver is the space-qualified CPUT VUTRX transceiver supplied by ClydeSpace. The communications system uses UHF downlink (430-440 MHz) and VHF uplink (140-150 MHz) bands. The transceiver provides 9600 baud downlink and 1200 baud uplink, and implements a GMSK downlink and AFSK uplink configuration. The AX.25 protocol is used for uplink packets, while a CCSDS convolutional encoder may be used for downlink.
ADM (Antenna Deployment Module): EIRSAT-1 will use a custom ADM designed and built at UCD which will be mounted on the -Z end of the satellite deploys two dipole antennas, one for UHF downlink and one for VHF uplink. Both dipoles are composed of two tape spring antenna elements, deployed from opposite sides of the module, as seen in many previous and COTS antenna designs. The elements are 5 mm wide, made from a Copper Beryllium alloy and attached to spring loaded doors at each side of the module. They are coiled inside the ADM before deployment, within the 7 x 100 x 100 mm overall dimensions of the module. When EIRSAT-1 is clear of the CubeSat deployer the ADM will activate a burn wire release mechanism allowing the module doors to open and the elements to uncoil into their operational positions and stay in that configuration for the remainder of the mission.
From the IRTS News - 16th Oct 2022... Jeremy Boot G4NJH reports on Amateur Radio Newsline that the team developing EIRSAT-1 has returned from Belgium, where the project underwent rigorous testing at the CubeSat Support Facility, including an assessment to ensure it would survive launch. The University College Dublin team includes David Murphy, EI9HWB, and Lána Salmon, EI9HXB. They are developing the low-earth-orbit CubeSat as part of the European Space Agency's "Fly Your Satellite" programme. ESA administrators have said in the past that they view the project as a way to grow a new generation of space scientists and engineers to nurture a space programme for Ireland. The satellite is tentatively scheduled for a launch from an ESA base in French Guiana by early 2023. The Project's website is at www.eirsat1.ie .
EIRSAT-1 is due to be released from the International Space Station sometime in 2021 and this will be Ireland's first satellite in space. See previous post.
South Dublin Radio Club are organising a special ZOOM presentation with two of the EIRSAT-1 team members on Tuesday the 27th of October 2020 at 9pm Irish time (21:00 UTC).
During the presentation, they will discuss how they will communicate with the satellite from the ground station at University College Dublin and how others can listen in and contribute as well.
EIRSAT-1 is Ireland’s first satellite and a team of students in University College Dublin (UCD) are designing, building, testing and will launch this satellite as part of the European Space Agency (ESA) Fly Your Satellite! Programme.
EIRSAT-1 stands for the Educational Irish Research Satellite 1. It is a satellite about the size of a shoe box, called a CubeSat and will be controlled from a ground station on the roof of the UCD School of Physics and collect data from the three science experiments on-board.
The first experiment is a novel gamma-ray detector, GMOD, which is being developed in UCD. GMOD will detect gamma-rays from both cosmic and atmospheric phenomena.
The second experiment, EMOD, consists of a payload developed with Irish company, ENBIO Ltd., to monitor the in-flight performance of their thermal spacecraft treatments, SolarWhite and SolarBlack.
The third experiment, Wave Based Control (WBC), is a novel attitude control algorithm, developed in the UCD School of Mechanical and Materials Engineering, which will be tested for the first time in space on EIRSAT-1.
The satellite was due o be delivered to the European Space Agency (ESA) in 2020 but this will probably be delayed due to the COVID-19 pandemic. Once launched, it is expected to last 6 to 12 months.
The video below gives a good overview of the project...
Some RF info...
On-board Communications: The on-board CMC (Common Mode Current) transceiver is the space-qualified CPUT VUTRX transceiver supplied by ClydeSpace. The communications system uses UHF downlink (430-440 MHz) and VHF uplink (140-150 MHz) bands. The transceiver provides 9600 baud downlink and 1200 baud uplink, and implements a GMSK downlink and AFSK uplink configuration. The AX.25 protocol is used for uplink packets, while a CCSDS convolutional encoder may be used for downlink.
ADM (Antenna Deployment Module): EIRSAT-1 will use a custom ADM designed and built at UCD which will be mounted on the -Z end of the satellite deploys two dipole antennas, one for UHF downlink and one for VHF uplink. Both dipoles are composed of two tape spring antenna elements, deployed from opposite sides of the module, as seen in many previous and COTS antenna designs. The elements are 5 mm wide, made from a Copper Beryllium alloy and attached to spring loaded doors at each side of the module. They are coiled inside the ADM before deployment, within the 7 x 100 x 100 mm overall dimensions of the module. When EIRSAT-1 is clear of the CubeSat deployer the ADM will activate a burn wire release mechanism allowing the module doors to open and the elements to uncoil into their operational positions and stay in that configuration for the remainder of the mission.
