r/cubesat

Hello, so I am pretty much new to satellite things, let alone cubesat. So, I am joining a cubesat competition and I'm planning to use Passive ACS as my attitude control mainly for detumbling my cubesat since it is cheaper and the least complicated compared to other methods. I have read some articles and journals about this but i can't really understand how this system would work. If you know how this passive attitude control works please share it on this thread. Your advises and opinion will be very appreciated.

Hi I am currently designing a 3U Nanosatellite mission for a university team. In the Concept of Operations there can be 2 possible options

1. Deploy Antenna then Detumble

2. Detumble then Deploy Antenna

Option 1

We will be able to get some confirmation about status of CubeSat from its telemetry as communications will be enabled. This will give us information about the health and status of the satellite.
However with this option, the communication losses will be high with no guarantee that we will get some data from sat, power generation will be low during detumbling and turning on the beacon/downlink would consume power from batteries and we might not have enough power to completely detumble and start nominal mission operations.

Option 2

This will ensure that satellite is in a suitable orientation for its nominal mission and also communication with the ground station. The power consumption during detumbling would be lower as only minimal components will be ON. However we are worried that if detumbling is not achieved we will have no way of knowing what went wrong as we have no comm link. I have heard that most CubeSats end up dead on arrival or are not able to successfully detumble.

Would appreciate if someone who has launched satellites before share their experience and guide us in deciding the optimal ConOps.

Which is the best open source SDK which can be used to convert from Body Frame to RTN to ECEF ? Or the reverse.

Hi, it's me again. I made a post about radiation a few months ago for those that remember. My uni club is more advanced in the project now but I've been thinking about which MCU we're going to use, specifically for our ADC system (i.e attitude control). There's a billion options to choose from so I've been struggling to analyze them all.

At a minimum, I think going with a STM32 MCU would be ideal, since they have good support. But other than that, I don't know where to go from here.

Of course, the MCU needs to be performant enough to handle the processing it needs to do, it needs to have enough memory to do the processing and to store whatever code/data we need, it needs to have enough peripherals to interface with sensors/other subsystems, it probably needs ECC memory and so on

Problem is, we're still early in the project so many of these variables are still unknown to me. I've seen people recommend the STM32H7 series as a good option, but they seem way to high performance for our purposes. This might not be that relevant I guess (if it works it works, and it is 20 USD I believe, so whatever), but I wondered if there wasn't a more suitable option.

I also looked at the STM32L4 series, some of them have ECC. They also seemed good options. But I wanted to ask here to see if someone more experienced had some advice on how to go about this.

Anyone know about the basic geolocation concepts or requirements for cubesat ?

Hello there I am new in Cubesat and I want to learn especially about the communication systems what are some main headlines that I need to learn before I dwell in various topics such as FDMA,TDMA, etc. ?

Hey everyone!

I'm excited to share an invite to a new CubeSat Community Discord server! Whether you're a professional, student, or an enthusiast, this is a place to share knowledge, ask questions, and connect with fellow CubeSat community members.

I created this Discord server to add another way for the community to interact in real-time.

Join us here:

Looking forward to seeing you there! 🚀

To clarify, I have started a Cubesat project 3 weeks ago and learned some things. (The system of the Cubesat is Arduino based and the objective of the Cubesat is to find, gather and send data back about the solar system like the sun, planets, earths magnetic field, particles, etc ) And have already a smal list of some sensors but wanted to hear from experienced people befor ordering something. (It can't be so expensive, I dont have a big budget :] )

For a GomSpace NanoCom AX100U Amateur Radio CubeSat transceiver that we’ve had lying around for some time, we (the Student Amateur Radio Satellite Ground Station FHASOF with call sign DL0FHA) are in urgent need of a NanoCom GS100 ground station modem/radio. Since this unit is no longer for sale by GomSpace, I am asking if anyone has a GS100 that they no longer have any use for? The radio may be as good as new, used, or needing repair depending on its condition and price. As radio amateurs, we have, of course, the ambition to make such a device functional again.

Join Our Mission!
Cheers!
Sash!

Hello!
I have recently been tasked to work on the mission design (specifically the system requirements, power budgeting and CONOPs) for a commercial 12U CubeSat mission. However, I have no prior knowledge in this field and I would really like some help and resources that could guide me to successfully execute this task. I have been putting together the system requirements and CONOPs based on papers I've been reading, but I am currently stuck on devising a power budget document. Any help would be greatly appreciated!

Where are the best places to learn about CubeSats, i.e., the best discussion groups or forums where people discuss what is current and new with CubeSats?

Certainty, static places like Youtube videos and the like are out there, but I'm looking for a more interactive way to learn about CubeSats as part of my PhD dissertation.

Anyone know where I can find a COTS kill switch (deployer switch) for a beefy cubesat ie ~20 amps? Ideally something TRL9 that can interrupt power when the cubesat is stowed in the deployer (eg space-rated limit switch). If not space-rated, recommendations for a terrestrial COTS limit switch that has been successfully flown before on a cubesat would be appreciated! Thanks!

Hi All!

I´m struggling to uderstand how to launch a 3U Cubesat.

I´m aware I require a dispenser or picosatellite deployer..but I don´t understand If that part is decided by the launch provider or if i have to buy and test my satellite with the dispenser/deployer.

For instance, I saw that Rocket Lab offers a Canisterized Sat Dispenser, but apart from that launch supplier I couldn't understand how for example I could organise a launch with Ariane or Space X or other launch supplier.

Any comments are welcomed :)

Thanks

Hello all, We're developing some solar panels for a CubeSat mission, and I just had a few questions about some general design decisions as electrical engineering was not my original field (hence a few weird gaps in knowledge). I figured this question might fit here a bit better than one of the EE subs.

My first is about the cabling and grounding scheme of several different circuits (e.g. solar cells, peripheral sensors, external programming/charging interfaces, etc.), and how best to avoid ground loops. In are several different configurations; I would just like to confirm that my thinking is correct:

• Configuration A) seems like the ideal one to work with. having several different grounds on the PCB and tightly coupled to their respective V_* trace.

• Configuration B) is the worst. Each circuit shares the same ground, which makes multiple loops between the CubeSat component stack and a solar panel

• Configuration C) is not as bad. Each circuit shares the same ground, but it is only routed along one cable. Loops could be introduced on the routing of the solar panel PCB itself however.

My second question is about the trace layout for solar cells, and how to best avoid loops that would produce a magnetic torque that would interfere with an ADCS. See the example configurations in using a two-layer PCB. Do any of these seem viable, or is there an alternative method? I figure these different configurations also have some implications for thermal design.

• Configuration A) seems like the worst one to use with discrete V_cell and ground traces. The traces laid out would create a wide loop with the solar cells.

• Configuration B) seems okay, with a single ground plane. If the ground plane is on the bottom layer there is a gap the width of the PCB between the plane and cells. If only one plane is used, would it be better to have it on the top layer with the cells? I don't think making it a ground or power plane makes much difference here.

• Configuration C) seems like it would also work, with both a ground plane and power plane. However there is still the gap between layers (width of the PCB).

If someone can provide some insight as to these questions, it would be appreciated!

Hi.

Our team plans to launch a satellite into LEO (no orbit defined yet, I believe, at least no one told me) so I started wondering about potential effects due to radiation since we'd be designing our CubeSat mainly with COTS components. I searched online for some references on the radiation tolerance of some common devices (I was initially mainly worried about the microcontrollers) but couldn't find anything conclusive.

From what I could gather online (and posts on the subreddit), in terms of TID there isn't that much to worry about, since at LEO the total dose will generally be low and our mission duration isn't that high either (<1 year). It seems most electronic components can handle around ~5krad before they break (depending on the component obviously).

There's also SEUs and SELs that could potentially be damaging, but using a watchdog timer, ECC-memory and power cycling seems to be enough for protecting the MCU, as I understand it. However, I'm still unsure about the level of risk for other components.

If anyone has some advice on this or knows some good sources on the problem, I'd appreciate it if you could post them here.

Thanks.

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Where do you guys usually get data to use in Structural Analysis, such as vibration simulation, mechanical loads and Thermal Analysis, for example? I'm new to this Cubesat and Aerospace world, so I'm having trouble finding some informations to apply to the project we're developing in my university.

(sorry for the bad english, brazilian here)

Hello, I am researching the topic of cubesat cameras for an exam at uni. I have been given a CMOS SENSOR, the Sony IMX342LLA but I can not understand how should I look for an appropriate optic. What parameters should I look for? Do you have any helpful site I can look at? The idea is to have a camera with a ground sampling distance of 4 meters at 500km of altitude.
Thanks

Hey guys!

I am an undergraduate student in my first year of Aerospace Engineering.

Well, I joined my university at an excellent time to do some science. They called me on a transmitter project for a cubesat that will be in low orbit. The cubesat would likely be launched in 2029. The transmitter will be embedded in the cubesat and must transmit telemetry data

I'm looking for some circuits or platforms but I can't find anything that helps me scale this..

What is the current launch cost for a 1U to SSO?

Hey i am trying to build a satellite. I am using raspberry pi to take photos and transmit it using sstv, I have seen people using dra818v module for transmission but due to my country i cannot find any way to buy it. Is there any alternative can i use the raspberry pi fm to transmit the signals?