Building a satellite

[Julian5]

Well, a couple months ago I decided to build a CubeSat to learn a bit more about them and collect data. It was powered by an Arduino nano and measured electromagnetic radiation, temperature, humidity, pressure, altitude, and light. It featured a fully working solar panel array, charge controller, and radio transmitter. However, due to radio license costs, I had to modify it to store data on an SD card for testing. I was about to test launch it on weather balloon but once again due to strict European launch regulations and the fact I was really busy moving I was unable to launch it. Here are a few pics of the initial prototypes

Spoiler

 

 

 I was also working on adding a CMOS camera but was having issues with power restrictions. However, as you can tell the initial board (can't find the pictures with all the sensors soldered) is not very neat and the 3d printed housing is not ideal. So I'm going to build a new satellite with a slightly different concept, the idea is similar to kicksat (http://kicksat.github.io/).

 

 

I would like to make the smallest satellite possible with as many sensors as possible and maybe even a camera, I will also design and manufacture the PCB with SMD components. So really its just a tiny PCB with solar cells, a chip (will most likely use an atmega) and a bunch of sensors, however, my ultimate goal is a CMOS camera.

 

For now, I'm the only person working on this project and I'm confident I can construct the initial prototypes and their corresponding software, however, I'm making this post to share the idea and see if anyone wants to collaborate. The ultimate goal probably isn't to launch this thing but to have fun along the way.

 

I might post updates on here or make another forum post. 

 

 

Best Regards,

Julian

 

 

 

 

[TheKinggAce]

This is actually really cool, I wish I could do stuff like this

[vanished]

I saw the title and was like "no... that can't possibly be what I think it is" but sure enough...

 

Sounds like you're not at this stage yet but any thought as to how you'll get it in orbit?  balloons are great for going straight up but the stuff they carry tends to come straight back down after they pop

[marten.aap2.0]

this sounds awesome!

I wish I could join you but I live over 1000km away...

[.spider.]

37 minutes ago, Julian5 said:

electromagnetic radiation,

I am curious, whats the sensor`s name?

[Julian5]

23 minutes ago, Ryan_Vickers said:

I saw the title and was like "no... that can't possibly be what I think it is" but sure enough...

 

Sounds like you're not at this stage yet but any thought as to how you'll get it in orbit?  balloons are great for going straight up but the stuff they carry tends to come straight back down after they pop

yeah, I still have a couple months/year to go. As far as If I launch, it lots of factors come into play. 2 possible scenarios could occur if I decide to launch it. It mostly depends on how I launch it, the main issue is that the only form factor that NASA, SpaceX, and other space launch companies accept for their launches are 1U, 2 U, 3U etc which are 10cm x 10cm segments of under 1kg and those launches cost over 10.000 USD per segment. In this case, a 1U CubeSat will need to be designed as a mothership to launch the smaller picosatellites. NASA sponsors a limited amount of CubeSats every year and provides the launches free of cost, however, I live in Europe and the ESA has more limited funding assigned to cubesat launches so it is highly unlikely I will get a direct sponsor from them. In that case I would probably start a fundraiser or get sponsored by other companies for the project like I have done before, the main issue with sponsors is that I am a single person and not an educational organization like a school or a university so it is hard for them to sponsor me. 

 

However if by the time I decide to launch it/them there is an option to launch these picosatellites without a 1U mothership then the cost will most likely be within my budget (I'm suspecting below 1,000USD since these satellites will weight below 10g).

 

Considering this, The research and development costs of actually making one of these and sending it, along with all necessary radio licenses and a Ground station will be in the several thousand and I will surely need to start a fundraiser or get sponsored. 

 

22 minutes ago, marten.aap2.0 said:

this sounds awesome!

I wish I could join you but I live over 1000km away...

Well, I will most likely need help with the software so if you know how to code in C hit me up

[marten.aap2.0]

1 minute ago, Julian5 said:

Well, I will most likely need help with the software so if you know how to code in C hit me up

I've done some (simple) things with my arduino nano, but I'm more noob than pro in C  

[Julian5]

7 minutes ago, .spider. said:

I am curious, whats the sensor`s name?

you will be surprised to know its actually just wire, The Arduino senses electricity coming from it. However, it is not very accurate and a more precise voltage sensors would make it more precise. It's actually an electromagnetic interference detector or EMF. Shielding the Arduino from the wire sensor is also an issue to avoid interference 

 

Here is a video about one:

 

[Hackentosher]

Something tells me law makers make it a lil bit more difficult to launch something into orbit. Still a cool project! 

[Julian5]

Just now, Hackentosher said:

Something tells me law makers make it a lil bit more difficult to launch something into orbit. Still a cool project! 

Yeah getting anything into orbit requires lots, and I mean lots of licenses and regulations to be approved. 

[NewHopeTech]

What is your plan on recovery from the weather balloon? Just parachutes? Airbags? I love the parachute and airbag combo.

[Julian5]

11 hours ago, NewHopeTech said:

What is your plan on recovery from the weather balloon? Just parachutes? Airbags? I love the parachute and airbag combo.

Its dead simple, the CubeSat is tied to a parachute and the parachute is tied to a balloon, the balloon gets released before it pops (monitored with Fpv camera) and a GSM GPS tracker is fitted with the CubeSat to find it. As its a first prototype I don't mind if it gets damaged since it transmits a live feed,

 

Update:

I  think I came up with a name for the Project: AttoSat

Atto meaning 1 trillionth (as in a really tiny thing), I also thought about the name FlatSat since the current design is a flat PCB with solar cells on each side. The main components of the first prototype have more or less been chosen:

CPU: ATMEGA328P 32kb storage, 2kb Ram, -40 to 85c, 1,8v to 5.5v

Communication: CC1101 500kb link, 15.7ma, -40 to 85c

Pcb manufacturer: Pcbway

Sensors: TBD

 

I have started to contact satellite solar cell manufacturers for information on High-efficiency gallium arsenide cells, the PCB will have cells on both sides to avoid the need for any directional control via electromagnets or gyroscopes, I'm also looking at adding deployable solar panels but they will most likely not be used since I'm using the lowest possible power components. I also will not use any sort of batteries in this model since they would most likely require heating. 

[marten.aap2.0]

7 minutes ago, Julian5 said:

32kb Memory, 2kb Ram

do you mean 32kb storage?

[Julian5]

13 minutes ago, marten.aap2.0 said:

do you mean 32kb storage?

yeah, I meant storage, my bad.

[Inductive]

On 11/4/2017 at 11:18 AM, Julian5 said:

 NASA sponsors a limited amount of CubeSats every year and provides the launches free of cost, however, I live in Europe and the ESA has more limited funding assigned to cubesat launches so it is highly unlikely I will get a direct sponsor from them. In that case I would probably start a fundraiser or get sponsored by other companies for the project like I have done before, the main issue with sponsors is that I am a single person and not an educational organization like a school or a university so it is hard for them to sponsor me. 

 

Get a partner who lives in the US.  Start a course on a place like coursera "launching sats" and become part of an educational organization - and also have a forum, which will build an organization/partnerships/networking to launch sats at same time.

[Julian5]

3 hours ago, Inductive said:

Get a partner who lives in the US.  Start a course on a place like coursera "launching sats" and become part of an educational organization - and also have a forum, which will build an organization/partnerships/networking to launch sats at same time.

That's some pretty good ideas you have there, I'm currently looking at some forums for some partners!

 

Update:

I have started creating the PCB's and have ordered some of the SMD components. I have also started making some of the code for the voice telemetry system since this satellite will probably have a voice telemetry system.

 

 

 

 

(The pcb's are missing most of the parts)

 

 

[TheRandomness]

Couldn't that PCB be made even smaller to help with the weight restrictions and launch costs? Or is it that big just to be form fitting with the solar cells?

[Julian5]

12 hours ago, TheRandomness said:

Couldn't that PCB be made even smaller to help with the weight restrictions and launch costs? Or is it that big just to be form fitting with the solar cells?

Yeah, the top third will house the components and the bottom will be all solar panels. The PCB will be much more crowded once I add the communication components and sensors

[ShredBird]

Hey Julian,

I don't have time to collaborate full time, but I have a master's degree in electrical engineering and I've worked on instruments and electronics for 3 different nano satellites.  I'd be happy to give you some tips and design advice when I can.

[ShredBird]

Some tips/observations right off the bat from what I've read:

 

1. Have a well defined mission.  You want to measure XYZ using sensors ABC and the mission will last N months.

2. Start defining budgets based on that mission:

• Mass Budget:  1U Cubesats generally have to fit within a certain mass range to be eligible for launch.  Most of this will be the shell of the satellite, the instruments will likely be a very small percentage of the mass.  Cubesats are also required to have their center of mass reside within a certain volume within the Cubesat.
• Power Budget:  You will need a battery, your microprocessor will need steady power from a switching regulator that will need a reliable supply of charge, solar panels alone will not give you a reliable experience.  You will have to calculate how much power your cells produce during an orbit to make sure your batteries are happy and make sure you have enough power to run your experiments during an orbit.  You must budget power to all your instruments.
• Telemetry Budget: How much data are my instruments collecting?  How much energy/time do I want to use to send that data. This will help you define your power budget and how to design your antenna system.

3. Deployable instruments/equipment are extremely difficult to get cleared for launches.  For NASA, they require that you prove that for any moving parts that if that part were completely missing, nothing potentially damaging could occur.  Debris in orbit is a huge hazard for real multi-million dollar missions and they're not going to let a little Cubesat mess that up.

 

4. Start paying attention to the different materials you are planning on using.  Your Cubesat will have to pass "shake and bake", that is it must survive the harsh vibrations of a rocket launch, extreme temperature fluctuations and the vacuum environment.  For example, no lead solder as lead will sublimate in a vacuum.  Certain plastics also out gas and can degrade in vacuum.

5.  Have fun!  Whether this makes it to space or not, building satellites is one of the most challenging multi-faceted problems an engineer can attempt and if your goal is to be a better engineer than before, you will undoubtedly learn a ton of new things going down this path.
 

[Julian5]

43 minutes ago, ShredBird said:

Some tips/observations right off the bat from what I've read:

 

1. Have a well defined mission.  You want to measure XYZ using sensors ABC and the mission will last N months.

2. Start defining budgets based on that mission:

• Mass Budget:  1U Cubesats generally have to fit within a certain mass range to be eligible for launch.  Most of this will be the shell of the satellite, the instruments will likely be a very small percentage of the mass.  Cubesats are also required to have their center of mass reside within a certain volume within the Cubesat.
• Power Budget:  You will need a battery, your microprocessor will need steady power from a switching regulator that will need a reliable supply of charge, solar panels alone will not give you a reliable experience.  You will have to calculate how much power your cells produce during an orbit to make sure your batteries are happy and make sure you have enough power to run your experiments during an orbit.  You must budget power to all your instruments.
• Telemetry Budget: How much data are my instruments collecting?  How much energy/time do I want to use to send that data. This will help you define your power budget and how to design your antenna system.

3. Deployable instruments/equipment are extremely difficult to get cleared for launches.  For NASA, they require that you prove that for any moving parts that if that part were completely missing, nothing potentially damaging could occur.  Debris in orbit is a huge hazard for real multi-million dollar missions and they're not going to let a little Cubesat mess that up.

 

4. Start paying attention to the different materials you are planning on using.  Your Cubesat will have to pass "shake and bake", that is it must survive the harsh vibrations of a rocket launch, extreme temperature fluctuations and the vacuum environment.  For example, no lead solder as lead will sublimate in a vacuum.  Certain plastics also out gas and can degrade in vacuum.

5.  Have fun!  Whether this makes it to space or not, building satellites is one of the most challenging multi-faceted problems an engineer can attempt and if your goal is to be a better engineer than before, you will undoubtedly learn a ton of new things going down this path.
 

 

1 hour ago, ShredBird said:

Hey Julian,

I don't have time to collaborate full time, but I have a master's degree in electrical engineering and I've worked on instruments and electronics for 3 different nano satellites.  I'd be happy to give you some tips and design advice when I can.

Hey ShredBird, Thanks,  the support is really appreciated and I will definitely need some help when it comes to wiring everything up especially since I'm planning to design a voltage regulator circuit for the solar panels and I might need help with hooking up the camera FIFO for sstv (similar to a buck converter). As far as the tips you mentioned above here are a couple of things I'm doing and let me know if there's anything I can improve on.  

 

1. I'm still deciding on the parts but most likely 6cm x 6cm PCB with 1 solar cell on each side, A temperature sensor, an accelerometer and an SSTV camera.

2. I still need to see whether there is a remote possibility of launching this thing on its own but Most likely will need a 1U mothership for launch, that's a whole other project haha. As far as power budget I have a spreadsheet with how much current every single component will draw and the smallest gallium arsenide solar panel I can find (with a slight current headroom) And as far as telemetry I'm also making a list of each set of data im sending and the lowest power consumption / Mw needed to send them.

3. I decided on not using deployable solar panels since it would add too much complexity and be too fragile on such a tiny satellite. 

4. I actually did not know that about lead, thanks! I'll make sure to solder the components on with lead-free solder. 

5. I definitely agree with this one, Building a satellite involves so many areas of engineering and is a great possibility to learn.  

 

Also since you seem to be experienced in this do you know where I could get gallium arsenide solar panels, I have contacted some suppliers but I'm still waiting for a response. 

 

[ShredBird]

Try looking into EMCORE, during my undergrad days they sold us cell scraps for pretty cheap.  I'm not how they operate with international customers though.

[ShredBird]

You may want to look into getting this book, it has lots of information on planning and budgets:

 

https://books.google.com/books/about/Space_Mission_Engineering.html?id=VmQmtwAACAAJ&hl=en

[Julian5]

On 9/11/2017 at 10:29 PM, ShredBird said:

Try looking into EMCORE, during my undergrad days they sold us cell scraps for pretty cheap.  I'm not how they operate with international customers though.

 

On 9/11/2017 at 11:26 PM, ShredBird said:

You may want to look into getting this book, it has lots of information on planning and budgets:

 

https://books.google.com/books/about/Space_Mission_Engineering.html?id=VmQmtwAACAAJ&hl=en

Thanks a ton  I'll contact emcore asap and take a look at the book

[Julian5]

On 9/11/2017 at 10:29 PM, ShredBird said:

Try looking into EMCORE, during my undergrad days they sold us cell scraps for pretty cheap.  I'm not how they operate with international customers though.

 

Unfortunately, EMCORE sold their photovoltaic company 2 years ago and looking at other companies like SolAero they seem to have 7,500$ minimum orders.....