
An Introduction to CubeSats - dyukqu
https://gereshes.com/2019/01/28/an-introduction-to-cubesats/
======
bArray
For a long time now I have been very interested in sending my own satellite up
as a hobbyist project. I have a good background in software, electronics and
hardware (top to bottom robotics), but not a solid background in physics.

A few questions:

1\. What's the cheapest you can put a satellite in space (in terms of launch)
and for how long would it orbit at that cost? Size wouldn't really be too much
of a problem (I can go as low as 3x3x3 cm at a push).

2\. Are there strict limitations about what you are allowed to put up into
space? (In terms of components and contamination). Also in terms of
transforming - is it allowed to unfold?

3\. Do the satellites have to undergo some formal testing to be allowed on the
space craft? What's that process and how much does it cost? I imagine they
can't risk it blowing up or falling apart?

4\. Has anybody looked to sub-divide the cubesat 10x10x10 into 8 smaller
satellites? If you could somehow keep them all attached in fixed locations,
you could have a much larger sensor surface area at a low cost.

5\. How do they get the satellites to the launch location and how long does it
have to be there in advance?

I think using reaction wheels is good for rotation and I don't think
propulsion will be as "easily" possible. Compliant communications would be the
most difficult part in my opinion, trying to keep it low power and effective.

As for the actual mission of the project, I'm still not decided. It could be
cool to host some kind of server from space, but just throwing some hobbyist
sensors up there and seeing how they behave would also be good.

Thank you in advance for any help with those questions.

~~~
Bonooru
I worked in a lab for the US government building cubesats for a summer during
college. I can't answer everything, here are a few answers.

1\. Last time I heard pricing per pound to orbit was ~$10,000 per pound. This
was for the shuttle though, so I don't know if this has changed. 2\. I would
guess this depends on the launch provider. Whoever's launch you're
piggybacking off of will probably get to make this decision. I never heard of
any real restrictions, but this wasn't my area of expertise. 3\. You'd be
right about that. I don't know about pricing, but your payload will need to go
through vibration testing and the like 4\. No clue on this one 5\. You'd
probably have to physically make the trip (and I'd think you'd want to. Seeing
a launch is always cool). Timing will depend on whose launch you're piggy
backing off of, but we needed to have everything done a few weeks before
launch day.

Hope this helped a bit.

~~~
MayorOfAmerica
Would you be able to give me more details on that program? That's something
I'd be really interested in pursuing!

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tectonic
Decent intro to CubeSat hardware. If you want to know about CubeSat software,
let me know. The company I work for, Kubos, builds an open source OS for small
satellites: [https://www.kubos.com/kubos/](https://www.kubos.com/kubos/)

(I work on our web-based ground control software, Major Tom.)

~~~
tyldum
(Say hi to Marshall!)

And if someone has any questions about the ground side of things I work at
KSAT which provides a global network of ground stations (both cubes and
larger).

We often find sat builders completely forgetting about the ground segment and
then struggle to communicate with the cube. Often by using exotic encoding
and/or modulation schemes or choosing frequency bands that are either too
crowded or hard to license in some parts of the world.

~~~
tomp
Does it make sense to run a ground station as a business, renting out the
bandwidth to those who need it?

~~~
elkos
Alternatively if you want to have open data and share it with the community
you can set up a SatNOGS ground station. Even if you don't have a Cubesat in
the works. Check out wiki.satnogs.org

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iracigt
I'm part of the same University at Buffalo group as the author. If this
interests you, we've open-sourced some of our stuff, including a VHF/UHF
communications radio and star-tracker software.

Radio: [http://lfradio.space](http://lfradio.space)

GitHub: [https://github.com/UBNanosatLab](https://github.com/UBNanosatLab)

~~~
jeanlucas
That's too awesome. I'm tearing up here. We will be using this for sure on our
project. Thanks!!

~~~
jeanlucas
And if possible would like to get in touch for possible collaboration. I have
a nanosatellite project in brazil.

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anon1253
As an amateur astrophotographer I’ve been following the development of
cubesats closely. It seems more and more likely that a small group or an
individual would be able to launch a space based telescope within my life
time. Right now it’s a bit tricky still, and not really sure if you’re allowed
to have a camera in space yet (might be considered espionage). But still,
extremely cool ... maybe someday soon a crowd funded mini Hubble might be an
option!

~~~
pdabbadabba
If you're in the U.S., and are interested in the licensing issue, this is
probably the page you want:
[https://www.nesdis.noaa.gov/CRSRA/licenseHome.html](https://www.nesdis.noaa.gov/CRSRA/licenseHome.html)

It is indeed an issue, but a surmountable one.

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bogomipz
I apologize if this is a silly question but given that this "democratizes"
satellites, is anybody allowed to launch satellites into orbit? Or is there
some formal application or protocol that people and companies need to adhere
to in doing so?

~~~
tomp
Yeah, launch providers (“rockets”) need to be certified by bouth their country
of incorporation and the country they launch the rocket from. But law between
countries doesn’t need to be synchronised.

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vinayan3
Planet Money did a series about going to space.
[https://www.npr.org/sections/money/2017/12/01/567267573/plan...](https://www.npr.org/sections/money/2017/12/01/567267573/planet-
money-goes-to-space)

They went over the history and changing economics of CubeSats.

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NelsonMinar
The recent Mars lander mission included a pair of 6U cubesats used to relay
communications. They worked great:
[https://en.wikipedia.org/wiki/Mars_Cube_One](https://en.wikipedia.org/wiki/Mars_Cube_One)

~~~
planteen
I worked on the software for the attitude determination and control system
(ADCS) for the MarCO spacecraft.

~~~
NelsonMinar
Well congratulations! Was it fun? Is working on a cubesat radically different
than other types of satellites, or do the control systems end up working more
or less the same?

~~~
planteen
Not radically different. The company that did this work was staffed with
engineers who had experience on larger spacecraft. The fundamental algorithms
are the same. The difference is that everything is much smaller - less
momentum, so less large reaction wheels, etc. The nice part is that you can
use commercial parts, so you get access to much more modern electronics than
old rad hard parts.

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elkos
Hi. If you are into open hardware and free software don't hesitate to check
[https://libre.space](https://libre.space) a non profit developing open source
space technologies

We've built SatNOGS a global ground station network
[https://network.satnogs.org](https://network.satnogs.org) with more than 100
stations online globally and 50 more in testing build by volunteers

We've also built the first Cubesat under CERNs OHL license.
[https://upsat.gr](https://upsat.gr)

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syntaxing
It seriously impresses me everytime I read about CubeSats. I still remember
the first couple times there was a Kickstarter for the CubeSat when the idea
came out. Admittedly, I scoffed at the idea because I didn't think it was
feasible. I'm pretty happy to be proven wrong.

~~~
josteink
To impress you even further, cubesats were a thing long before Kickstarter
existed.

I wrote my masters thesis on one back in 2003, and it was launched in 2004.
Even back then this was such an established concepts there were niche
conferences for it.

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pushedx
The question I ask when small satellites are promoted is, how do we avoid
Kessler syndrome?

[https://en.m.wikipedia.org/wiki/Kessler_syndrome](https://en.m.wikipedia.org/wiki/Kessler_syndrome)

~~~
tectonic
CubeSats are low mass and tend to be in low orbits that decay in time periods
between a few weeks and 10 years. Also, all modern satellites have to be
launched with a deorbit plan.

~~~
pvarangot
I'm not sure the de-orbit plan thing is successfully being enforced by any
launcher.

That being said kessler's syndrome impact are usually over-exaggerated by "big
space" as a reaction the disruption going on in the business.

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benj111
"To answer that, let’s first define a U. A U is 10x10x10 cm cube of space from
which cubesats derive their name"

So, what's a U? Is it a mathematical constant, or just arbitrary?

~~~
tectonic
A "U" is a Unit, which was arbitrarily defined as a 10x10x10 cm cube.

~~~
benj111
I cant tell if you're being facetious. Does U just literally stand for unit
then?

~~~
WrtCdEvrydy
You'll see this in server hardware as well...

1U servers, 2U servers..

~~~
sizzzzlerz
different size, however. in servers and equipment racks, 1U = 1.75 inches.

~~~
isostatic
Height wise. Width is 19”

Depth varies dramatically - from maybe 1” to 1m

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EGreg
Why do you need to send up atoms when you can beam up bits?

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int_19h
To beam bits down.

~~~
EGreg
I am saying rent cubesat software like AWS. Why send more hardware?

~~~
int_19h
Because you need certain sensors over a certain location on Earth? I don't
think we're at the point yet where such needs can be covered by renting.

~~~
EGreg
We have enough cubesats to make that happen. You can rent time slices for
software.

That’s like saying you need to access certain sectors of a hard disk.

~~~
TeMPOraL
There are two important reasons for creating and launching cubesats:

1) Learning opportunity - that's how people get experience with space
technologies.

2) Equipment testbeds - companies that would like to sell technology for use
in space need to prove it actually works in space. If you can get a CubeSat
project to use your component (by e.g. donating it + some money) as a part of
their satellite, you can test it in space for much cheaper than it would take
to build an entire satellite on your own. It meshes nicely with 1), as people
who want to learn space technologies tend to not have money to build and
launch satellites on their own.

As for your original question: we're far from the point of having all
necessary sensors in orbit. There's not much to rent out yet.

