Discussion Developing my first satellite

[Pipcard]

Not a real CMG. Something akin to one should be fine. IIRC, LDEF didn't even have one of those. It used gravity gradient and a fluid coupler with a viscous fluid in it to stabilize it. I have no idea how you would do that in SC3. The tiny RCS, however, should be no problem. just scale back the size of the force.

I want to use real technology/real engines. [redacted section]

Aren't Cubesats practical because they're cheaper?

 

[MaverickSawyer]

Kinda. It's less mass to launch, so it can be a secondary payload. Howver, it has to hitch hike on someone else's LV, so you're really limited in your options for orbits. It's a tradeoff.
The thrusters could be very simple, even as simple as compressed nitrogen. However, you could easily make a set of gyros for the cubesat on a lathe at home. they're just not gonna be very big . the upside is, there's not much to move around. :lol:

 

[Pipcard]

Kinda. It's less mass to launch, so it can be a secondary payload. Howver, it has to hitch hike on someone else's LV, so you're really limited in your options for orbits. It's a tradeoff.
The thrusters could be very simple, even as simple as compressed nitrogen. However, you could easily make a set of gyros for the cubesat on a lathe at home. they're just not gonna be very big . the upside is, there's not much to move around. :lol:

"Not very big" is an upside. For the "gyros", maybe you can make RCS thrusters with blank textures and minimal thrust?

 

[RisingFury]

My first satellite will be very simple: a Cubesat.

Oh, great! A 6 poly addon!

 

[Pipcard]

Oh, great! A 6 poly addon!

It will be simple, but not that simple.

---------- Post added at 06:53 AM ---------- Previous post was at 06:27 AM ----------

Just found these:[ame="http://en.wikipedia.org/wiki/SPHERES"]SPHERES[/ame]

using carbon dioxide to fuel 12 thrusters

But if I were to use carbon dioxide or nitrogen for the RCS, how would I know the amount of attitude thrust? I don't know about the parameters of the particle effects either (but carbon dioxide is invisible, so I don't need to worry about particles if I use that).

---------- Post added at 08:32 AM ---------- Previous post was at 06:53 AM ----------

And this is the basic shape of the satellite (the antenna will fold/unfold but I haven't learned animations yet):

I will use the [ame="http://www.orbithangar.com/searchid.php?ID=5177"]Spacecraft3 to DLL&C++ converter[/ame] so it will be easy to spawn satellites with the Scenario Editor.

---------- Post added at 12:45 PM ---------- Previous post was at 08:32 AM ----------

Thanks for moving it to Addon Development!

Okay, the satellite won't have bevels or insets. (will cause the texture to be more complicated)
Is it okay if the solar panels are just a flat texture?

 

[Izack]

Regarding RCS, if you want any realism then forget Spacecraft3. You have no control over the placement of thrusters - they're placed 1m from the centre of the vessel and given whatever thrust you define. Best you can do is some calculation to determine what thrust the imaginary engines 1m away would need to achieve the same effect as your chosen thrusters at their chosen positions.

Spacecraft is a hack, and anyone who uses it has to accept that his addons will suffer as a result. :rant:

(But yes, it's great as an intro to development. But PLEASE aspire to greater things down the road.)

 

[Pipcard]

Regarding RCS, if you want any realism then forget Spacecraft3. You have no control over the placement of thrusters - they're placed 1m from the centre of the vessel and given whatever thrust you define. Best you can do is some calculation to determine what thrust the imaginary engines 1m away would need to achieve the same effect as your chosen thrusters at their chosen positions.

Spacecraft is a hack, and anyone who uses it has to accept that his addons will suffer as a result. :rant:

(But yes, it's great as an intro to development. But PLEASE aspire to greater things down the road.)

Looking at the DSCS's (made with Spacecraft3) .ini file, I can see a bunch of stuff that looks like this:

[EX_ATT_0]
;top, left
OFF=(0.1164,-0.9321,-1.3017)
DIR=(1,0,0)
LENGTH=1.0
WIDTH=0.1
ROT_AXIS=Z
ROT_CW=0

I think [EX_ATT_0] refers to one of the attitude thrusters (there seems to be 16 of them), and OFF refers to offset, so I think you can control the placement of thrusters. All I need is a proper fuel for a 1.3 m^3 cube's RCS, and know the thrust and ISP of it. And I need to know realistic parameters for particles (if the thrust requires it).

[ame=http://www.orbithangar.com/searchid.php?ID=2748]Spacecraft.dll parameters[/ame]

 

[Izack]

That's the location of the exhaust. No effect on the logical thruster...

 

[Pipcard]

Okay. So you don't want me to develop and subsequently "suffer", is that right? You expect me to learn C++?

I can't just learn C++ in a jiffy.

 

[RisingFury]

Okay. So you don't want me to develop and subsequently "suffer", is that right? You expect me to learn C++?

I can't just learn C++ in a jiffy.

With that attitude, you'll never learn anything.

 

[Luke Skywalker]

Okay. So you don't want me to develop and subsequently "suffer", is that right? You expect me to learn C++?

I can't just learn C++ in a jiffy.

That's why you never stop trying and never lose hope until you learn it.

 

[Izack]

Not at all - all I mean is that Spacecraft3 is a starting point and nothing more. Too many developers restrict themselves to simple tools because "I can't code LOL," and if you think that you'll really never get any better at it, despite the capability being right there, as-yet unused. So start now, and keep progressing instead of stagnating in the Spacecraft3 continuum.

 

[Napalm42]

Not at all - all I mean is that Spacecraft3 is a starting point and nothing more. Too many developers restrict themselves to simple tools because "I can't code LOL," and if you think that you'll really never get any better at it, despite the capability being right there, as-yet unused. So start now, and keep progressing instead of stagnating in the Spacecraft3 continuum.

I have the same game-plan, should I learn to model.

Step 1: Make vessels in SC3.

Step 2: Learn programming from the major I'll be starting next year.

Step 3: CUSTOM DLLs, YAAAAY!!!!!!!

 

[Pipcard]

[deleted]

 

[Scruce]

Has River Crab decided to learn programming in college?

Here we go again. Will you please stop comparing everything to River Crab?

Now, on topic, before you get anything done you need to stop and think. Brainstorm what you want to do, preferably on a sheet of paper. Draw your satellite (or whatever it is) and make all the drastic changes there. Don't just jump in, say 'Allons-y' and hope for the best, you're sure to fail if you do that (speaking from experience here).

Think:

• What will my satellite do?
• What era of spaceflight is it set in?
• Are we going for small (e.g Sputnik) or large (e.g KH-11)?
• Will it have 'bus-mounted' solar panels or 'stalk' solar panels?
• Does it even need solar panels, if not, do you consider an internal battery?
• Does it need antennae, is it a communications satellite (it will need antennae) or is it a simple technology demonstration satellite (e.g. Dnepropretrovsk Sputnik II)?

 

[Pipcard]

• What will my satellite do?
• What era of spaceflight is it set in?
• Are we going for small (e.g Sputnik) or large (e.g KH-11)?
• Will it have 'bus-mounted' solar panels or 'stalk' solar panels?
• Does it even need solar panels, if not, do you consider an internal battery?
• Does it need antennae, is it a communications satellite (it will need antennae) or is it a simple technology demonstration satellite (e.g. Dnepropretrovsk Sputnik II)?

-Tech demo or some small scientific experiments. Basically most of the things Cubesats do.
-"Next Sunday A.D." or "Twenty Minutes Into The Future" (some scenarios will have it packaged in a UCGO box -MaverickSawyer's idea-)
-Small (1.3 m^3), of course
-Bus-mounted solar panels
-Yes, it needs solar panels
-Can a tech demo satellite have small antennae (two, each on opposite sides)? Some Cubesats have them. How can I find out about the different types of antennae on spacecraft?

 

[Izack]

Has River Crab decided to learn programming in college?

Irrelevant. One doesn't need college to learn computer language. Admittedly it is harder to grasp using tutorials on the internet than it is to have a programming course shove the paradigms down your throat, but with time and persistence anything is possible. As a bare-bones minimum example, I squeezed out the LSS module in a few months or so with 0 prior experience. (If you saw the source you'd realise it's even more hackey than it already seems, but at least it's a compiled DLL.)

(And no, I don't think Crab is with a degree like that. A good many Orbinauts are though, including this one. )

 

[N_Molson]

Never had a single course of programming in my whole life. Learned everything from Orbiter samples, tutorials & various help ressources on the Net. Don't mistake though, it took me several years and I'm still learning.

 

[Pipcard]

Okay, here's what it looks like so far:

(the gold parts are where the solar panels will go; they are only on four sides of the cube)

I want to learn about the different types of antennae (shapes, frequencies) found on spacecraft.

 

[n122vu]

FWIW, I have learned more about C++ from developing for Orbiter than I learned from the semester of C++ I took in college 5 years ago. Part of it was poor instructor knowledge of the course content, the rest was just the poor content of the course.

I'll echo what others have said, but with some differences.

1. For your first addon, spacecraft3 is a great place to start. I used SC3 to tweak Jason Benson's Explorer class vessel, which I later released as a DLL-based craft (EAS Cortez). The knowledge I gained was invaluable (thruster positions/offsets, animation sequence and timing). Having everything sitting in the .ini file makes it easy to tweak the values and see their effect.

2. Spacecraft3 is very limited for larger craft. It does assume all thrust is applied no further than 1m from the center of gravity. For a 1.3m x 1.3m x 1.3m cubesat, this is perfect. But for a 6km-long Deep Space Vessel, it was very, very limiting.

3. Once you get the Spacecraft3 vessel complete and are satisfied with how it looks/works, release it. But don't stop there. Start learning C++. Something like this Cubesat is a perfect first project. Thrusters and 2 antennae animations. And if you get the animation working in SC3 first, you'll have those numbers to start from on the sequence timing.

4. Take full advantage of the resources on this forum. Ask questions. If you don't understand how something works, or should be coded, someone here has been there before and will be able to help. There are years of cumulative knowledge in the developers on this forum. If it gets to be too overwhelming or feels like a burden, just take a step back, take a deep breath, and visualize the end result and know what you want to accomplish. When it's done, you'll be glad for every step you had to take to get there.

5. Last but not least, and this is the most important one. Have fun. Whether it be having fun learning a programming language, or knowing you're making something you can share with the community and the world, make it something you enjoy doing. Otherwise you'll be discouraged more easily and are less likely to press through any issues.