[Spreadsheet] Orbit Night/Darkness, Req. Battery Capacity, Satellite Relay Coverage

[Peppe]

Was tinkering with probes and wanted to min/max the battery capacity. Made a spread sheet:

input - planet, circular orbit, and energy consumption.

Output- orbital period, darkness period, and minimum battery capacity.

Use the white boxes to input some stats on your craft and calculate how much battery capacity you will need for the orbital dark/night periods.

Satellite Tab can be used to find orbital ranges and spacing for satellite relay networks (remotetech 2).

Using the formula on the wiki

http://wiki.kerbalspaceprogram.com/wiki/Orbit_darkness_time

Sample:

Battery Tab

Satellite Tab

Google Doc (Use, File -> Make a copy, to set values in your own instance of the sheet)

https://docs.google.com/spreadsheet/ccc?key=0AkXf-77s6gmFdEdVeGFqX0xobTczYkhEaEVrVTdWV3c&usp=sharing

Excel Spreadsheet

http://www./download/c25qjwjidphijum/ksp.xlsx

Edited January 1, 2014 by Peppe

[henryrasia]

This... is so useful... Thanks mate!

[flightmaster]

This is sick! Thanks heaps

[Lojik]

Rep for this, very useful tool, have saved this to my computer

I also added two more boxes so I could calculate the maximum energy usage I can have on something already in orbit with a set amount of battery

[Peppe]

Rep for this, very useful tool, have saved this to my computer

I also added two more boxes so I could calculate the maximum energy usage I can have on something already in orbit with a set amount of battery

Glad people are finding it useful.

Updated to add your use per second option.

[The Darkness]

I love it. Taking an "Old School" approach to your KSP Calculations. Keep up the good work.

[radinator]

I think there is an error in the spreadsheet when calculating the total orbital period, if Kerbin is not selected. It works fine for Kerbin, but not for other bodies. I was surprised when I went to the Mun and did not get the orbital period I expected.

Replacing B10 with the following seems to fix it:

=PI()*2*SQRT((C3+D6)^3/C6)

Simple test for any planet: Insert an orbital altitude of zero. Since half the planet is sunlit the dark period should be ~1/2 of the full orbit period for an equatorial orbit (which this spreadsheet assumes). This was originally true in the spreadsheet for Kerbin, but not for other bodies.

Explanation:

The original contents of that cell,

=PI()*2*SQRT(((C3*2+1200)/2)^3/C6)

has that factor of 1200 (which is 2 * kerbin_radius). This should be generalized to 2 * D6 to get the appropriate radius for the planet in consideration. My substitution removes the factor of 2 to simplify it.

[Peppe]

I think there is an error in the spreadsheet when calculating the total orbital period, if Kerbin is not selected. It works fine for Kerbin, but not for other bodies. I was surprised when I went to the Mun and did not get the orbital period I expected.

Replacing B10 with the following seems to fix it:

=PI()*2*SQRT((C3+D6)^3/C6)

Simple test for any planet: Insert an orbital altitude of zero. Since half the planet is sunlit the dark period should be ~1/2 of the full orbit period for an equatorial orbit (which this spreadsheet assumes). This was originally true in the spreadsheet for Kerbin, but not for other bodies.

Explanation:

The original contents of that cell,

=PI()*2*SQRT(((C3*2+1200)/2)^3/C6)

has that factor of 1200 (which is 2 * kerbin_radius). This should be generalized to 2 * D6 to get the appropriate radius for the planet in consideration. My substitution removes the factor of 2 to simplify it.

Good catch. Thanks for the fix.

Updated both files.

[Ferrit]

Oh this is so handy! Had been meaning to do something myself but you've saved me the effort and done a far better job of it

[Peppe]

To anyone subbed to the thread. From my first foray into remote tech satellites I decided to go with eccentric orbits to cover KSP.

I have reconfigured the spreadsheet to accept any orbital Ap and Pe.

Updated in first post.

[Peppe]

Added a satellite tab today. Help plan minimum orbits for line of sight, maximum orbit for antenna or sphere of influence limit.

Sat example:

[Justy]

This is a great tool; I'd been doing a lot of these calculations on paper. I had been doing some of the minimum & maximum orbit calculations on paper, hadn't gotten around to spreadsheeting it yet... and coincidentally was looking for how to calculate darkness time for satellite batteries.

But could you please explain what you're showing with "Optimal Field Of View" on the Satellite Relay tab?

[Peppe]

This is a great tool; I'd been doing a lot of these calculations on paper. I had been doing some of the minimum & maximum orbit calculations on paper, hadn't gotten around to spreadsheeting it yet... and coincidentally was looking for how to calculate darkness time for satellite batteries.

But could you please explain what you're showing with "Optimal Field Of View" on the Satellite Relay tab?

That is for Remote Tech mod. If you don't use the mod don't worry about it.

My calculation for it is +-3 degrees from the minimum safe separation between a set of satellites.

Not sure it is truly optimal, but more a rule of thumb i tried to make for myself. I know i did not want the lowest orbit (drift -> failure risk) nor the max orbit (too much fuel cost), so how to find something in-between?

My thought was, take 3 satellites equidistant to each-other -- with perfect orbits you could have orbits as low as the radius of the planet. For kerbin that is 600km. My orbits aren't perfect, so lets add some flex to the numbers. If we allow for +-3 degrees of drift on each satellite we could setup safe orbits ~720km that survive drift. The extra orbit height means the planet blocks less of our line of site to the other orbiting satellites increasing our time to failure.

[Justy]

Ah! That makes sense then. I *am* using RemoteTech. I just didn't understand that "optimal" meant drift-proofing.

My own calculations usually tried to keep the Line Of Sight between two satellites above the atmosphere, and that gave plenty of play for drift. It did end up a bit higher though (740km?). I'm using your specs now (721.61 km / SMA 1.32161). You have helped prepare the Kernadian Space Agency's Stayputnikom Series II constellation to support missions throughout equatorial cismünar space!

[Gaugeforever]

Best spreadsheet evar!!! Thank you so much.

[mecki]

Thank you! Really really helpful!

One question: What is the "Gravity Parameter" and where would I find it in the map view?

I'm trying to use this together with Real Solar System so the numbers don't match.

[Peppe]

Thank you! Really really helpful!

One question: What is the "Gravity Parameter" and where would I find it in the map view?

I'm trying to use this together with Real Solar System so the numbers don't match.

The numbers for the kerbin universe are on each wiki page for the planet/moon:

http://wiki.kerbalspaceprogram.com/wiki/Kerbin

How accurate is the real solar system mod? Not sure if you could use real world numbers or if they would have some of these numbers calculated already and posted somewhere on another wiki.

You might try these numbers, but again the real solar system mod may be scaled in someway to work in the KSP engine:

http://en.wikipedia.org/wiki/Standard_gravitational_parameter

Edited August 8, 2014 by Peppe

[mecki]

The numbers for the kerbin universe are on each wiki page for the planet/moon:

http://wiki.kerbalspaceprogram.com/wiki/Kerbin

How accurate is the real solar system mod? Not sure if you could use real world numbers or if they would have some of these numbers calculated already and posted somewhere on another wiki.

You might try these numbers, but again the real solar system mod may be scaled in someway to work in the KSP engine:

http://en.wikipedia.org/wiki/Standard_gravitational_parameter

I guess it is pretty accurate. But all the numbers are found in the map view. I just didn't know that "Gravity" meant the gravitational parameter.

Thank you!

[chaoservices]

Hey,

I added a sheet and a table on the main page for calculating parts electric use and battery additions. And conditional formatting when current battery is less then min battery. Yellow!

With updates and mods I can't promise the numbers are accurate and certainly haven't even attempted to add non stock parts.

But the framework is there so anyone with a millimeter of savvy can update the partData sheet with correct/more data.

Enjoy and feel free to copy it into the your main sheet if you like the additions.

https://docs.google.com/spreadsheets/d/18RLfn4Gdbc5PqCcUkjsD_7kbDgviIkgHR9LktX1TO5U/edit?usp=sharing

Edited November 5, 2014 by chaoservices

[Kerbas_ad_astra]

I use LibreOffice, and somewhere in the Google-to-LibreOffice transition, the string lookup and splitting functions broke, so I reimplemented them and saved them in the native OpenDocument Spreadsheet format: http://www./view/63tyil19qwo417r/KSP_Battery_Calculator_LibreOffice_fix.ods

[bgeery]

What about adding back in the "optimal field of view" calculation? under the Sat Relay tab? I'd rename it "Optimal Stable Orbit" to be more descriptive.

Wouldn't this be exactly the average between the max and minimum calculated orbits? Wouldn't this orbit allow the maximum amount of drift (on average) between sats over time and still remain functional, or am I wrong? There might be a special case with a couple of the moons that have a SOI less than the omni antenna range being used, where the max orbit (SOI) would then be the optimal orbit, instead of the average between min and max orbits (but I don't know the math to confirm this.)

Can anyone confirm either idea?