Scanning for Ore

[the_sky_calls]

Starting with KSP version 1.0, the developers introduced ore. This is a natural resource found in planets, moons, and asteroids in varying amounts that can be mined and turned into fuel such that you could fly a craft to a world, mine it, process it, refuel your craft and fly on.

And, of course, in creating a resource, they created a science scanner to find and exploit that resource: the M700 Survey Scanner. It has a strange in-game characteristic in that it scans the entire body all at once (unlike the SCANsat mod scanners) but it is a basic tool to give generalized results.

So let's build a satellite to scan Kerbin for ore.

A Probodobodyne HECS, the M700 Survey Scanner, and FL-T100 Fuel Tank, and an LV-909 "Terrier" Liquid Fuel Engine is a good core to start with. That's a lot of fuel for such a small craft and so this design should be good for sending out to the Mun or Minmus.

The M700 Survey Scanner does a single scan but provides two reports. The first report is the conventional science report much like any other scientific device. This reports consists of 20 Mits of data to be transmitted. A Communotron DTS-M1 (because this will also be used for the Mun and Minmus) transmits 5.71 Mits/s and spends 34.3 e/s doing so. That totals only 120 e of power. A single Z-200 Rechargeable Battery Bank would be fine for this report.

But the second report is the one that will produce the low resolution map of the body's resources and that scan consumes electricity based on the size of the body it is scanning. The KSP Wiki has the entire table but for this craft, the scan of Kerbin will produce 123 Mits of data. Transmitting that report through the Communotron DTS-M1 will consume 738 e of battery power and so using a single Z-1k Rechargeable Battery Bank is appropriate.

A couple of OX-4L 1x6 Photovoltaic Panels and it's done.

Even though this is a Career game, I sometimes will build a craft in a Sandbox game to see how it will fly, make sure my staging is correct, and other things it makes sense to test for. Sometimes I don't, which is most of the reason for any craft that fails spectacularly. In this case, I found that when the satellite's engine was throttled up, the craft would pitch over. The center of thrust did not pass through the center of mass and the fault was the Communotron DTS-M1.

On a larger craft, adding a 50 kg antenna to the side of 10 ton craft is not going to unbalance the craft much but that 50 kg on the side of a 2 ton craft can be significant. One way to balance a craft is to use radial placement and just put an identical part on the other side. I don't want to have two DTS-M1 antennas, though. That's more expense and transmission power than is necessary.

Another technique, and the one I typically try to use to balance the center of mass, is to put other radial parts opposite of the antenna. The Z-1k Rechargeable Battery Bank weighs the same as the Communotron DTS-M1 and so would be the perfect balance were it a radially mounted part. Since all batteries have the same mass to electrical storage ratios, 1,000 e of smaller radial mount batteries would do the same thing but there isn't enough physical space on the side for, say, ten Z-100 batteries. A couple of Z-400 batteries plus shifting the solar panels to the one side might have done it.

For this satellite I used the Offset Tool and carefully moved the probe core to one side. You can see the center of mass shift using the stock Center of Mass and Center of Thrust tools but I used the mod called RCS Build Aid which gives a more precise accounting of the torque that might be applied to a mis-balanced craft. This technique isn't really any better than the other, that is, if the parts you are shifting can balance the craft out. I actually kind of like the asymmetrical look. I may even try mounting the Z-1k on the side on the next version rather than shifting the probe core to have it look even more asymmetrical. A purely aesthetic decision.

Once that's all done, it's time to put it on top of a booster and launch it into a polar orbit.

Mission Designation : SS-10
Rocket Model : SurveySat A-II
Mission Objectives : Resource scan of Kerbin
Total Mass (Mass to Orbit) : 22.3 tons (1.9 ton)
Total delta-V (dV to Orbit) : 5,805 m/s (2,152 m/s)
Surface TWR : 1.48
Contract for Construction : Year 3, Day 276
Nominal Build Time : 14 Days
Total Cost : 15,605 funds
Launch Site : Woomerang Launch Site
Launch Date/Time : Year 3, Day 309 @ 03:25

The best orbital altitude for the M700 Survey Scanner is listed in the in-game parts list as 175 km, but at the KSP Wiki there is a more complicated explanation saying that the minimum altitude is 1/10 the body radius or 10 km, whichever is higher, and the maximum altitude is 5 times the body radius or 1,500 km whichever is lower. For Kerbin this is anywhere between 60 km and half way to kerbostationary orbit.

That's a pretty broad orbital requirement so I just put it at the recommended 175 km.



Once in orbit, you run the orbital survey and get the result overlaid on the planet below. At the normal setting it shows that ore is available pretty much everywhere on the surface of Kerbin. In the part settings, though, there is a +/- adjustment to narrow the field to just those places where the ore is over a certain concentration. When you narrow this, at least in this playthrough, it shows that the most ore is to be found in and around the badlands on the continent opposite the planet from the Space Center. In a different game, the concentrations may be different.

What can you do with this information? Honestly, on Kerbin, not much. You could mine the ore, turn it into fuel, and then recover it back at the Space Center. This would provide some profit but unless you have tightened the settings on monetary returns from contracts by this time in the game you have likely amassed a significant surplus of funds mining for profit isn't necessary. (I have 6 million funds at this point.)

This will be much more useful out in space where you can mine ore and convert it to fuel on site rather than having to haul it up out of Kerbin's gravity well.