2014-04-10

Mission Report: DMap2 "Macroscope"

And so here we are with mission 2.

"Macroscope" atop a "Javelin" IPL.
The objectives for "Macroscope" are pretty straight forward:
  • Flight test the "Javelin" IPL
  • Test a more immediately optimal polar orbit
  • Conduct a high-res scan of Kerbin
  • Conduct a biome scan of Kerbin
The "Javelin" lifter was better than the first one.  I discarded the fully-fueled transfer stage rather than use it, to simulate the amount of delta-v that the orbiter alone would have.  I still had to use half of the orbiter's fuel to circularize (for 220km x 145km values of "circular") and in that elongated orbit, we began scanning.

The goal about a more immediately optimal polar orbit: DMap1 goes behind Kerbin once per orbit.  This starves the solar panels.  Now S.C.A.N. doesn't use any electricity right now, but I like to play fair.  So we launched at dawn, which put our orbit in view of the sun throughout the entire orbit.  At some point in the year as Kerbin moves around the sun we will go into shadow, but I'm betting that the mapping mission will be complete before then.

Revised Orbit
One interesting thing that this map shows at this point is that the high-res scanner doesn't work near the orbital periapsis of 145Km. So I raised the periapsis up to 219Km -- making this probably the most circular orbit I've ever manually flown -- and the scanning of the southern hemisphere almost immediately improved.

Mapping with the high-resolution scanner is slower, but after 7 days and 10 hours, we had more than 92% of the surface covered, resulting in this map:

That looks like more than 92% to me
I've inspected all the dark spots -- as you can see, most of them are over the water, and the rest are very small ones that don't look like they are in interesting locations.

"Macroscope" is also flying the "multispectral" scanner, which is the biome/anomoly mapper.  So at this point I shut down the high-res scanner and started the "multispectral" scanner in its place.
Oooh -- Extended Multispectral
This scanner seems to have a wider footprint, so if DMap1 is any guide, the prediction was for more or less full coverage in less than another week -- a prediction which was hilariously overkill.  Again less than two days to get the biome map:


...and the slope map:


...and a beautiful composite map showing the anomalies:


So while I could probably continue on in order to try to pick out the missing data, I think at this point this mission can be classified as almost a complete success.

Lessons learned:

  • The revised "Javelin" may not be sufficient for interplanetary missions.
  • The flight path for polar orbit was better executed this time.
  • The high-res scanner is slow, and doesn't seem to work below 170km.
  • The biome scanner is about as fast as the low-res scanner.
  • Both scanners can be operated at the same time.
The next mission will be a polar mapper to either the Mun (because it is closer) or to Minmus (because it is easier to get a polar insertion around Minmus because it is out-of-plane with Kerbin).

I will probably also upgrade to 23.5, and I might add MechJeb to assist with the interplanetary navigation.  Or I might try to find another interplanetary navigation plugin -- I would like to fly these missions myself, but sometimes you need robotic help...