Reactordrone

A 150km polar orbit will give you about a 36 min orbit and your field of view is about 36° so you should get a reasonable coverage looking at only the daylight side in 10 orbits.

In the real world Sun synchronous orbits are usually slightly retrograde (around 98°) and set up so that the orbit precesses eastwards to keep them aligned to the Sun throughout the year but I don't think that applies in KSP.

Scott Manley did an annotated version at correct speed. The twitter one seems a little time accelerated. https://www.youtube.com/watch?v=unEbg_dt3DM&t=0s

With a common bulkhead you might end up with tanks something like this in the hopper, That's assuming the upper dome is allowed to protrude into the upper aerodynamic section and a similar engine mount geometry to a Merlin.

The turbopumps on a raptor engine, for example, make and use about 100,000 hp to maintain propellant flow. The design of the combustion chamber also helps. Pressure wants to go out through the big hole at the bottom rather than the tiny injector nozzles at the top.

Might be a double wall system with the cooling channels built into the structure.

With Duna you could consider aerocapturing into orbit and then waiting there until the next Duna-kerbin transfer window. The aerocapture is almost free in terms of Delta-v and heating isn't much of an issue (as long as you can retract your antennas and solar panels to protect then from aero forces you should be good.) Don't forget to click on Duna once you've got an encounter and select focus view to fine tune the manoeuvre.

Although the left hand part of that vehicle is a capsule. https://en.wikipedia.org/wiki/TKS_(spacecraft)

I think mission control and the tracking station have to both be upgraded to get nodes. Navigation modes are dependent on pilot level or probe type. More advanced probes give you all features, early tech probe core have limited options.

If you want to role play it you can build modules that have to meet certain weight and size parameters and launch everything on a standard type of launch vehicle.

He usually takes a size 36.

The Orion time of year, Twelve 45 sec exposures stacked. 10" Meade SN with Canon 500D.

And a much cleaner shot from the deployment arm camera, https://www.jpl.nasa.gov/news/news.php?feature=7310

ESA scrubbed a Soyuz launch because of high winds the same day

Back in my day we had to do all the basic arithmetic by hand until year 10 (with working shown). After that calculators could be used.