I've been using info from the forum to build a big cargo SSTO, specifically from Here on air intakes and Here on Shock-cone VS precooler drag and airsupply.
Based on the second mainly, I have chose to go with a pre-cooler and radial adjustable ramp intake per whiplash and 1 pre-cooler per rapier topped by a type b tail cone instead of 1 shock cone per 4 whiplashes/rapiers.
This has lead me to building the following plane:
It has a MK3 small cargo bay with science, a large reaction wheel and extra X200-8 tank, 1 MK3 small cargo bay with a convertotron 125, 2 large drills, 4 fuel cell arrays and 1 large heat radiator, a MK3 crew cabin, a long MK3 rocket fuel fuselage, a long MK3 cargo bay, and the rest are MK2 liquid fuel fuselages and adapters with full liquid fuel and oxidizer.
The ultimate purpose of this craft is to be the 1 stop shop for everything I might want to do. It should be able to land on minmus, refuel by mining, and then get to about anywhere in the solar system. All the while it should be able to carry cargo the size/weigh of a Rockomax Jumbo-64 Fuel Tank, or about 40/45 tones, to all the science that would not need a permanent station or orbit such as asteroid spotting, the cargo is for carrying that. And it should be able to do so carrying up to 20 kerbals, be they for tourism or for a massive training mission to get everyone to level 5. And all of this on the same single mission.
However, I am struggling to get this thing into a 100KM orbit with enough delta-V to reach minmus even without cargo.
I realized the posts I referenced were 2 years old, and came across a newer post claiming the shock cone now has a much lower drag than any other nosecone.
My question is, is this true and are these posts I found outdated, or am I missing something else entirely?
What am I doing wrong?
Bewing has mentioned that it is way oversized for a space plane, and I agree to an extend.
I have a much smaller space plane for small trips and fun, so for just having a functioning space plane it is way oversize.
But for all the purposes I mentioned I don't think it is.
I'll be tinkering with the design in a bit.
EDIT:
So, I got the plane to minmus with a mock cargo of 44 tones and the 16 kerbal passenger cabin still attached. Flight path is tricky, since I was struggling to get the plane over 900 m/s at 21 km. But using an ascend profile based on accelerating and rapid climbing I could still reach orbit. I'm not sure if that is because my engines are oxygen deprived or for other reasons, but it worked.
Based on bewing's advice I swapped out the all the pre-coolers and radial intakes for shock cones. Following AeroGav's advice I ended up replacing my front wingets with the big-s tail fins, added big-s delta wings with control surfaces to the tail section, and completely reworking the wings switching out the MK2 for 2.5m and using only big-s wings and strakes and slightly slanting these. I also replaced the rapiers with aero spikes but maintained the overall number of engines. The aerospikes weigh only half as much and had an ISP of 340 in stead of 305 in vacuum without any (closed cycle) thrust loss. RAPIERS might be good for small planes but as soon as you go into over 8 engines it might be worth while to look into ditching them for straight up whiplashes and aero spikes. I further managed to squeeze the contents of the science cargo bay in with the contents of the refueling and refinery cargo bay, saving me a cargo bay. I could add one or two more 2.5m fuel tanks to increase he amount of delta-V once out of atmo, but I spent enough time on this already.
Overall, I am quite happy with the end result:
There is one strange thing however, the lift of the front Big-S tail fins is uneven.
It's not that big of a deal, the craft still flies, but it annoys my sense of perfection, or that might just be my OCD
.