KerbalX

Tier 7 tech space plane that can launch from Tier 2 Runway and Hanger, can be researched with Tier 2 R&D facility.   In fact,  I have deliberately excluded any items that are not on a prerequisite tech node for the Panther or NERV engines. 3 Seats and over 4700 delta V from a 90km orbit, this could send your Kerbals just about anywhere.

The Kerbal Wind Tunnel charts on right show 3 conditions - jet power only (left chart), jets and NERVs (middle chart) and NERV flight after jet separation (right chart). Note, this tool does not yet take account the reduced effective weight of the craft that results from orbital freefall effect at high speed, in practice it wants to fly well over 20km above 1000 m/s.

Flight tips 

The airplane’s wings are angled up and will make lift even if the nose is on prograde.   It also flies a degree or two above prograde even when prograde hold is set, and the nose rises a few degrees further if SAS is taken off completely.

You can more aggressively force  the nose down by activating Orbit mode on the Navball while in Prograde Hold mode, since this makes the airplane attempt to point its nose at the horizon, rather than the prograde marker, which is likely climbing.

Abort action group toggles nukes.   Jettison the jet engines once their tanks empty.  Once you’ve lit the nukes,  stay on Prograde Hold mode and keep Navball in Surface mode until passing over 70km.

Details

• Type: SPH
• Class: spaceplane
• Part Count: 68
• Pure Stock