Stock VTOL SSTO + ISRU Spaceplane to Laythe: The FengHuang H-77!

[Jamie Logan]

Hello once again!

Today I bring you,

 

My latest attempt at an interplanetary VTOL SSTO. When launched fully fueled, it can reach LKO with ~2,200 m/s of delta-V remaining. From there, it can be flown non-stop to Laythe and back, using ISRU to refuel on Laythe's surface. The design is oxidizer-free, and the fuel tank layout preserves the C.O.M. position regardless of fuel levels. The engine layout includes two forward-fixed Nervas, four R.A.P.I.E.R. engines (two forward-fixed and two pivotable), and two pivotable Panther engines.
 

When flying in VTOL mode, it's easiest to set the throttle to allow for a TWR<1 while the Panthers are running dry, and a TWR>1 while running wet. This will allow some fine throttle control by switching the afterburners on and off during landing.

When flying to orbit:

1) Once off the ground (via either VTOL or STOL to save some fuel), set the pivotable engines forward (AG1) with the Panther afterburners off (AG2).

2) Activate the fixed R.A.P.I.E.R. engines (AG4).

3) Cruise up to ~10 km before turning on the Nervas (AG5). While this is normally a tad too low to be using Nervas, the ISP should already be 700+ and we'll need as much thrust as we can manage.

4) Once all jet engines flame out, shut them down (AG3 + AG4) and continue to push to orbit on the Nervas. The TWR will be fairly low once you're running on the Nervas alone, so pitch up slightly to keep your time to AP around a minute. Eventually, when your orbital velocity reaches ~2,300 m/s you'll be safe to cruise to AP and circularize.

 

Action Groups:

AG1: Toggle VTOL engine pivots

AG2: Toggle Panther afterburners

AG3: Toggle VTOL engines

AG4: Toggle fixed R.A.P.I.E.R.engines

AG5: Toggle Nervas

 

Gallery:

 

 

 

I really hope y'all liked it, and if you want to try your hand at flying it, you can download the craft here:
https://kerbalx.com/Jamie_Logan/Fenghuang-H-77

 

 

Also, check out my last build!

 

 

 

Edited April 28, 2020 by Jamie Logan

[RoninFrog]

I love the ISRU setup.  Makes me want to get Breaking Ground.

[Jamie Logan]

On 4/26/2020 at 6:24 PM, RoninFrog said:

I love the ISRU setup.  Makes me want to get Breaking Ground.

Both DLCs are absolutely worth it