CNA-2 Ascender SSTO
by ssTALONps
uploaded 2016-01-21
stock spaceplane
#SSTO #Minmus #shuttle


Designed from the beginning as a reliable crew shuttle, the Ascender is Minmus return capable aircraft. Capable of reaching 100x100km LKO with 2.3km/s of dV left. Intended to operate on both Kerbin and Laythe; current variant designation is E.

Ascent profile

  1. Rotate at ~55m/s.
  2. Pitch up & maintain 5 deg.
  3. At altitude of 5km, pitch up & maintain 10 deg.
  4. At altitude of 20km, pitch up & maintain 20 deg and press 3 to ignite LV-Ns.
  5. At altitude of 25km, switch RAPIER mode.
  6. At altitude of 50km, pitch down to prograde.
  7. Keep burning until desired apoapsis is met.
  8. Deploy service bay and circularize at AP.


  • Stock?: Yes
  • Version: 1.0.2~1.0.5
  • Type: Minmus crew shuttle
  • Crew: 6 (remote operation capable)
  • Operational weight: 38.07t
  • Empty weight: 18.02t
  • Payload capacity: N/A
  • Propulsion: 2x RAPIER, 1x LV-N
  • Size: 17.1m x 12.6m x 3.5m
  • Part count: 87

Development history

[Origin of CNA series]

The Combined Nuclear-propulsion Aircraft series aims to create SSTOs with pre-1.0 performance.

With (personally) welcomed nerfing of turb-OP-jets, SSTOs of post-1.0 era have generally inferior performance. Now, creating a SSTO with at least 2km/s of dV on orbit must include nuclear propulsion system. But this presents another problem as LV-N has terrible TWR. This rules out high performance, LF-only SSTOs from emerging. To deal with a wide gap of safe transition speed - 200~300m/s between high TWR (RAPIER) to low TWR (nuclear) - one must use RAPIER’s closed cycle mode for a while. This resulted in the above-mentioned naming of my series.

All CNA series crafts have ascent profile embedded into in-game craft description for convenience.

[CNA-2 Ascender]

While the Apex demonstrated promise of ‘2R-1N’ engine layout, it lacked practicality as it only had crew capacity of 1. So I decided to make a crew shuttle with capacity of no less than 4 for use in mission to Minmus.

The Ascender has aesthetically pleasing wing layout. 2.3km/s of on-orbit dV capacity is more than enough for Minmus landing and return. Thanks to its additional SAS units, the Ascender can effortlessly perform high AoA reentry.

In 1.0.5, a unique variant of the Ascender called CNA-2IR Raven was introduced. This Self Contained Retriever variant was my first Mk 2 sized, ISRU capable SSTO. It is qualified as single-stage-to-anywhere, but I do not intend to publish it as it has been replaced by more powerful variant.

Although the Ascender has adequate performance, its poor ascent performance prompted development of SSTOs with higher level of performance.

Current variant, E, has some convenient features such as tail-strike proof gear and more balanced RCS layout.


I impose myself a strict SSTO usage doctrine; SSTOs should not embark on a mission to other bodies alone (except for Mun and Minmus), and interplanetary missions using SSTOs must include mothership(s) to dock to. Feel free to use the CNA series as interplanetary SSTO, but I cannot guarantee your mission’s success.

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