STV Block 3 Fully Reusable SSTO Spaceplane
by RundownPear
uploaded 2020-11-16
(updated 2020-11-16)
stock+DLC ship
#spaceplane #spaceshuttle #space #shuttle #STS


The STV is back and better than ever with my Block 3 variant, released on the vehicles one year anniversary. This vehicle has been the workhorse of KSP for me and I have flown close to 40 times on a plethora of missions. During those missions I have worked to fine tune and polish the vehicle as much as possible and identify what needed an overhaul the most.

The Block 3 aims to increase efficiency and modularity, notable changes include:
* A new modular command module system allowing for an easily detachable crew module that now has an integrated launch escape system and orbital lifeboat capabilities
* An improved aerodynamic profile with the vehicle being setback much more on the booster, the weird nose mounted configuration was left over from when the booster was a flyback system and had a large rear rudder
* Removal of the modularity nodes on the booster as those upgrades were never needed and added to cost
* New lighter and inline orbital maneuvering system
* Added a tenth engine pod to help manage the tricky aerodynamics of the orbiter
* A new orange pain job for users with the ReStock mod installed
* Swapped out the forward nosecone for an aerodynamic docking port to allow for easier orbiter-to-orbiter access and to complement the orbital life boat
* Rear arm nodes so that the arm (sold separately) can be attached in more than one place

Action Groups

  1. Toggle fuel cells
  2. Disable main orbiter engines, activate orbital maneuvering system
  3. Activate jet engines
  4. Toggle payload bay
  5. Toggle orbital maneuvering system
  6. Nothing :(
  7. Deploy orbital life boat
  8. Activate fuel valves
  9. Toggle gimbal for main booster engines

The Orbiter

The Orbiter is a multipurpose spaceplane designed to service the 80km-1000km orbital range. It has a 5 segment payload bay with multiple attachment nodes allowing it to carry multiple payloads at once. The payload bay can be outfitted with a multitude of different arms, science racks, airlocks, and habitation units to serve any mission profile. The vehicle includes the main engines which help power the STV to orbit, orbital engines which help it maneuver in orbit, and 10 atmospheric engines to power it after descent.

The Booster

Officially known as the Space Launch Vehicle (SLV) the booster is its own standalone launch system that carries the Orbiter to orbit. Powered by 8 KS-25 engines, It is designed from the ground up to be reusable. The booster deorbits with its main engines and lands via an engine assisted parachute touchdown. The Block 3 uses a new light weight tank to reduce mass and increase payload as well as removing the bulky inline shroud that was rarely utilized. Helping to boost payload capacity significantly.

The System

The Block 3 system is designed to be the most efficient and modular system out of the bunch. As before, the booster puts the entire stack into orbit with up to 40 tons of payload. The booster then flips around and returns while the orbiter plays out a traditional spaceplane flight profile. The Block 3 is more aimed towards smaller commercial payloads rather than large and bulky military ones. The block 3 also places a stronger emphasis on safety with a integrated launch abort system and with the command module detachable as an orbital life boat Major modularity nodes include swappable airlocks, multiple arm mounting nodes, and a detachable command module.

Multipurpose Life Boat

The MLB is a newly designed crew module that can easily be detached from the orbiters hull. This allows for the inclusion of a pusher abort system and orbital maneuvering engines. The module has one of the STV’s four fuel cells attached to power it, as well as two header tanks to fuel four orbital engines allowing it to transport the crew to a station for rescue. In the event of a launch abort the life boat can function as an actual life boat and float in the ocean for extended periods of time.


I have a whole host of upgrades and optional modules that I will hpoefully release with time. The only compatible modules from the previous generation STV are the:

Optional airlock modules and an updated odyssey will be coming shortly. The arm is not included so that you can download this without the Breaking Ground DLC.



Once in orbit, perform a retro burn to re-enter and target the Desert Launch Site for recovery. Before re-entry, you should move all remaining fuel to the lowest fuel tank and deploy the air brakes. Turn on pitch and yaw for the air brakes. When appropriate, deploy the parachutes and use the remaining fuel to reduce speed to around 5 m/s for touchdown. You might need to relight the engines if the ground is uneven bu you should be fine.


Pretty standard procedure just as if it was any other Space Shuttle. The craft is built for stable reentry so just pitch it like normal and turn on SAS and it should be very stable. The Block 3 has a difficult aerodynamic profile and relies more on gliding but can still sustain stable flight, with the help of the mechjeb altitude hold. Without mechjeb you can still fly it just the pitch is a little difficult, this is due to a 3 ton weight increase in the front of the vehicle and a 1 ton decrease in the rear. In the event of an abort, the life boat command module has parachutes to land and in the event your orbiter doesn’t wanna land the right way you can pop the abort system and lose the vehicle, saving the crew. Also remember to jettison fuel with action group 8 so it stays balanced for reentry.


  • Type: VAB
  • Class: ship
  • Part Count: 286
  • Pure Stock
  • KSP: 1.10.1
  • Restock recommended
  • MechJeb or other autopilot recommended *Mk3 mid deck for more crew capacity


And here it is, my next iteration of the STV. The vehicle has currently over 350 downloads between the Block 1 and Block 2 which I think is a healthy number. Block 3 was designed after looking through the data from a few dozen Block 2 flights and figuring out what needed major change the most. Overall I think I am happy with it, i’ve only flown the vehicle on one operational mission but it seems to have performed very well with good margin and a perfect reentry. We’ll see how long I fly this vehicle, might take a break as it has a high part count and kinda makes my PC run like crap, I’ll probably start playing more after I upgrade my CPU in a few weeks.

Here is the vehicles flight manifest which tracks every mission I fly with it.

This vehicle is special to me as I have never kept up a vehicle like this. Most vehicles you build, fly it a few times, and move on, the STV has stayed with me for a year now. My life has changed so much in 1 year but this vehicle was always there to modify and fly at the end of a bad day. Its weird having a 1 year anniversary with a KSP craft file but hey, 2020 is weird.

Feedback is appreciated, hope you enjoy.

A stock rocket called STV Block 3 Fully Reusable SSTO Spaceplane. Built with 286 of the finest parts, its root part is Decoupler.1p5.

Built in the VAB in KSP version 1.10.1.


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