STS v4 - STS Mun-2
by Fulgora
uploaded 2021-06-07
| Version 5 of 7
10 downloads /
1
points
VAB
stock+DLC ship
#shuttle

Description


A stock rocket called STS v4 - STS Mun-2. Built with 257 of the finest parts, its root part is mk3CargoBayL.

Built in the VAB in KSP version 1.10.1.

This shuttle version is easy to launch manually - both with max payload (45t) and empty.
The STS Mun-2 mission has a medium / light payload configuration that allows you to place an escape rocket on the surface of the Mun (at any location/inclination of your choice).

The payload of this craft-file is meant to be docked to the other base modules using the STS Mun-4 base rover.
In the video this is used as the root module of my base but you can also drive this around using the rover if you like.

If you would like to checkout all other payloads please click the view other versions text in the details view.

Details

  • Type: VAB
  • Class: ship
  • Part Count: 257
  • Pure Stock
  • KSP: 1.10.1
  • Max. takeoff mass: 740t

Mission

  • 1x Escape rocket base module
  • Runway landing

Launch profile

You can also launch it using the Mechjeb Ascent guidance - the recommended settings for that are displayed in the screenshot above. Alternatively you can use my kOS launch script which has been written specifically for this design and has been used in the video.


The launch profile for this is a slow turn as the shuttle has a very low TWR after the booster separation. You need to aim for at least 60 seconds to apoapsis at booster separation (~30k altitude) so you have enough time to compensate for the low TWR.

Right before booster separation it is recommended to activate RCS to reduce the angular momentum generated during the last seconds on solid rocket motors.


When launching with Mechjeb you can stop the guidance once your time to apoapsis increases again. This will happen shortly before your time to apoapsis has dropped to 20-30 seconds. After that just point prograde until you reach your desired apoapsis height.


The external fuel tank can also deorbit and land on its own (it has two tiny engines + reserve fuel tank) and is able to boost the shuttle with max payload all the way to a moon encounter if you so choose.


Once in orbit the shuttle has roughly 900m/s left in the external tank and another 1770m/s after external tank separation with max payload. When launched empty the shuttle has together with the external tank roughly 5100m/s left.


Note: While the external tank is attached in orbit the shuttle does not work well with Mechjeb with the default control point. You have two options:

  1. To fly the maneuvers with the tank manually. The shuttle is able to hold the target / prograde marker. Especially with RCS enabled so executing any maneuver nodes is fairly easy.
  2. To switch the control point to the Probodobodyne OCTO2 probe core under the top nose cone of the external tank (shown in the screenshot album). This probe core is aligned with the thrust vector you have in orbit with the external tank attached so Mechjeb will be able to execute maneuvers when controlling from this node. In order to switch to this node I recommend:
    1. Use the resource menu to highlight all parts with electricity
    2. Pin the probe core (its quite easy to find as there are few electrical parts in the top)
    3. Un-highlight all electrical parts again so you get all the probe core actions
    4. Select Control from here
    5. Done :)



After the vector engines burn out (< 100ms of LF in the external tank left) switch back to control from the MK3 shuttle cockpit and throttle down to 66% or cut the middle Nerv engine if you use Mechjeb.

Mun Landing


First you need to set the thrust limiter of the Vector to 0%.

In order to safely land on the Mun slow down to ~300m/s on the Nerv engines (Oxidizer is a bit scarce) before you reach 60 seconds to impact. If you are at 60 seconds to impact activate the Thud engines (AG 2). This allows for an easy vertical landing. Deploy landing gear before touchdown and drop on the wheels.

It’s easier than it sounds, promised ;-)

Mun Takeoff


Find a nice flat spot, preferrably slightly uphill with a crater edge coming up and set the Vector thrust to 25% (gimbal enabled).

Make a run for the crate edge on Nerv engines only and toggle the chemical engines with AG 2 once you are at the crater edge or going above 100m/s. Having RCS enabled at this point helps ;-).

Generally speaking the takeoff is reasonably easy too.

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