ModuleNoEVA.cs

using System;
using System.Collections.Generic;
using System.Text;
using UnityEngine;
using KSP;

namespace RP0
{
    public class ModuleNoEVA : PartModule
    {
        protected List<Collider> airlocks = new List<Collider>();
        protected Transform airlock = null;
        public override string GetInfo()
        {
            return "Cannot EVA from this part. Can still exit when landed on Earth or flying at low (20km) altitude.";
        }

        public override void OnAwake()
        {
            base.OnAwake();

            airlocks.Clear();

            foreach (var c in part.GetComponentsInChildren<Collider>())
                if (c.gameObject.tag == "Airlock")
                    airlocks.Add(c);

            airlock = part.airlock;
        }

        protected void FixedUpdate()
        {
            if (!HighLogic.LoadedSceneIsFlight || vessel == null || vessel.mainBody == null || airlocks == null)
                return;

            bool evaOK = vessel.mainBody == Planetarium.fetch.Home &&
                (vessel.situation == Vessel.Situations.LANDED
                    || vessel.situation == Vessel.Situations.PRELAUNCH
                    || vessel.situation == Vessel.Situations.SPLASHED
                    || (vessel.situation == Vessel.Situations.FLYING && vessel.altitude < 20000));

            foreach (var c in airlocks)
            {
                if (evaOK)
                {
                    if (c.gameObject.tag != "Airlock")
                        c.gameObject.tag = "Airlock";
                }
                else
                {
                    if (c.gameObject.tag == "Airlock")
                        c.gameObject.tag = "Untagged";
                }
            }

            if (evaOK)
            {
                if (part.airlock != airlock)
                    part.airlock = airlock;
            }
            else
            {
                part.airlock = null;
            }
        }
    }
}