Drill baby Drill!

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

public class MuMechModuleDrill : PartModule
{
    GameObject rock1, rock2;
    double spawnTimer = 0;

    public void FixedUpdate()
    {
        if (vessel == null)
        {
            return;
        }

        if (!rock1)
        {
            rock1 = PartReader.Read(KSPUtil.ApplicationRootPath + "Parts/mumech_drill/rock1/", "model", ".mu");
            rock1.name = "rock1";
            rock1.transform.position = new Vector3(1e10f, 1e10f, 1e10f);

            rock2 = PartReader.Read(KSPUtil.ApplicationRootPath + "Parts/mumech_drill/rock2/", "model", ".mu");
            rock2.name = "rock2";
            rock2.transform.position = new Vector3(1e10f, 1e10f, 1e10f);
        }

        if (part.Landed)
        {
            spawnTimer += TimeWarp.fixedDeltaTime;
            if (spawnTimer >= 5)
            {
                print("Spawning rock!");
                spawnTimer -= 5;

                GameObject newRock = (GameObject)GameObject.Instantiate((UnityEngine.Random.value > 0.5) ? rock1 : rock2);
                newRock.transform.position = part.transform.position + UnityEngine.Random.onUnitSphere;
                newRock.transform.rotation = UnityEngine.Random.rotation;
                newRock.AddComponent<Rigidbody>();
                newRock.rigidbody.AddForce(UnityEngine.Random.onUnitSphere * UnityEngine.Random.value * 10, ForceMode.Impulse);
            }
        }
        else
        {
            spawnTimer = 0;
        }

        base.OnFixedUpdate();
    }
}