Problem with a prefab, need help

Hi.

I am making a videogame in 2D that is in the space. I wanted to give some cool effects to the spaceship, so i put under them an afterburner.

I want that when they hit a black hole their size will fall off, but iget the bug on video. How can i solve it?

The video click me

This is the script on hit with "Buco Nero" And it's attached to the player (Dark hole)

 using UnityEngine;
 using System.Collections;
 
 public class ContattoConBucoNero : MonoBehaviour {
     float perditamassa;
     int stack;
     float time;
     GameObject afterburner;
     // Use this for initialization
     void Start () {
         GetComponent<Transform> ().localScale = new Vector3 (2.631793f, 2.631793f, 0.3427396f);
     }
   
     // Update is called once per frame
     void Update () {
   
     }
     void OnCollisionEnter2D(Collision2D myCollider){
         if (myCollider.gameObject.tag == "Buconero") {
             afterburner=this.transform.GetChild(1).gameObject;
             perditamassa=FindClosestBucoNero().GetComponent<CreazioneBucoNero>().stack*0.15f;
             stack= FindClosestBucoNero().GetComponent<CreazioneBucoNero>().stack;
             if(perditamassa<(GetComponent<Transform>().localScale.x-2.631793f)){
                 GetComponent<Transform>().localScale= new Vector3(GetComponent<Transform>().localScale.x-perditamassa,GetComponent<Transform>().localScale.x-perditamassa);
                 GameObject.Find("Main Camera").GetComponent<Camera>().orthographicSize=GameObject.Find("Main Camera").GetComponent<Camera>().orthographicSize-(0.3f*stack);
                 while (time<=2f) {
                     time+=Time.deltaTime;
                     afterburner.GetComponent<ParticleSystem>().startSize= GetComponentInChildren<ParticleSystem>().startSize-(0.76f*(2/stack));
                 }      
             }
             else{
                 Debug.LogWarning("Game Over");
             }
             Destroy(FindClosestBucoNero());
         }
     }
     GameObject FindClosestBucoNero() {
         GameObject[] gos;
         gos = GameObject.FindGameObjectsWithTag("Buconero");
         GameObject closest = null;
         float distance = Mathf.Infinity;
         Vector3 position = transform.position;
         foreach (GameObject go in gos) {
             Vector3 diff = go.transform.position - position;
             float curDistance = diff.sqrMagnitude;
             if (curDistance < distance) {
                 closest = go;
                 distance = curDistance;
             }
         }
         return closest;
     }
 
 }
 

Thanks for all the help