Before beginning I highly recommend you beat the Drones Only mode, this will make it the easiest to create the setup you want to complete this mission. I personally had the maximum essence objective on every essence before doing this just to make it easier.

• Blue hole
  Blue hole is the crux of Mission 40. The blobs that the Detonator D94's destroys while charging count towards the 400 blobs needed to complete this mission.
  
• Solitude
  Solitude significantly increases the detonation size of the detonator drone.

• Haste
  Haste is not required if you are maxing out your Blobs Spawn Rate and Orbital Capacity but can make this mission easier.

• Data Breach
  I think this mission is still possible with Data Breach enabled and Saggitarius Essences appearing but I highly recommend to avoid it because the hacked blobs in the hack wave have a 25% chance of self-destructing which can significantly lower the amount of blobs that the Detonator D94 will be able to destroy itself.

Absolutely do not buy Saggitarius Blobs if you are using the Data Breach Stellar Upgrade as it will make this mission significantly harder or impossible.

Do NOT upgrade the Detonator D94's charge duration, the more time that the drone has to destroy blobs before the actual detonation the better.

This should go without saying but you should upgrade Detonator D94's range to get the maximum range possible. With Blue hole and Isolation the range should cover the entire blob orbit.

Upgrade the Blobs Spawn Rate and Orbital Capacity to maxium, there needs to be as many blobs possible so when the detonation happens there are lots for it to explode.

With all above steps completed, disable all drones except for Detonator D94 and move your cursor to one of the corners of the screen to avoid activating the early detonation. Hopefully when the detonation occurs you'll complete Mission 40.