This is easily done through the use of the in-game admin panel, which can be opened by pressing

+

simultaneously, so long as you are the host of the game or have been promoted to admin of the game you are in. Here you will find a few settings that will make going for this achievement much easier. I would suggest the following settings enabled...
- Enable creative mode tools
- Invulnerable
- Untargetable
Then, you will play through the scenario as normal completing all tasks you are prompted with, up until you reach the planet and are then tasked with disabling the pirate facility. While doing so you must not come within approximately 50km of the planet's surface in order to remain out of its atmosphere, otherwise you will void this achievement.
What you will want to do at this point is make a backup save just in case for some reason the achievement doesn't pop. Then open the admin tools once again (

+

), and from the drop down menu at the top of the panel select "entity list". Scroll down until you see "pirate base" and hover over it so its selected, wait until the facility has fully loaded in on your screen then at the bottom of the panel click the option to "depower". This will disable the pirate facility and pop the achievement, no need to do the same with the pirate defenses.
Doing so you will also unlock the following achievements, granted you completed all tasks without dying...
And if you then proceed to complete the final task of disabling the pirate commander's ship (you can use the same method as above to disable it in the entity list) you will also unlock the following achievement...
That's all there is to it! Four easy achievements that can be knocked out in roughly half an hour using this method. Hope this helps :)