OVERVIEW:
         Alright, before we get started I want to forewarn that this review may seem rather harsh. I have a lot of critiques as far as structure, character, plot, pacing, and what not. However, the biggest problem you have is the one people want to hear the least, you have an undeveloped writing style. I checked your bio and saw where you admit to not reading much. This is a big problem if you want to achieve an appreciable level of skill as a writer. There's an incredible amount of craftsmanship necessary to weave an intriguing and enrapturing story, and you'll never be able to achieve it unless you study how others do and where others fail. There's no way to work around it. TV and what not can inform your views and give inspiration, but they can never teach you how to perform.
         This piece ended up very flat. So you have an interesting concept and the idea for a fictional universe, but lack the skill to bring it to life. I felt no emotional connection with your protagonist. I didn't feel any tension when his ship was going down. Not because the story doesn't have potential for it, it does. I'm sure it all exists in your head, you just need to develop the ability to communicate it all in a more engaging fashion. Now you have a rather dispassionate narrative.
         That being said, forming ideas is really the hard part. Set aside a certain portion of your day EVERYDAY and read. Pay attention to what really captures your attention, what kind of language packs an emotional punch, how writers build tension and release tension throughout the plot. Also pay attention to what you don't like. Study different literary devices and how they're used effectively. I also highly recommend reading, at least, Stephen King's On Writing: A Memoir Of The Craft, when it comes to "how to write" books.

         You have a rather soft opening. You have the first couple sentences to draw the reader in and hook them. This is especially true now where the next story is a click away, and a lot of people will shoot right passed anything that looks like it's more then 1,000 words. Your first paragraph is your story's first impression, and it needs to be intriguing enough to pull the reader deeper into the story. It needs to pose questions in there mind about the characters, setting, plot, or some combination of them. I'd suggest opening with Joe's internal conflict in regards to the challenges he faces in his relationship with Sabrina. You could definitely take some of your stuff about Sabrina from later, which is great, and rearrange it up front to create some intrigue.

Example:
She was perfect. Joe could almost taste the hint of salt on her skin as he imagined gently kissing her soft shoulders. It had been months since they had laid in each others arms discussing philosophy, the stars, the universe, they variety of different cultures they had come across. He couldn't stand having to spend another moment away from her. Her father, on the other hand, he had no problem with being separated from.

So here, I took your words, and tried to construct something that's more intriguing to open with. Something that poses a question in the reader's mind, namely "what's up with that chick's dad?" From here maybe he starts illustrating to distract himself from the problem at hand and you can describe the planet and continue on from there.

In conclusion, you have a good concept you just need to work on the delivery. I hope this isn't discouraging in any way. You're not going to pick up a pencil and draw amazingly realistic landscapes without ever studying perspective, color theory, and composition. Writing's no different.

PLOT:
         You establish two plot-lines in this piece; Joe's forbidden relationship with Sabrina, and the alien invasion. You build towards the confrontation with the father, which in my opinion should be the climax point of the story. I think the tension in regards to this needs to be built a little more slowly from the beginning. We find out quite a bit about Sabrina, then later we find out her father wouldn't approve and within a couple paragraphs they have an awkward confrontation. You're missing out on a great opportunity to capitalize on the emotional strain of this relationship. We should feel some Joe's reticence flying to Sabrina's village. He know's he might run into her father there. We should feel his conflict in the beginning when he's pining for this woman knowing their relationship is facing serious obstacles.
         Then the whole thing is offhandedly tossed aside for the alien invasion plot to come center stage. Joe's reaction is not that of a man in love and dejected. You spend all that time establishing this bond between Joe and Sabrina and it all get's tossed aside in a single sentence. "Oh well. Now I can focus on my duties of training the men and women that are in my charge. Keeping them alive and in one piece," Joe reassured himself. This is not a believable reaction to what just occurred. This doesn't help to establish a bold, active character that people want to root for and connect with.

CHARACTERS:
Joe
Joe came to life to me during the discussion of Sabrina. There was a hint of passion there.

I think the contrast of him being a soldier of some sort and an artist could be very interesting. Perhaps, you could work in more art terminology into the narrative from Joe's perspective to capitalize on his uniqueness. So when describing environments from his perspective ask yourself "how would an artist describe this".

SETTING:
         I like the idea of this native village on an alien planet. It gives you a lot of opportunity to contrast modern technology and ancient ideas.

SPELLING and GRAMMAR:
You're missing a lot of indentations on new lines.

After spending months in the near claustrophobic confines of the New Terran Starship BillyZane, he was finally granted leave, and he really wanted to see Sabrina right now.
You switch from past tense into present here.

"Look, my daughter is not right for you. She is going to marry someone in her own class. Do you understand?"

Looking for a safe place to land, Joe adjusted the controls to make the craft tilt upward in order to soften the blow when he hits the pack of trees.
Switch to present tense here.

SUGGESTIONS AND NIT-PICKING:
Avoid use of obvious "set-up" terminology. Saying things like "he stopped to view this" or "she stopped to observe that" are often as these blunt segues by us authors to establish setting. It's like saying "alright now have to tell you what the place looked like because that's what I'm supposed to do as an author and so he surveyed the environment around him", it's peeking around from behind the curtain. It's always better weave in settings and description into the narrative more naturally. Here you have a great opportunity in that you already have Joe painting the landscape. So, as I suggested earlier, you could open with him sketching, describe what's in the sketch the sketch, have it hold it up against the view to check his work, and the reader can establish the connection in their mind. Here you would would have to really have to focus on making those first descriptions very intriguing. This is what you're opening up you work with, this has to draw them in quickly.
Not to say we shouldn't ever use these "set-up" terms. Sometimes they come in handy. If what's going on in the setting is vital to the plot of the story then maybe it should be highlighted in a blunt fashion. I'm just mentioning it as something to keep in mind.

A lot of generic terminology "Space Force Marine", "Spaceport", and "blaster rifle". So instead of "blaster rifle" it should have a specific name like an "assault rifle" could be an M4, AK47, or G36. These are the little details that give a world depth without drawing attention to themselves.

I'm not feeling the naming of systems and ships after actors, it's more on the silly side which doesn't really fit into the more serious tone of the piece.

...he was finally granted leave, and he really wanted to see Sabrina...
Now that he was on leave he was looking forward to seeing her again.
Repeating sentiments

he finally approached the gate and said "Technical Crewchief Joe Bridges requesting access."
The finally here is unnecessary, this would insinuate he approached the gate after some long delay for whatever reason which doesn't seem to be the case in the story.

While he was overlooking the landscape on the way to see Sabrina, all he could think about was not only how beautiful the scenery was, but also about the last time they were together.
You might consider taking out the "how beautiful the scenery was" portion. It weakens the impact of the idea that she is overwhelmingly on his mind.

...especially at the range at which he was so close...
This is a little clunky, you might try something along the lines of:
...especially at such close range

Shouldering his rifle...
Shouldering your rifle is what you do when you place the butt against your shoulder and prepare to fire. Perhaps he slung his rifle?

Shouldering his rifle, he fired up the chute and jumped out the window, and thanks to the chute catching somewhere, that had Joe swinging back and forth about 5 feet from the ground.
The sentence structure here is rather confusing. You might consider something like:
Joe slung his rifle, fired up the chute and vaulted out of the cockpit. His descent was brought to an abrupt halt and he found himself swinging back and forth 5 feet off the ground looking up at a tangle of branches and rope above him.

Looking around for a hiding space before the approaching Hostiles were to find him, Joe looked around for a safe place to hide
Repetition of thought

...activated the GeoTrans("Geographic Translation)
This is backwards to how the introductions of abbreviations are usually handled. Typically you'd use the full terminology first, then parenthetically the abbreviated version.
activated the Geographic Translation(GeoTrans)