system
Given the following post, respond as if you're commenting on Reddit:
human
[ALIENS] Where the hell is everyone on that goddamn ship?

Alright, this is something that has **always** bugged me, and I'm hoping for an answer. As we all know, when 'Archeron' went out of contact, a UCSM ship (the Sulaco) was sent put to find out what happened and, if needed, smack some heads or evacuate people from the planet. An easy mission, just a checkup with potential to become something more serious if even an *inkling* of what Ripley was shouting was to be believed.

So who do they send to this world for such a huge mission? **ONE SQUAD WITH TWO ADVISORS AND A SYNTH**. And that's just not the people going planetside, *that's the entire ship!* Where's the captain? Where are the medics, secuirty, engineers, the very prominent crew that should be running this massive ship and making sure things don't belly over- was the Mission to Archeron just deemed a suicide mission and never intended to work?
gpt
To move at 1G, a ship has to accelerate at 32.2 feet per second squared. Assuming you stop at the halfway point and start braking (again at 1G), this would get you to Pluto in about 15 days. 

The starships in this universe have a jump drive, allowing instant travel* between vast distances, but they cannot function in close proximity to a gravity well. 

* Instant to a static observer. Anyone traveling down an artificial wormhole will experience travel at the speed of light and a trip to LV-426, 39 light-years from Earth, would therefore cause intense stress or insanity - hence the necessity for hypersleep chambers. The name *hyper*sleep hints at the perils of inverse time dilation.

A starship uses its fusion drive to accelerate to a safe distance and then to jump to a safe distance from its destination. At that time, the ship begins accelerating and the human crew is awoken once the ship is past the halfway mark of its trip into a star system. 

The Colonial Marines maintain rapid reaction forces throughout human space, consisting of jump-ready platoons at bases outside solar gravity wells. Once they receive a go order, they require less than a day to prep their ship and enter hypersleep before jumping and then starting their acceleration/deceleration burn. 

So why don't the Colonial Marines, with a strength over 200,000, send larger forces? Because they are overstretched dealing with peacekeeping duties. The Offworld Colonies attract an interesting mix of people who present significant law enforcement challenges; you have the wealthy who fled Earth and require protection, you have massive workforces of synthetic humans who occasionally go rogue (although only a handful ever make it back to Earth), you have entire planets filled with fringe cults and refugee populations and libertarians and misfits. The Colonial Marines are absolute badasses, honed and tried in constant conflict, a band of brothers against a civilian world that sees them as the fist of a corporate Moloch, and their fights against cultists and secessionists and frontier sociopaths have reinforced their self-declared vision of righteousness and elite fighting prowess. 

The Marines have nothing but contempt for settlers, especially those who can't stand up in a one-to-one fight against hostile alien animals. They can take out a world of guerrillas, but Joe Shake-and-Bake can't take care of himself against a rogue Arcturian? 

It's a bug hunt. The Marines *hate* bug hunts, from top to bottom, and don't assign a single person more than they have to for these assignments. The *Sulaco* doesn't need a medic or navigator; the synthetic can handle that. 

And just maybe a snotnose kid named Carter Burke learned how the Marines operate. Maybe that's how he rose to become an ambitious executive in the Company's bioweapons division, with access to secret information. Maybe that's how he knew how he could get a handful of people onto LV-426- just enough to secure a specimen. Just enough for him to handle on the way back.

Source: Largely the Colonial Marines Handbook.