This episode won't make much sense unless you've seen other episodes like "Day of the Daleks" as the episode features a couple of Who Monsters that aren't talked about much today, the Ogrons (very strong mercenary type of aliens).
"Frontier in Space" to me is more a political adventure story so those seeking outer space stories with a lot of action might be disappointed although the storyline does have a couple of memorable scenes here.
First when Jo and The Doctor arrive (more like crash land) on board an earth vessel a mysterious sound devices makes the pilot see them as Draconians. The Draconians are in conflict with Earth. We actually see that the Ogrons are involved in this deception but as The Doctor points out such advance technology seems above their intelligence. Later on in about episode three we see who is helping the Ogrons.
Episode one then is decent at establishing the conflict with Ogrons and earthlings. Like I said it's a political adventure oriented story because it shows how two races from two government can be easily motivated to start a war with each other based on lies (Iraq anybody, Vietnam?). Above that it has decent acting from everyone involved. You get the feeling that with more complex story the actors really understood the material so they didn't quite have to resort to usual Who formula at throwing monsters in our faces.
Anyways, I liked it, it's a tad different from a couple of the Who stories and has a couple of nice cliffhangers.