Think about whether you're on this mission as crew (piloting, navigating and maintaining the ship and landers) or as a scientist (learning about planetary systems). Crew will generally have more spacefaring skills and backgrounds; scientists may well never have been away from Earth before.
Exploration ship personnel are the best that Earth has to offer. Start with 200 points for "relevant" traits; "irrelevant" traits are useful only for background, and are free (whether positive or negative).
These are skills all PCs will have. If you didn't have them when you were recruited, you've been trained to at least 1 point.
You may not have Space Sickness without a Mitigator (daily drug treatments, -60%) - and even then such a person is likely not to have chosen a career as space crew.
You may have Hypersickness (see Timesickness, p. B158).
You may not have any Exotic or Supernatural traits.
There should probably be a relevant skill that you're really good at - skill level 16+. That's why the Exploration Service is sending you out on this mission.
You may well have some G-Experience (probably on the Moon (0.17G), Mars (0.38G) or Titan (0.14G); the former two might even be your home gravity.
Recruiters are also looking for, but do not insist on, some degree of wilderness experience (Survival and Hiking skills).
You will have G-Experience (Zero G), and significantly higher levels of Free Fall, Spacer and Vacc Suit. Particularly relevant ship skills are:
If you can fill in for one of the scientific roles too, so much the better. The ship's doctor will most probably be on the crew side (but may be an NPC).
Your major skill will probably be one of:
You will also have at least some Research and Administration. You may well have Tenure.
While it's not a primary selection criterion, experience with more sapient-orientated sciences (Archaeology, Anthropology, etc.) is welcome.
If you can fill in for one of the ship crew roles too, so much the better.