Triplanetary is a fun, unique game with realistic space velocity rules in which you spend your fuel to change your movement vector rather than to move directly. And it comes with a variety of different scenarios, including "Prospecting." However, that scenario has a critical flaw: It requires ore to show up, but whether it does is based 100% on a random die roll.
Long story short? We played a four-hour game of Prospecting where we explored 33 different sectors and only one of them -- on the very last turn we bothered with -- ever had ore. Now, I realize that's extremely unlikely, but the point is that it can (and did) happen. So why use a die roll when you could achieve random-yet-consistent results with a card draw? Plus this change lets us make ore a little bit more common than CT shards, which feels right.
This is a very good house rule. I'd go so far as to call it necessary. Use it.
Prospecting (house rule)
In the first Prospecting paragraph, replace sentences two through four with the following:
Draw from a standard deck of 54 cards (with Jokers). If the card is a diamond, ore is present (mark an O); if not, it isn't (mark an X). If the card is a King, Ace, or Joker, the ship has encountered a contraterrene (CT) shard.
And if you want some additional complexity, add this:
Optional Rule: If a Joker is drawn, the CT shard is particularly potent. If captured and sold, it earns an additional 50% profit; if not, the damage roll is at +1 (max 6)!