The key card is present but its support is thin.
Prioritize useful support such as Interface Ace or Spotcycle Scouter.
Develop Interface Ace and Spotcycle Scouter before Voyager Quickwelder; later cast a discounted artifact or Voyage Home while retaining creatures able to crew your Vehicles.
Your deck enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before another expensive payoff.
Artifacts that cannot attack on their own are not a complete curve. Keep real creatures and enough untapped crew power before adding another expensive Vehicle.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.