Answer:

probe

Answer	Crossword Clue
PROBE	Investigation
PROBE	Pioneer 1 or Voyager 2
PROBE	Inquest

PROBE	Investigate
PROBE	Data-collecting craft
PROBE	Official investigation
PROBE	Dig deep
PROBE	Explore deeply
PROBE	Legislative investigation
PROBE	Poke into
PROBE	Voyager or Pathfinder

PROBE	Ask questions
PROBE	Deep-space vehicle
PROBE	NASA project
PROBE	Pioneer 1, for one
PROBE	Serious investigation
PROBE	Voyager 2, for one
PROBE	Delve
PROBE	Look into

PROBE	Scrutiny
PROBE	Seriously look into
PROBE	Space exploration vehicle
PROBE	Space explorer (Ford)
PROBE	Inquiry
PROBE	Research project
PROBE	Delve into
PROBE	Dig into

PROBE	Penetrating investigation
PROBE	Thorough investigation
PROBE	Major investigation
PROBE	Investigate in depth
PROBE	Investigation by a legislative committee
PROBE	Senate investigation
PROBE	Unmanned craft
PROBE	Investigation.

PROBE	Lawmaker's activity.
PROBE	Examine.
PROBE	Investigate.
PROBE	Inquiry.
PROBE	Search into