What was found
CREW REPORTED BAGGAGE SMOKE INDICATION AFTER TAKEOFF AT ABOUT 1000 FT AGL. A TAKEOFF ATTEMPT, JUST PRIOR TO THIS DEPARTURE, WAS ABORTED FOR THE SAME INDICATION AFTER WHICH THE CREW CONFIRMED NO EVIDENCE OF FIRE IN THE BAGGAGE COMPARTMENT AND THE EICAS MESSAGE EXTINGUISHED. THE ACFT RETURNED TO THE DEPARTURE AIRPORT AND LANDED SAFELY. MX FOUND THE BAGGAGE SMOKE DETECTOR EXTREMELY DIRTY. ONCE CLEANED, NO FURTHER DISCREPANCIES WERE REPORTED.