SPACECRAFT. TOM COSTELLO HAS A LOOK AT WHAT IS NEXT FOR STARLINER AND ITS CREW. >> Reporter: THREE MONTHS INTO WHAT WAS SUPPOSED TO BE A 10 DAY MISSION, ASTRONAUTS BUTCH WILMORE AND SONNY WILLIAMS ARE NOW PREPARING TO CLOSE THE HATCH AND SEND THE BOEING'S STARLINER HOME WITHOUT THEM. JUST AFTER 6:00 P.M. ON FRIDAY NASA WILL REMOTELY UNDOCK THE TROUBLED SPACESHIP FROM THE SPACE STATION THEN GUIDED BACK TO EARTH. AS WILLIAMS AND WILMORE SETTLE IN FOR ANOTHER FIVE MONTHS STAY ON THE STATION. >> THEY ARE VERY MUCH ENGAGED, ASKING QUESTIONS. I THINK THEY ARE HAPPY THAT THE DECISION WAS MADE AND THEY UNDERSTAND THE PLAN FORWARD. >> Reporter: STILL HAUNTED BY THE CHALLENGER AND COLUMBIA DISASTERS THAT KILLED 14 ASTRONAUTS, MISSION MANAGERS DECIDED LAST MONTH THEY WILL NOT RISK PUTTING WILLIAMS AND WILMORE ON A STARLINER WITH ENGINE THRUSTERS THAT COULD POTENTIALLY MALFUNCTION ON RE- ENTRY. >> NASA HAS DECIDED THAT BUTCH AND SUNI WILL RETURN WITH CREW NINE NEXT FEBRUARY. >> AND LIFT OFF. >> Reporter: THE SPACEX -- MISSION WILL LAUNCH LATER THIS MONTH WITH TWO ASTRONAUTS RATHER THAN FOUR WILLIAMS AND WILMORE WILL FILL THE EMPTY SEATS UNTIL THEN. UNTIL THEN THEY WILL CONTINUE WORKING AND DOING LONG-DURATION CARDIO AND STRENGTH EXERCISES. NASA INSISTS THE CREW IS NOT STUCK IN SPACE. SINCE THEY COULD RIDE THE STARLINER HOME IF THE STATION WERE IN DANGER. >> THEY WERE NEVER STUCK OR STRANDED. HE ALWAYS HAD A WAY TO DEPART THE SPACE STATION. >> THAT WOULD ONLY BE IF THE SPACE STATION HAD AN EMERGENCY. >> 170 METERS. >> Reporter: TO SEND STARLINER HOME WITHOUT THE ASTRONAUTS, NASA PLANS TO USE THE TROUBLED THRUSTERS TO GENTLY BACK AWAY FROM THE STATION TO AVOID CAUSING ANY DAMAGE. >> THAT'S TO TAKE THE STARLINER AWAY FROM STATION AND IMMEDIATELY START GOING UP AND AWAY. EVENTUALLY IT WILL CURVE AROUND TO THE TOP AND ABOVE STATION ORBIT. >> Reporter: IF ALL GOES WELL, STARLINER WILL LAND WITHOUT ITS CREW IN THE NEW MEXICO DESERT JUST AFTER 12:00 A.M. SATURDAY. >> TOM COSTELLO JOINS US NOW. OUR VIEWERS AT HOME WHO MAY BE FOLLOWING THIS STORY REMEMBER THE PULSING SOUND COMING FROM THE STARLINER THAT THEY COULDN'T IMMEDIATELY EXPLAIN. SOME CONSPIRACY THEORIST STARTED GOING WILD WITH THAT. LET'S TAKE A LISTEN AND CLEARED UP ON THE BACK END. IT DOES SOUND LIKE SOMETHING FROM THE MOVIE ALIEN. WHAT IS IT REALLY AND IS THERE CAUSE FOR ALARM? >> I DON'T THINK IT'S ALIENS. THE BOTTOM LINE IS, THERE ARE MULTIPLE SPACECRAFTS DOCKED TO THE SPACE STATION AND THEY ARE RUNNING MULTIPLE COMMS CHANNELS AND THAT CAN SOMETIMES CREATE FEEDBACK THAT GOES BACK AND FORTH BETWEEN THE STATION AND THE SPACECRAFT, IN THIS CASE, STARLINER SO THEY WERE GETTING A FEEDBACK LOOP THROUGH THEIR SYSTEMS, MULTIPLE AUDIO CHANNELS AND IT TOOK A LITTLE BIT BUT EVEN NASA MISSION CONTROL WASN'T QUITE SURE AT FIRST WHAT IT WAS. >> I WANT TO ASK YOU ABOUT THE OPTICS OF THIS. YOU COULD HAVE SPACEX BRING THEM HOME. I'VE GOT TO THINK THIS HAS GOT TO BE AN EMBARRASSMENT FOR BOEING. >> HUGE EMBARRASSMENT. BOEING HAS NOW LOST 1.6 BILLION DOLLARS ON ITS STARLINER PROGRAM. AS YOU KNOW IT IS YEARS BEHIND SCHEDULE AND BILLIONS OVER BUDGET AND NOW THEY'VE GOT TO TURN TO ELON MUSK'S SPACE X TO BRING THOSE ASTRONAUTS HOME IN FEBRUARY. NASA IS STILL COMMITTED TO THE STARLINER. IT NEEDS AN ALTERNATIVE TO SPACEX NOT JUST RELYING ON