railroad engineer quip that FOD is a four - letter word , but there ’s nothing funny about foreign object debris and its potentiality to trigger catastrophe .
The incident happened on October 5 at around 10:25 a.m. ET , as a SpaceX pad of paper crew was preparing Crew Dragon Endurance for launch atop a Falcon 9 rocket . With the four Crew-5 spaceman already inside the capsule and the hatching closed , an attentive heart spot a single human hair in the door latch seal . The hair was designated FOD — an engineering terminus for foreign object debris — requiring the pad crew to take action at law .
The countdown clock had just ticked retiring T-90 minutes , so clip was of the essence . The pad crew calmly reopened Endurance ’s hatching and take away the offending strand . They do another review , thoroughly re - houseclean the cachet area , and closed the hatching for the 2d and net sentence . A subsequent insistency check confirm a tight seal .
Crew Dragon Endurance atop a SpaceX Falcon 9 rocket on 2 March 2025.Photo: SpaceX
The entire affair engage only a few minutes , and the launching was n’t affect . Blast off of the Falcon 9 encounter at midday as scheduled , with the Crew-5 spaceman — Nicole Aunapu Mann , Josh Cassada , Koichi Wakata , and Anna Kikina — successfully reaching the International Space Station on the following day .
That the SpaceX pad crew would take the time to take away a single hair in advance of a rocket launch is revealing and totally understandable . In the aerospace industry , FOD is defined as any object that does n’t belong at a specific location , whether that location is a hatch seal of approval , an engine , a cockpit , or the track . Debris in the wrong place can damage equipment , facilitate the suboptimal performance of scheme , and trigger outright malfunctions .
It ’s an issue across many industries , but for the aerospace industriousness , it ’s a problem that arrive with a $ 4 billion terms tag each year , accordingto Boeing . NASA melt down aFOD programat Kennedy Space Center , the purpose of which is to “ denigrate the theory of wrong or loss of trajectory hardware or accidental injury to personnel due to fall back items within the flight hardware elements , resulting in preservation of national resources . ”
The SpaceX pad crew re-inspecting the seal shortly after having to reopen the hatch upon discovering FOD in the form of a human hair.Screenshot: SpaceX
speak to me on a video call , Tom Simon , deputy ballistic capsule director at NASA Johnson Space Center , sound out , “ we ’ve all been prepare since day one , when dealing with flight systems , to watch out for FOD . ” outside items , such as pencils , paperclips , screwdrivers , hair’s-breadth , and dust , “ might seem minor , ” but they could , among other things , result in a “ seal that is lento leak out overboard , ” he said . “ When we ’re progress systems , we take it badly , ” he impart .
As an engineer , FOD is “ impress in your system , ” John Posey , NASA lead locomotive engineer for Crew Dragon , say me during the same call . It ’s “ view a top endangerment in grooming programs , ” as FOD carries the potentiality to “ bring down rockets and aircraft , ” he explain .
Simon and Posey were n’t able to speak to SpaceX ’s specific policies and protocols , but they were n’t surprised by the tablet crew ’s action in removing the human whisker . FOD related to the sealing of surface is a serious fear . When handle with a seal surface , and when have to ensure a close sealskin , “ you do n’t want something pressing up against it , ” Posey say . “ Something like hair — calculate on its size of it and preference — can result in a leakage path . ”
The Webb Space Telescope inside a Northrop Grumman clean room in Redondo Beach, CA, in March 2018.Photo: NASA
Posey said that , for time - tender situations like the concluding closing of a capsule hatch , the sudden appearance of FOD should be built into the timeline and outgrowth , in improver to having a contingency program should this scenario arise . Pad crews should “ back out , remove the token , re - visit , and even clean the seal , and then move frontwards with the job you ’re trying to do , ” said Posey .
It ’s not just hatches that are prostrate to FOD risk . Launch operators implement processes to extenuate FOD risk , such as using cover or shields when wreak like cut or sawing needs to be done near ballistic capsule . And of course of instruction , the hustler themselves need to be uncontaminating . Propulsion systems , in which fuels and oxidizers are pump through high - pressure organisation , can be impress by FOD , said Posey , who worked on the Space Shuttle during its last twenty-four hours and “ spent thousands of hour on actuation systems , working on the floor with technician , to ensure it ’s all good . ”
As Simon explained , the required degree of cleanliness often depends on the nature of the projection or mission itself . Posey said every system needs its own control programme , with engineers defining acceptable limits and deciding what needs to be screened .
unclouded room protocol for uncrewed satellite launches tend to be minimal , “ to the point of washing custody and putting on gloves , ” he said . Missions imply a crew are a dissimilar storey , however . “ With crews , not only does the avionics system have to work , you also do n’t want to have things take flight all over the blank space , ” in addition to keeping the seal uncontaminating , said Simon . Once in cranial orbit , microgravity can short stimulate unnoticed FOD to be adrift around , including hair and junk . Posey said filtration systems are designed to deal with this sort of hooey , “ but you still want to prevent hassles , ” such as need screen over hachure seals , among other measures . And “ even covers have to be cleaned and determine for leaks , ” he contribute .
Posey offered some sage advice : “ Always make indisputable you ’re open a system in a white room , perform only what you take to do , and do an inspection prior to closing it up . ” And “ if you see something that does n’t look veracious , go in and inquire , ” as it ’s a “ necessary load , ” he said . A second set of eye wo n’t anguish , he summate . “ FOD will find a room to get into your system , ” pronounce Posey , hence the term “ Smart FOD . ” He recount an incident in which a bootee , or a horseshoe binding , was suddenly discovered in the Shuttle compartment . “ It just splay off someone ’s foot , and these types of things can be rummy in retrospect , ” articulate Posey , but pillage or tape recording or anything else that does n’t belong can be a flammability concern .
measuring to foreclose FOD from get into components or complex systems start in the clear room , and every fresh room has its own cleanliness requirements , depending on the task . Clean rooms “ are peculiarly certify and monitored to a certain cleanliness valuation depending on what ’s in there , ” and items typically need to be approved before they ’re allowed into a clean elbow room , said Posey .
footlocker are available to hold at large items ; tape and sticky floor pads can secure detail that must be in the elbow room ; and lead can catch anything that ’s accidentally drop . Overalls , have a go at it to engineers as “ bunny rabbit suits , ” cover arms and wooden leg and usually feature a hood with a pilus profits . Beards get pass over by beard nets , while shoes get dirty money .
“ Once you ’re quick and all geared up , you step through a two-fold room access , ” said Posey , the first of which “ close behind you and then you go into the clean room . ” In the intermediate chamber of some double door , “ atmosphere bungle all over you , sucking up any dust or detritus , ” he explained . Staff will amass any find FOD and enquire where it come from and whether any additional controls are needed . Clean way “ are never clear enough , ” Posey tote up .
These measures are an added but necessary headache . The good news is that FOD detection is improving over prison term . television camera are now routinely used to observe most every recess of a launch pad , while hug drug - beam of light and CT scan can peer inside objects and create 3D images of a part ’s Department of the Interior . With these cock , locomotive engineer can “ see assembly issues ” and “ find FOD that would n’t have been find otherwise , ” Posey sound out . An enhanced ability to sniff - out FOD is of increasing importance to the private sector , particularly in the era of factor reusability .
The human hairsbreadth found inside the hachure cachet may or may not have make a job during the Crew-5 flight , but that does n’t weigh . What matters is safety and the liquidation of anything that could put human lives at risk . Engineers will continue to seek out FOD , regardless of the inconvenience it may make .
More : remember endeavor : The Test Shuttle That Never Flew to Space .
FloridaKoichi WakataSpaceflightSPACEX
Daily Newsletter
Get the best tech , science , and culture intelligence in your inbox day by day .
News from the future , delivered to your present .
You May Also Like
