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at home many people can and do weigh the

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food they eat it's as easy as putting it

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on a scale but scales don't work without

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gravity so how do astronauts measure the

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weight of small items in a microgravity

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environment like the International Space

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Station they measure mass instead what's

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the difference

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mass is the measure of how much matter

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something contains weight on the other

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hand is the measurement of the pull of

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gravity on an object we can actually

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know how much our plants are weighing

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that the astronauts will consume so they

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use the Newton's second law of motion

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which has force mass and acceleration

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under the same amount of force an object

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with more mass will accelerate less so

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to apply this in space astronauts use

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that mass measurement device mm D which

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launched to the space station in 2017

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they then put these plant samples inside

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a little ziploc bag and then the mass

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measurement device goes back and forth a

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few times the mo D applies a known

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acceleration to the sample and measures

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the resulting force allowing the system

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to determine its mass it can measure

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between 1 and 100 grams and has an

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accuracy of 0.1 grams it's wonderful

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it's really really accurate so it's it's

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a great new tool that we have there are

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multiple mass measurement devices on the

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space station they measure everything

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from astronauts who are monitoring their

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health to freshly harvested produce from

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the station's veggie growth chamber

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so when microgravity makes it impossible

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to tip the scales its mess that matters