The bulb is single-serving beverage container suited for portability in low gravity environments.


Drinking fluids such as water, grape juice, lemonade, coffee, beer, or gin in low or null gravity requires special containers to prevent the fluid from drifting around. In the books, these containers are continuously called “bulbs”. They can be imagined as a bulbous container of a durable, non-breakable, or resilient material with a flat, magnetic bottom and a sealable suction nipple on the opposite side. They are even described as made with foil. They can be attached to any metallic surface, like spaceship tables.

Design and Function Edit

Bulbs allow a control of liquids by exploiting capillary action. This effect is driven by the adhesion forces between the liquid and its container as well as the liquid's own surface tension to propel the liquid along its container. On Earth and other moderately high-g environments, the effect is typically and most pronounced in narrow containers. Without an external force, such as gravity, pulling the liquid in one direction, the liquid will conform much more explicitly to the contours of its container, allowing the container's geometry to dictate the liquids flow. Thus, in zero-g, the shape of the bulb allows for constraining liquid at a much higher efficacy than a tradition cup that would allow for free-floating liquids.[1]

Antecedents Edit

Capillary cup
The technology allowing for open fluid containers in zero-g environments was developed in the early 21st century by the National Aeronautics and Space Administration (NASA) of the United States of America. Such "space cups" were successfully employed on the International Space Station (ISS), improving over the vacuum-sealed beverage pouches that were then standard. Via capillary action, their unusual shape directed a narrow vein of the liquid from the cup's body to its winged mouth, ready for an astronaut to drink upon applying suction.[1][2]



Historical single-use beverage containersEdit

canaluminum with pop tab
stay-on pull tab
carton1970s through early 1990s
topside cap
pouchlate 1980s through early 2000spunch-through straw
boxarguably an evolution of the carton, this came in more varied dimensions than the traditional carton and also adopted the punch-through straw of the pouch


  • In the TV series, they appeared in the first episode "Dulcinea" such as while Miller was in the Medina on Ceres monitoring the public demonstration delivered by the Gaunt Belter. In most subsequent occasions on the show, they are replaced with what look more like metal travel mugs.
  • These bulbs might be compared to drink pouches contemporary to the late 20th and early 21st centuries. The early 21st century also had "drink boxes". The eighties also had "drink cartons"


See alsoEdit