Using the density equationwe get the equation . Where V is the e volume of helium needed to get the system neutrally buoyant. With our calculations, the total system weighed 3.75 kg, this included a kilogram lift charge so that balloon would get off the ground and float upward. This mass was calculated by summing up all the parts of the system (measured individually). However, some small pieces such as cord and zip-ties were not measured adding some unmeasured mass to the system.