A lighter-than-air high altitude balloon system comprising: a zero-pressure balloon configured to receive therein an LTA gas to provide an upward lifting force to the balloon system; a super-pressure balloon having an outer skin and configured to couple with the ZPB, the outer skin defining an interior volume configured to receive therein a variable amount of ambient air from a surrounding atmosphere to provide a variable downward force to the balloon system; a centrifugal compressor in fluid communication with the ambient air and with the interior volume of the SPB, the centrifugal compressor configured to compress the ambient air and pump the compressed ambient air into the interior volume of the SPB to increase the downward force to the balloon system; an adjustable valve in fluid communication with the ambient air and with the interior volume of the SPB, the valve configured to be adjusted to release the compressed ambient air from the interior volume of the SPB to the surrounding atmosphere to decrease the downward force to the balloon system; a sensor coupled with the balloon system and configured to detect an environmental attribute; a control system in communicating connection with the sensor, with the centrifugal compressor, and with the adjustable valve, the control system configured to control the centrifugal compressor and the adjustable valve based at least on the detected environmental attribute to control the amount of compressed air inside the SPB to control an altitude of the balloon system; and a plurality of tendons coupled with the SPB and extending along an exterior of the outer skin of the SPB, the plurality of tendons configured to bias the SPB into a pumpkin-like shape at least when a first pressure inside the SPB is greater than a second pressure of the surrounding atmosphere; a payload support coupled with the SPB and configured to support a payload; an elongated ladder assembly coupling the payload support with the SPB such that the payload support is located below the SPB when the balloon system is in flight; and an air hose fluidly coupled with the centrifugal compressor, wherein the centrifugal compressor is mounted with the payload support and is fluidly coupled with the interior volume of the SPB via the air hose, wherein the air hose extends along and is supported at least in part by the elongated ladder assembly. a zero-pressure balloon configured to receive therein an LTA gas to provide an upward lifting force to the balloon system; a super-pressure balloon having an outer skin and configured to couple with the ZPB, the outer skin defining an interior volume configured to receive therein a variable amount of ambient air from a surrounding atmosphere to provide a variable downward force to the balloon system; a centrifugal compressor in fluid communication with the ambient air and with the interior volume of the SPB, the centrifugal compressor configured to compress the ambient air and pump the compressed ambient air into the interior volume of the SPB to increase the downward force to the balloon system; an adjustable valve in fluid communication with the ambient air and with the interior volume of the SPB, the valve configured to be adjusted to release the compressed ambient air from the interior volume of the SPB to the surrounding atmosphere to decrease the downward force to the balloon system; a sensor coupled with the balloon system and configured to detect an environmental attribute; a control system in communicating connection with the sensor, with the centrifugal compressor, and with the adjustable valve, the control system configured to control the centrifugal compressor and the adjustable valve based at least on the detected environmental attribute to control the amount of compressed air inside the SPB to control an altitude of the balloon system; and a plurality of tendons coupled with the SPB and extending along an exterior of the outer skin of the SPB, the plurality of tendons configured to bias the SPB into a pumpkin-like shape at least when a first pressure inside the SPB is greater than a second pressure of the surrounding atmosphere; a payload support coupled with the SPB and configured to support a payload; an elongated ladder assembly coupling the payload support with the SPB such that the payload support is located below the SPB when the balloon system is in flight; and an air hose fluidly coupled with the centrifugal compressor, wherein the centrifugal compressor is mounted with the payload support and is fluidly coupled with the interior volume of the SPB via the air hose, wherein the air hose extends along and is supported at least in part by the elongated ladder assembly.