Aerospace balloon system and method of operation

A balloon system comprising a balloon configured to contain a lighter-than-air fluid, the balloon comprising:

• a plurality of gores substantially defining a balloon envelope;
• a plurality of load members comprising a first set of load members and a second set of load members;
• and
• an apex fitting arranged at a balloon apex, the apex fitting comprising a first apex member attached to the first set of load members and a second apex member attached to the second set of load members;
• wherein:
• the first and second sets of load members are disjoint;
• each load member of the plurality defines an apex end and a nadir end opposing the apex end along a length of the load member;
• each load member of the plurality mechanically connects a respective pair of adjacent gores along a length of the gores;
• in a first mode, the balloon is partially inflated by the lighter-than-air fluid and each load member of the plurality is mechanically connected to the apex fitting proximal the apex end of the load member, thereby holding each load member of the plurality in tension;
• in the first mode, the first apex member is mechanically connected to the second apex member;
• the apex fitting is operable to transition the balloon from the first mode to a second mode by mechanically disconnecting the first set of load members from the second set of load members,
• the apex fitting is operable to mechanically decouple the first set of load members from the second set of load members by detaching the first apex member from the second apex member,
• wherein, in response to mechanically disconnecting the first set of load members from the second set of load members, the balloon opens and the lighter-than-air fluid vents from the balloon.

A method for operating a balloon system comprising a balloon and a payload mechanically connected to the balloon, the method comprising, at the balloon system:

• while a lighter-than-air fluid is contained within the balloon, descending from an Earth stratosphere to an Earth troposphere, thereby partially deflating the balloon, wherein descending from the Earth stratosphere to the Earth troposphere comprises landing the payload such that the payload is at least partially supported by a surface of the Earth, wherein the balloon comprises:
• an apex fitting arranged at an apex of the balloon;
• a first balloon portion mechanically connected to the apex fitting;
• and
• a second balloon portion mechanically connected to the first balloon portion via the apex fitting, wherein the apex fitting maintains a tension between the first and second balloon portions;
• and
• while in the Earth troposphere, while the balloon is partially deflated, at the apex fitting, mechanically disconnecting the first balloon portion from the second balloon portion, thereby releasing the tension between the first and second balloon portions, wherein, in response to mechanically disconnecting the first balloon portion from the second balloon portion, the balloon opens and the lighter-than-air fluid vents from the balloon, wherein mechanically disconnecting the first balloon portion from the second balloon portion is performed while the payload is at least partially supported by the surface.