Analysis Code for High Altitude Balloons - FedOA - Università degli ...

Introduction Chapter 1
Balloon systems usually consist of a balloon envelope (see letter A in Figure 1.3), a
flight chain (B, C), and a scientific payload (D). The flight chain usually consists of a
parachute (B) that allows the entire unit to descend safely when needed, and a
gondola (C) that serves as interface between the payload and the balloon and is
equipped with communication instruments that enable to track the balloon during its
flight.
Scientific balloons can lift payloads that weigh over 3000 kilograms to float altitudes
that can be higher than 35 km with a flight time of hours or days or sometimes even
of several weeks according to the balloon type 2,5,6 .
There are essentially three different concepts of scientific balloons:
� the zero-pressure balloon, in which ducts at the base of the balloon film allow
a very small pressure differential between the inside and the outside;
� the super-pressure balloon, which, on the contrary, is sealed and must
withstand high internal pressures when it reaches the float altitude;
� the infra-red Montgolfier (MIR) 2 , which is basically a zero-pressure hot-air
balloon that takes great advantage of the Earth’s thermal radiation (during the
night) and of sunlight (during the day) in order to heat the lifting gas (air),
thanks to a specifically conceived envelope made of different plastic
materials.
Table 1.1 reports typical performances of several kinds of scientific balloons.
Scientific Balloon Type Volume [m 3 ] Payload [kg] Altitude [km] Duration
Zero-pressure 5000 to 2000000 50 to 2000 25-40 Hours - Days
Pressurized Sphere 50-600 2-20 12-19 Weeks - Months
Super-pressure Pumpkin 1000000 1000 35 Weeks - Months
IR Montgolfier 45000 60 27 (day) 18 (night) Weeks - Months
Table 1.1 – Typical performances of scientific balloons (From Ref. 2).
Balloons are commonly used as observation platforms in studying the atmosphere.
They are used more frequently than orbital satellites. Indeed, if satellites are unique
in providing a global view of the Earth’s atmosphere, they also suffer several
limitations 2 . For example, meteorological parameters can be observed from satellites
with difficulty at stratospheric altitudes.
Balloons have also been used to carry payloads and instruments for scientific
purposes in a number of different research areas: astronomy, particle physics,
magnetospheric physics, atmospheric sciences and much more.
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