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(the cost of parachute fabric is about 3 times the cost of the yarn, based on information from a colleague at Du Pont Industrial Fabrics), cost of controls, dust dispensing, and so on, $15/kg can be estimated or 1.5 × 105 kg/balloon × $15/kg = 2.25 × 106 $/balloon.

Twenty lifts are necessary in 40 years:

2 × 106 balloons × 2.25 × 106$/balloon = $4.25 × 1012.

Consider the additional costs of infrastructure and support: there will be 2 × 106 lifts in 40 years or

If there are 100 crews (each responsible for 2 lifts per day on 250 days a year) and each crew has 100 people,

104 people × 105 $/person/yr × 40 years = $4 × 1010

$1011 with an overhead of 150%.

If each station is capitalized at $109, another $1011 is required, but this infrastructure barely affects costs, as does the cost of dust even at $0.50/kg or hydrogen at $10/kg.

Hydrogen can currently be purchased as liquid hydrogen in 1500-gallon lots (equivalent to 169,000 standard cubic feet) for $2.5/100 ft3. For conversion, 1 kg of hydrogen = 432.3 standard cubic feet. Thus the cost is

In quantities of 100 × 106 ft3/day, Ogden and Williams (1989) quote costs lower than $30/GJ. This is

Each balloon has a mass of 4.2 × 106 m3 × 1/14 × 8.8 × 10-2 kg/m3 = 2.6 × 104 kg of hydrogen. At 5 × 104 balloon lifts per year, the annual quantity is

13.2 × 108 kg 109 kg = 423 × 109 ft3 109 ft3/day = 102 × 106 ft3/day.