Low-cost launch of payloads to low earth orbit

A CRITICAL factor for the viability of a sustained human presence in space is launch cost. The exploration vision brings a heavy lift requirement for thousands of metric tons of propellant and hardware to establish, resupply, and expand moon and Mars bases. Because the basis for the exploration effort is guided by budget limitations, it is expected that the development of off-planet infrastructure will be chiefly driven by launch dollars per kilogram. High launch costs have a multiple budgetary impact. With present heavy lift technology, launch costs are in the range of $6000-$20,000/kg. Because high launch costs severely constrain system mass, ultralightweight reliable structures and payloads must be developed at high cost. Consequently, budget limits and high launch cost determine the scale of the entire exploration effort,.