Evaluating Technology Projections and Weight Prediction Method Uncertainty of Future Launch Vehicles

Aeromechanics and Vehicle Configuration Demonstrations. Volume 3: A Hybrid Probabilistic Method for Estimate Design Margin

“…At a confidence level of 95%, this study showed growth of 25% and 31% for the bimese and single stage concepts respectively. [146] In support of the Constellation program, a study was conducted to determine the performance requirements of the Ares V launch vehicle. Because the requirements of the Ares V depended on the entire architecture of the Constellation program, three separate uncertainties had to be accounted for: the uncertainty of the dry mass of Constellation's in-space elements, the performance of the in-space propulsion, and the performance of the Ares V. The uncertainty of the dry mass was accounted for using historical regression as discribed in Section 4.3.1.…”

Forecasting airplane technologies

“…Range (Gillett and Stekler, 1995;Kumar and Hefner, 2000), speed (Esposito, 2004), number of passengers (Gillett and Stekler, 1995;Kumar and Hefner, 2000;Wall, 2006b), and weight of aircraft (Mavris et al, 1999;Wilhite et al, 2008) appear to have been strong drivers and technological measurements over the last few decades. These also have a strong interaction with material composite advances (Manufacturing Engineering, 2007;Fraser, 1985;Gillett and Stekler, 1995;Goehler, 1990;Kumar and Hefner, 2000;Sprague, 1988;Wilhite et al, 2008) which along with information technology (IT) advances in recent times driving analysis/design tool evolution (Fraser, 1985;Goehler, 1990;Kumar and Hefner, 2000) are increasing the rate of design aircraft changes (Ashford, 1985;Butterworth-Hayes, 2001;Fraser, 1985;Gillett and Stekler, 1995;Kumar and Hefner, 2000). Environment (Goehler, 1990;Kumar and Hefner, 2000;Masson et al, 2007;Ruffles, 2003), noise control (Gillett and Stekler, 1995;Kumar and Hefner, 2000;Ruffles, 2003) and safety concerns (Goehler, 1990;Kumar and Hefner, 2000;Ruffles, 2003) are three external influences driving design aircraft change.…”

“…The analysis/design tool evolution is also enabling what several researchers thought were needed to move from more mature technology which was the increased need for a multidisciplinary integration of technology (Ashford, 1985;Fraser, 1985;Kumar and Hefner, 2000). This multidisciplinary approach was particularly needed with the advancements in materials (mentioned above), propulsion technology (Fraser, 1985;Kumar and Hefner, 2000;Wilhite et al, 2008), structures (closely related to materials advancements) (Manufacturing Engineering, 2007;Fraser, 1985;Kumar and Hefner, 2000;Sprague, 1988), electronic controls technologies (Fraser, 1985;Kumar and Hefner, 2000) and avionics (Fraser, 1985;Kumar and Hefner, 2000;Wilhite et al, 2008).…”

“…The multitude of parameters, it should be noted, creates a higher risk for good results from many analytical study methods (Martino, 1993). Some analytical methods studies which attempt more than one or two parameters of commercial airplane technology include: computer technology as a leading indicator to avionics controls advancements (Fraser, 1985); simulation for selected design and economic factors (Mavris et al, 1999); simulation for four design factors (Wilhite et al, 2008); integral calculus function to study technological change-same used for intensity of earthquakes (Coccia, 2005); and the building of an efficiency method for studying state of art technology (Sahal, 1976).…”

“…Maximum cruising speed (Esposito, 2004) is the typical speed at which a plane is designed to operate over long distances efficiently. Maximum takeoff weight, although a derived variable, was chosen along with operating empty weight (Mavris et al, 1999;Wilhite et al, 2008) because of the natural dynamics of tradeoff between weight and range. Fuel capacity was chosen as a proxy for fuel efficiency (Gillett and Stekler, 1995;Kumar and Hefner, 2000;Masson et al, 2007;Ruffles, 2003) as fuel efficiency has economic and technology trade-offs such as allowing longer ranges and reduced overall weight.…”