Low-Cost Launch Systems for the Dual-Launch Concept
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IAA-00-IAA.1.1.06 LOW-COST LAUNCH SYSTEMS FOR THE DUAL-LAUNCH CONCEPT Jerome Pearson, Wally Zukauskas, Thomas Weeks, and Stein Cass Ball Aerospace Martin Stytz Air Force Research Laboratory 51st International Astronautical Congress 2-6 Oct 2000/Rio de Janeiro, Brazil For permission to copy or republish, contact the International Astronautical Federation 3-5 Rue Mario-Nikis, 75015 Paris, France IAA-00-IAA.1.1.06 LOW-COST LAUNCH SYSTEMS FOR THE DUAL-LAUNCH CONCEPT Jerome Pearson, Wally Zukauskas, Thomas Weeks, Stein Cass, Ball Aerospace Martin Stytz, Air Force Research Laboratory ABSTRACT The Orbital Express1 would replenish low-value payload such as spacecraft fuel, cryogenics and Current launch costs into low Earth orbit (LEO) batteries and upgrade or repair satellites. are extremely high. This study identified cost ASTRO, the Autonomous Space Transporter reductions possible using a dual launch and Robotic Orbiter, is a “micro-Shuttle” with a strategy—using high-reliability/high-cost launch mass of 100 to 500 kg. It would have vehicles for high-value payloads, and lower cost propulsion to change orbits and to service launch vehicles for low-value payloads. The multiple satellites. ASTRO could also place approach was to assess existing expendable microsatellites into their intended orbits. launch vehicles for development, production, and operations cost using a parametric mass- The Orbital Express concept calls for 50-500-kg based cost model, TRANSCOST 6.2. packages of fuel and electronics to be launched Performing fewer engine tests, designing into space, which are then grabbed by ASTRO structures with lower structural margins, parallel and taken to operating satellites. Because these processing, eliminating payload clean-room packages will be small and relatively cheap, the requirements and extensive testing before booster to launch them would not require high launch, horizontal integration, lower-cost labor, reliability. Furthermore, because ASTRO can and reduced insurance costs were examined to rendezvous with and pick up the payloads, they lower costs. Nearly an order of magnitude can be launched into imprecise orbits, allowing reduction can be achieved from current launch for the use of less accurate launchers. The costs to LEO for low-value payloads. The use payloads might even be gun-launched. of conventional expendable rocket vehicles, however, keeps costs above $2,000 per kilogram Dual Launch Concept to LEO. Revolutionary methods, such as first- The Orbital Express concept is made affordable stage lasers, electromagnetic and ram if the payloads of fuel and supplies are launched accelerators, and upper-stage orbiting tethers, into orbit on a low-cost launch system. This led were examined to achieve even lower launch DARPA to the Dual Launch concept, in which costs. The best combination examined uses the high-value cargo such as fragile instruments, ram accelerator and orbiting tether, with an humans, and satellites are launched on reliable, estimated cost of $250-$350 per kilogram into higher-cost vehicles, whereas low-cost cargo LEO. That might be further optimized to achieve such as fuel, water, and other bulk supplies are $100/kg. No launch techniques were discovered launched on less reliable, lower-cost vehicles. that show launch costs below $100 per kilogram. This study, by Ball Aerospace and the Air Force Research Laboratory, addressed the low-value INTRODUCTION cargo of the dual-launch concept, with the focus 2 The Defense Advanced Research Projects on expendable launch vehicles . A major goal Agency (DARPA) has a program to demonstrate was to quantify the predominant cost drivers and on-orbit repairing and refueling of satellites by to find means to reduce their cost effects. A an autonomous, space-based robotic spacecraft. conservative, top-down cost analysis method was selected that could be applied to current, Copyright 2000 by the International Academy of evolutionary advanced, and even revolutionary Astronautics. All rights reserved. 1 launch systems. Thus a single cost analysis was with the capacity to launch 5,000 kg into orbit, used to evaluate all systems with the same that costs $1 billion to develop and has 100 consistent method. flights, must charge $2000 for each kilogram of COST METHOD SELECTION AND payload just to amortize the system development CALIBRATION costs. And very few launch vehicles systems have flown more than 100 times. To make a After screening several candidates, the cheaper launch vehicle, development costs must 3 TRANSCOST (TCS) model, version 6.2, was be drastically reduced, or the number of flights chosen for cost analysis of the Dual Launch must be greatly increased. system. TRANSCOST is a parametric method based on component mass and regression The effect of the number of flights on the total equations based on a large database extending cost in dollars per kilogram is shown in Figure 1 over virtually every launch system of the past 40 for a typical launch vehicle. The total number of years. The model’s equations are available to flights is spread over 10 years. Development the user, and the regression equations have been costs are amortized over the total number of checked against the known costs of existing flights, so the share of the development cost per systems. The mass-based equations provide flight drops directly with the number of flights. simple means by which to extend the cost The cost of the vehicle is much more constant, analysis to advanced and revolutionary systems. but the higher number of flights implies greater The model is used extensively by the production rates, yielding some savings due to international launch community, and is available the learning effect for serial production. without the payment of fees or licenses. Operations costs decline with the number of flights, reflecting more efficient use of the The TCS model was applied to current launch launch crews. systems for calibration. A launch vehicle database was prepared using the International Reference Guide to Space Launch Systems4 and Mark Wade’s Encyclopedia Astronautica5, as Ariane 44L Payload Cost to LEO well as information from Ball Aerospace proprietary sources. About two dozen different 10,000,000 Total Cost kg launch systems were analyzed. The data was $/ 1,000,000 Dev. st, OPS entered into Excel spreadsheets so that the cost o C Vehicle d a o 100,000 equations could be automated easily for l y a calculation of system costs. P 10,000 The TCS results are consistent, following the 1 10 100 1000 10000 Number of Flights relative costs of small, medium, and large launch vehicles. However, the results averaged 20-50% higher than advertised prices. This discrepancy Figure 1. Effect of Number of Launches on was resolved by the observation that current Cost market prices do not include development cost amortization. Mission Requirements Cost Drivers Because of the requirement to amortize the large development costs, a low-cost launcher must be The total number of flights, or the number of flown many times, at a high annual rate. With launches per annum, is a key parameter in just 100 flights, the amortization of the overall costs. If development costs are to be development cost is as high as the production amortized over sufficient numbers of flights to cost of the vehicle. However, the number of make them reasonable, there must be a large flights is related to the size of the vehicle and to number of flights. A medium launch system customer demand. The effect of mission 2 requirements is shown in Figure 2. The cost in The conventional method for improving engine dollars per kilogram is calculated, based on the reliability is to conduct a large number of test size of the vehicle and the mission demand. The firings. Typically, an expendable rocket engine curves have a minimum cost, with both the small will undergo 1000 development firings to payload and the large payload cases costing achieve a reliability of 0.995. This translates more. Vehicles with smaller payloads cost more directly into development costs for rocket per kilogram because smaller vehicles require engines, and therefore the reliability of engines more structure per kilogram of payload. can be directly related to cost. Vehicles with larger payloads cost more per TRANSCOST 6.2 relates the number of test kilogram because they fly fewer times, and their firings, the reliability, and a quality cost factor, development costs are amortized over fewer f2, which is used in developing the engine flights. development cost estimating relationship (CER). This relationship can be used to quantify the cost Cost vs Mission Demand of engine reliability in terms of man-years 1,000,000 (MYr). The TRANSCOST regression lines for engine development and vehicle stage 200 Launches g k development in terms of reference mass are: 100,000 $/ 1 million kg st, o 10 million kg 0.59 C HE = 228 M MYr l a 100 million kg t 10,000 o T 0.583 HV = 80.1 M MYr 1,000 100 1,000 10,000 100,000 1,000,000 Because both engines and stages must go Vehicle Payload, kg through similar design, manufacturing, and basic testing processes, the difference must lie mainly in the repetitive testing required to make rocket Figure 2. Effect of Mission Demand on Cost engines more reliable. The average test cost, Each mission requirement shows a minimum CT, can then be approximated by the difference cost at a different size vehicle. Interestingly, the between these costs, divided by 1000 firings: minimum cost occurs for about 200 flights, C = 0.148 M0.59 MYr regardless of the size of the vehicle. This means T that the 1-million-kg mission is best served by Here the higher exponent has been used to be 200 launches of a 5,000-kg-payload vehicle, and more conservative.