1. AAE 450 Spring 2008 David Childers February 21, 2008 Structures Cost Center of Mass Thanks to John Tsohas for the contacts Structures Group for research

2. 2 AAE 450 Spring 2008 Big Change in Cost  Previous Cost Inclusions –Sheet Metal Rolling –Raw Material –Rivets –Welding Structures Major Change Tank cost Two Methods: ATK Satellite Tanks Spincraft Manufacturing Costs

3. 3 AAE 450 Spring 2008 Test Case: LG-CA-DA-DT (ATK Costs) Structures Cost ItemStage 1 (Al)Stage 2 (Al)Stage 3 (Ti) Tanks (Fuel &Ox)$2.04 million$690,000$95,000 Material$17,100$820$1,250 Welding$8,400$1,800$1,750 Rivets$310$85$50 Manufacturing$29,400$8,400$46,200 Stage Sum$2.09 million$700,000$145,000 Total≈$3 million Structures Costs Only Tank Cost Equation: y = 157169Ln(x) + 714253, where x=volume

4. 4 Test Case: LG-CA-DA-DT (Spincraft Costs) Cost ItemStage 1 (Al)Stage 2 (Al)Stage 3 (Ti) Material$17,100$820$1,250 Welding$8,400$1,800$1,750 Rivets$623$78$50 Manufacturing$475,000$470,000$948,000 Stage Sum$502,000$473,000$951,000 Total≈$1.93 million Structures Costs Only

5. 5 Cost Breakdown  Welding –$150/hr –Times: Al=0.6m/hr Stl=0.65m/hr Ti=0.325m/hr  Rivets –1 rivet/6in (1r/0.152m) –$0.73/rivet –0.049 hr/rivet –$52/hr AAE 450 Spring 2008 5  Material  Rate:  Al=$13.23/kg (Space grade)  Stl=$0.23/kg  Ti=$88.91/kg  Manufacturing  With ATK Tanks  $70/hr for 5 hrs/sheet  Ti 5.5 times longer than Al or Stl  Performed for:  Nose cone, Skirts, Skin between tanks  Spincraft  Labor=$150/hr  Al &Stl: 26 wks (40hrs/wk)  Ti: 52 wks Structures

6. 6 ATK Tank Costs Volume (m 3 ) [in 3 ]Cost ($) (Existing Tanks) Tank Shape 0.461 [28100]600,000Sphere 0.432 [26350]400,000Cylinder w/ Dome Ends 0.229 [14000]250,000Cylinder w/ Dome Ends 0.059 [3600]250,000Sphere 0.015 [890]60,000Sphere Walter Tam, ATK Tank Notes Composites $2 mil for small volume tank & 2 yrs to build AAE 450 Spring 2008 Structures

7. 7 Tank Costs 7 Plots by David Childers Lower left plot used for cost determination AAE 450 Spring 2008 Structures Above plot scheme fails due to dip between 0.15 and 0.4m 3 Cost does not decrease then increase again

8. 8 AAE 450 Spring 2008 References  Paul Morissette, Gilchrist Metalfab  Walter Tam of ATK Space Systems, Inc. (PSI Operations), http://www.psi-pci.com/.  Mike Murphy, Spincraft http://www.spincraft.net/aerospace.htm.  Mark Sutton, G.E.  COST CONSIDERATIONS IN USING TITANIUM, GREEN, E. A., COULON, J. F. Lockheed-California Company, Burbank, California v AlAA Paper.  http://www.metalprices.com/  TitaniumJoe.com  Youngstown Tool & Die Co.  RobotMarketplace.com Structures