Economics of Separated Economics of Separated Ascent Stage Launch Ascent Stage Launch

VehiclesVehiclesBy Chris Y. TaylorBy Chris Y. Taylor

4242ndnd AIAA/ASME/SAE/ASEE Joint AIAA/ASME/SAE/ASEE Joint Propulsion ConferencePropulsion Conference

July 11, 2006July 11, 2006

chrisytaylor@yahoo.com

Separated Ascent Stage Launch Separated Ascent Stage Launch VehiclesVehicles

Multiple vehicles launch separately but cooperate to Multiple vehicles launch separately but cooperate to put one of their number into orbitput one of their number into orbit..

Flock Space Launch ArchitectureFlock Space Launch ArchitectureBy Allan Goff, Novatia Labs, Folsom CABy Allan Goff, Novatia Labs, Folsom CA

Examples:•FLOC/Flock•Black Horse Variation

c = R Γc = specific cost ($/lb.) = Launch Cost/Payload Mass R = structure - payload mass ratio

= Structure Mass/Payload MassDriven by Technology & Physics

 Γ = structure cost ($/lb.)

= Launch Cost/Structure MassDriven by Management & Economics

c = R ( Γvehicle + Γops+ Γrisk + Γpropellant) + RD(Γnr/a)

Recurring CostΓvehicle = Cost of Vehicle HardwareΓops = Cost of OperationsΓrisk = Cost of RiskΓpropellant = Cost of Propellant

Non-Recurring CostRD = Developed Structure–Payload Mass RatioΓnr = Non-recurring Structure Costsa = Amortization Factor

Γvehicle= f Chardware 

f = fraction of vehicle expended= 1 (completely expendable)

 Chardware = cost of hardware ($/lb)$1100 < Chardware <$2300 $1100 < Γvehicle < $2300

Γops = L Clabor 

L = labor intensity (manhours/lb)= Total Labor Hours / Structure Mass

1 < L < 20 (for current launchers) Clabor = cost of labor ($/manhour)

= $100 $100 < Γops < $2000

Γrisk ≈ Pfail[Cpayload/r + (1-f) Chardware]

Pfail = probability of failure0.02 < Pfail < 0.05 

Cpayload = cost of payload ($/lb)= payload cost/payload mass ≈ $10,000

 

r = 2, f = 1 $100 < Γrisk < $250not including indirect costs

Γpropellant = q Cpropellant 

q = Propellant Mass/Structure Mass= r[η/(1-η)]= 18 (assuming r=2, η=0.9)

 $0.1 < Cpropellant <$0.25 $1.8 < Γpropellant <$4.5

Amortized Non-Recurring Cost(Γ nr/a)

Γnr = non-recurring costs$20,000 < Γnr < $120,000(assuming R&D only) a = amortization factor

flight rate= 27

(10 yr. payback, 4 yr. r&d , flight rate of 27/6 yr, 0% interest & inflation) $750 < (Γ nr/a)< $4500

Current Structure Launch Cost Estimate

$0

$1,000

$2,000

$3,000

$4,000

$5,000

R&D Vehicle Ops Risk Prop.

Costs

/Stru

cture

Mas

s

R and RR and RDD

R = Structure – Payload Mass RatioR = Structure – Payload Mass RatioVehicle r (to LEO)

Atlas V 400 2Proton M 2.2Ariane 5 5.2Space Shuttle

12

Typical Values:

RRDD = Developed Structure – Payload Mass = Developed Structure – Payload Mass RatioRatio

= R (for entirely new launch vehicles)= R (for entirely new launch vehicles)Assumed R = RAssumed R = RDD = 2 for initial launch cost = 2 for initial launch cost

estimate.estimate.

Current Specific Launch Cost Estimate

$0$1,000$2,000$3,000$4,000$5,000$6,000$7,000$8,000$9,000

$10,000

R&D Vehicle Ops Risk Prop.

Costs

/Pay

load M

ass (

$/lb.

)

R&D costs must be lowered!

Launch costs >$1000/lb. payload to Launch costs >$1000/lb. payload to LEO with current development & flight LEO with current development & flight rate even if all recurring costs are rate even if all recurring costs are zero!zero!

How can RD(Γnr/a) be lowered?

a Γnr RD

Reduce Cost through Lean Reduce Cost through Lean Operation and Good ManagementOperation and Good Management

Reduce Cost through Evolutionary DesignReduce Cost through Evolutionary Design

Griffen, M.D., “Heavy Lift Launch for Lunar Exploration”, presented U. of Wisconsin, April 11, 1999, http://fti.neep.wisc.edu/neep533/SPRING1999/lecture33.pdf

R&D costs must be lowered!

Launch costs >$1000/lb. payload to Launch costs >$1000/lb. payload to LEO with current development & flight LEO with current development & flight rate even if all recurring costs are rate even if all recurring costs are zero!zero!

How can RD(Γnr/a) be lowered?

a Γnr RD

Using Identical Stages for Using Identical Stages for Reduced Development CostReduced Development Cost

BimeseImage from:

THE BIMESE CONCEPT: A STUDY OF MISSION AND ECONOMIC OPTIONS by Dr. John R. Olds

and Jeffrey Tooley, 1999

Trimese

With Identical stages RD < R

even for an entirely new launch vehicle.

Identical stages increases

development cost (Γnr).

N-mese?N-mese?Flock S

pace Launch Architecture

Flock Space Launch A

rchitectureB

y Allan G

off, Novatia Labs, Folsom

CA

By A

llan Goff, N

ovatia Labs, Folsom C

A

Separated ascent stages could allow a large number of identical stages with a simple vehicle configuration.

FLOC Weight GrowthFLOC Weight Growth

0.00

5.00

10.00

15.00

20.00

25.00

5 10 15 20 25 30 35Structure Mass Fraction, % (Ms/GLOW)

Stru

ctur

e R

atio

, % (M

s/M

pl)

SSTO

2STO

4STO

FLOC16StructureFLOC16Designed

Calculated Launch Vehicle Structure-Payload Mass Ratio vs. Structure Mass Fraction (Isp = 372)

Separated Ascent Stage Separated Ascent Stage TradeoffTradeoff

Large number of identical stages mean low RLarge number of identical stages mean low RDD..

Simple configuration allows low Simple configuration allows low vehiclevehicle Γnr.

Flock flexibility might allow high flight rate and a.

Requires demonstration of safe, reliable mid-ascent rendezvous. This requires expensive and risky development effort. TANSTAAFL!

Mid-Ascent Rendezvous? Mid-Ascent Rendezvous? Are You Serious?Are You Serious?

““The idea of refueling an airplane in flight must have The idea of refueling an airplane in flight must have seemed bizarre to anyone witnessing the Wright seemed bizarre to anyone witnessing the Wright Brother’s first flights. By the 1920s it had been Brother’s first flights. By the 1920s it had been demonstrated and today it is done routinely.” demonstrated and today it is done routinely.”

- R.M. Zubrin- R.M. Zubrin

Black Horse Proposal: 6 min. of exo-atmospheric Black Horse Proposal: 6 min. of exo-atmospheric coasting, fuel transfer via. extendable boom needs 2coasting, fuel transfer via. extendable boom needs 2

FLOC Proposal: Exo-atmospheric rendezvous, mating FLOC Proposal: Exo-atmospheric rendezvous, mating booster to orbiter instead of refueling, only 1 restartbooster to orbiter instead of refueling, only 1 restart

Is Rocket Is Rocket Rendezvous Worthwhile?Worthwhile?

Duration and cost of development program to Duration and cost of development program to demonstrate rocket mid-flight rendezvous demonstrate rocket mid-flight rendezvous unknown.unknown.

Novatia estimates specific cost of FLOC system Novatia estimates specific cost of FLOC system at about $100 to $200 per pound to LEO.at about $100 to $200 per pound to LEO.

Are Novatia’s cost estimates accurate?Are Novatia’s cost estimates accurate?

FLOC Performance EstimatesFLOC Performance Estimates

Data taken from: Goff, A., “The Flock Booster Architecture – Low Cost Access to LEO via Sustained Fueling,” presented at

the 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, AIAA-

2004-3730, Ft. Lauderdale, FL, 2004.

RocketCost.xls (beta)RocketCost.xls (beta)1 stage simple linear cost analysis + risk to Contents

Summary Structure Propellant Total Vehicle DescriptionPayload Mass (lbs.) n/a n/a 8,100 Mass Ratio R 6.752 dimensionless

Vehicle Masses (lbs.) 6,706 85,162 99,969 Structural Mass Ms 6,706 lbs.Specific Cost ($/lb) 1,161 Propellant Mass Mp 85,162 lbs.

Structural Ratio R 0.828 dimensionlessRocket Equation Variables Initial Mass Mi 99,969 lbs.

Specific Impulse Isp 415 s Final Mass Mf 14,806 lbs.Change in Velocity ΔVbo 23,500 ft/s Production Vehicle Cost Cs $6,706,409

Velocity Loss due to Gravity & Drag ΔVloss 2,000 ft/s Program Development Cost Cd $670,640,947Ideal Change in Velocity ΔV 25,500 ft/s Fraction of Theoretically Possible ΔV Vratio 0.729682972 dimensionless

Propellant Mass Fraction η 0.927 dimensionlessPayload Mass Mpl 8,100 lbs. Total Cost of Launch

Cost of Hardware Expended Ch $134,128Vehicle Cost Characteristics Cost of Propellant Cp $10,816

Fraction of Hardware Expended f 0.020 dimensionless Cost of Operations & Refurbishment Co $502,981Combined Propellant Price Cp 0.127 $/lb Cost of Risk Cr $2,045,723Specific Cost of Hardware cs 1,000 $/lb TOTAL COST w/o Development Ct $2,693,647

Hourly Cost of Labor cl 75 $/hr Development Cost Assigned to ea. Launch Cd $6,706,409Labor Intensity L 1 hr/lb Total Cost including Development $9,400,057

Vehicle R&D Cost per lb. of Ms cr&d 100,000 $/lbCost per lb. of Vehicle of Additional Facilities cf 0 $/lb Cost per unit Mass of Payload

Fraction of Development Attributed to ea. Launch d 0.01000 dimensionless Payload Mass Mpl 8,100 lbs.Non-Vehicle Cost Mission Failure Cfail $198,000,000 Specific Cost of Hardware Expended ch 17 $/lb

Probability of Mission Failure pfail 0.01000 dimensionless Specific Cost of Propellant cp 1 $/lbSpecific Cost of Ops & Refurb co 62 $/lb

Specific Cost of Risk cr 253 $/lbSpecific Cost of Developoment cd 828 $/lb

SPECIFIC COST ct 1,161 $/lb

http://www.jupiter-measurement.com/research/rocketcost.xls

32 Unit FLOC Baseline Cost 32 Unit FLOC Baseline Cost EstimateEstimate

InputInput ValueValueff 0.010.01cHcH $1000/lb$1000/lbLL 0.10.1

cLcL $100/hr$100/hrPFAILPFAIL 2%2%cPLcPL $10,000/lb$10,000/lbcPcP $0.25/lb.$0.25/lb.ΓnrΓnr $20,000/lb$20,000/lbaa 2727

ResultResultAmortized Vehicle Amortized Vehicle DevelopmentDevelopment

$481/lb.$481/lb.

Vehicle HardwareVehicle Hardware $209/lb. $209/lb. OperationsOperations $209/lb.$209/lb.RiskRisk $20/lb.$20/lb.PropellantPropellant $4/lb $4/lb

TOTALTOTAL $923/lb.$923/lb.

InputInput ValueValueff 0.010.01cHcH $500/lb$500/lbLL 0.010.01cLcL $100/hr$100/hrPFAILPFAIL 2%2%cPLcPL $10,000/lb$10,000/lbcPcP $0.25/lb.$0.25/lb.ΓnrΓnr $9,500/lb$9,500/lbaa 2727

ResultResultAmortized Vehicle Amortized Vehicle DevelopmentDevelopment

$229/lb.$229/lb.

Vehicle HardwareVehicle Hardware $104/lb. $104/lb. OperationsOperations $21/lb.$21/lb.RiskRisk $20/lb.$20/lb.PropellantPropellant $4/lb $4/lb

TOTALTOTAL $378/lb.$378/lb.

Rocket Plane

Is FLOC a Rocket or a Plane?Is FLOC a Rocket or a Plane?Structure Mass / GLOW

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

AtlasV +CentaurIII

Ariane 5 FLOCBaseline

KC-135 B-58Hustler

Rocket Specific Cost Estimate: $923/lb.Plane Specific Cost Estimate: $378/lb.

ConclusionsConclusionsAmortized development cost is really important for Amortized development cost is really important for

economical space access. Don’t spend $$$ to develop economical space access. Don’t spend $$$ to develop more than you have to.more than you have to.

Separated ascent stage launch systems can achieve low Separated ascent stage launch systems can achieve low amortized amortized vehiclevehicle development cost. development cost.

Keeping operations labor intensity low and reusability Keeping operations labor intensity low and reusability high would be key to realizing the cost savings of high would be key to realizing the cost savings of separated ascent stage launch systems.separated ascent stage launch systems.

The cost, duration, and risk of developing the mid-ascent The cost, duration, and risk of developing the mid-ascent rendezvous capability needed for separated ascent rendezvous capability needed for separated ascent stage launch systems is unknown.stage launch systems is unknown.

Do vehicle savings justify mid-ascent rendezvous Do vehicle savings justify mid-ascent rendezvous development costs? I don’t know, but it is a serious development costs? I don’t know, but it is a serious question.question.

Selected Bibliography•Griffin, M. D., and Claybaugh, W. R., “The Cost of Access to Space,” JBIS, Vol. 47, 1994, pp. 119-122.•Claybaugh, W. R., AIAA Professional Study Series Course: Economics of Space Transportation, Oct. 12-13, 2002, Houston TX.•Taylor, C.Y., “Propulsion Economic Considerations for Next Generation Space Launch,” presented at the 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, AIAA-2004-3561, Ft. Lauderdale, FL, 2004.•Griffin, M.D., “Heavy Lift Launch for Lunar Exploration,” presented at the U. of Wisconsin, Madison, WI, Nov. 9, 2001, http://fti.neep.wisc.edu/neep533/FALL2001/lecture29.pdf.•Chang, I.S., “Overview of World Space Launches,” Journal of Prop. and Power, Vol. 16, No. 5, 2000, pp. 853-866.•Isakowitz, S. J., Hopkins, J., and Hopkins, J. P., International Reference Guide to Space Launch Systems, 4th ed., AIAA, Reston, VA, 2004.•Clapp, M. B., and Zubrin, R. M., “Black Horse:One Stop to Orbit,” Analog Science Fiction and Fact, June 1995, pp. 63-82•Goff, A., “FLOC Tradeoff Study – Minimizing Technical Risk with Zero-g Sustained Fueling,” presented at the 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, AIAA-2005-32493, Tuscon, AZ, 2005.•Goff, A., “The Flock Booster Architecture – Low Cost Access to LEO via Sustained Fueling,” presented at the 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, AIAA-2004-3730, Ft. Lauderdale, FL, 2004. •Dore, F. J., “Aircraft Design and Development Experience Related to Reusable Launch Vehicles,” Reducing the Cost of Space Transportation: Proceedings of the American Astronautical Society 7th Goddard Memorial Symposium, edited by George K. Chacko, American Astronautical Society, Washington, D.C., 1969.•Rocketcost.xls spreadsheet, Rev. K., Jupiter Research and Development, Houston, TX, 2006.