Suborbital Space - Telespazio VEGA Deutschland

© Telespazio VEGA Deutschland11/11/2015

Telespazio VEGA Deutschland

COULD REUSABLE AIR-LAUNCH BREAKTHE SPACE ACCESS PARADIGM?

13th Reinventing Space Conference9-12 November 2015Oxford, UK

David J. Salt - Senior Consultant

© Telespazio VEGA Deutschland11/11/2015 2

PRESENTATION OVERVIEW

The Current Space Access Paradigm

The Reusability Dilemma

The Potential for Air-Launch

Assessing Market Size & Elasticity

An RLV Conceptual Design

The Business Case Analysis

Future Potentials

Conclusions

Could reusable air-launch break the space access paradigm?


THE SPACE ACCESS DILEMMASpace access is expensive… the price to get into low Earth orbit is on the order of $10,000/kg because current launcher vehicles are extremely expensive to operate

Expendables (e.g. Ariane 5) throw away expensive hardwareRepairables (i.e. Shuttle) take too much time/effort to turn-around

Fully reusable launchers with airline-like operations could lower the cost of space access by at least an order of magnitude (less than $1,000/kg) but…

the estimated cost to develop such vehicles is $10-20 billioncurrent markets are insufficient to reach flight rates that would justify such a cost because… space access is expensive!



THE CURRENT SPACE PARADIGM Growth of space activities is slow or even stagnant compared to the rapid developments in the first two decades of the ‘Space Age’

government programmes face cut-backs and/or cancellation due to major constraints on government discretionary spendingcommercial space activities are limited to working with ‘photons’ rather than ‘atoms’ because of the space launch dilemma


THE POTENTIAL FOR ‘DISRUPTION’

The current paradigm is very unlikely to overcome these limits to growth, especially if current launch markets remain ‘inelastic’

lower prices stimulate only limited market growth and, worse still, result in a significant decrease in total yearly revenue!

One way to break the dilemma may be to stimulate new markets with better elasticity that can be serviced by smaller/cheaper vehicles



IS THERE A POTENTIAL FOR GROWTH?Perspective: The 2014 global space revenue was $330 billion, which is less than the annual revenue of one large commercial company (e.g. $476 billion for Wal-Mart in 2014)

World airline revenues in 2014 were $743 billionLufthansa’s revenue in 2014 was $25 billion

Question: Without another major government initiative like Apollo, how can we encourage and/or create new space markets?



ADVANTAGES OF REUSABILITY

Reusability promises to improve space access by enabling:major reductions in marginal costs, as expensive components tend not to be discarded after use;better amortization of investments, as costs can be spread across more users;higher reliability and safety, due to the intrinsic value of the vehicle.


OVERHEADS OF REUSABILITY

Compared to an ELV with equivalent payload performance, reusability forces significant additional design and operational requirements via:

more robust structures and propulsion, plus the addition of systems for recovery (TPS, landing gear, etc.) and maintenance (access ports, interfaces, etc.);the need for additional testing at all levels (i.e. component, unit, system, in-flight) to verify both safety and reliability;additional equipment/facilities/personnel to both return the vehicle back to the launch site and then perform all necessary refurbishment/maintenance.

These factors are critical as they must be less than ELV production cost in order to ensure the RLV can be in any way competitive



THE BASIC TRADE-OFF: EXPENDABLE – VS – REUSABLE

TotalSystemCost

TotalSystemLaunches

ELV Ops.Cost

RLV Ops.Cost

RLV Dev.Cost

Critical Market Size

Choose RLVChoose ELV

ELV Dev.Cost




THE BENEFITS OF SUBSONIC AIR-LAUNCH

Performance benefitsrocket operations above the dense atmosphere reduce significantly both drag and gravity lossesenables significant increase in engine specific impulse (Isp) by using a larger expansion ratio nozzle that would be over-expanded at lower altitudes so cause destructive instabilities

Operational benefitsenables operation out of existing airports with reduced launch range constraintsincreases launch window flexibility and orbital rendezvous opportunitiesup-range launch enables 1st stage to land back at base, minimising ferry flights

Cost & Evolutionary benefits

existing aircraft can be procured/modified at relatively low costaircraft can be modified incrementally to increase performance (e.g. better thrust/weight/performance engines and/or introduction of in-flight LOx transfer)




AIR-LAUNCH DECREASES THE IMPACT OF STRUCTURE MARGINS


This effect is of much greater benefit to RLV’s than ELV’s



ASSESSMENT OF DEMAND FOR HUMAN FLIGHT TO ORBIT

Originally, we considered comsats to be the only real and addressable market that could justify a commercial RLV development

Recent evidence suggests human passenger flights to LEO could be a far more substantial and addressable market

Wealth statistics for the world’s Ultra High Net-Worth Individuals (UHNWI) used as basis for current assessment

Findings from Futron study (2002AD ) then used to factor UHNWI data for:

fraction of their net-worth an individual would pay for a ticket (1.5%, 5%, 10%,);

likelihood that any UHNWI would purchase a ticket at a specific price point;

fraction sufficiently fit to fly (61%);

additional fraction who would fly if training were in US, instead of Russia (+24%);

additional fraction who would fly if training were reduced from 6 to 1 month (+50%)

also factored to account that only ~25% of the UHNWI wealth is held in cash

Spreadsheet used to assess trends in market size/value in 2020AD




DEMAND ELASTICITY FOR HUMAN SPACEFLIGHT TO ORBIT


Due to the number of assumptions and limited nature of the population survey, great caution must be taken when interpreting these results

Nevertheless, results are sufficiently encouraging to justify an assessment an RLV capable of flying a payload of 500kg (i.e. 2 humans + life support) into LEO

Plots show significant elasticity:essentially linear above the $10M per ticket price point;significant growth begins below the $10M per ticket price point;growth below the $2M per ticket becomes exponential



RLV PERFORMANCE & GROWTH POTENTIAL

Scalable mass model of subsonic air-launched RLV concept used to investigate the impact of aircraft size on LEO payload performance

TSTO configuration (1st stage LOx/RP + 2nd stage LOx/LH2)RLV mass/performance based on NASA/DARPA & ESA studiesaircraft baseline assumed 767-300, plus 747-100 & 747-400

Mass model also used to investigate the impact of in-flight LOx transfer


Candidate Aircraft CargoAn-225 200tB747-400F 140tB747-100 (SCA-911) 109tA330-200 68tB767-300 52t



SUBSONIC AIR-LAUNCHED RLV – CONCEPTUAL DESIGN


RLV mass model’s propellant loads enable rough sizing of tanks to assess configuration and integration issues

1.5m tank diameter to give sufficient ground clearance below the aircraftaircraft ground clearance raised 0.4m (red lines) by increasing oleo fluid/gassingle LH2 (light blue) tank + LOx (green) & RP-1 (red) split to shorten stages



STRUCTURE OF THE RLV BUSINESS SCENARIO

Assumes a staged development of the business scenario that incorporated four key operational phases:1a) NASA flights, over the 1st and 2nd year of service, with ticket price of $20M;1b) Pathfinder flights, over the 1st and 2nd year of service, with a ticket price of $10M;2) Pioneer flights, over the 3rd and 4th year of service, with a ticket price of $10M;3) Initial Operations, in the 5th and 8th year of service, with a ticket price of $5M;4) Routine Operations, in the 9th and 12th year of service, with a ticket price of $1M.

A ramp-up of launch rates is enabled by fleet replacements/improvements:100 flights performed by 1st fleet over first 4 years (2020 – 2023)400 flights performed by 2nd fleet over second 4 years (2024 – 2027)800 flights performed by 3rd fleet over third 4 years (2028 – 2031)


2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031Pathfinder Flights = 8 18

Pioneer Flights = 30 45Initial Operation Flights = 60 100 120 120

Routine Operation Flights = 160 200 220 220Flights/Year = 8 18 30 45 60 100 120 120 160 200 220 220Seats/flight = 2 2 2 2 2 2 2 2 3 3 3 3Seats/year = 15 35 60 90 120 200 240 240 480 600 660 660



CASH FLOW ANALYSIS OF THE RLV BUSINESS SCENARIO

Fleet sales to third parties also included as single operator flight rates capture only a fraction of potential passenger pool (i.e. < 20% of 5%NW)

Assuming an IRR above 20% is needed to justify the initial investmentinvestment > $2500 million would be unacceptable with respect to this scenarioInvestment < $1500 million would be very acceptable!

This RLV business case appears much stronger that one addressing the GEO comsats market due to the smaller vehicle and better market elasticity



Future Potentials

COMMERCIAL GEO OPERATIONS

A suborbital air-launched RLV with 4000kg LEO payload performance can also launch GEO comsats

40% of GEO comsat launch mass is propellant to go from GTO to GEO

Operational scenario would involve launch/assembly of a kick stage to perform LEO to GEO transfer

number of launches depends on satellite’s Beginning of Life (BoL) massfinal launch delivers/mates satellite with kick-stage

Preliminary business case analysis suggests an RLV with development costs below $1billion could be a commercially viable proposition!



Future Potentials

LEO OPERATIONS & BEYOND… “HALFWAY TO ANYWHERE”

Most space station crew and logistics transport requirements could be supported by a subsonic air-launched RLV

Mass of many GEO and lunar transport elements could also be supported by this same RLV

The vast majority (~80%) of mass launched to LEO will be propellant, which is infinitely divisible!

ISS Servicing Vehicles LEO Mass (Mg)Soyuz (Government – Russian) 7200Progress (Government – Russian) 7200ATV (Government – European) 20200HTV (Government – Japanese) 19000Dragon (Commercial – SpaceX) 6000Cygnus (Commercial – OSC) 4500



Conclusions

CONCLUSIONS

Space activities have so far failed to achieve the great expectations set out at the dawn of the space age, over half a century ago

Stimulation and growth of new markets is the key factor that will govern the development of future space activities

The market for flying humans to LEO may have sufficient size and elasticity to justify the commercial development of a small subsonic air-launched RLV

Evolved versions of this RLV could support new space infrastructures that would enable a major and sustainable growth of space activities

This analysis serves to underscore the value of building up any space launch business in a series of small steps rather than one giant leap

Although more detailed analyses are needed in order to confirm these results, they do tend to suggest that…

…YES, reusable air-launch could break the space access paradigm!



THANKS FOR YOUR ATTENTION…

… ANY QUESTIONS?



SUPPLEMENTARY SLIDES



The Case for Subsonic Air-Launch

MARKET ELASTICITY EVOLUTION WITH LAUNCH COST




SUBSONIC AIR-LAUNCH OPERATIONS & WINDOWS

Cruise to launch point has major benefitsincreases daily launch window opportunitiesreduces ‘dog-leg’ for LEO rendezvousenables in-flight LOx transfer or ‘harvesting’



The Case for Subsonic Air-Launch

ROCKET VEHICLE MOUNTING/INTERFACE OPTIONS



Supplementary Slides

AIR-LAUNCH MODEL INFO.

Wing & TPS Mass: Scales directly with materials factor (S) and the change, with respect to the baseline, in the sum of Fuselage, Tank, Systems, and Engine masses (Ms3 + Ms4 + Ms5 + Ms6).Fuselage Mass: Scales directly with materials factor (S) and the change, with respect to the baseline, in the propellant tank mass (Ms4).Tank Mass: Scales directly with materials factor (S) and the change, with respect to the baseline, in the propellant mass (Mf) raised to the power of 2/3.Systems & Engine Mass: Scales directly with the change in the propellant mass (Mf), with respect to the baseline.

RLV Design & Mission1 Baseline mission delta-v to 400km LEO = 7820 m/s2 Delta-v loss: 1750 m/s from sea-level; 850 m/s from 10km3 Existing rocket engines (e.g. Merlin 1C & RL10A-4-2)4 Oxydised/Fuel ratio: 2.28 for LOx/RP; 5.24 for LOx/LH25 Isp: 450s @10km for LOx/LH2; 300s @10km for LOx/RP6 Current available structural materials (i.e. TRL 6+)7 TPS mass: 5% Booster dry mass; 20% Orbiter dry mass8 Wings + Empennage + body flap: 7% dry mass

ACES Characteristics [RD.10]1 LOx collection plant (LCP) mass / volume = 4Mg / 6m3

2 Collection Ratio (CR) = 2.0 (i.e. 1kg LH2 => 2.0kg LOx)3 LOx collection purity = 90% (i.e. 10% N2)4 LOx collection rate = 9 kg/sec5 Isp = 292s @10km for LOx/RP with 90% purity LOx6 Isp = 435s @10km for LOx/LH2 with 90% purity LOx


Separation Mach number (Mn) = 8Materials density scaling factor (S) [%] 1.00 1.00TSTO Booster Details TSTO Orbiter DetailsSpecific Impulse (Isp) [sec.] 300 Specific Impulse (Isp) [sec.] 450Rocket equation factor (R=Exp(dV/Isp/g) 2.8228 Rocket equation factor (R=Exp(dV/Isp/g) 3.5685TSTO Gross Mass (MTg=MBp+MBs+MBf) [kg] 52095 Orbiter Gross Mass (M0g=MOp+MOs+MOf) [kg] 10010

Booster Dry Mass (MBs=SUM(MBs1:MBs6)) [kg] 8445 Orbiter Dry Mass (MOs=SUM(MOs1:MOs6)) [kg] 2260Wings Mass (MBs1) [kg] 645 Wings Mass (MOs1) [kg] 259TPS Mass (MBs2) [kg] 463 TPS Mass (MOs2) [kg] 458Fuselage Mass (MBs3) [kg] 1824 Fuselage Mass (MOs3) [kg] 592Tank Mass (MBs4) [kg] 1888 Tank Mass (MOs4) [kg] 713Systems Mass (MBs5) [kg] 797 Systems Mass (MOs5) [kg] 220Engines Mass (MBs6) [kg] 2827 Engines Mass (MOs6) [kg] 278

FSSC-16 Defined Propellant Mass (MBf) [kg] 33640 FSSC-16 Defined Propellant Mass (MOf) [kg] 7205Booster Payload (MBp=MOg, Orbiter Gross Mass) [kg] 10010 Resultant TSTO Payload (MOp) [kg] 545

Booster delta-V loss (LdV) [m/s] 850 Orbiter delta-V loss (LdV) [m/s] ---Booster delta-V (BdV) [m/s] 2204 Orbiter delta-V (OdV) [m/s] 5616

TSTO System DetailsTotal Mission Delta-V [m/s] 8670

TSTO Dry Mass (MTs=MBs+MOs) [kg] 10705TSTO Gross Mass (MTg=MTs+MBf+MOf+MOp) [kg] 52095


Supplementary Slides

ADVANTAGES OF AIR LAUNCHING - DAN DELONG1. The airplane carrier contributes to the overall altitude and velocity. These advantages are small.

2. Meteorological uncertainties are mostly below launch altitude. Propellant reserves can thus be less.

3. Total integrated aerodynamic drag losses are less, as the launch is above much of the atmosphere.

4. Max Q is less, which reduces structural mass, and may allow lower density thermal insulation.

5. Engine average Isp is increased because the atmospheric back‐pressure effect affects a smaller fraction of the trajectory.

6. Engine expansion ratio (non‐variable geometry assumed) can be greater because overexpansion is less problematical.

7. Wing area can be smaller because the wings do not need to lift the gross weight at low subsonic speed. Air launch Q is greater than runway rotation Q.

8. Wing aerofoil shape need not be designed to work well at high gross weight and low subsonic speeds.

9. Wing bending structure need not be designed for gross weight take‐offs or gust loads. Wings can reasonably be stressed for 0. 7 g working plus margin. This is a large weight advantage made possible by the carrier aircraft flying a lofted trajectory and releasing the orbiter at an initial angle of at least 15 degrees. (25 degrees is much better but not crucial, more than 60 degrees has no value) This initial angle decays in the first 10 seconds of flight but picks up again as propellant is burned and the constant wing stress trajectory yields a better lift/weight ratio. The thing to keep in mind is that the wings are sized and stressed for landing, and that insofar as they exist, are used to augment launch performance.

10. Thrust/weight ratio can be smaller because the low initial trajectory angle does not have large gravity losses. This allows a smaller engine, propellant feed, and thrust structure mass fraction. I found 1.25 at release to be about optimum. This is a bigger advantage in air launching because total integrated aerodynamic drag losses are less and the trajectory need not get the orbiter out of the thick stuff as fast.

11. The lower mass/(total planform area) yields lower entry temperatures. I assumed inconel foil stretched over fibrous blanket insulation for much of the vehicle undersurface. Titanium over blankets, or no insulation worked on the top surface. Payload bay doors peaked at 185 F.

12. Mission flexibility is greater. For example, the carrier airplane can fly uprange before release to allow a wider return‐to‐launch‐site abort window. Good ferry capability, etc.


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