Suborbital Space - Telespazio VEGA Deutschland

© Telespazio VEGA Deutschland11/11/2015
Telespazio VEGA Deutschland
COULD REUSABLE AIR-LAUNCH BREAK
THE SPACE ACCESS PARADIGM?
13th Reinventing Space Conference
9-12 November 2015
Oxford, 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 DILEMMA
Space 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 hardware
Repairables (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 billion
current 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 spending
commercial 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 billion
Lufthansa’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
Total
System
Cost
Total
System
Launches
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 benefits
rocket operations above the dense atmosphere
reduce significantly both drag and gravity losses
enables 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 benefits
enables operation out of existing airports with reduced launch range constraints
increases launch window flexibility and orbital rendezvous opportunities
up-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 cost
aircraft 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 studies
aircraft baseline assumed 767-300, plus 747-100 & 747-400
Mass model also used to investigate the impact of in-flight LOx transfer
Candidate Aircraft Cargo
An-225 200t
B747-400F 140t
B747-100 (SCA-911) 109t
A330-200 68t
B767-300 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 aircraft
aircraft ground clearance raised 0.4m (red lines) by increasing oleo fluid/gas
single 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 2031
Pathfinder Flights = 8 18
Pioneer Flights = 30 45
Initial Operation Flights = 60 100 120 120
Routine Operation Flights = 160 200 220 220
Flights/Year = 8 18 30 45 60 100 120 120 160 200 220 220
Seats/flight = 2 2 2 2 2 2 2 2 3 3 3 3
Seats/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 investment
investment > $2500 million would be unacceptable with respect to this scenario
Investment < $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)
mass
final 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) 7200
Progress (Government – Russian) 7200
ATV (Government – European) 20200
HTV (Government – Japanese) 19000
Dragon (Commercial – SpaceX) 6000
Cygnus (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 benefits
increases daily launch window opportunities
reduces ‘dog-leg’ for LEO rendezvous
enables 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 & Mission
1 Baseline mission delta-v to 400km LEO = 7820 m/s
2 Delta-v loss: 1750 m/s from sea-level; 850 m/s from 10km
3 Existing rocket engines (e.g. Merlin 1C & RL10A-4-2)
4 Oxydised/Fuel ratio: 2.28 for LOx/RP; 5.24 for LOx/LH2
5 Isp: 450s @10km for LOx/LH2; 300s @10km for LOx/RP
6 Current available structural materials (i.e. TRL 6+)
7 TPS mass: 5% Booster dry mass; 20% Orbiter dry mass
8 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/sec
5 Isp = 292s @10km for LOx/RP with 90% purity LOx
6 Isp = 435s @10km for LOx/LH2 with 90% purity LOx
Separation Mach number (Mn) = 8
Materials density scaling factor (S) [%] 1.00 1.00
TSTO Booster Details TSTO Orbiter Details
Specific Impulse (Isp) [sec.] 300 Specific Impulse (Isp) [sec.] 450
Rocket equation factor (R=Exp(dV/Isp/g) 2.8228 Rocket equation factor (R=Exp(dV/Isp/g) 3.5685
TSTO 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] 2260
Wings Mass (MBs1) [kg] 645 Wings Mass (MOs1) [kg] 259
TPS Mass (MBs2) [kg] 463 TPS Mass (MOs2) [kg] 458
Fuselage Mass (MBs3) [kg] 1824 Fuselage Mass (MOs3) [kg] 592
Tank Mass (MBs4) [kg] 1888 Tank Mass (MOs4) [kg] 713
Systems Mass (MBs5) [kg] 797 Systems Mass (MOs5) [kg] 220
Engines Mass (MBs6) [kg] 2827 Engines Mass (MOs6) [kg] 278
FSSC-16 Defined Propellant Mass (MBf) [kg] 33640 FSSC-16 Defined Propellant Mass (MOf) [kg] 7205
Booster 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 Details
Total Mission Delta-V [m/s] 8670
TSTO Dry Mass (MTs=MBs+MOs) [kg] 10705
TSTO Gross Mass (MTg=MTs+MBf+MOf+MOp) [kg] 52095

Supplementary Slides
ADVANTAGES OF AIR LAUNCHING - DAN DELONG
1. 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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