Mountain Launch System utilizing gravity assisted launch Conference... · Mountain Launch System...
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Transcript of Mountain Launch System utilizing gravity assisted launch Conference... · Mountain Launch System...
Keith Watts
May 3, 2014
Mountain Launch System
utilizing gravity assisted launch
• Introduction
• Conventional approach and limitations
• Mountain launch concept
• Design case study
• Design details
• Energy & Cost/Benefit analysis
• Other considerations
• Summary
• Questions
Table of contents
Conventional Approach
• The rocket problem is one of exponential growth
• Fuel to carry payload plus fuel to carry fuel
• Start from a standstill, 0 velocity
• Start from near sea level, 0 altitude
• Start where air is thickest, 14.7 psi
• No outside assistance, must carry all required
fuel and oxidizer on board
• 30-50 lbs for 1 lb payload to space
• Atlas V 401, 3% of total mass is payload
– Mass to LEO: 10,470 kg
– Lift off mass: 334,500 kg
Fuel &
engines
Payload
Rocket performance defined by propellants
Chemistry determines propellant performance
Space Launch System Performance First Stage (Block I) - Core Stage
Diameter 8.4 m (330 in)
Empty mass 85.27 kg (188.0 lb)
Gross mass 979.452 kg
(2,159.32 lb)
Engines 4 RS-25D/E
Thrust 7,440 kN
(1,670,000 lbf)
Specific impulse
363 seconds
(3.56 km/s) (sea
level), 452 seconds
(4.43 km/s) (vacuum)
Fuel LH2/LOX
World launch sites
• Most of the world launch sites located in coastal areas near sea level
• Countries want their own site
• Transportation of rocket to launch site is a limitation
• Vulnerable to weather, attack
1 Vandenberg
2 Edwards
3 Wallops Island
4 Cape Canaveral
5 Kourou
6 Alcantara
7 Hammaguir
8 Torrejon
9 Andova
10 Piesetsk
11 Kapustin Yar
12 Palmachim
13 San Marco
14 Baikonur
15 Sriharikota
16 Jiuquan
17 Xichang
18 Taiyuan
19 Syobodny
20 Kagoshima
21 Tanegashima
22 Woomera
23 Sea Launch
23
Rocket + Earth’s contribution= hardware in space
Rocket + Earth’s contribution= hardware in space
• Decades of development
• Billions spent
• Not much room for improvement
• Get as close to the Equator as you can
• Sea Launch is only real improvement by actually
getting on the Equator, 17.5 to 25% over Cape
• Is there room for improvement?
BUILD SOMETHING BETTER
What if ? • What if you could use gravity
instead of fighting it?
• You can with a simple counter
weight elevator.
• Limitation of a man made structure
on the order of 1000 ft.
• What you need is a large natural
structure, a big pile of dirt and rock
• Fortunately, such natural structures
exist, they are called “mountains”
• Use low cost energy to hoist
counterweights
Mountain Launch System concept
Pulley Counterweight
Mountain
Launch
platform
Rocket
Cable
A A
Access tunnel
Counter weights 12 places
Main launch tube
View A-A
Mountain Launch System concept
• Multiple counterweights, like numbers on a clock face
• Increased mechanical advantage
• Acceleration up to 1G
• Principle of the trebuchet, large mass moving small distance = small mass moving a large distance
• Terminal velocity is reached
when aerodynamic drag equals
the force of gravity
• Remove the air and there is no
terminal velocity
Mountain Launch System concept
10,000 feet
Mountain
Rocket
Launch tube
Thin membrane
Vacuum pump
Lower hatch
Mountain Launch System concept
The numbers: • Launch tube length 10,000 ft
• Counterweight to payload ratio 4:1
– 0.5 M lb rocket and 2 M lbs counterweights
• Resulting vertical acceleration ¾ G
• Time in tube 29 sec
• Exit velocity 475 mph!
• Equatorial launch
• Full fuel load
• Thinner air
• 3-4 miles up
Mountain Launch System concept
Q:Are there mountains on the equator?
A: Yes, there are at least two
X X
Mt Chimborazo, Ecuador • South America
• Elevation: 20,560 ft
• Coordinates:
1°28′9″S78°49′3″W
• Type: Stratovolcano
• Last eruption:
640 AD +/- 500 years
• Nearest city: Quito
Mt Chimborazo, outermost point on Earth
equator
Mt Kenya, Kenya
• Kenya, west coast of Africa
• Elevation: 17,058 ft
• Coordinates: 0°9′0″S37°18′0″E
• Type: Stratovolcano (extinct)
• Last eruption: 2.6-3.1 Ma
• Nearest cities: Nairobi & Mumbasa
equator
BUILD SOMETHING BIGGER
Location selection: Mt Kenya • East coast of Africa minimizes
over flight concerns
• Approx 6 mile horizontal tunnel required
• Seismically stable
Site Selection
6 miles • Choose location
away from National Park popular areas
Sizing for market Design sizing targets, (starting point) • Diameter 25 ft (rocket), 50 ft launch tube
• Height 235 ft (rocket), 10,000 ft launch tube
• Weight: up to 1.5 M lbs (rocket), 4 M lbs counter weights
Target this market
50 ft
75 ft
“keyhole shape”
Tunnel Sizing Horizontal tunnel • Keyhole shape 50ft wide, 75 ft tall
• Concrete lined
• Need to accommodate upright payload fairings
• 6 miles long = 4 M yards of material to be removed
Fueled satellite and
fairing on it’s way the
launch pad
Big room and launch tube
Vertical tunnel • Round 50 ft diameter, 10,000 ft long
• Concrete lined
• 1 M yards of material
The Big room • Vehicle assembly area
• Overhead crane
• Unload rocket and erect
The Big room Horizontal tunnel
Overhead crane
Tunnel Boring Machines Tunnel Boring Machines (TBM) built by Robbins, OH • Recently completed Niagara river project, 6.3 miles, 42 ft dia
• No concerns drilling volcanic rock
• Would construct vertical shaft from bottom up
• “Gripper” type, grips shaft, then thrusts up
• Cuttings fall and can be removed
• Concrete lines shaft as it goes
Cheyenne Mountain Complex
Tunnels and complex • 4700 ft access tunnel, 29ft wide, 22.5 ft high
• 470,000 cuyds material removed (see parking lot)
• 4.5 acre main chamber grid
Assured access to space • Protected from extreme weather
• Protected from hostile attack
Support Infrastructure
Other Infrastructure needed • Airport 10,000 ft long
• Satellite processing facility
• Housing
• Medical
• Fire
• Food
Housing
Road to tunnel
Satellite processing
Food Medical Fire
Airport
Transportation Considerations
Rocket boosters ship by sea • Mombasa, deep water port
• Transport by truck to Mt Kenya
Zenit 3SL 1st & 2nd stages Delta Mariner, Atlas & Delta
Mombasa sea port
DESIGN DETAILS
Linear Bearing platform guidance
Launch platform
Open linear
bearing
Bearing shaft
8 places Counter weights
typical
Bearing shaft
mounted to wall
Adjustable to allow
precise alignment
Pulley system concept Pulley system concept • Located around the top of the launch tube
• 2 wheels to reduce wire rope bending, 2x90⁰ vs 1x180⁰
• Electric motor to add more energy
• Regenerative braking to slow platform and re-capture energy
• 1” wire rope rated load 100,00 lbs
Counter
weights
Launch platform Counter
weights
Pulleys Electric motor(s)
Clutched to engage or
dis-engage
Top cover & Membrane Concept Membrane concept • Seals to of launch tube to allow vacuum inside
• Rocket could pierce or could have heater burn through
Sliding cover • Camouflaged to minimize ascetic impact
Plastic membrane
Launch tube
Sliding cover
ANALYSIS
Energy Analysis Energy to orbit approx 30 MJ/Kg
• Atlas V 401 mass to LEO: 10,470 Kg
• 30 x 10,470 = 314,100 ≈ 315,000 MJ
• Atlas V 401 to 475 mph @ 17,000 ft, ETotal=EPE+EKE
• Launch mass = 334,500 Kg
• PE = mgh = 16,984 ≈ 17,000 MJ
• KE = ½ mv2 = 7,538 ≈ 7,500 MJ
• Etotal = 24,500 MJ
• 24.5/315 = 8% performance gain
• Increase performance to 1G using electric motors
• Speed now 800 mph
• KE = 21,676 ≈ 21,700 MJ
• 12% performance gain
• Gains conservative, 315,000 MJ would be less due to improvements in drag, distance & momentum
• Additional gains for equatorial launch
Low cost version • Build launch facility at 17,000 feet on equatorial mountain
• Potential energy 17,000 MJ
• 17/315 = 5% min performance gain
• Thinner air, less distance to space
• Saves 1 B tunneling cost, and counter weight system design
• Build a suitable road for rocket transport
• Build assembly and launch complex
Cost Analysis
• Approx 30 launches per year @100 M per launch = $ 3 B/yr
• Estimate for tunnel construction 1 B
• WAG for everything else, $500 M, Total cost $1.5 B
• Value of 12% gain of $3 B = $360 M
• 1500/360 = 4 yrs, 2 months, not a payback number but estimate of value
Help needed • Rocket performance improvement with these parameters:
• Start from 15,000 ft
• Initial velocity 500 & 800 mph
• What would be optimum speed at 15,000 ft to avoid Qmax?
• What are the needs of vehicle assembly?
MISCELLANEOUS
Improvements, Other uses • Additional power (electric motors) past 1G, how fast is too fast?
• Magnetic induction could be added
• Sufficient speed to start a ramjet? Use atmosphere O2
• Optimized low cost rocket, ramjet stage, modified 2nd stage?
• Microgravity research, 25 sec 0 G free fall
• Thrill ride
• Space tourism, sub-orbital flights
• Quick way to top of mountain
Design Challenges • Geothermal, what is the environment inside mountain?
• Counter weight deceleration and energy recovery
• Design and support of big room
• Design packaging of launch tube
• Moving platform & weighs in opposite directions
• Need stair and elevator access
• Pressure sealing top & bottom
Kenya • Government generally perceived as investment friendly
• Enacted reforms to simply foreign investment
• Well developed social and physical infrastructure
• Main alternative to South Africa for corporations seeking Africa markets
• 45 million people, growth rate of 2.3%
• 25% live in cities, the rest live in rural areas (farming)
• 40 different ethnic groups
• English and Kiswahili are official languages
• Best literacy rates in Africa, 87%
• 50% live below poverty line, 40% unemployment
• Need for clean safe water
Next Steps • Preliminary design concepts and trades
• Sizing & packaging
• Counterweight system design
• Tunnel boring machine
• Cost estimates
• Launch vehicle improvements and partnerships
• Technology demonstrator
• Discussion with governments on use of Mt Chimborazo & Mt Kenya
Odds and ends • Other titles:
• Most efficient means for launching payloads to space
• Using volcanoes to launch rockets
• “Ken ya” launch my rocket?
• US Patent No. 753053, issued May 12, 2009
• Submitted Small Business Innovation Research (SBIR) proposal for “Innovative Technologies for Operationally Responsive Space” Feb 2014, not selected
Summary • Improvement in rocket performance limited by chemistry &
physics
• Optimize system performance by increasing the contribution from the Earth and low cost energy
• Can use existing rockets as is, or minimal modifications
• Existing materials and technology
• Shielded from weather or military action
• Benefit to Kenyan and African economy and prestige
• World space port close to European and Asian populations
Thank you!
Q & A