Mountain Launch System utilizing gravity assisted launch Keith Watts May 3, 2014
Table of contents Introduction Conventional approach and limitations Mountain launch concept Design case study Design details Energy & Cost/Benefit analysis Other considerations Summary Questions
Conventional Approach Payload Fuel & engines 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
Rocket performance defined by propellants Chemistry determines propellant performance
Space Launch System Performance First Stage (Block I) - Core Stage Diameter Empty mass Gross mass Engines Thrust Specific impulse Fuel 8.4 m (330 in) 85.27 kg (188.0 lb) 979.452 kg (2,159.32 lb) 4 RS-25D/E 7,440 kn (1,670,000 lbf) 363 seconds (3.56 km/s) (sea level), 452 seconds (4.43 km/s) (vacuum) LH 2 /LOX
World launch sites 23 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 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
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 Cable Pulley Counterweight Rocket A A Mountain Launch platform Access tunnel
Mountain Launch System concept Multiple counterweights, like numbers on a clock face Increased mechanical advantage Acceleration up to 1G Counter weights 12 places Main launch tube Principle of the trebuchet, large mass moving small distance = small mass moving a large distance View A-A
Mountain Launch System concept 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 Thin membrane Vacuum pump 10,000 feet Launch tube Mountain Rocket 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
Q:Are there mountains on the equator? A: Yes, there are at least two X X
Mt Chimborazo, Ecuador equator 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
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
Site Selection Location selection: Mt Kenya East coast of Africa minimizes over flight concerns Approx 6 mile horizontal tunnel required Seismically stable Choose location away from National Park popular areas 6 miles
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
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 75 ft 50 ft keyhole shape 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 Overhead crane The Big room Horizontal tunnel
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 Airport Road to tunnel Satellite processing Housing Food Medical Fire
Transportation Considerations Rocket boosters ship by sea Mombasa, deep water port Transport by truck to Mt Kenya Mombasa sea port Delta Mariner, Atlas & Delta Zenit 3SL 1 st & 2 nd stages
DESIGN DETAILS
Linear Bearing platform guidance Bearing shaft mounted to wall Adjustable to allow precise alignment Open linear bearing Launch platform Bearing shaft 8 places Counter weights typical
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 Pulleys Electric motor(s) Launch platform Counter weights Counter weights 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 Sliding cover Plastic membrane Launch tube
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, E Total =E PE +E KE Launch mass = 334,500 Kg PE = mgh = 16,984 17,000 MJ KE = ½ mv 2 = 7,538 7,500 MJ E total = 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 2 nd 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