= Short Intro =

MoreLater, work in progress, links will be added

 * '''Launch loops are assembled over and float the ocean for safety and security'''
  . A good place is 8 degrees south, 120 degrees west, west of Ecuador and south of San Diego
   . The "most boring weather in the world" according to one meteorologist
 * '''Launch vehicles will travel on a magnetically levitated and coupled sled'''
  . Aerodynamically shaped launch vehicles are 5000 kg,  and ride above a 2000 kg magnet sled
  . Magnet sleds (perhaps 50 meters long) couple to the rotor through a [[ http://launchloop.com/VelocityTransformer | velocity transformer track ]]
  . Magnet sleds will use a lot of expensive Neodymium magnets
   . Nanostructured iron nitride may be a cheap, earth-abundant replacement someday; theoretical for now
  . After payload release, sleds are decelerated, retested, repaired, and reused
 * '''Launch loops must be very long'''
  . at 30 m/s² (≈ 3 gees) payload acceleration to 11.1 km/s exit velocity:
   . 370 seconds of acceleration, and a 2053 km launch path.
  . at 150 m/s² (≈ 15 gees), the empty sled stops in 74 seconds over 411 km
  . A 2500 km launch path means a 6000 km total rotor length
 * '''The launch loop rotor masses 3 kg/m, with a 4 cm hexagonal cross section'''
  . Each hexagonal is a row of iron-faced '''bolts''', each perhaps 10 meters long.
 * '''Loop failure'''
  . The entire rotor stores almost 2e15 joules
   . A "1 megaton" bomb releases 4.2e15 joules instantly
  . The rotor circulates in 430 seconds
  . The rotor "power rate" is 4100 GW
   . A failing launch loop releases some rotor at the point of failure
   . most will be deflected and fanned into the ocean at two places, boiling a '''LOT''' of seawater '''''fast'''''
  . some material may be thrown into Earth escape orbit
  . a very small amount of material will re-enter
  . the bolts should be designed to disintegrate into small fragments during re-entry or ocean penetration
 * '''The launch loop track and stabilization cables mass 6.5 kg/m'''
  . the track contains velocity transformer coils, which couple sled magnets to the rotor
 * '''Stabilization cables to the surface transmit N/S and radial forces'''
  . cables must be aluminum-sheathed to carry lightning strokes
   . perhaps they can be actively charged to "cloud neutrality", but this seems unlikely
 * '''Launch loop launch altitude is 80 km'''
  . Post-release payload drag and blunt nose heating will be significant but not extreme
  . The tenuous atmosphere above 80 km will de-orbit smaller (and hard to track) space debris
   . Larger debris objects must be dodged or intercepted.
 * '''Launch loop ''inclines'' descend from the tracks to turnaround ''ambits'' at the ends'''
  . an upwards curve supports "west station" at 30 km altitude
  . the inclines enter '''upward deflector''' structures at the ocean surface at a 20 degree angle
  . presuming a 6 km turn radius, and a 100 meter superstructure:
   . the deflector structures will descend 300 meters below the ocean surface
   . they will deflect the rotor back up to 50 meters below the surface and wave agitation
   . they will be able to release a failing rotor into the ocean floor
 * '''The return track will also be at altitude'''
  . the return track will support most of the stabilization cable mass
  . the return track can provide backup power (through optical fiber) to the track above
  . the return track can be an additional reference platform for stability
 * '''Launch loop ambits will deflect six "tracks" of separated bolts'''
  . turn radius estimated 6000 meters
  . The ambits will have GW power plants and 10 km long linear motors
  . The ambits will be associated with "spare bolt racetracks"
   . These will also store burst power
  . High speed inspection stations will photograph each bolt at speed, to micrometer resolution
  . Bolt measurements will be "synopsized" by large parallel computers, and compared to previous measurements
   . Significant changes will cause a bolt to be diverted into a "used bolt racetrack
  . The ambits and deflection magnets will resemble a low-tech version of the [[ https://en.wikipedia.org/wiki/Large_Hadron_Collider | Large Hadron Collider ]]
   . Loop design will shamelessly steal technologies and best practices from LHC
   . If no particles are discovered after the Higgs, thousands of brilliant technicians may be available
 * '''Be aware that lateral stability''' 
  . is described by eight coupled, fourth order, nonlinear partial differential equations.  Without proper control, involving whole system measurement and rapid computed optimization, ''these equations can be unstable and diverge rapidly''.  I am still working on this complex mathematical problem.
 * '''Launch loops require [[ http://server-sky.com | Server Sky ]] constellations overhead'''
  . Providing redundant and precision interferometric positioning to the loop controllers
  . Providing multiple redundant whole system control
  . Capturing diagnostic information for modelling and optimization, or failure analysis
  . Tracking vehicles and managing orbital traffic
  . Tracking incoming debris objects and planning mitigations
=== Destinations ===
 * Launch rates for this "small" loop can be 400 tonnes per hour
  . up to 3.5 million tonnes per year
 * Stations in 23h56m geosync ConstructionOrbits can gather and assemble large missions, 100 tonnes per sidereal day
  . 3 years is 110,000 tonnes per construction orbit, perhaps a fueled 60,000 tonne Aldrin Cycler
 . A [[ https://en.wikipedia.org/wiki/Stanford_torus |Stanford Torus ]] for 10,000 inhabitants is projected to weigh 10 million tonnes
  . Not any time soon; industrial infrastructure isn't easy
  . ask the North Koreans, they have air, food, ores, and millions of people ... and impractical ideas
 * Space Solar Power Satellite Assembly
 . MoreLater
=== Power Storage ===
 * '''At realistic launch market growth rates, it will be decades before launch loops are profitable'''
  . Space solar power has been ''just around the corner'' for half a century
  . Missions to Mars will be robotic, and humans can't compete economically
  . Mars will never be a practical "second Earth" (the asteroids might).
  . Deep space missions to deflect asteroids are way too expensive
  . Asteroid mining missions are proposed only by non-geologists and non-miners
  . We will do all of these things someday, but advocates must first start talking economic sense.
 * '''Grid scale energy storage is an urgent need'''
  . Grid demand varies hourly and seasonally
  . Wind and solar is intermittent and unpredictable
  . Nuclear is steady but not "peakable"
  . Carbon fuel stinks
 * '''Loop technology can store huge amounts of power'''
  . The fast loop described above stores 500 GW-hours
  . A slower, heavier loop running at 7900 m/s will "orbit" in its tunnel without vertical deflection forces
   . A kilogram of 7.9 km/s rotor stores 17 kWh.  
   . Cycled 200 times per year, buying power at \$3/MWh and selling at \$10/MWh, a kilogram earns \$24 per year
   . purchase and automated forming cost might be \2 per kg ... '''≫≫profit!≪≪'''
  . Most of the system losses are in the ambits; a longer "straightaway" adds storage with little loss
   . power storage loops can span the Pacific Ocean, time-shifting power across 10 time zones.
  . Much heavier rotors can store more energy
  . Power storage rotors can be simpler and safer than launch rotors
 * '''Lessons learned from power storage will speed the design of launch loops'''
 * '''Manufacturing lines for power storage can be used to build launch loops'''

=== Small experimental power storage loops are being built in Finland in 2018 ===
 * Not directly associated with launchloop ... yet