Differences between revisions 1 and 22 (spanning 21 versions)
 ⇤ ← Revision 1 as of 2018-09-24 23:16:33 → Size: 1438 Editor: KeithLofstrom Comment: ← Revision 22 as of 2021-01-28 18:43:41 → ⇥ Size: 5405 Editor: KeithLofstrom Comment: Deletions are marked like this. Additions are marked like this. Line 1: Line 1: #format jsmath Line 2: Line 4: Launch Loop vehicle rates will be very high, perhaps more often than one 5 tonne vehicle per minute. The very low cost of launch (and the very high infrastructure costs) require high throughput handling with many automated inspection stages. It also means that missions will typically be assembled from many combined low-cost payloads.For example, an Apollo style Moon mission series might assemble a 100 tonne vehicle and a 200 tonne support station in a [[ HighApogeeConstruction | high apogee construction orbit ]], with a permanent support staff on the support station readying a series of monthly manned lunar orbit or landing missions. Every step of each mission will involve multiple redundancies; for example, a complete spare unmanned lander and return vehicle will be landed on the Moon a month in advance of a crew in an identical lander a month later. If the later crewed lander is somehow disabled, they can return in the spare, or survive on the supplies in both vehicles. These manned probes would be sent to sites identified by orbital mapping and robot landers as sites needing specialized human attention; the vast majority of missions will either be small tele-operated robots controlled from Earth or lunar orbit, or large-crew long-duration missions with shielded centrifugal habitats buried under lunar regolith. Launch Loop vehicle rates will be very high, perhaps more often than one 5 tonne vehicle per minute. The very low cost of launch (and the very high infrastructure costs) require high throughput handling with many automated inspection stages. It also means that missions will typically be assembled from many combined low-cost payloads in a construction orbit. Line 7: Line 7: == Cargo ==The vast bul === Cargo ===The vast majority of launches will be cargo: critical repair parts, supplies, and construction materials. Humans are launched after temporary accommodations are assembled by robots and thoroughly tested------.MoreLater=== Repair Parts ===Repair parts will be often be unplanned, urgent and survival-critical, and must be sent fast, anywhere, anytime. The quickest method to near-Earth destinations will be redundant multistage high performance liquid fuel rockets lofted at maximum loop velocity (11.5 km/s?), perhaps further accelerated into a [[FastHyperbolic | fast hyperbolic]] with an additional boost stage to perhaps 14 km/s while in the deep gravity well, then decelerated fast near arrival.MoreLater Line 11: Line 21: MoreLater---------== Acceleration Run ==For most of the acceleration run, the iron launch loop rotor is temporarily magnetized by coupling through the track windings to rhe field of the exciter magnets on the front of the launch sled, the first sled magnets encountered by the retrograde rotor as it passes under the vehicle. The velocity and acceleration profile is the same for every sled (with minor exceptions) and designed into the relative pitch of the rotor windings to the sled coupling windings. The winding pitch ratio is designed into the track, decreasing towards the launch release distance to the east, and is proportional to the velocity ratio:$${ { rotor~pitch } \over { sled~pitch } } ~=~ { { sled~velocity ~+~ rotor~velocity } \over { sled~velocity } }$$The sled moves towards the rotor, so the sled interaction zone moves at the $sled~velocity$ relative to the stationary track, and $sled~velocity ~+~ rotor~velocity$ relative to the "incoming" rotor.=== Initial Acceleration, Bypassing the Transformer Track Process ===Since the sled pitch (WAG 10 cm} and the rotor velocity {14 km/s} are fixed, the '''rotor pitch''' must be very long, longer than the sled, when the sled velocity is small near the start of the launch run. Also, the first test of the acceleration and the vehicle will verify that it can tolerate 30 m/s^2^ acceleration, and the end of that acceleration at vehicle release.==== Acceleration Test ====The first short section of track use direct magnetic acceleration from electronically synthesized currents in a few meters of track winding, not coupled directly to the rotor, while abundant telemetry measures the vehicle and its contents, generating gigabytes of images and sensor data that are rapidly compared frame-by-frame and millisecond-by-millisecond to pre-computed simulations for that particular sled and vehicle and cargo. If the reality and the simulation differ too much (perhaps too much free play in the cargo tiedowns), the vehicle and sled are quickly lifted off the track, and that particular mission is aborted until the next launch window. note: Synchronous orbit destinations are preferred, because the next launch window will be one sidereal day (86164 seconds, 23 hours 56 minutes 4 seconds) later for elliptical synchronous orbit destinations, and immediately for an antipodal geostationary destination.The first test might consist of a fast acceleration ramp from 0 to 30 m/s² over 1 second, followed by an acceleration reduction from 30m/s² to -30m/s² over the next second, followed by one second ramp from -30m/s² . The vehicle velocity peaks 1.5 seconds after startup at 22.5 m/s and 15 meters distance, and returns to zero 30 meters eastwards on the test track section. If the vehicle plus sled masses 7000 kg, the peak acceleration power is 31.5 MW at 1 second, and the peak kinetic energy is 1.77 megajoules at 1.5 seconds.||<)> time ||<)> acceleration ||<)> velocity ||<)> distance ||<)> power ||<)> energy ||||<)> sec ||<)> m/s² ||<)> m/s ||<)> m ||<)> MW ||<)> MJ ||||<)> 0.0 ||<)> 0 ||<)> 0.0 ||<)> 0 ||<)> 0.0 ||<)> 0.05 ||||<)> 0.5 ||<)> 15 ||<)> 3.75 ||<)> 0.6 ||<)> 0.39 ||<)> 1.77 ||||<)> 1.0 ||<)> 30 ||<)> 15.0 ||<)> 5 ||<)> 3.15 ||<)> 0.79 ||||<)> 1.5 ||<)> 0 ||<)> 22.5 ||<)> 15 ||<)> 0.0 ||<)> 1.77 ||||<)> 2.0 ||<)> -30 ||<)> 15.0 ||<)> 25 ||<)> -3.15 ||<)> 0.79 ||||<)> 2.5 ||<)> -15 ||<)> 3.75 ||<)> 29.4 ||<)> -0.39 ||<)> 0.05 ||||<)> 3.0 ||<)> 0 ||<)> 0.0 ||<)> 30 ||<)> 0.0 ||<)> 0.00 ||If the vehicle and sled fails the test, it is rapidly slid sideways on its test track section across the launch platform, and an alternate section of test track with a new vehicle slides into the test position.MoreLater - add a longitudinal rotation to simulate negative gee.==== First Acceleration, Electronically Synthesized Track Power ====The first four kilometers of the track are not coupled through transforming windings to the rotor

# Launch Sequence

Launch Loop vehicle rates will be very high, perhaps more often than one 5 tonne vehicle per minute. The very low cost of launch (and the very high infrastructure costs) require high throughput handling with many automated inspection stages. It also means that missions will typically be assembled from many combined low-cost payloads in a construction orbit.

### Cargo

The vast majority of launches will be cargo: critical repair parts, supplies, and construction materials. Humans are launched after temporary accommodations are assembled by robots and thoroughly tested

.

### Repair Parts

Repair parts will be often be unplanned, urgent and survival-critical, and must be sent fast, anywhere, anytime. The quickest method to near-Earth destinations will be redundant multistage high performance liquid fuel rockets lofted at maximum loop velocity (11.5 km/s?), perhaps further accelerated into a fast hyperbolic with an additional boost stage to perhaps 14 km/s while in the deep gravity well, then decelerated fast near arrival.

## Acceleration Run

For most of the acceleration run, the iron launch loop rotor is temporarily magnetized by coupling through the track windings to rhe field of the exciter magnets on the front of the launch sled, the first sled magnets encountered by the retrograde rotor as it passes under the vehicle. The velocity and acceleration profile is the same for every sled (with minor exceptions) and designed into the relative pitch of the rotor windings to the sled coupling windings. The winding pitch ratio is designed into the track, decreasing towards the launch release distance to the east, and is proportional to the velocity ratio:

{ { rotor~pitch } \over { sled~pitch } } ~=~ { { sled~velocity ~+~ rotor~velocity } \over { sled~velocity } }

The sled moves towards the rotor, so the sled interaction zone moves at the sled~velocity relative to the stationary track, and sled~velocity ~+~ rotor~velocity relative to the "incoming" rotor.

### Initial Acceleration, Bypassing the Transformer Track Process

Since the sled pitch (WAG 10 cm} and the rotor velocity {14 km/s} are fixed, the rotor pitch must be very long, longer than the sled, when the sled velocity is small near the start of the launch run. Also, the first test of the acceleration and the vehicle will verify that it can tolerate 30 m/s2 acceleration, and the end of that acceleration at vehicle release.

#### Acceleration Test

The first short section of track use direct magnetic acceleration from electronically synthesized currents in a few meters of track winding, not coupled directly to the rotor, while abundant telemetry measures the vehicle and its contents, generating gigabytes of images and sensor data that are rapidly compared frame-by-frame and millisecond-by-millisecond to pre-computed simulations for that particular sled and vehicle and cargo. If the reality and the simulation differ too much (perhaps too much free play in the cargo tiedowns), the vehicle and sled are quickly lifted off the track, and that particular mission is aborted until the next launch window.

• note: Synchronous orbit destinations are preferred, because the next launch window will be one sidereal day (86164 seconds, 23 hours 56 minutes 4 seconds) later for elliptical synchronous orbit destinations, and immediately for an antipodal geostationary destination.

The first test might consist of a fast acceleration ramp from 0 to 30 m/s² over 1 second, followed by an acceleration reduction from 30m/s² to -30m/s² over the next second, followed by one second ramp from -30m/s² . The vehicle velocity peaks 1.5 seconds after startup at 22.5 m/s and 15 meters distance, and returns to zero 30 meters eastwards on the test track section. If the vehicle plus sled masses 7000 kg, the peak acceleration power is 31.5 MW at 1 second, and the peak kinetic energy is 1.77 megajoules at 1.5 seconds.

 time acceleration velocity distance power energy sec m/s² m/s m MW MJ 0.0 0 0.0 0 0.0 0.05 0.5 15 3.75 0.6 0.39 1.77 1.0 30 15.0 5 3.15 0.79 1.5 0 22.5 15 0.0 1.77 2.0 -30 15.0 25 -3.15 0.79 2.5 -15 3.75 29.4 -0.39 0.05 3.0 0 0.0 30 0.0 0.00

If the vehicle and sled fails the test, it is rapidly slid sideways on its test track section across the launch platform, and an alternate section of test track with a new vehicle slides into the test position.

MoreLater - add a longitudinal rotation to simulate negative gee.

#### First Acceleration, Electronically Synthesized Track Power

The first four kilometers of the track are not coupled through transforming windings to the rotor

LaunchSequence (last edited 2021-01-28 18:43:41 by KeithLofstrom)