electromagnetic launch with microwave propulsion

SpaceNut · 2020-04-01 19:35:46

Take the rotary motor design and cut it in one location to bend it flat and you have a linear machine.

The linear machine applies power for the full length on each coil that is part of a phased system as a 3 phase would do. So count 1 ,2 ,3 and repeat the powering as the rocket moves from the ac being applied. The coils that are working will draw lots of current to push the mass along but the coils that are not doing anything are also getting power. The unloaded coil at that point looks like a resistive load to the power and drives up the wattage for it to make the rocket move up the launch ramp. To move faster and faster up the ramp we are applying more and more voltage with a fixed frequency and that makes the wattage go up as well.

Ok so lets look at turning off coils that are not in the active zone of moving behind and ahead for making that rocket mass move far off in front of it such as to lower the total wattage needed at any point in time as its moving.

I am sure that the alloy is a copper percentage mix with a bit of steel to make it magnetic. That rail slide needs to be strong enough to support the rockets mass as its moved up the ramp.

Lets make the ramp a tube that has the linear motor pusher at the top center of the tube and the air hockey table holes along the bottom. That will lesson the mass power wattage for the motor and would allow for a less drag launch system. Not sure if cooled air would work better but I think that it would as it will have a higher density to make the rocket lift off from the ramp so that it can fly up the tube quickly..

tahanson43206 · 2020-04-01 20:33:29

For SpaceNut re #151

Following up on the points included in this post, I found a Britannica article that includes them and expands a bit.

The article is about transport designs, but some of the concepts appear applicable to the launcher case:

https://www.britannica.com/technology/e … ion-motors

A linear induction motor provides linear force and motion rather than rotational torque. The shape and operation of a linear induction motor can be visualized as depicted in the figure by making a radial cut in a rotating induction machine and flattening it out. The result is a flat “stator,” or upper section, of iron laminations that carry a three-phase, multipole winding with conductors perpendicular to the direction of motion. The “rotor,” or lower section, could consist of iron laminations and a squirrel-cage winding but more normally consists of a continuous copper or aluminum sheet placed over a solid or laminated iron backing.

In an alternative arrangement for vehicle propulsion, the copper and iron sheets of the figure can be placed on the underside of the vehicle and sections of stator can be placed at intervals along the track. This has the advantage that no electric power need be supplied to the vehicle itself.

The quote immediately above is very similar to the concept under discussion here.

One element of the discussion I'd like to toss into the mix now is that the metal plate used for acceleration by the EML need NOT be slowed down after the launch for reuse at the launcher. It can simply be permanently welded to the body of the vehicle, and delivered to the customer site with as much of the material as has survived the rigors of launch and passage through the atmosphere. Any material left would be valuable in the context of an on-orbit construction site. That would be highly refined material, suitable for immediate use (if still intact) or suitable for deferred use after smelting on orbit to make required shapes.

In an earlier post, I made a point which I'd like to repeat ... There is no reason to use only ONE keel blade. There can be as many as four, at 90 degree intervals around the body of the cargo vehicle. The forces of acceleration will thus be distributed more evenly over the vehicle structure, and the linear motors can each operate at 1/4th the power levels that would be required for a single keel blade.

Re #151 last paragraph ... putting the linear motor at the top of the tube is an interesting idea. It is a significant variation from the default of having the motor underneath the vehicle. Gravity will be hard at work on Earth, pulling the 3 Metric tons of the vehicle onto the surface of the launch track.

The transport train patent idea mentioned in a recent earlier post envisioned using air lift to carry a fully loaded train, so (I deduce) the inventors must have thought that a multi-ton vehicle could be supported by such a method.

(th)

SpaceNut · 2020-04-02 09:19:35

At first when I saw this I got a good laugh until I realised that placing the payload rocket into the fuesalage or cabin area that we had solved to ramps rolling mass issue. That makes it simular to a shuttle Z bay launching.
BB123HPC.img?h=194&w=300&m=6&q=60&u=t&o=t&l=f

Yes its a learjet plane turned into a limousine....

That means changing the engines to make them a scramjet and providing auto pilot return to a runway is an easy alteration to make.

tahanson43206 · 2020-04-02 10:15:20

For SpaceNut re #153

Impressive custom work! Should do well on the television series about customized cars, if it were selected, and if that series still exists! Haven't seen it for a while.

***
This post is offered as a search point for study of the US Navy ELM deployed on the Gerald R. Ford.

https://en.wikipedia.org/wiki/Aircraft_catapult

The size and manpower requirements of steam catapults place limits on their capabilities. A newer approach is the Electromagnetic Aircraft Launch System (EMALS). Electromagnetic catapults place less stress on the aircraft and offer more control during the launch by allowing gradual and continual acceleration. Electromagnetic catapults are also expected to require significantly less maintenance through the use of solid state components.[18]
Linear induction motors have been experimented with before, such as Westinghouse's Electropult system in 1945.[19] However, at the beginning of the 21st century, navies again started experimenting with catapults powered by linear induction motors and electromagnets. EMALs would be more energy efficient on nuclear-powered aircraft carriers and would alleviate some of the dangers posed by using pressurized steam. On gas-turbine powered ships, an electromagnetic catapult would eliminate the need for a separate steam boiler for generating catapult steam. The U.S. Navy's upcoming Gerald R. Ford-class aircraft carriers includes electromagnetic catapults in its design.[20]

https://en.wikipedia.org/wiki/Electroma … nch_System

Linear induction motor
The EMALS uses a linear induction motor (LIM), which uses electric currents to generate magnetic fields that propel a carriage along a track to launch the aircraft.[6] The EMALS consists of four main elements:[7] The linear induction motor consists of a row of stator coils with the same function as the circular stator coils in a conventional induction motor. When energized, the motor accelerates the carriage along the track. Only the section of the coils surrounding the carriage is energized at any given time, thereby minimizing reactive losses. The EMALS' 300-foot (91 m) LIM will accelerate a 100,000-pound (45,000 kg) aircraft to 130 kn (240 km/h; 150 mph).[6]

The Wiki article provides plenty of References for study: In particular, #8 covers Electronmagnetic Launchers.

SearchTerm:ELMALS
SearchTerm:USNavy
SearchTerm:Catapult

(th)

kbd512 · 2020-04-02 12:16:41

SpaceNut,

Is that a "Learmousine"?

tahanson43206 · 2020-04-02 12:21:45

This is a follow up to Post #154, which records Wikipedia information about the US Navy electromagnetic catapult system ...

2020/04/02 Physics 101 EML Study

The focus of this post is the US Navy Electromagnetic Catapult

From Wikipedia, we are given:

Velocity of aircraft at conclusion of acceleration: 240 km/hr 66 2/3 meters per second
Mass of aircraft: 45,000 Kg
Length of catapult: 91 meters

The numbers to be derived are:

Time in seconds:
Acceleration in Meters per Second Squared
G Force (above / 9.8)

Using Physics 101 to find Acceleration:

Initial velocity: Zero
Distance: 91 meters
Seek: Final velocity: 66.67 meters per second
Derive Acceleration: 24.45 meters per second squared
Derive G force (Divide by 9.8): 2.5 G's

Those figures represent the state of the art for a passenger launcher, in 2020.

Adjustments of the input parameters are possible, if there are updates available from other sources.

However, it is likely the input values shown are close to whatever the actual values are.

(th)

SpaceNut · 2020-04-02 13:56:18

Was reminded of the Sabre reaction engine that is still being work as another optional avenue for how to get to space with this system....

https://snebulos.mit.edu/projects/refer … _Guide.pdf

As for the ramp distance and exit speed there is a compromise to be had for moving larger mass as a result of the slow start.

We know that we can solve to a number but building of a design to achieve the numbers are the problem.

To give aid for lauch lets work to a solution by adding up the numbers in reverse order to what we want to have for a payload in orbit.
1. payload initial perfecting amount of increase later
2. payload fairing of shroud protection mass with thrusters, power source ect to make it dockable and able to station keep while we wait to have it bring its cargo to the ship that is using it.
3. stage for boost finish and circularization
4. boost stage after initial launch from catapult

the stage and boost have mass that are dependant on the fuel, engine capability, mass to achieve speed duration

edit
Fairing information

https://ntrs.nasa.gov/archive/nasa/casi … 009204.pdf

https://www.ruag.com/en/products-servic … /launchers

RUAG Space fairings are built in composite technology based on aluminum honeycomb cores with carbon fiber reinforced plastic face sheets. This construction method allows the combination of low mass with high stiffness.
Key Data Ariane 5    Atlas V-500    Vega
Diameter    5.4 m    5.4 m    2.6 m
Height    17 m (long version) 20.7 / 23.4 / 26.5 m 7.8 m
Mass    2’400 kg 4’100 / 4’700 / 5’200 kg 400 kg
The ISA 400 Interstage Adapter forms the link between the booster stage and the upper stage of the Atlas V-400 rocket. It is a nearly cylindrical structure with a diameter between 3.80 m at the bottom and 3.00 m at the top and a height of 4.20 m, which surrounds the engine of the Centaur upper stage during the first flight phase. The structure of the Interstage Adapter comprises an aluminium honeycomb core with carbon fibre face sheets, a design that allows the weight of the entire Interstage Adapter to be kept to around 730 kg while still enabling it to withstand the enormous loads encountered during launch. An insulation of cork is used to protect the interior of the adapter from the high temperatures produced by atmospheric friction during flight.

https://www.spaceflightnow.com/falcon9/001/f9guide.pdf

https://ntrs.nasa.gov/archive/nasa/casi … 009204.pdf
COMPOSITE PAYLOAD FAIRING STRUCTURAL ARCHITECTURE ASSESSMENT AND SELECTION

https://www.lockheedmartin.com/content/ … 0sheet.pdf
MA-25S® Ablative Material is a medium density, room temperature curing, ablator/insulator, which has been used extensively for thermal protection on aircraft and space launch vehicles.

tahanson43206 · 2020-04-02 14:31:10

This is a continuation from Post #156

For SpaceNut re #157 ... Your recollection of Sabre is interesting in light of the results I'll be posting below.

I went back to Physics 101 and asked for a prediction of how fast a vehicle would be moving if it is accelerated at 2.5 G's over various distances.

Edit#1: This post has been updated to show Earth LEO, Earth Escape, Lunar Escape and Mars Escape.

Please keep in mind that the STATE OF THE ART on Earth, for electromagnetic acceleration of a passenger carrying vehicle is 2.5 G's.

For anyone who has not been reading the topic, 2.5 G's is the acceleration delivered by the US Navy catapult on the Gerald R. Ford.

Physics 101 Session to compute velocity at 2.5 G

Starting at a velocity of Zero, and accelerating at 2.5 G:

Distance Velocity in Meters/Second Velocity in km/hour Velocity in Miles Distance in Miles

1000 meters 221+ = 795+    494+ .621+
2000 meters 313+ = 1126+    700+ 1.24+
3000 meters 383+ = 1378+    856+ 1.86+

10000 meters 700 even = 2520 1565+ 6.21+

20000 meters 989+ = 3560 2212+ 12.4+

30000 meters 1212+ = 4363+ 2711+ 18.6+

40000 meters 1400 even = 5040 3131+ 24.8+

50000 meters 1565+ = 5634 3500+ 31+

Updated 2020/04/03 to include Orbital and Escape velocities:

1840000 meters 9495+ = 34182 21240+ 1143+

3350000 meters 12812+ = 46123+ 28660+ 2081+

Updated 2020/04/04 to include Lunar and Martian Escape velocities:

Lunar Escape Velocity is given as 2.38 km/s (per Google)

115600 meters 2380 even = 8568 5324+ 71+

Martian Escape Velocity is given as 4.25 km/s (per Google)

370000 meters 4257+ = 15325+ 9522+ 229+

SearchTerm:Physics101

(th)

Last edited by tahanson43206 (2020-04-04 13:11:59)

tahanson43206 · 2020-04-03 12:26:51

This is a follow up to the table of velocities available from an EML that operates at 2.5 G's, in Post 158

The track length that looks most interesting to me, is the one that is shown at 2000 meters. That track would deliver a vehicle at just under the speed of sound at sea level. A track that length could be located most anywhere on Earth.

The next step up that I find of particular interest is the one at 10000 meters. The vehicle would break the sound barrier while still accelerating, which is a problem for the neighbors, but it would deliver a vehicle at the velocity which should be sufficient to give an ordinary ram jet the air flow it needs for continued operation and subsequent acceleration per the 2009 NASA plan as shown by kbd512 in Post #5 of this topic.

Edit#1: It would be quite interesting to know if the flight characteristics of the SABRE vehicle would be improved by starting at just under Mach 1.

As I understand the goal of that design effort, it is to achieve a single stage to orbit capability. Launching from an EML might be cheating a bit, but if the goal is achieved, and a modest payload (such as a passenger) is safely delivered to orbit, then perhaps the departure from "pure" SSTO can be excused.

(th)

Last edited by tahanson43206 (2020-04-03 12:30:11)

SpaceNut · 2020-04-03 12:36:14

One issue that GW identified is the low angle of launch in that the cutting drag of going through the dense atmosphere is time dependant effort that slows the initial velocity with the seconds ticking by. Its the firing of the scram jet or other engines that when coupled with the ascent angle change which gets that bang for the buck with a carrier plane cradled rocket to bring it upward towards the thinning atmosphere which is ahead for the rocket to be deployed at before the rocket finally fires to finish its trip towards orbit.

Edit
just adding in the escape velocity formular page
https://softschools.com/formulas/physic … ormula/90/

The escape velocity from Earth is 11,184 m/s, or approximately 11.2km/s.

https://softschools.com/formulas/physic … ormula/76/

The velocity of this orbit depends on the distance from the object to the center of the Earth.

g-Acceleration Calculator - Linear Motion

tahanson43206 · 2020-04-04 13:22:36

Post #158 has been updated to show:

Earth LEO

Earth Escape

Lunar Escape

Mars Escape

Lunar Escape is most likely to be seriously considered in the near term (decades) because the distance to be covered is feasible with existing technology.

The acceleration of 2.5 G's would be acceptable for passenger traffic, and the US Navy Catapult model could (presumably) be used "as is" to launch full sized vehicles (ie, 24,000 Kg). The absence of air is a plus, and the availability of abundant sunlight during the lunar "day" would/should be sufficient to provide power.

The situation for Mars is less convincing (to me at least).

It ** is ** imaginable to build a straight track up the side of Mount Olympus, but at this point I don't know if a laser straight path can be excavated on the slope so that a launch would head straight for Phobos. That would be ideal if it is feasible.

Launch from the surface of the Earth appears to be limited to giving a hybrid vehicle a healthy subsonic start.

(th)

tahanson43206 · 2020-04-05 05:20:13

This is a follow up to #161

For kbd512 .... this is your topic ... what do you think is needed next, to move the topic forward?

For SpaceNut ... in the past when I asked about creating dedicated topics for specific projects, you requested more work be done. What additional information do you think is needed?

I'd be interested in seeing task forces started up (depending upon finding volunteers willing to work them):

1) Texas Passenger/Freight launcher to follow kbd512's original citation of the 2009 NASA design
2) Northern Mexico the same
3) Puerto Rico the same
4) Malasia the same

5) Lunar Passenger/Freight launcher to achieve Escape velocity with a 17 mile 2.5 G run

6) Investigation of higher G capability

The 2.5 G figure is derived from the stated performance of the US Navy EML installed on the Gerald R. Ford

That launcher may have been designed to meeting the requirements of the customer, and it may not reflect what is possible.

I have seen reports that rail gun technology is in test by the US Navy, with deliverable velocities (and G force) far greater than the carrier example.

Higher G force is a requirement to achieve a practical SSTO launcher on Earth.

(th)

Last edited by tahanson43206 (2020-04-05 06:33:47)

tahanson43206 · 2020-04-05 12:43:03

In another topic, it has been noted that a 71 mile long EML based upon the US Navy catapult on the Gerald R Ford is capable of providing a smooth launch to Lunar Escape velocity at an acceleration of 2.5 G's. The 2.5 G's figure comes from reports of the performance of the carrier catapult. By the time an effort were made to actually build a lunar EML, better performance may be possible.

It was noted that Lunar dust may be a problem for both construction and operation of such a launcher. A suggestion was given to sinter the regolith, and indeed, it turns out that serious attention has been given to that idea.

However, after reading the article at the link below, I no longer think the track can be installed out in the open on the Moon. Instead, it seems reasonable to imagine that the entire 71 miles would have to be enclosed in a shelter of some kind.

In another topic (yet again) it has been proposed to wrap an asteroid in basalt thread, and it was then proposed to mine the needed basalt on the Moon, where the material is abundant in selected regions.

Thus, the possibility of making a shelter fabric of basalt thread comes into view.

(th)

Last edited by tahanson43206 (2020-04-05 12:49:38)

tahanson43206 · 2020-04-05 14:51:30

The working example of an electric (electromagnetic) launcher at the heart of this topic is the one installed and working on the Gerald R. Ford.

The Electromagnetic Aircraft Launch System (EMALS) is a type of aircraft launching system developed by General Atomics for the United States Navy.
Electromagnetic Aircraft Launch System - Wikipedia

Edit#1: http://www.ga.com/general-atomics-emals … 8-aircraft

This is a very recent update on the status of the catapult.

In another article I noticed in the search for this one, I noticed that General Atomics secured a contract for repair of the catapult.

This next item is more of a comment upon a reporter's lack of knowledge than it is about the Chinese effort to duplicate or replicate the Ford catapult.

The article reporting on their intentions said they plan to use "capacitors" rather than a nuclear reactor to power the launcher.

Someone at the responsible organization should have caught that, but obviously no one there knew the difference either.

(th)

Last edited by tahanson43206 (2020-04-05 14:58:15)

kbd512 · 2020-04-05 17:26:21

tahanson43206,

We need to decide what the payload mass will be and what the final launch velocity will be. The combination of those two things determines the power requirement for the launch track, what aerodynamic and thermal loads will be (vehicle structures mass fraction), and what the the vehicle structure plus propellant mass will be. If you're dead set on a subsonic launch, then the booster mass becomes much more significant and the power requirements for the launch facility go up.

Let's use 1,000kg as the payload mass. It's a nice round number that happens to cover most satellites going to LEO or transfers to higher orbits. If we commit to subsonic launch with a 10g acceleration limit, then most of our satellites as well as raw materials to construct larger ships could be delivered via this method. At 10g, pretty much all aerospace electronics are quite happy. I think we should consider LOX/RP-1 or LOX/LCH4 propulsion and turbo pump bleed pressurization of the propellant tanks (no liquid Nitrogen or Helium pressurants).

For the first iterative design, let's stick with pure rocket propulsion. Rockets are very well proven propulsion technology that do not require substantial development to power hypersonic vehicles. Perhaps we could invoke the better sea level to high altitude specific impulse performance of aerospike nozzles for the booster only. We can also invoke battery powered turbo pumps to suck the propellant tanks dry, so nearly all of the propellant mass fraction is usable.

d= distance
t = time
Vf = final velocity
Vi = initial velocity
a = acceleration rate

Let's use 750mph / 335m/s as our final exit velocity from the launch track. From a dead stop, that means our acceleration time is 3.418 seconds.

t = (Vf - Vi) / a
t = (335m/s - 0m/s) / 98m/s^2
t = 3.418 seconds

Now let's figure out the minimum length for the track:

d = (Vi * t) + ((at^2)/2)

Vi = 0, so d = ((at^2)/2)

d = (98m/s^2 * 3.418s^2) / 2

d = (98 * 11.685) / 2

d = 572.577m

I believe that was correctly calculated, but someone with more letters behind their name is welcome to check.

So, our horizontal track is 1,878 feet, or slightly less than the length of 2 aircraft carriers. Let's call it the length of 2 aircraft carriers for sake of having some extra distance incorporated for a lower initial acceleration rate, one of the EMALS advantages over steam catapults, and a length of track with a ramp to ensure that the trajectory of the booster / orbital vehicle stack gains some altitude after separation, even if the rocket engine fails to ignite- basically, lofting the stack into the ocean and at least providing a chance for aerodynamic controls to determine where it ends up upon engine ignition failure. Alternatively, we could have another length of track the same distance in which to bring the vehicle to a halt.

The only way I'd consider putting a nuclear reactor onsite was if that reactor would also supply a nearby city. Daylight operations only would allow for normal work days and for repair or cleaning activities to occur at night. I'm not opposed to the idea of using super capacitors, but flywheels would require far less electrical and electronic infrastructure (computerized control over that many banks of super capacitors is not so simple) and are less costly than super capacitors. Aluminum flywheels are also easily recyclable in the event of a failure, whereas super caps are not.

SpaceNut · 2020-04-05 18:43:08

The calculations for launch are fine and the orbital speed that we desire is based on the circular atltitude that we are trying to place that payload at for the rockets final speed that we need. Since escape is 11.2km/s we will be traveling something less than that for the orbits that we want the payload at. The same calculator can be used to see how much more speed is needed to get the rocket the remaining way to orbit.

edit
The final portion of the rocket once the carrier is removed is a mass momentum equation for each stage that burns and is then dropped off to return to earth for reuse. The key to the momentum is the duration of thrust from burn to acceleration for the mass before its exhausted and what remains to transfer that momentum to.

kbd512 · 2020-04-05 19:24:11

SpaceNut,

We need around 9.5km/s of dV capability between the booster and upper stage, although at this point we've nearly entirely negated the utility of this new proposed system in terms of propellant economy, which is why nobody would ever build something such as this. There's no point. Shaving 335m/s off the dV requirement does almost nothing at all, which is why subsonic stratospheric air launch was abandoned. We still have to supply nearly all of the dV and now we're taking a sub-optimal ascent trajectory through the thickest part of the atmosphere. It's a fun thought exercise, but that's really about it.

Our meager 1,000kg payload could easily be lofted into orbit by StratoLaunch using a conventional rocket the same size or smaller. Any dV gains we made with electromagnetic launch are negated by the atmospheric drag reduction and specific impulse gain from starting 40,000 feet up- where the air density is less than 1/3rd that at sea level. As a result, insisting upon a subsonic launch has removed all of the desired benefits from this system and the math regarding the remaining propellant requirement to achieve orbit will demonstrate that. Now we've arrived at where those sling-a-tron launcher people are at. If you can't achieve a significant fraction of the dV increment required to achieve orbital velocity with your launcher, then you may as well just use a conventional rocket, which is what all companies in the launch services business have elected to do. There's nothing wrong with doing that, but no average Joe will ever be going to Mars with the associated fuel bills being what they are for conventional rockets.

SpaceNut · 2020-04-05 20:21:10

I think the real trick is to solve how to get speed while making the parts reuseable with quick inspection and refueling for the next use. Thats how we get scale of economy by multiple trips. I think multiple stages that are basically stacked planes get there but keeping the mass down on each is the issue for the launch system.
I am reminded of the sli stack up...

Getting rockets into space

The official beginning of space is 100 km above the Earth’s surface. The gases that make up the Earth’s atmosphere thin out rapidly as height increases. If you were in a rocket travelling upwards, at a height of 11 km, you would have passed 77.5% of the Earth’s atmosphere. At 31 km, you would have passed 99%. At this height, you would see the blackness of space above you rather than the blue of the sky.

https://en.wikipedia.org/wiki/Air_launch_to_orbit

We can lower the cost of a plane that is huge in size by changing the starting configuration.

https://www.grc.nasa.gov/WWW/k-12/rocket/rktrflght.html

https://wiki.kerbalspaceprogram.com/wik … into_Orbit

https://www.quickanddirtytips.com/educa … s-to-space

edit
atmpheric drag equations
https://www.grc.nasa.gov/WWW/k-12/rocket/drageq.html

flight plus drag
https://www.grc.nasa.gov/WWW/k-12/rocket/flteqs.html

https://orbitalaspirations.blogspot.com … ckets.html

https://ocw.mit.edu/courses/aeronautics … 2_lec1.pdf

https://earthweb.ess.washington.edu/spa … namics.pdf

tahanson43206 · 2020-04-06 05:18:51

Continue Post #165

Paragraph 1: Givens for Post

Paragraph 2: Givens for Post

Paragraph 3: Givens for Post

Paragraph 4: Given for Post plus calculation

Note that in this post, G is rounded down to 9.8 meters per second squared

Note that in this post, 750 mph is rounded down to 335 meters per second

Calculation: 3.418 seconds found. Match.

Note that with a value for G of 9.81 meters per second squared, time is 3.415 seconds

Calculation of track length:

Using 0 – 572.577 – 98 Velocity is 335. Match.

Paragraph 5 … the results appear to be correct given rounding as shown.

Paragraph 6 …

Ramp: SpaceNut will probably approve of the ramp

The angle of the ramp was left as an exercise for the reader.

I'll offer 45 degrees for the next calculation:

According to Physics 101, the range of a projectile fired at 45 degrees at a velocity of 335 meters per second is 11451 meters or just over 7 miles, given a planetary gravitational field of 9.8 meters per second squared. A vehicle which failed to ignite engines would go into the ocean, if the facility is located near the shore of one.

Paragraph 7:

Nuclear reactor power vs some other power source:

This is a customer option. The project designer can make a recommendation, but ultimately the entity that pays the bills will decide how best to allocate their resources.

Capacitors vs rotating mass:

Here the proven experience of the proven and working example would appear to be a useful guide to how to proceed.

The metal of which the existing rotors were fabricated may be aluminum.

A reference for this explicit material would be helpful.

(th)

Last edited by tahanson43206 (2020-04-06 11:01:51)

tahanson43206 · 2020-04-06 09:43:32

2020/04/06 Continue 167

What I have in mind for this post is to examine the prediction that the meters per second momentum imparted by an EML would not be significant.

I am imagining a three stage launch, similar to the one NASA envisioned in 2009, with a couple of adjustments.

The first and third stages of the NASA plan are retained in this post.

The middle stage is the one I'm thinking about here.

A Falcon 9 second stage is traveling at a velocity and in a direction that will allow it to reach LEO by running as a rocket for a while.

The velocity and direction of a Falcon 9 stage differs from one mission to the next, but all are reported to have been in the range of:

Velocity between X and Y <<== values to be added

Direction between Vertical and Horizontal <<== values to be added

Mass of Falcon 9 Second Stage at MECO/Stage separation: <<== value to be added

My vision is of a vehicle that uses jet engines (not ram jets) to take advantage of the abundance of oxygen in the lower atmosphere, and to complete its trajectory as a pure rocket.

This vehicle would be equipped with wings, and it would fly back to base instead of landing vertically.

This vehicle would be equipped with outriggers that would engage with the EML. Note that there is no reason why an EML has to have just one drive track.

A heavy vehicle could have as many EML tracks as make sense.

The metal plates engaged by the linear motor windings would be a permanent part of the aircraft structure. These could be expected to degrade with use due to heating and the rigors of flight, so they would be replaceable. This design would eliminate the need for a separate sled that currently engages with a fighter aircraft on an aircraft carrier. There would therefore be no need to slow the sled after acceleration, since the metal plates would fly out with the aircraft.

The vehicle itself would be supported by wheels, just as fighter aircraft on an aircraft carrier are supported now.

(th)

Last edited by tahanson43206 (2020-04-06 11:09:01)

tahanson43206 · 2020-04-06 12:04:18

Updates were applied to posts 169 and 170.

In addition, I submitted a request for publicly available information about EMALS to the Information Contact form of the General Atomics web site.

Edit#1: This link has probably been posted before in the forum, but it is so helpful for study of EML that I decided to post it again:

https://www.explainthatstuff.com/linearmotor.html

SearchTerm:EMLNASA
SearchTerm:NASAEML

(th)

Last edited by tahanson43206 (2020-04-06 18:10:10)

SpaceNut · 2020-04-06 22:35:00

I was looking at the rockets and launch G forces that can be present. The lighter mass payloads would see higher g forces for each rocket that we have been meantioning.
https://space.stackexchange.com/questio … hers-cause
https://www.quora.com/How-many-Gs-of-ac … ion-to-LEO

I think the limit of the 10g eml launch could be more like 15g which would improve the launch speed of course it appears that missles are even higher but to make best use of that we need is a low mass carrier that can get the main rocket to that mach 5 speed in short order.

edit
Adding in other related topics:
Magnetic Rifle? - Earth Based Rail Gun...?
Mass Drivers on Mars - "Space gun" to shoot stuff to Earth???
Mass Drivers
Magnetic Launching Points
Elastic Launch Loop (Space Elevator)
Space Elevator or Scramjet?

kbd512 · 2020-04-06 22:59:20

SpaceNut,

Acceleration certainly could be higher, but once you go much beyond 10g you're now in the realm of missile electronics rather than fighter jet electronics.

tahanson43206 · 2020-04-07 13:38:26

The links given below are about the Falcon 9.

I'm posting them here because I am interested in the status of the second stage of Falcon 9 at MECO.

The original NASA paper from 2009, cited by kbd512 in Post #5, imagined an EML "first stage" followed by a ram jet "second stage" followed by a rocket third stage.

While topic manager kbd512 recently suggested 1 Metric ton of payload for a practical system to compete in the existing market place, I am interested in seeing what an EML/air breathing first and second stage might look like if the third stage is an off-the-shelf Falcon 9 second stage.

The information I've been able to collect so far is limited to altitude of MECO, and velocity.

If anyone knows of mass of the vehicle at MECO, I'd appreciate addition of that information to the topic. It is that mass that a competitive system would have to deliver. The cost of the competitive system would have to at least match that of the reusable Falcon 9 first stage booster, AND achieve the same order of reusability. An EML-air-rocket substitute for the Falcon 9 first stage could have a number of competitive advantages.

First of all, it would be MUCH quieter. Second of all, it could achieve airline-like reusability, because the EML and the carrier vehicle would be reusable with no more than "normal" airliner inspection/service between flights.

https://www.nasa.gov/sites/default/file … sKit-2.pdf

At this point, Falcon 9 is 80 kilometers (50 miles) high, traveling at 10 times the speed of sound.

https://forum.nasaspaceflight.com/index … c=40983.20

The thread at the link above contains some graphics computations by a German contributor, and a number of comments about the flight of a Falcon 9.

(th)

Last edited by tahanson43206 (2020-04-07 13:44:31)

SpaceNut · 2020-04-07 16:23:33

edit: tahanson43206 for post 174 Information on post your for falcon 9...

The falcon 9 second stage and remaining top of that for payload delivery are beyond the capability of the eml launching system.

https://en.wikipedia.org/wiki/Falcon_9

https://sma.nasa.gov/LaunchVehicle/asse … -sheet.pdf

not sure why you add that into your post....

edit 2
https://infogalactic.com/info/Falcon_9_Air
was the air launch of a small falcon 9 Payload to low Earth orbit was projected to be 6,100 kg (13,400 pounds) but did not happen

edi3
rockets are mass and velocity changing device that start at rest or at some initial velocity as in air launch, with the catapult mimicking air launch to a degree.
We are talking about momentum and how we make that change to gain orbital speed for a given mass.

https://www.calculatorsoup.com/calculat … mentum.php

http://libvolume6.xyz/mechanical/btech/ … ation1.pdf

MASS, MOMENTUM , AND ENERGY EQUATIONS

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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Re: electromagnetic launch with microwave propulsion

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