SpaceX and space-relevant hyperloop updates and discussion thread

[JasonAW3]

The Hyperloop idea can be built on existing interstate highway mediums or along the sides.

How would you like to go around a corner designed for 55mph, at 550mph?  Remember, g-forces go up with velocity squared.

EDIT:  Just looked it up.  Highway curves are generally designed for a g-load of 0.28g.  So, at 10 times the velocity, that's 28g's.  Hmmm.....don't think so.

Most highways are built as straight as possible to minimize transit time between cities.  Those areas that would require turns, would most likely drift off to either side of the highway, into the right of way, to minimize the G loads.  Those areas where they couldn't reduce the curve and the G load, would require purchase of right of way areas as needed.  As the foot print of the Hyperloop pylons would be rather small, most likely the land use in the right of ways would not be interupted, except for maintenance or repair purposes.

      In most cases, as the Hyperloop system will likely have solar panels covering the upper surface, to both shade the tubes from excessive sun and weather, as well as generate power, there will be enough excess power generated locally that local land owners would likely be allowed to share in part of this excess, as part of the right of way agreement.

     The main issues I have with this system is that it would most likely require a series of powered superconducting electromagnets for the suspense of the cars.  While the air cushion idea first presented by Elon looks good on paper, mass issues could prove problematic.  However, on the otherhand, inductive recharging of the Hyperloop train's batteries from the solar panels mounted on top of the tubes, could proviode sufficent power to compensate for excess mass contingencies.

     Overall, I see a number of ways that this system could be made to work, but I also see a number of issues that would need to be addressed in order to ensure its functionality.

     In regards to its potentile use in space flight; the similarities that this has to guns introduced in Germany during WWII and another gun built for the Iraquis, are not entirely lost on me.  Creating a sufficently long hyperloop tube, with the end point sufficently elevated, the system, as described, could be used as a primary booster to place payloads into orbit, as a fraction of the current fuel requirements.  Note that this would also allow more robust upper stages which could be recovered and reused multiple times.

[Lee Jay]

The Hyperloop idea can be built on existing interstate highway mediums or along the sides.

How would you like to go around a corner designed for 55mph, at 550mph?  Remember, g-forces go up with velocity squared.

EDIT:  Just looked it up.  Highway curves are generally designed for a g-load of 0.28g.  So, at 10 times the velocity, that's 28g's.  Hmmm.....don't think so.

Most highways are built as straight as possible to minimize transit time between cities.  Those areas that would require turns, would most likely drift off to either side of the highway, into the right of way, to minimize the G loads.  Those areas where they couldn't reduce the curve and the G load, would require purchase of right of way areas as needed.  As the foot print of the Hyperloop pylons would be rather small, most likely the land use in the right of ways would not be interupted, except for maintenance or repair purposes.

I think you're dramatically underestimating the difficulty of obtaining rights-of-way, and how curvy even main roads are.  Take 101 from LA to SF.  Have a look a this one spot between them:

https://goo.gl/maps/sWO90

[llanitedave]

The interstate highway system was designed in the 1950's for 90 mph, not 55 mph.  The corners could be cut via crossing the road.  Also, If you are going between towns in the East, one wouldn't go 700mph, but probably 200-300mph.  Popular science had some ideas in the early 1970's for 300 mph elevated trains along the interstate system.  In the real world, It would not replace planes, nor automobiles.  We have a speed-transportation-time gap between 70 mph and 600mph taking longer than 2 hours, so 300 mph would be right in the middle.  It would fill the gap that puddle hopper planes fill now.  At least that is the way I see it.  Yes, across the plains states or desert, 600 mph is possible, but we have too many people who drive all day between cities that are 200-300 miles away for business trips, thus the interstate highway system is full of vehicles.  I drove 150 miles for many many business trips from where I was located to a larger city where the meetings were held.  Took me 2-1/2-3 hours each way, depending on traffic.  I see hyperloop as a gap filler, not replacing planes for trips taking longer than two hours.  I could have taken this trip in 30-45 minutes with a hyperloop.  I worked normally 8-5 with an hour for lunch.  Meetings were 9am and usually lasted to 3 or 4pm.  So, I had to leave home at about 6am, and get home round 7pm.  That was for a long day.  With a hyperloop, I could have stayed within my normal 8-5pm.

Wouldn't matter, if you're going to spend two hours being strip-searched by the TSA before the train leaves the station, and sit packed like cattle during the trip, you're still better off driving.

[Oli]

The Hyperloop idea can be built on existing interstate highway mediums or along the sides.

How would you like to go around a corner designed for 55mph, at 550mph?  Remember, g-forces go up with velocity squared.

EDIT:  Just looked it up.  Highway curves are generally designed for a g-load of 0.28g.  So, at 10 times the velocity, that's 28g's.  Hmmm.....don't think so.

The biggest competitive advantage trains have, in my opinion, is comfort. There is little lateral acceleration and the ride is smooth. I take the train because I can actually use the travel time productively.

If you want to keep that comfort that means the faster you go, the straighter the track must be.

Now with hyperloop you cannot even look ahead, as you can when you drive a car, so it must be a vomit comet indeed, especially at those speeds. At least if you do not make the tracks straight as a ruler.

 

[Hotblack Desiato]

In regards to its potentile use in space flight; the similarities that this has to guns introduced in Germany during WWII and another gun built for the Iraquis, are not entirely lost on me

There were the cannons Dora and Gustav.

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



800mm and 1000mm kaliber, accellerated the projectiles to  up to 1 km/s, a 4-7mt weight.

I'm not entirely sure how this beast is going to be used as an accellerator for hyperloop or a spacelaunching-hyperloop based system, as the g-forces are way too high, and the cannon pipe was not able to endure even the 100 shots it was built for.

regarding train transportation (but it's getting a bit off topic):

The interstate highway system was designed in the 1950's for 90 mph, not 55 mph.  The corners could be cut via crossing the road.  Also, If you are going between towns in the East, one wouldn't go 700mph, but probably 200-300mph.  Popular science had some ideas in the early 1970's for 300 mph elevated trains along the interstate system.  In the real world, It would not replace planes, nor automobiles.  We have a speed-transportation-time gap between 70 mph and 600mph taking longer than 2 hours, so 300 mph would be right in the middle.  It would fill the gap that puddle hopper planes fill now.  At least that is the way I see it.  Yes, across the plains states or desert, 600 mph is possible, but we have too many people who drive all day between cities that are 200-300 miles away for business trips, thus the interstate highway system is full of vehicles.  I drove 150 miles for many many business trips from where I was located to a larger city where the meetings were held.  Took me 2-1/2-3 hours each way, depending on traffic.  I see hyperloop as a gap filler, not replacing planes for trips taking longer than two hours.  I could have taken this trip in 30-45 minutes with a hyperloop.  I worked normally 8-5 with an hour for lunch.  Meetings were 9am and usually lasted to 3 or 4pm.  So, I had to leave home at about 6am, and get home round 7pm.  That was for a long day.  With a hyperloop, I could have stayed within my normal 8-5pm. 

In european cities, the rail transportation has one big advantage: railway-stations are in the center of the city. Look at cologne, the station is right next to the dome in the very center of the city. Same applies to munich, vienna, paris, london and so on. Nowadays it would be immensely expensive to tear down buildings to create a track for a railway, but 100-150 years ago, that was no problem (because either the major could just decide to do so, or the are was still unoccupied back then). I guess, the french and german networks are the best example for that. They operate at 300-400 km/h, are relatively cheap and provide direct links between cities.

Would be interesting how a train-based system would work on mars. Thin atmosphere, no neighbors who complain about noise, they could easily travel at 400-500km/s with classic rail-systems, reducing the time people are exposed to the surface radiation (I know, that isn't much, but reducing exposure time is always a good idea).

[spacenut]

Again, from what I have seen, a hyperloop car has minimum capacity.  It is not a train, more like a van.  Therefore people might not be "stripsearched" like they are at an airport.  A bomb on a hyperloop car will affect a minimum of people and a miminum of damage to a section of tube.  They would not be able to highjack a vehicle to drive it into a building or such.  Many of these tubes or terminals could be built underground. 

High speed trains would require new electromagnetic tracking, thus more disturbance to the environment.  Using existing railroad tracks means 200 mph is about maximum, and that is not counting curves on railroads.  Hyperloop vehicles can be able to slow down for curves and speed up on long straight a ways.  Since they would be much lighter than trains, they can be elevated.  From what I have read they would be cheaper and easier than high speed trains. 

Also, if they are picking up power from overhead solar panels, the system can reduce power in curves. 

Europe rebuilt their rail system after WWII since it was mostly bombed out.  The US never had to.  Also their cities were bombed out.  It is also not such a big deal to build a station 10 miles from a downtown area, since most people flying or using a train, would have to get a taxi to get to their destination anyways.  Blighted areas could be demolished and used as the transportation hubs.  To me, if it is a choice of high speed train or hyperloop, it seems hyperloop wins out every time.  I also don't believe they will be going 700 mph in hyperloop, but more like 300 mph average due to station stops and curves. 

[guckyfan]

To me, if it is a choice of high speed train or hyperloop, it seems hyperloop wins out every time.  I also don't believe they will be going 700 mph in hyperloop, but more like 300 mph average due to station stops and curves.

There is that one metric of passengers/hour. I would be interested what the max ist for hyperloop. Most likely train will win this.

[R7]

I think you're dramatically underestimating the difficulty of obtaining rights-of-way, and how curvy even main roads are.  Take 101 from LA to SF.  Have a look a this one spot between them:

https://goo.gl/maps/sWO90

This thread has derailed from spaceflight to terrestrial land legalities, TSA searches and city planning.

I'd report to mod but even the mod is off the track.

One more locomotive pun .... ... I got nothing.

[BusterSky]

@ oldAtlas_Eguy


Glancing over the wiki on the launch loop, it seems the limitating factor is if you want to send people into LEO. Wouldn't such a thing be feasible if you only wanted to blast up simple cargo like spare parts or fuel ? Without requiring any other propulsion system ? Hyperloop for space cargo ?



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

[spacenut]

I still believe hyperloop would be great land transportation on Mars between various colonies.  For instance, one colony is near a large source of water would farm and make methane gas.  One farm might be at a mining location for a particular mineral.  A hyperloop connection between the two would be easier than rocket hopping, or rovers with having to pressurize-depressurize when transporting between colonies.  Excess power from the hyperloop can be used at either colony. 

[Star One]

No updates for a while on this thread so here is one from the BBC.

http://www.bbc.co.uk/news/technology-35361093

[Falcon8]

The Spacex Hyperloop Pod Competition Design Weekend will be held at Texas A&M on Saturday (Jan 30th).

They have some activities open to the public from 2:30 pm to 5:30 pm.

http://hyperloop.tamu.edu/schedule-for-public/

[theebag]

A couple of days ago a Dutch team (Delft university of technology) presented their design. They've abandoned the concept for an air fan and went for magnetic propulsion.

Team: http://www.delfthyperloop.nl/

Introduction Movie:

Article (in Dutch): http://tweakers.net/reviews/4327/3/tu-delft-onthult-hyperloop-ontwerp-het-ontwerp-van-de-tu-delft.html

[Dante80]

This is an interesting design which essentially describes a maglev train/capsule of shorts. But a couple of questions.

1. This is a LOT more expensive than the hyperloop concept (you need the magnets on the track).

2. For this to work as expected (and at the speeds the video says), you need a total vacuum (very expensive). If you don't have that, you need a system to "remove" air somehow from the front of the vehicle. The hyperloop uses a compressor, this project seems to have nothing. However good your Cd may be, you are going to encounter problems sooner or later.

Any thoughts? Does the article talk about the things mentioned above?

[Chris_Pi]

From a quick look at their website, Particularly the articles in the blog section - No magnets in the track, just the cars. There is a raised center guide to limit side-to side movement and provide something for the emergency brakes to grab.

They do not expect an extremely good vacuum. I couldn't find anything the explicitly said so, But it looks like the plan is to have the capsule quite a bit smaller than the tube and just live with some drag. The design does have a longish conical tail to help with this.

[Robotbeat]

If at least part of the tube is aluminum instead of steel, they can levitate using that one hover board technology at low speeds and induction at higher speeds.

At the moment, aluminum is SUPER cheap.

[theebag]

I’ve loosely translated the article regarding the propulsion. I’m not affiliated in any way with the team, so should one of the team members stumble on this translation please correct it were necessary .

The envisioned system by Hyperloop is according the students not efficient enough and too expensive. Their system has permanent magnets underneath the capsule. The tunnel needs to have a conducting aluminium plate, which provides thrust under influence of the magnets. Normally aluminium is not magnetic but by the Law of Lenz, Eddy Currents will be generated under influence of those magnets.

Wheels are provided in case of emergency to reach the next station/stop. An extra set of magnets is provided for guidance of over a guidance rail and they can also be clamped down for an emergency stop. In such event this should happen automatically.

As there is a still some air in the tube they choose an aerodynamic shape. The capsule is made from CRFP and has a third of the total passenger and luggage mass. There are no windows and the doors placed alternately for strength.

Source: http://tweakers.net/reviews/4327/3/tu-delft-onthult-hyperloop-ontwerp-het-ontwerp-van-de-tu-delft.html

[OxCartMark]

      As to it's application for SpaceX?  Add magnetic coils around the tube, elevate same at a fourty-five degree angle, place a break away lid on the upper lid, and you have a pretty good magnetic linear accelerator that could act as a first stage for putting payloads into orbit even cheaper tham SpaceX is doing now.  Using such a system on Mars or the Moon would allow a fully fueled space craft to launch into orbit using only a minimal amount of fuel to circularize the orbit.   Remember, getting to orbit takes most of the fuel required to get anywhere in space.

But that wouldn't be possible right ? To reach sufficient speed you would need the launch track to be enormously long and enourmously high, or so wikipedia says 2000 km long and 80 km high 

At a 3g acceleration, in order to be a replacement for a first stage (3km/s Delta V) the tube would need to be 51km long. The vehicle being accelerated would be a little larger than a current LV US and more streamlined as well as sporting wings and probably a scramjet to increase speed even more as it travels up through the rest of the atmosphere to up to 4-5km/s before the rocket engines take over for the remainder of the 8.6km/s needed to reach orbit.

A 3km high mountain next to a near sea level plain in which it is possible to have a gentle curve from the horizontal to a high upward angle >60 degrees in which most of the tube is on the plain and only the last 5-10 km is the curve and trip up the mountain. This also helps in lowering the power requirements for acceleration since only the last part needs to overcome earths gravity to maintain the 3g acceleration.

If I'm following, the 3G you're thinking of is in the horizontal direction.  But what about the G loading to make that curve in the last 10-20% of the track length, the portion where they'd be moving at ~90% of your 3km/sec.?  That 5-10km ramp up would cause you to accelerate vertically 3km in about 2.8 seconds.  That's gonna hurt a bit.  But let's put a number to it [scribble scribble, cypher] 79G.  Yep, definitely gonna hurt.

I think the more practical space application would be launching from an airless or near airless body such as the moon, launching from the highest available near horizontal landmass, and then with some additional rocket propulsion to circularize the orbit to avoid bumping into the launch on the next orbit.

I don't think HyperLoop has anything to do with Mars, I think it was put forward in hopes of avoiding California traffic.

Yep.  Born of the frustration of a guy who has businesses in two distant cities in California and who has no good way to get between them (assuming personal jet is seen as polluting) and who has napkins and pens on said jet.

This is an interesting design which essentially describes a maglev train/capsule of shorts. But a couple of questions.

1. This is a LOT more expensive than the hyperloop concept (you need the magnets on the track).

If you move to an architecture where the track propels the cars electromagnetically (more expensive as stated) then there is one mild benefit, which is that electric power for the fan doesn't need to be provided from onboard batteries but rather can be provided by electromagnetic coupling to the track.

In my estimation this thread's grasp on NSF is tentative at best.  Let me help it along with a hairbrained concept.  For long distance interplanetary ships you could create artificial gravity by having part of the ship be a circular hyperloop track with pods going around it to create artificial gravity.  And angularl momentum.  Yep, hairbrained.

[gregpet]

Elon was at the Hyperloop competition at Texas A&M (my alma mater!) and took questions.  I caught the very last bit on Ustream but I'm assuming that a replay will be up at some point...

http://www.ustream.tv/channel/uAPmkVhqjrx

[theebag]

The winners of the Hyperloop competition have been announced. MIT won with the TU of Delft coming in second. In total 22 teams (with possible 10 more) will get the change to test their pod on the testtrack currently under construction.

More information and source : http://www.theverge.com/2016/1/30/10877442/elon-musk-spacex-hyperloop-competition-awards

Winning team: http://hyperloop.mit.edu/