rLoop: We Are Pushing the Limits of the Open Source, Online Think Tank Model
rLoop team member and moderator of /r/SpaceX Richard Behiel on evolving from brainstorming on subreddit to building a Hyperloop pod in Sacramento
Last June, the SpaceX fan subreddit (not affiliated with the company in any official capacity) was buzzing with the news that SpaceX had announced plans to host a Hyperloop pod design competition, with the intention of furthering the development of Elon Musk’s Hyperloop concept. Immediately, some of the members of the reddit community began to mull over the idea of jumping into the competition. Despite the fact that we had never met each other in person, were spread out all over the globe in different time zones, and would be competing against both universities and other teams who could meet in person frequently, we all felt compelled to at least give the competition our best shot.
As a group of internet strangers, our first hurdle was keeping the rLoop spark alive and keeping morale high, so we spent the first two weeks assigning roles to each team member and mapping out our team’s structure, with the intention of solidifying ourselves as an organization before beginning the real work. Any gaps we had in the team were quickly filled by recruiting more redditors, primarily from the SpaceX subreddit which is known for its engineering-oriented community members and their high quality discussions. After those initial few weeks, rLoop had grown into a stable organization with well-defined sub-teams and hierarchical managerial structures, and we began to design our Hyperloop pod (the aptly-named rPod).
Who is rLoop?
rLoop is a global team of over one hundred and forty active members from fourteen different countries. Our team is comprised primarily of motivated college students and young engineers, but we have some older professionals on our team as well, whose industry experience has provided excellent guidance. For instance, our engineering lead Thomas Lambot is an aerospace engineer who works for NASA. This mixture of experienced professionals and enthusiastic young engineers has fostered an incredible hands-on learning environment at rLoop.
Over the past six months, we have had over three hundred volunteers sign up for rLoop. Although some of these people have since left the team, the most motivated of the group have stayed and continue to work on the project. Since we are all doing this on our free time and the work is entirely voluntary, those who continue to devote their time to rLoop are all exceptionally passionate about what we are trying to accomplish. The one thing that we all have in common is that we have our minds set on winning the competition and doing what we can to accelerate the development of the Hyperloop.
Creating the rPod
The rPod is a half-scale Hyperloop pod, designed to compete in the SpaceX Hyperloop competition. It is 3.8 meters long and 1.2 m high (that’s 12.5 by 3.9 feet, for those of you whose country has been to the moon). Most of the pod structure is based around a pressure vessel, like the ones built for aircraft cabins, and the rPod will be built using the same alloys and standards.
The rPod will levitate above the track at a height of a few millimeters, thanks to its eight Arx Pax hover engines which are gimbaled to also provide thrust and braking force. We had initially considered using air bearings rather than magnetic levitation, as did most teams, but found that the mass flow rate required to lift the pod a safe distance off the track was larger than what we could feasibly draw from the surrounding near-vacuum. The Arx Pax motors, which levitate using magnetic field architecture technology and require no air supply, were found to be a more appropriate fit for our pod design. In addition to the magnetic hover motors, eddy brakes will be used around the central rail to provide another braking force, and will operate in conjunction with our stability system which uses wheels that can bring the pod to a full stop.
Our pod is built to be robust and safe; hypothetical human safety aside, no team wants to have their pod fail at the competition and ruin the test track! To mitigate our risks, we created a 40-page Failure Method and Effect Analysis where we came up with all the things that can go wrong, and devised ways to prevent and work around them. For example, if the hover engines fail, the pod can cruise safely on its backup wheels as the eddy brakes automatically deploy with a system of springs, bringing the pod to a safe stop. In other areas of the design, we have kept the level of complexity low in order to reduce the number of potential failure modes.
Rendering showing an exploded view of the rPod
On the Ground at the SpaceX Design Weekend Event
The nine of us rLoopers who were able to attend the design weekend woke up at the crack of dawn on Friday, put on our matching rLoop t-shirts, and drove our rental cars over to Kyle Field at Texas A&M to set up our booth. The air was buzzing with excitement and anticipation, as hundreds of students, judges, corporate sponsors, and other event attendees began to fill the thirty-thousand square foot Hall of Champions.
Along the back walls of the room were the non-student teams, including rLoop, as well as presentations put on by various corporations including Hyperloop Technologies, Arx Pax, and ANSYS. There were demos for virtual reality headsets, flight simulators, and even the Hendo magnetic levitation hoverboard. Beyond the Hall of Champions, in the anteroom leading to the football field, was a long row of other teams presenting on their Hyperloop pod and subsystem designs.
We decided to do a live stream for the members of rLoop who were unable to attend in person, and for anyone else who may have been interested in seeing the progress of the Hyperloop teams. We had a peak viewer count of at least two-hundred and fifty-two, which occurred during the Hendo hover board demonstration, and many of our viewers turned out to be friends of members from other teams.
Just after noon, it was announced that astronaut Gregory Chamitoff, who had spent nearly two-hundred days in space and had flown on the last mission of the shuttle Endeavor, would be giving a speech. In his speech, Chamitoff recalled having been inspired by watching the launch of Apollo 11, the first spaceflight to land humans on the moon, and drew a connection between that historic launch and the Hyperloop design weekend event. The audience grew quiet as we all tried to calibrate the significance of the event, the first-ever collaborative meeting intended to bring to life what may become the fifth mode of transportation (after cars, trains, planes, and ships). An air of historical reverence swept through the room as it dawned on us that, should the Hyperloop concept become a reality, this weekend was destined to become a tell-your-grandkids-about-it moment.
Later that evening the US Secretary of Transportation, Sec. Anthony Foxx, gave a speech regarding the future challenges faced by the US transportation systems as the population continues to grow. Although he admitted to being initially skeptical of the Hyperloop concept, Sec. Foxx emphasized the importance of not immediately disregarding new ideas, and suggested that future Hyperloop research and development may be eligible for government funding, should the technology prove sufficiently feasible. What stood out to me the most was something he said during a Q&A session: “Let’s figure this out. Let’s see if there’s something to it.” Those simple sentences really summed up why we were all there, and what we had all worked so hard towards.
What surprised me the most about the event is that most of the people I talked to had not only heard of rLoop, but were excited to meet us in person and talk to us about our design. As the only online and open source Hyperloop team, rLoop had apparently served as a valuable guide for many of the rest of the teams in the competition, and on a number of occasions it turned out that teams had actually copied some of our design decisions. This is fine with us, of course, as the goal of rLoop from the start has been to promote collaborative exploration of the hyperloop concept. In fact, quite a few of the students at the event had actually joined rLoop before switching over to their university team, so we were extremely proud to see that our collaborative online effort had inspired so many people to join in on the fun of helping to make the Hyperloop a reality.
rLoop Wins Best Non-Student Team
rLoop was given a trophy, signed by Elon Musk himself, for being the best non-student team in the competition. Although many of our team members are in fact students, we have experienced professionals on the team as well, and were therefore put into the non-student category. In addition to winning the award, rLoop was also invited to the final round of the Hyperloop competition, which involves building our pod and testing it on SpaceX’s 1-mile test track in Hawthorne, California this summer.
At the beginning of the Hyperloop competition, there were over 1,200 teams competing worldwide. That number had been reduced by roughly a factor of ten by the time of the design weekend, and is now down to only twenty-three teams who have been selected to move on to the final round. Of those, rLoop is the only remaining non-student team, and the rest are backed by universities.
Building the rPod
We have recently found a 600-sq-ft manufacturing space in Sacramento, where the rPod will be built. Subsystems which are small enough to ship may be assembled in other locations, so that the workload can be more evenly distributed across our team. Although manufacturing is a task which requires physical, hands-on work, we believe that we now have the experience and organization required to finish what we have started, build a working rPod, and hopefully win the competition. With great excitement and anticipation, rLoop is preparing to push the limits of the collaborative, open source, online think tank model which has carried us this far.
What’s Next for the Hyperloop?
There has been, and will continue to be, a major push among engineers and entrepreneurs to make the hyperloop concept a reality. The market potential is absolutely enormous, and perhaps more importantly for the dreamers in all of us, the idea is futuristic and cool. Although it is not uncommon to hear criticism of the practical potential of the Hyperloop, almost everybody is anxiously waiting to see what will happen when someone actually builds one.
The truth is that the Hyperloop is nowhere near developed enough, from a technical standpoint, for any accurate predictions to be made regarding its potential impact on the world. Right now, there are a million ideas floating around out there as to how exactly the Hyperloop should be designed, and one of the purposes of the SpaceX competition is to have engineers throw a bunch of ideas out there and see which ones float to the top. The competition will end by testing twenty-three half-scale Hyperloop pod designs on a one-mile test track, and aside from being a fun engineering event, this will also provide valuable insight toward Hyperloop research and development.
In my personal and somewhat cynical opinion, the main challenge involved with the Hyperloop is going to be building and maintaining a massive, many-hundred-mile-long, near-vacuum tube. The tube will have to robustly withstand cyclic thermal stresses as it expands during the day and contracts at night, which will be a major challenge because of the sheer length of the tube; if the tube is five-hundred miles long and made out of steel, for instance, it will want to expand and contract by a hundred yards or so every day and night. A trade-off exists between holding the tube rigidly in place, thereby stressing it when it tries to expand, and allowing it to expand, which introduces logistical complexity. It is not uncommon for railroad tracks to buckle and form “sun kinks” as a result of this problem, and those are just simple metal rails; finding a way to cheaply avoid this problem with an airtight vacuum tube will be quite an exercise in engineering.
There are other foreseeable threats to the Hyperloop idea, such as seismic conditions, maintenance costs, claustrophobia, accidental rapid pod depressurization, and susceptibility to terrorist attacks, to name a few. However, it is important to stress that none of these threats would be insurmountable with modern technology and sufficient funding, so whether the Hyperloop will become a reality is not a matter of physics, but of optimization and economics. Will the Hyperloop emerge as a viable fifth mode of transportation, or will it simply be exposed as an idealistic fantasy? Only time will tell, and it will be extremely interesting to keep an eye on the development of the Hyperloop over the next few years.
Aside from its potential practical implications, the Hyperloop concept raises the opportunity to inspire a generation of young engineers. It is one of the next goalposts in mankind’s historic quest for technological mastery of an often inconvenient world, looming just over the horizon and taunting us with its promise of a brighter future. We all feel a certain obligation to keep marching forward, and to keep pushing at the boundaries of what is possible so that we may further bridge the gap between our dreams and reality. The development of the Hyperloop, should the concept turn out to be feasible, will go down in the history books along with the invention of the automobile and airplane, and this is largely one of the reasons people are so excited about it.
If the Hyperloop turns out to be feasible, we may eventually find ourselves in a future where you can hop in a pod and be hundreds of miles away in a matter of minutes. This is certainly an idea worth pursuing.
Richard Behiel is rLoop Public Relations Manager & Moderator of /r/SpaceX. He is a fourth year Mechanical Engineering and Materials Science BS/MS student at UC Santa Barbara.