Starship Enterprise

https://drive.google.com/drive/folders/1wfQ1aqB0LRpO43eEVcqUP-2JDKUoiZzF?usp=sharing

https://drive.google.com/drive/folders/1Lf0TS3dQ0w11mj0W6Sq8jqI-diJG8OiA?usp=sharing

For the let it go challenge we designed a new type of attaching/detaching mechanism for space. To develop this mechanism, we have reused an old coupler mechanism, called "Janney coupler", made for a stronger and more secure connection between train wagons. Due to being originally used for such heavy duties (it can transfer more than 600 Tones, modern ones over 9000 Tones. Roughly 2,5 MN force), we assumed it'd be good to use it in space. Before we talk about our modernizations of this coupler let's discuss how it works. This Janney coupler is one of the first types of contact hitches (one of the two types of hitches). When two identical heads move towards each other they push out adjacent movable letches, and they close. This connection is also known as "death grip", because it's almost impossible to separate them. In order to release the letches later, you need to pull on two grip release levers associated with the return springs. We decided to use the said technology to solve this challenge, as it provides several opportunities:

• It could handle a tremendous number of forces, as mentioned before. of course, our version is much smaller than the original, which reduces the power roughly tenfold or fifteenfold. Even so, the force is more than enough to hold parts together and even survive huge acceleration. Even the plastic demo model we made can take a pretty large force, if we make it from the mixture of metals such as carbon and titan (to survive high and low temperatures and give us a stronger grip) it will be able to hold up a lot more than it's required for this challenge (4000 N). While opening our mechanism, a spring placed inside will return the identical heads to their default, open positions. Of course, this would provide some impulse, but the force from both sides cancels each other out, therefore making it produce even less force.

• The planned design is fully resettable, not requiring a landing or complicated procedures to reattach the two modules. It also has to be said, as per requirement, no pyrotechnics were used, therefore this doesn’t produce any debris.

• Our mechanism boasts with an ability to unlock with both mechanical and electrical force. We plan to integrate step motor or SMA materials (nitinol spring). The reason we used old version of a “Janney Coupler” is because latter versions are made to work with gravity. Modern couples close by locking a small pin in position, but the older ones do it by using the force of a spring which is set inside. In our case, we are using a step motor/ SMA material to open the locker remotely without physical interfere. We will attach a cog to the step motor which is fixated on the base of the prototype. After a step motor rotates to a certain degree (for example 60°), a cog will touch the locker of the "CLAW", which then pulls it away and opens it. After the locker is pulled to the end, the cog won't touch it anymore and the locker will return to its initial position. After that step, the motor will stop rotating automatically, as set from the computer. Instead of a motor, as already mentioned, one could use Nitinol springs. Just by heating up nitinol with electricity current, it will return to the starting, shrunk position, due to its shape memory effect. This will pull the locker. After we stop the electricity flow, temperature falls down and the object returns to initial position. This, although, will be unstable, in case it is equipped outside, as temperatures can change rapidly. Both with an engine and smart materials, electricity which is used is extremely low (standard step motor- maximum 4.7 W; nitinol spring ≈0.8W-1.5W; both of them are suitable for this challenge < 20 W).

• In the worst-case scenario, if somehow one of the CLAWs stops working the coupler still can be opened even without any physical interference. Our mechanism is built in this way that even if one of the CLAWs gets stuck, the second one alone is able to still detach. Even if the latter fails, it's possible to manually detach it by simply pushing the locker. In the future, further measures can be taken.

There are few other problems that we will attempt to solve in the future too, with further research, but something has to be mentioned – As mentioned, temperature difference between sun and it’s shadow is huge. This will affect nitinol spring if we use it wrong, and on motors we’ll have to add some temperature protection layers, for which we could use Titanium, because of its heat properties. Another problem is vibration. Huge oscillations occur while accelerating, which can possibly deform the locks without sufficiently strong materials. Currently there are two ways of avoiding this problem: Using tighter materials, or a mixture of materials that will cancel out the vibrations. It's possible to use another variation of the “Janney Coupler”, commonly known as "Willison hitch". This hitch works similar to the “Janney coupler", the difference is that the locker there isn’t held by a spring. It uses a complex and more secure locker made by the combination of movable and more fixated parts, which could potentially solve problems we mentioned before.

We have used data from NASA's research in this particular topic to see alternatives that they used in space, therefore being able to develop something that would rival them. Of course, many of those are better alternatives in terms of strength, but most of them lack the ability to reattach, or in other cases the size is the problem. So lets discuss some of this alternatives and find the differences between them and ours.

One of them is using SMA materials, which by triggering some action, expands causing a bolt that goes through this device, to break. It has 2 minuses, first is that this mechanics breaks so it could not reattach anymore and the second - it produces debris in space. In our case this problems are solved and also we think that our coupling technology is on much higher level of power. Also, that NASA's use of SMA inspired us to use them in our mechanics, too, but as locker controller, not as detacher. We already made some experiment for it, measured produced/created force, necessary energy for working, controllability and etc. We decided which SMA to use and why, and what's left is to very detailly design the structure to be absolutely capable with SMA material(NITINOL Spring).

This SMA is NITINOL, which we have mentioned before. We decide to use it because of having quite big experience in working with it and also because this SMA is the most affordable and everyone is able to buy it. Even with that there are we are thinking which NITINOL would be better to use in space. We've investigated standard NITI(nitinol) and new NITICU, which has different abilities and parameters. So, to find this out is needed more experiments to do, but we already can say that both of them can be freely used in space.

Other NASA's separation devices are bigger than SMA using device. That's why we still are trying to make our prototype as small as possible. Built 3d model parameters already are capable with given size limits(should be smaller than cylinder with length-15cm and diameter - 2cm).

And while doing other researches we found out that no-one before had thought about using train couplers mechanics this way just by simply modifying it, so we think that this idea is truly innovational and quite easy makeable, because main structure was made 140 years ago in 1881.

The other way how those NASA's separations make us thought was the way of producing and testing the product. In producing with new 3d printing technologies it shouldn't be a big problem and also because of simple mechanics. And in testing we truly have overcome other separation devices. Those devices(few of them can't be tested like if you would activate SMA separator it will break so after that you can't send it to space, of course you can run tests and simulations but still it may not be able to be 100% sure of work, but our mechanism can be easily checked on earth in all ways and sent it to space by guarantee knowing that it works. (Again, some of separation devices can be checked fully)

We enjoyed the experience a lot. Not in a long time have we met so many interesting people at once, people who have shown us things from a different view. These two days were full of information, cooperation with each other and most important of all, having fun! The work was quite a lot too, this has to be said, however we learned a lot with both from experience and from interesting people we listened to.

https://ru.wikipedia.org/wiki/%D0%90%D0%B2%D1%82%D0%BE%D1%81%D1%86%D0%B5%D0%BF%D0%BA%D0%B0_%D0%94%D0%B6%D0%B0%D0%BD%D0%BD%D0%B5%D1%8F

https://azbukametalla.ru/entsiklopediya/a/1025-avtomaticheskaya-stsepka.html

http://information-technology.ru/sci-pop-articles/27-transport/303-kak-stseplyayutsya-vagony-drug-s-drugom

https://sapr.ru/article/24483

https://vmasshtabe.ru/transport/rzd/chertezh-avtostsepki-sa-3.html

http://www.xn--80adeukqag.xn--p1ai/2016/04/blog-post_20.html

http://www.rzd-expo.ru/history/rolling_stock/automatic_coupler/

https://ru.wikipedia.org/wiki/%D0%A1%D0%90-3

https://railroad.lindahall.org/essays/couplers-brakes.html

https://alabamanewscenter.com/2017/11/23/day-alabama-history-andrew-beard-granted-first-patent/

https://www.nasa.gov/mission_pages/constellation/ares/parachute_results.html

https://spinoff.nasa.gov/Spinoff2020/ip_8.html

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

#CLAW #Janney #space_coupler #hardware

This project has been submitted for consideration during the Judging process.