You are not logged in.
Pages: 1
In order for the Large Ship idea to move from Blue Sky to Real Universe, it is necessary to track the myriad details to be addressed.
The forum is fortunate to include members with experience in a variety of aspects of Information Technology.
While no one individual is a specialist in database design or operation, such specialists are available for consultation as needed.
In the meantime, I am (moderately) confident the talent and experience available in the existing membership will support a modest database implementation.
My proposal, subject to modification as better ideas appear, and as we gain experience, is to start with Open Source software, and to place the database itself on the NewMars dropbox for anyone to download.
There is nothing proprietary about the Large Ship effort .... it is Open Source now, and (hopefully) will so remain.
This new topic is intended to become a focal point for announcements of enhancements to the database(s), and for discussion of alternatives that may become advisable as we proceed.
The opening post (#1) is intended to be announcement of the first (trial) implementation of a simple database.
The powerful tools available in more sophisticated database software may seem appropriate in future. An Example would be referential integrity.
In a modern database, the software automatically cleans up all references to an element that is deleted. In a crude, elementary database, it is up to the operator to perform such cleanup activities.
As a point of clarification (speaking of modern databases) this is intended to be a traditional RDMS (Relational Database Management System)
(th)
Offline
This post is reserved for announcement of availability of a simple Open Source database intended to launch the concept for the Large Ship project.
The initial implementation is (tentatively) planned to be a simple Open Office database, stored on Dropbox, and available for anyone to download and run locally.
Open Office software is available to run on all current major platforms, so anyone with a computer should be able to run it.
At some point, if the needs of the group call for enhanced features (such as Referential Integrity) a conversion to something more sophisticated may be in order.
SearchTerm:Link to Database in NewMars Dropbox
SearchTerm:database link to NewMars Large Ship database in Dropbox
https://www.dropbox.com/s/znvxjskclk93f … p.odb?dl=0
(th)
Offline
In Housekeeping, SpaceNut commented that it is not yet clear what data might go into a database for Large Ship.
I think that is ** such ** a helpful way to start this topic!
Google came up with this snippet, when I asked how to design a relational database from scratch:
Relational Database Design Process
Step 1: Define the Purpose of the Database (Requirement Analysis) ...
Step 2: Gather Data, Organize in tables and Specify the Primary Keys. ...
Step 3: Create Relationships among Tables. ...
Step 4: Refine & Normalize the Design.Relational Database Designhttps://www3.ntu.edu.sg › ehchua › programming › sql
For a project on the scale of Large Ship, there are multiple purposes for a database, and that's assuming a single database can handle the variety of data that must be recorded and retrieved rapidly and efficiently when it is needed.
The material components must be tracked throughout their lives.
Vendor relationships, and contracts must be kept up to date.
During preparation for a flight, many thousands of details of supply provision must be managed.
During operation, the locations of supplies must be tracked with precision, because the lives of passengers and crew will depend upon those supplies being where they are supposed to be, and what is expected when they are pulled from storage.
(th)
Offline
tahanson43206,
I think what you're after is an object-relational database. The database objects can have both properties and methods, and analyses can be performed using coded procedures. These sorts of databases can be and frequently are many times faster than the most performant relational databases, which is why they're most frequently used in real-time systems.
Offline
For kbd512 re #4
Thanks for the tip for a bit of reading! I have experience with relational databases, which is why I start there, and it seems to me an nosql database is better suited for modern high volume transaction management, but I like the idea of planning ahead for performance.
Hopefully an ordinary relational database can be converted to the object-relational concept, but at this point I've just learned this technology even exists.
I would point out that MySQL (as just one example) is able to perform remarkably well under load, as demonstrated by the performance of the forum. There are pauses occasionally, but it is impossible to tell if these are caused by delays in the database, or in any of the many other delay points in the Internet flow.
Update at 11:54 local time:
Thanks again for the suggestion to study the object-relational concept. The wikipedia article on the subject reveals that work on these concepts goes back to 1990. My exposure to database technology has been via commercial (and government) real-world applications, so I have been blissfully unaware of all the work going on in the ivory towers.
https://en.wikipedia.org/wiki/Object%E2 … l_database
I came away from reading this article uncertain of how to proceed.
Since this database is being constructed from scratch (unless an existing suitable Open Source model is discovered), we certainly have the option to try versions of database theory that are not familiar to present forum members. Someone who is interested in working on this part of the Large Ship project is welcome to contact us via the Recruiting topic.
As it happens, I have dusted off some C++ books I bought in 2007, and have started the long slog through them, so object oriented thinking is ** right there ** on the agenda.
For the short term, I'm planning to proceed (as best I can) using traditional data base theory (and practice) while keeping an open mind for suggestions to step up the game to the next level.
If there is a volunteer "out there" who is willing to enlist for a ten year stretch, the database piece of the project is yours for the asking.
A higher priority (for me at this point) is to develop something that every NewMars member can run on any computer that uses the three major flavors of OS ... Linux, Microsoft Windows, or Apple (whatever they use).
The universal candidate is Open Office or Libre Office ... I understand the split was of a political nature, but each seem to work reliably, and to be supported, with the caveat that Open Office is not being developed. It remains well advanced and reliable ** and ** available for download.
My short term goal set includes:
1) Create simple Open Office database with one table (Ship ID) >> Completed 2022/03/30
2) Create DropBox folder for NewMars Large Ship Database >> Decided to use existing NewMars Dropbox folder
3) Create a link to the database for download from Dropbox by NewMars forum members and readers. >> Completed 2022/03/30
The file is a simple LibreOffice Database ... it consists of one table and one view.
That goal set should be achievable today.
(th)
Offline
The experiment reported in Post #5 was not a success.
Transfer of the database from a Linux system to Dropbox, and back to the Linux system, resulted in damage to the file.
I assume the file contains binary data, and quite possibly Dropbox is configured to handle files that contain normal ASCII characters.
Until this problem is corrected, an alternative is to deliver reports to Dropbox.
I'll try that next.
Here is a link to a report:
https://www.dropbox.com/s/v1n8jg2vrv8hk … 1.odt?dl=0
(th)
Offline
tahanson43206,
While I haven't used MySQL in many years, I use SQL Server and Oracle databases every day. I've done quite a bit of pl/sql and Transact-SQL programming over the past 15 years or so. I was a SQL Server DBA for a time. I've had to learn quite a bit about Oracle database administration and performance tuning from my work with Demantra and Advanced Supply Chain Planning.
This is what I use on a regular basis:
PowerApps / PowerAutomate / PowerBI
Transact-SQL and pl/sql
Excel and Access VBA
Batch or shell scripts
JavaScript
Java
I lost my job yesterday, so I have at least a little time to work on this. Unfortunately, I only received about a month of severance pay, so I'll be pretty focused on finding a new job since dreams and wishful thinking don't pay my bills. With any luck, I'll have an interview on Monday with a relatively new startup that's expanding and involved in supply chain management software solutions.
Word to the wise- you can receive a glowing annual review from your boss, with a bonus, and still be fired the next week. When you're the low man on the totem pole, expect that they'll call your number first. All jobs are very temporary affairs, which I learned from my time doing consulting work. An executive who I was friends with told me about two weeks prior that this was always a possibility and that even he was looking outside the company for other work.
Offline
For kbd512 re #7
First! Best wishes for success in finding your next position and opportunity!
I have a stack of emails from Microsoft telling me of free education they are offering on Azure, so I'll forward them to you. It is unlikely I'll be able to take advantage of them, although I did open an Azure account back when a new member seemed to be interested in helping with NewMars projects.
I bring up Azure because there seems to be some momentum building up for implementation of the technology. I'm a member of a local .Net group, and also a member of a mailing from SQLServer.com, which provides a steady flow of snippets about developments in the industry.
Second ... thanks for taking an interest in the NewMars Database problem ....
Open Office / Libre Office offer a simple little database feature that (apparently) is based on SQLite.
What I'm looking for is something that could be shared with many folks, without their having to be college trained or experienced with decades in industry.
However, an attractive alternative is to set up a free Azure web site (operated by NewMars Admins/Operators) and readable by anyone. I'm thinking of the NewMars Large Ship project as Open Source in every sense, so the suggestion of a database accessible/readable by anyone seems compatible with the NewMars forum itself.
Suggestion ... would you want me to let my contact at North Houston know you are looking?
He is a veteran of the oil industry (on the finance side) and he might have contacts ... I expect that ** any ** company is going to need robust and experienced IT support these days.
(th)
Offline
kbd512: consolances. But yes, it happens. I've been terminated with no severance what so ever. If you got a month's severance, you did well.
Offline
Tom,
I sent my updated resume to you.
Robert,
I'm moving on, just as I always have. For better or worse, the world always changes and so I must change with it.
It was foolish of me not to see the writing on the wall. An executive even gave me fair warning about what could (and did) happen. My manager told me he wasn't sure he'd still have a job in six months on my way out the door. My former manager was fired during COVID after more than 20 years with the company. The group I belonged to escaped the chopping block with no losses during COVID, but now that COVID is over with our group is being subjected to the same downsizing forces. I was the person with the lowest time in the group and also the one with the job role (that I was hired for) made obsolete by the introduction of new software that I was not the subject matter expert for, so what management did made perfect sense, even from my perspective. My manager said he was pleased with my work, that I worked well with others, and that nothing I said or did lead to the company's decision, so that's about the best I know how to do.
I was happy to have a job with the company and worked with great people from around the entire world. Unfortunately, all good things must come to an end. I'm not the least bit upset and I have nothing but good memories of the time I spent there. I also understand why so many of the people I worked for or with, left of their own accord. Energy is a rough industry to be involved in, and takes no prisoners. Everything is do or die. Despite the daunting challenges, I hope the company continues to grow and thrive.
Offline
Hello Kbd512, sorry to hear that you have reached the end of the road with your present company. There are always opportunities on the other side of the pond. We are short of engineers other here. Especially engineers with naval nuclear experience.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
Kdb512 I was at work when I read your post of the job lose and know that with you talents jobs will become available but where and when is the real question.
I have been there as well in the 80's when on a Friday news was that all employees were safe and come Monday morning by 8:30 I was being terminated as corporate said all facilities would lose 2% of there staff. Never felt so wronged in my life to be face on lied to.
Good luck my friend.
Offline
I could post stories of all the times I've been terminated. A couple times my boss terminated me to cover his ass. In both cases he was terminated soon after. Unfortunately, the entire department lost their jobs. Currently I'm not an employee, I'm a contractor. Only get paid for billable hours. If the service company doesn't get clients, I don't get working hours. For some unknown reason, I haven't been dispatched to service McDonald's self-order kiosks any more. Lenovo service stopped due to COVID restrictions. No more Vizio TV service after one customer complained after I asked to reschedule. But I still service retail post offices in my city. COVID restrictions since January 15 mean I can't board an airplane, so work in northern reservations stopped. But I'm getting work doing other things: the Liquor Mart is replacing all their retail Point-Of-Sale (POS) systems with new ones. New owners of Safeway grocery stores are replacing debit/credit PIN-pads with new ones. Bank of Montreal upgraded their computers. Odd one-off assignments: an engineering firm needed me to install an upgrade to their network storage, a business insurance company needed help with their server rack, a pharmaceutical wholesaler needed help with their server rack. Actually I did work for that warehouse earlier installing workstations. Before COVID a hair specialist had me replace their time clock for a different payroll service, this time they had me de-install their entire server rack. They were expensive, more than just a hair salon, couldn't weather COVID lock-downs. My income is not great, but I paid off the mortgage on this little house many years ago, so I can live well on little income.
Offline
Getting back to large ship databases, what are we going to use it for?
Offline
With no account you download and then open the file in post 2.
When opened I needed to add a java jre package for the 64 bit machine that I have.
Offline
For SpaceNut re #15 ... thanks for trying the database download ... Please let me know if you get it to work. It was uploaded to DropBox with the data you see in the report, but when I pulled it back down, it had been damaged, and the table and view I had created were not accessible. I believe they were still there, but a few bits had been changed, so the file was no longer recognizable to Libre Office.
For kbd512 ... that is an excellent question! May I suggest we schedule a minute or two for that in Sunday's Zoom?
I assume you read Post #1 of this topic, and found it lacking. If you found it lacking, then I need to rewrite it (obviously).
I'll write a suggested agenda for Zoom now, while the thought is fresh.
(th)
Offline
tahanson43206,
Yes, let's do that.
I want a database to assist with the propulsion system analysis for my own ship design.
I have settled on Hydrogen-fueled MPD thrusters. The H2 will be stored in the form of LNH3. The LNH3 will be split using the technology developed for transporting H2 to refueling stations the PEMFC-powered Toyota Mirai. Prior to H2 being fed into the thruster, the N2 is used as coolant before being ejected into space. For a 500t payload and MPD thruster with a specific impulse of 3300s, I need about 350t of LNH3 propellant, which will be stored in a total of 8 spherical tanks with a 5m diameter / 65m^3 volume. LNH3 is 682.6kg/m^3, so 350t works out to about 512.75m^3 in volume. That quantity of propellant is sufficient for a little over 17km/s of ΔV. A historical MPD thruster design (MY-III) was tested, and rather extensively at that, that provided all of the characteristics (237.4V at 14,141Amps; 3357.2kW; 2.75g/s mass flow rate; 26.6mN/kW; 3,316s Isp) I require in a single package, so this engine and its capabilities were demonstrated using real hardware in a vacuum chamber. 4,800kW of power will be supplied by 8 MegaFlex 37.5m diameter solar arrays with a total mass of a bit less than 40t.
LN3 is currently priced at around $580/t, widely available since it's an agricultural fertilizer product, and storable without cryogenics or the special handling precautions associated with metallic Lithium. Lithium has the potential to plate-out spacecraft surfaces as well, and Lithium Carbonate is about $17,000/t. As such, LNH3 made the most sense of all the propellant options for a ship that will only be refueled at Earth. A single Starship can deliver 3 fully loaded propellant tanks (146,418kg, given a 10% allowance for tank mass) to orbit with some margin to spare. At $2M/launch and $203K for the LNH3, 3 Starship refueling launches works out to $12,406 per person. For 2 adults with 2 children, paying the bill for the transit propellant is like purchasing a brand new Tesla Model 3.
I'm reducing the consumables mass budget to 9 months / 243t, because the colonists will be on Mars in 9 months time. The ship has enough ΔV to make it to Mars and come back. However, I still can't think of an emergency that would cause them to come back to Earth except for the colony being seriously damaged or destroyed. That simply shouldn't be possible if we compartmentalize the colony to the extent that these ships are compartmentalized. To contend with even that remote possibility, we're also sending cargo freighters to Mars that will carry foodstuffs along with other goods such as clothing / bedding / cooking utensils / furnishings / electronics / etc. There's no practical abort scenario, either, since the ΔV requirement is so high. Ship-to-ship rescue is feasible if traveling in convoy, but that's about it.
I have also given up on the ring geometry. There's simply too much pressurized volume and mass required for that, and much of it could never be properly shielded during the spiral out from LEO for any reasonable mass. I was enamored with the idea, but form must follow function. Beyond that, I clearly don't know enough to calculate the forces on the fabric in that geometry. That was way more complicated than I initially thought it would be. Aramid fibers suffer fiber-on-fiber abrasion and creep-to-failure under excessive load, and you need an expert in this area of design to do that kind of analysis. I can compute how much strain is placed on the fabrics in a single direction and determine if that's too much, but multiple directions with fiber-on-fiber abrasion is a bridge too far (for me). Instead, each ship will consist of 10 Bigelow Aerospace BA330 modules connected by spokes to the center barrel section.
The BA330s and food represent 473t all on their own. The solar panels are 40t. The crew / passengers are 50t. The ship will be at least 293t lighter when it comes back to Earth, because nobody is coming back. Coming back is even more wildly impractical than living on Mars to begin with. At 72F, 3,300m^3 of pressurized volume, air at 8psi with 50% relative humidity only weighs 2,127kg. There will be more pressurized volume than this due to the air in the spokes, but the atmospheric mass in the giant inflatable torus was considerable. The ship will be at least 144t lighter by the time the colonists get to Mars. We're going to vacuum dessicate the poop and bid farewell to it. We'll recycle the air and water, but that's it. We have more than enough electrical power to do that at all times.
Anyway, all of this is so much of a technical challenge that it's not even funny. Every time I think I have something thought through, then I think of something else and all my calculations are shot to hell. That's why I need a database. We need a tool that can rework all the calculations instead of trying to redo them by hand, which is what I have been doing. There's no possibility of making any progress that way. We can start with reasonable assumptions, but every minor deviation changes every other computed value by enough to make the idea unworkable.
Oracle has a special feature I've used in various forecasting activities that they call "SQL for Modeling". Basically, it allows you to turn your tables into a giant spreadsheet with cell-by-cell calculations. Object databases are capable of even more complex modeling, and in server mode they run circles around the best relational databases money can buy. That is why Demantra's analytical engine extracts data from the database first, runs the matrix solve in memory, and then bulk uploads the results back into the database after the engine has performed its statistical forecasting calculations. The engine can perform its work far faster using its object database, as well as execute various mathematical operations that would be impractical to implement in pl/sql, and certainly less performant. Excluding FEA, there's very little that we would do that may go beyond the capabilities of a good relational database.
Offline
For kbd512 re #17
Thanks for explaining how a database can be used to help with calculations! What you described sounds a lot like what GW Johnson is doing with spreadsheets.
He has data in some cells, and calculations in others. I have only seen databases used to keep track of information (eg, banking) so I appreciate having my field of view enlarged to include engineering calculations.
In earlier posts, we have considered how the forum itself exists ONLY because of the services of a database. I expect we will quickly discover that a lined pad, or a bit of text in a forum post, is insufficient to manage a project the size of Large Ship.
I'd like to open this discussion to others ... Please begin by reading post #1, and then report here if the contents of the post are not clear or need rewriting.
Because I have been embedded in industry for a considerable period of time, I've absorbed the use of databases as "natural" and "just how we do things", so it helps me to receive insights from other perspectives.
(th)
Offline
Pages: 1