Taleb Aerospace

[Jarod]

Hi,
I'll start building my space station and just wanted to share a concept drawing of it.
I won't use any spaceplane so the first payload will be a Tranzit tug with a robotic arm and during others launches the modules will be captured by the Tranzit to be assembled with the station.
Capsules will be used to send crew and cargo to the station.
At some point the station will be put in rotation, the design is different than a wheel station, more space can be added on each arm at any time.
The practical limit would be the strenght that the radial arm is put through.
On the long term, engines could be added to make an interplanetary ship.
Any comment appreciated

 

[Capt_hensley]

Strength on the radial connections will be an issue, torsion as well as tension. What would you use to join the modules together? Docking, Berthing or sealed union joints?

If the entire station is to rotate, what orbit do you propose? LEO, GEO, BEO, Lagrange? Will the solar arrays have rigid frames? If not how will you keep them from flapping, bending, or altogether collapsing from the g-force of rotation and excessive vibration, solar winds?

Why does the entire station have to rotate? Is there some purpose tied to science? Very few docking ports if you limit the visiting vessels to only one or two, how do you plan to resupply it when a crew capsule is docked? What do the occupants use for life boats? Rotation of the entire station requires rotation of a docking vessel, this could muck up navigation for both objects. Such a large station would need a large crew to maintain it. How many crew members are there aboard at any given time?

Sending a transit tug first can work, but it implies urgency of orbiting more elements. Refueling will become a necessity at some point. Placing the tanks to the outside of the structure would reduce total loss should an explosion occur, however heating and boil-off become issues.

The radiators are placed well, with multiple placement you create a redundant system possibility.

These are but a few things one must understand and incorporate if one is to build a practical space station.

Nice schematic, and logo. Covalent? its a bond between atoms using two electrons, interesting name. It will be interesting to see the evolution of the design.

 

[Jarod]

Strength on the radial connections will be an issue, torsion as well as tension. What would you use to join the modules together? Docking, Berthing or sealed union joints?

Docking, and just to be clear I am not trying to make a realistic space station .
The 4 central arms could be plain materials to provide strenght and the others could be linked to each others by passageways in a square-formation not a cross one. But I don't think I'll do that.

If the entire station is to rotate, what orbit do you propose? LEO, GEO, BEO, Lagrange? Will the solar arrays have rigid frames?

LEO for a start and rigid frames for the solar arrays.

Why does the entire station have to rotate? Is there some purpose tied to science?

The space station will be used in part as an orbital hotel, so artificial gravity is to accomodate clients.
With engines, the station will become a ship, artificial gravity will be necessary for long duration trip.

Very few docking ports if you limit the visiting vessels to only one or two, how do you plan to resupply it when a crew capsule is docked? What do the occupants use for life boats?

I thought about that but didn't draw it. The docking port in the drawing should be seen as the place where several docking ports will be available, a radial arm like the hab modules.
Occupants will have capsules for life boats at several places on the "hab modules" arm, and in case people wonder, no I won't replace them every few months.

Rotation of the entire station requires rotation of a docking vessel, this could muck up navigation for both objects.

Vessels dock at the end of the central radial arm, crew enter the station, and then robotic arm is used to undock and redock the vessel to its final parking dock.

Such a large station would need a large crew to maintain it. How many crew members are there aboard at any given time?

well, construction will not be done in a day, I'll think about that. Do you have a ratio crew/hab module in mind ?

Sending a transit tug first can work, but it implies urgency of orbiting more elements.

My english is not that good, I don't understand what you mean by "it implies urgency of orbiting more elements".

These are but a few things one must understand and incorporate if one is to build a practical space station.

and thanks for pointing them, while I'm not looking to create a perfectly realistic station, I would like to avoid big mistakes.

Nice schematic, and logo. Covalent? its a bond between atoms using two electrons, interesting name. It will be interesting to see the evolution of the design.

Thanks, yeah chemistry at school leaves scars even after years.

 

[Columbia42]

Radial strength would indeed be a problem. In order to circumvent this I would suggest eliminating as much weight as possible from the ends of the arms. Moving the solar panels to the center of the station would accomplish this as well as help the panels track the sun more effectively. I don't think docking will be too much of a problem, I've docked to the rotating Luna-OB1 in Orbiter many times without too much difficulty. The number of docking ports could be a potential problem as well, as Capt_Hensley pointed out. Although rotation does not pose many navigational problems and would be beneficial to the crew, keep in mind that to generate significant gravity a space station of this size would have to rotate quite fast (what's the diameter of the station?) which adds support problems to the arms.

 

[Jarod]

This is how I should have drawn it, with Lifeboats and central docking port area.

a space station of this size would have to rotate quite fast (what's the diameter of the station?) which adds support problems to the arms.

For the size, I don't know yet but since Orbiter don't manage that kind of things, I won't make a big deal of it.

 

[Capt_hensley]

Well the pace I set for my Gateway Station was an average of 1 launch every 8 days. While the first and second launch were autonomous launches, the following third launch was manned, it would rendezvous with the first module and take it to the second module, mating(berthing) the two together. Both modules remain unpressurized and in orbit long enough to get the fourth up, with a manned launch shortly there after.

It's a long process after that, with about every other launch being manned. Pressurization takes place on or about the tenth launch-rendezvous. This allows me to keep the station unmanned for about the first 80 days, and lets me build a living space that will be less crowded once occupied.

Now I say this because I have committed to a very stringent launch schedule once it starts, the pace never stops. 1 launch every 8 days for 5 years. Over 400 launches to build the station. It generates long term jobs, and a huge asset in orbit.

Now that you understand that pace, here's why it would place urgency on your first few modules. With a remo tug in orbit it will keep station for itself, but without other modules to work with, the asset just loiters burning up precious on orbit lifetime. To make the mission and lifetime of the tug worth it, getting more modules, if only two, into orbit with the tug, gives the tugs "lifetime" a more profitable and worthy expenditure.

It's why I chose the third mission to place a reusable spacecraft (the SpaceX Dragon) into orbit to gather the first two modules and finish the boost to GEO. If you use a permanent tug, everyday on orbit is a day off it's available lifetime. A reusable vehicle(orbit to earth and back to orbit) enables me to "monitor" the location of the station objects, without expending a valuable long life tug. I have the tugs for my station going up shortly before the third year of construction to stretch the lifetime out as much as possible. I use manned launches that return to earth in reusable craft to prevent premature loss of valuable on orbit propellant and longevity. It's going to take me time to get my tankers into orbit, but you may have another plan, that I have not thought of.

Although this is one scenario, it seems the NASA engineers I've spoken with, would agree it is the better path to take with a station that will become so large. Unpressurized modules in a GTO orbit of up to a month by them selves use no resources and face little danger, but with a LEO object facing orbital debris and altitude decay it becomes more important to place a higher value on the object with every opportunity.

One plus you have given is that the tug has propulsion and guidance that my first two modules do not have. Either way we both take some risk with our method. Yours is about the same as mine, but you have a slight edge with an orbital maneuvering system.

About the rigid frame, good choice, don't forget to compensate for the additional launch weight when deciding on a LV. You could use guy wires to add a light-weight stability to the modules structure, like the old WWII bi-planes used to use from wing to wing. Don't forget to balance the station as much as possible, a rotating structure will wobble out of navigational parameters if it's too nose heavy, otherwise you have a nice design idea, let's see how you develop it.

For long duration occupancy, the fewer crew you have aboard the better, concentrate the population to the core modules for a reduced foot print for pressurization, allow the crew and occupants to traverse only one length of the modules and you get all the benefits of the artificial gravity, safety, and reduced atmospheric gas consumption. Use the outer modules to store consumables, and keep the consumption on a rotational schedule and your balance will stay in check, the ship will get lighter if the modules become expendable, and are used for trash. You could eject them into a destructive orbit as they become used up. This makes the return trip use less propulsion and fuel, and take stress off the the ship as a whole.

The initial manning should be three to six, with one additional crew member for every four hotel members. That's 6 + (1:4) A max occupancy of twenty to thirty seems like a good number. This will keep the lifeboat count to a minimum, consumption to a manageable level, and a 10 year mission(trip) within the realm of possibility. Remember to include strength to counteract the propulsion of the engines to be used. Slow acceleration would greatly benefit this design. You might even pull the craft in tow, as opposed to pushing it to help relieve some of the stresses. It's a rare technique.

 

[Jarod]

With a remo tug in orbit it will keep station for itself, but without other modules to work with, the asset just loiters burning up precious on orbit lifetime.

The first modules will be sent rapidly after the tug, and it can provide fuel/electricity for whatever reasons and tug the early station to a high orbit, I don't know yet how high I will put it.
Thanks for your insights.

I made some changes to spread the stress on the station.
Don't forget that is just a concept drawing, the station will have more length than width.
And fuel tanks in real life could have a panel or fairing placed on a arm to keep them in the shadows to limit boil-off.