11

Let's say you have a 6500kg piece of equipment you want to launch into space, but your rocket design can only lift 2500kg to the desired orbit. You can: Build five of these Strap them together Put said piece of equipment on the nose of the middle one. Launch That's already worse than designing a new rocket, but at least it cuts down on R&D time. The ...


10

There is clearly a trade off that needs to be made. If your components are only 2 feet cubed, then it is not more efficient to build a ship for humans out of it. If your components are 10,000 cubic feet each, then it is not more efficient easier, or conversely, you only need one or two. It depends on many things. If you have cheap launch for a useful ...


9

A mix of manned shuttle missions and unmanned boosters carrying larger modules. They planned to use Saturn Vs to launch pre-assembled stations (like Skylab) and have the shuttles bring up experiment and logistics modules. This whole report is available here but the illustrations are poorly reproduced in black-and-white.


9

The ISS modules were launched pressurized, if for no other reason than that to pressurize them in orbit would be a drain on ISS resources. The mechanical interface between a new module and the ISS is the Common Berthing Mechanism (CBM), which has been discussed on this site quite a bit. This answer will focus on the process of opening a pressurized path ...


8

Expedition 1 in 2000 was the first long duration stay on the International Space Station, but in 1998 the construction of the station began, with several spacewalks and using Space Station Remote Manipulator System (SSRMS) installed on the Space Shuttle used to assemble and prepare for operation first three ISS modules, Russian Zarya and and Zvezda, and ...


8

What is missing from your timeline in when Zvezda, the Service Module arrived. It was launched July 12, 2000 and docked on July 26, 2000. The actual living quarters in the station, initially were all in Zvezda. Zarya could maintain orbital control, provide minimal power, and life support, but it is Zvezda that is really the main module of the station, at ...


7

They could be, in theory. Let's talk about some of the levels by which this could be done: If you had the right equipment, you could melt it and create whatever you wanted. However, if you are just using it a raw resources, why not go to an asteroid? If you want to use some of the resources as is, you could probably have some use. What would it take? Well, ...


7

At NASA, the type of vehicles you are describing go by the name Orbital Transfer Vehicles (OTVs). While none are currently funded or planned for, there were studies underway as recently as the 80s. Upper stages are sometime considered "space tugs" but I don't think that is a good description as they are only used once and are really just, well, an upper ...


6

There are a couple of things that have to be considered in this assessment. What is the total launch cost? How does the cost of the components scale, with changes in the launch? How difficult is the assembly? Big rockets typically are more efficient, especially if they are aerodynamically shaped. However, there is somewhat of an optimal ratio of diameter ...


6

I'm interested in any considerations to EML2 docking that are different to orbital docking. Some aspects of EML2 docking will be much easier. Some will be a bit harder. Some, we'll have to completely rethink. On the plus side, the EML2 region is much closer to flat space than is low Earth orbit. Docking will be much more intuitive. That pesky orbital ...


5

The debris ranges from complete, defunct satellites to flecks of paint. Satellites are put into a graveyard orbit or deorbited at the end of their lives, so they're not a concern. That leaves random crap (bits of insulation etc. coming off during stage separation, and the wreckage of a couple of collisions), which would have to be reduced to raw material to ...


5

Should be noted that Zvezda was planned to be launched soon after Zarya and Unity. It was delayed by Proton launch failure in 5 July 1999, and by another failure in 27 October 1999. https://en.wikipedia.org/wiki/List_of_Proton_launches_(1990%E2%80%9399) There was a requirement of at least 2 successful Proton launches before putting ISS components on it. I ...


4

Legally, this would be outlawed by the Outer Space Treaty of 1967, as well as the "daughter" treaties which dictate ownership of space objects. There is currently no law of salvage in space, such as there is on the earth's oceans. Whatever is launched belongs to the launching country or launch provider unless specifically given to a third party. So, even if ...


4

Making this a community wiki answer so others may add to it as they see fit: Advantages LEO assembly allows less mission risk if assembly does not go completely as planned. It's much easier to schedule and launch replacements or corrective hardware. LEO assembly allows for checkout and stress testing of hardware in a location where failure allows a safe ...


4

Better by what criteria? It's a tradeoff. Assembly from parts makes less efficient use of mass, due to the need for mating structures and a larger area of hull wrapped around smaller bits of volume, and greater complexity due to the need to design all the separate parts and assemble them in orbit. A modular spacecraft is also unlikely to be able to ...


4

Obvious caveat: the BFS isn't completely real right now, and what The Public knows about it is even less limited than whatever has been finalized in the design. I guess what I'm saying is some of this might sound stupid, but I claim that's not my fault. First question: Based on what we know about the ITS per the video on it, the BFS will be vertically ...


3

tl;dr the P6 truss had a special cooling system installed on it to provide thermal control of the proto-ISS until the full external thermal system was installed. This system incorporated two special radiators that were eventually stowed. For a spacecraft that had to provide all the normal functions (GNC, life support, thermal regulation, propulsion, etc.) ...


3

Robert Zubrin of Mars Direct fame has discussed the issue of how to return to the Moon, to stay, to do ISRU (In Situ Resource Utilization) all without the need for neither SLS nor the Lunar Toolbooth Gateway. You can read more details here: New Atlantis article: Moon Direct and here: Mars Society article: Moon Direct Short version: A Falcon Heavy can ...


3

The building of things is already split across nations - but it's much easer to assemble them here on Earth than remotely in space. Due to various factors, but mostly due to surfaces increasing as the square of size, and volumes increasing as the cube, it is more expensive to have two launches of one tonne than one launch of two tonnes. There are a lot of ...


3

There has been at least one semi-recent (2012) paper on the topic. The design is called the Flexcraft. There is a wikipedia article here. It appears to be purely in the proposal stage. The concept was more common in the '50s and '60s. You can see a lot of concept art at the wonderful Atomic Rockets page (search the page for "A space pod is a small ...


2

Prior to the Shuttle approach, there were really two modes of station building. Skylab first, which used a Saturn-IVB third stage outfitted before launch, and was basically all done in a single launch. (Dry workshop. Wet workshop idea was launch it full of fuel with a big payload and have the stuff submerged in the fuel/oxidizer). Salyut/Mir second, used ...


2

LEO is a bit dangerous in my book. If anything goes wrong you may not have enough of a margin to fix things. Put the station in a little higher orbit and make your deliveries to LEO and use tug to push building blocks to the higher orbit. That way you have advantages of both. A big problem with LEO is the space junk. When you are done the higher orbit is ...


2

The Dragon trunk is mostly a simple structure used to provide an interface between the second stage and the Dragon. It carries the solar panels, and allows for carrying bulky unpressurized cargo. It has no orbital maneuvering system, docking module, or anything else of use. On the other hand the Chinese Shenzou design is heavily influenced by the Soviet/...


2

The current trunk design has no thrusters and no flight control system. It's basically an empty shell that needs a Dragon to control it. The trunk doesn't have a means to attach it to the ISS. You'd need a parking spot on the ISS and an attachment mechanism on both the ISS and trunk. Doable, but not present in the current version. The trunk is not built for ...


2

The Orbital Sciences entry in the CRS program is the Cygnus vehicle. It has two components a cargo module and an orbital module. While not officially offered as a tug, it functions as a tug to bring the cargo module to the station. While the Cygnus payload module is not that big, it seems likely that Orbital could provide such functionality, should the ...


2

Googling around, I couldn't find any mention of a space tug program being officially announced by NASA. From Wikipedia: A reusable space tug was studied in 1969 as part of NASA's Space Transportation System, but went unfunded, as did every other component of that system except the Space Shuttle.


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