Thursday, December 30, 2010

A Room With A View

It's an old theme - a pretty lady looking out a window. At least, it would be old if not for the location of this window:
Caption: We said farewell to our teammates Sasha, Misha and Tracy this weekend and they are safely back on planet Earth. Tracy in quiet reflection of an incredible journey…homeward bound[.]

Image credit: Astro_Wheels/NASA

This "picture window", the Cupola, was a recent addition to the International Space Station. Here's how its builder, the European Space Agency, describes it:
Cupola will become a panoramic control tower for the International Space Station (ISS), a dome-shaped module with windows for observing and guiding operations outside of the Station. It is a pressurised observation and work area that will accommodate command and control workstations and other hardware.

Cupola, ISS Observation Module
Plus, as the article mentions later, it's a great place for astronauts to just sit and watch the world go by.

It was installed early this year, during Space Shuttle mission STS-130

Caption: Cupola's 'eyes' open, its window shutters are moved. After the insulation blankets and launch restraint bolts had been removed from each of the seven windows, by spacewalking astronauts of the STS-130 crew, Cupola window shutters could begin opening.

Image credit: ESA/NASA

That's a view from outside the Cupola, with one of the shields pulled back so someone can see out that window. Given how complicated this thing is, it may not be a big surprise that, prior to the installation of the Cupola, there weren't a lot of ways to look out of the ISS.
The cupola will be like a mini control tower sticking out from the Tranquility node, as opposed to the other station windows, which are flush with the station’s exterior. Its seven windows – one in the center and six around the sides – will provide the only views of the outside of the station from the inside, in particular the Russian and Japanese sections. And with the station just about finished, there’s more to see out there than ever.

Endeavour to Deliver a Room With a View
Maybe this description of what the Cupola was meant to withstand explains why:
The windows are protected by external shutters, which can be opened by the crew inside with the simple turn of a wrist. Afterwards, the shutters are closed to protect the glass from micrometeoroids and orbital debris, and to prevent solar radiation from heating up Cupola or to avoid losing heat to space.

Each window has three subsections: an inner scratch pane to protect the pressure panes from damage inside Cupola; two 25 mm-thick pressure panes to maintain cabin pressure (the outer pane is a back-up for the inner pane); and a debris pane on the outside to protect the pressure panes from space debris when the shutters are open.

Caption: Internal view of Cupola during vibro-acoustic testing.

Image credit: Alenia Spazio/ESA

The 10-year on-orbit lifetime calls for user-friendly replacement of the windows while in space. The entire window or the individual scratch and debris panes can be replaced. To replace an entire window, an astronaut would first fit an external pressure cover over the window during a spacewalk.

ESA Node 3 and Cupola
Here's part of what the ESA site has to say about how the Cupola was constructed:
Cupola is a 1.6-tonne aluminium structure about 2 m in diameter and 1.5 m high. Its dome is a single forged unit with no welding. This gives it superior structural characteristics, which helped to shorten the production schedule and lower overall costs.

ESA Node 3 and Cupola
I'll bet it took a few tries to stamp out that puppy - not to mention a big press.

That vibro-acoustic testing the picture caption referred to is just one of a whole battery that have to be done in order to be certain that the assembled module and its parts won't shake apart, rust or rot, or fail due to unforeseen stresses. There are other tests to make sure that the electronics will work in all the conditions they need to, and that the software operates correctly in all foreseeable circumstances.

The cupola is part of the Tranquility module, which is meant to be a sort of all-purpose area, as well as a control room for station operations:
At 15 feet wide and 23 feet long, the Tranquility node will provide a centralized home for the station’s environmental control equipment – one of the systems that remove carbon dioxide from the station’s air, one of the station’s bathrooms and the equipment that converts urine into drinkable water, all of which is currently taking up space in the Destiny laboratory. And there’s enough room left over to house the station’s new treadmill and its microgravity equivalent of a weight machine, moving it out of the Unity node where it’s in the way whenever spacewalk preparations are going on inside the adjacent Quest airlock.

Endeavour to Deliver a Room With a View
I added that link to the article on the urine conversion equipment. It's an example of how the ISS and other space projects are still pushing technology that we may need here on Earth some day. Even if we don't, it's clearly going to be needed in space at some time in the future.

Sometimes I think that most people don't really understand what is so hard about building things like a space station. There are many reasons - it's work that's done where the assemblers have to bring everything they could possibly need, where the people doing the work must either do it in space suits, which allow almost no freedom of movement whatsoever, or by remote control. The things they're assembling are almost insanely complicated, with connections for electronic, plumbing, and pneumatic systems. But perhaps the most important reason is that it's such an incredibly harsh environment, where if radiation doesn't kill you and you don't run out of oxygen, some little speck of metal or rock moving at ten thousand miles per hour will. We're shielded from all that down here on the surface by the atmosphere and the magnetosphere.

The fact is we have it pretty good down here on the surface, compared to up there.

So it's great to see an engineering project of this magnitude up there and working. Four different space agencies, and no doubt dozens of contractors, all have to cooperate and communicate well enough to make sure that the different sections of the ISS all work together. That they've managed to do that says volumes about what people are capable of when they put their minds to it.

1 comment:

Suzanne said...

wow, amazing views out of that cupola .... and awesome engineering