In the relatively realistic (hopefully), near future, scifi book I am writing I am at a point where I am describing the observation deck of a large ship belonging to a wealthy "business man" (see space-age mob boss). The idea is that his private yacht/destroyer is unique because the observation deck is a ring that wraps around the ship externally, with roughly half of its exterior surface being essentially transparent. This would give the effect that while inside the observation deck the floor is completely clear and an external view of space would be visible downward as well as through several front and rear facing windows (think Space Needle or Sears Tower).

This is also unique, because in my book most of ship design is very submarine-esque. There is no artificial gravity, so crew still uses simulated gravity through rotating rings (meaning no "gravity generator" or "gravity plates" BS). The design of the ship hasn't really changed too much from a 2001 Space Odyssey type design, except that the entire ship has a sort of armor shell around it, giving it that submarine look.

My main concern is:

Would radiation and/or heat build up be a concern for having so much of the ship not behind some sort of protective shielding?

My current understanding is that existing designs for glass (or transparent composites) on spacecraft isn't great at reducing these risks, therefore the windows are small (and possibly have removable covers) to block as much heat and radiation as necessary. I could be wrong about that of course though.

Some secondary questions might be:

Is current glass/window technology at a point where it is able to effectively resist these forces?

If not, what sort of limits would I have on spaceship window placement and/or design?

Also, no energy fields or radiation deflector hocus-pocus. I am actually planning to use handwavium to get this appearance anyway, but I would prefer it be a unique aspect of the ship, rather than something that is totally normal and relatively achievable with known engineering standards.

Edit: I guess I hadn't thought to take speed of the craft into account so I would say it takes about 3 to 4 months to reach the heliopause from the inner planets (Venus, Earth, Mars). I probably did my math wrong, but thats roughly 1 million km/h max speed (I think we will go metric in space). I know thats 22000 times faster than the space shuttle has ever gone, so I suppose I'm gonna have to handwavium that one. Thanks for pointing out a huge flaw in my physics though.

Edit: I think I may already know my answer, but I am adding a little more just to further the discussion some before I make a choice. I am avoiding the projected screens and specifically looking for actual windows. The reasoning being that this is the unique feature of the ship. For all the reasons not to do so, that's why I want to. It's like the mob boss is showing off that he doesn't fear the risks of attack, and to give it a kind of "see with my own eyes" kind of feel. Like arguing that vinyl records sound better than MP3s despite the many reasons they are more convenient.

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    $\begingroup$ A comment... you call gravity plates "bullshit", and radiation deflector "hocus-pocus"... immediately followed by "I am [using] handwavium". May I suggest you follow the zeroth rule of conduct on your all glass observation deck: "No rock-throwing"? :-D Also, if you need a transparent radiation shield... use water. Sandwich a layer of water between two thinner glass panes and you are good to go. Water shields you from gamma, neutrons, and beta radiation very effectively (alpha and heavier stuff is no issue because even tissue paper stops that). $\endgroup$
    – MichaelK
    Commented Jun 19, 2018 at 15:30
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    $\begingroup$ "Transparent aluminum... that's the ticket!" $\endgroup$
    – Spudley
    Commented Jun 19, 2018 at 16:11
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    $\begingroup$ @Spudley transparent aluminum exists, it's called aluminum oxynitride or ALON, it has three time the srenght of steel and is a better ballistic protector than most bulletproof galsses in existence, it has many of the same properties as sapphire and similar strength. $\endgroup$
    – Efialtes
    Commented Jun 20, 2018 at 2:13
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    $\begingroup$ "I think we will go metric in space" :-D "We" (the rest of the world) went metric a long time ago! ;-) $\endgroup$
    – Aaron F
    Commented Jun 20, 2018 at 8:48
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    $\begingroup$ More accurate: There are two types of countries: Those which have switched to metric and everyone knows it, and those who have switched to metric for everything critical and pretend they haven't for everything else. $\endgroup$ Commented Jun 20, 2018 at 20:30

6 Answers 6


Transparent Aluminium

This is actually a thing these days, its called ALON (Aluminium Oxynitride), this would at least have the strength required for the job, its actually what the reinforced perspex in the observation pod for the ISS is being replaced with, and those current windows are scratched quite badly these days, ALON doesn't scratch easily. Adding a polarizing layer around the outside would reduce heat build up a little bit as would a slight reflective coating, so some of the suns energy would be reduced to slightly more manageable levels.

Material Density

ALON is denser then glass per cm of thickness so that means it would be a little bit better at Gamma radiation absorption/shielding. as the best thing that stops Gamma Radiation is having lots of atoms of "something" between you and the radiation source.

When mixed with WillK's magnetic field generator and cover shielding which can be retracted when conditions are optimal would allow you most if not all the of the shielding you need.


As for speed issue you've figured out, here's a little bit about the Casini space probe:

The maximum speed clocked by Cassini was 44.0 kilometers per second (98,346 miles per hour) relative to the Sun on June 25, 1999. Relative to Saturn, the spacecraft reached 30.7 kilometers per second (68,771 mph) during the Saturn Orbit Insertion maneuver on July 1, 2004

Most of this was done with gravity assists, so you could achieve some of the speed you need using this same method, again if you maximise the Oberth Effect:

Oberth maneuver, is a maneuver in which a spacecraft falls into a gravitational well, and then accelerates when its fall reaches maximum speed.1[2] The resulting maneuver is a more efficient way to gain kinetic energy than applying the same impulse outside of a gravitational well. The gain in efficiency is explained by the Oberth effect, wherein the use of an engine at higher speeds generates greater mechanical energy than use at lower speeds. In practical terms, this means that the most energy-efficient method for a spacecraft to burn its engine is at the lowest possible orbital periapsis

So your ship doesn't have to be super overpowered with handwavium if you take advantage of the correct orbital manouevers.

transparent aluminum http://www.ohgizmo.com/2012/05/09/did-you-know-that-transparent-aluminum-exists/

Sorry to wade in but I wanted to see this stuff. Now you can too! I could not find the ISS windows but found a lot about bulletproof windows. There are some awesome videos testing it against 50 caliber rounds.

Cheers for the Pic Willk! the ISS windows was in a press realease i read a couple of months ago, if i find it i'll post it.

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    $\begingroup$ Silicon carbide and sapphire can both be used for windows (the former also in armour) though we can't yet grow them that big. But obviously artifical diamond is the way to go for the discerning space-tycoon's interplanetary yacht. In a few centuries we should be able to grow it both large and transparent enough $\endgroup$
    – Chris H
    Commented Jun 19, 2018 at 15:17
  • $\begingroup$ "Alon is denser then glass so that means it would be a little bit better at radiation absorbtion/shielding." per cm of thickness, yes. Not per kg, as shielding properties are ≈ proportional to the kg / square meter between you and source. $\endgroup$
    – Mołot
    Commented Jun 19, 2018 at 15:21
  • $\begingroup$ @Mołot, i'm not sure i understand your point, i didn't mean replaced it by the kilogram, but ensure that there was a sufficient thickness to provide the adequate strength required, and that amount would be required to be sufficiently thick that its density per cubic cm would provide better radiation shielding that regular glass or worse yet the Reinforced Perspex that is currently used on the ISS, sorry if you meant something else $\endgroup$ Commented Jun 19, 2018 at 15:31
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    $\begingroup$ If aluminium oxynitride deserves to be called "transparent aluminium," then let's rename sugar as "sweet carbon." $\endgroup$ Commented Jun 20, 2018 at 3:11
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    $\begingroup$ @BladeWraith What you got wrong is that gamma is not the only radiation there is. Alpha, beta and neutron are common results of nuclear reactions. Solar wind is pretty much a stream of protons (in case of other stars it contains ions of heavier elements too). Cosmic radiation is made principally of very high energy protons with some betas and heavier nucleus. Then, there's the fact that charged particles emit bremsstrahlung, and all particles may cause showers of secondaries due to inelastic scattering. Shielding needs to be designed specifically to radiation it's supposed to shield against. $\endgroup$
    – M i ech
    Commented Jun 20, 2018 at 13:05

Since you haven't given any data on travel velocities this is a bit awkward.

Assuming typical LEO orbital speeds small windows could be made using modern materials, the ISS has several.

For any larger window, or any windows at all at higher relative velocities, I would suggest ditching the transparency altogether while keeping the illusion of transparency. Build the walls of the observation deck using a single tiled high definition screen. From the outside it looks no different to a normal ship's hull, because that's exactly what it is. On the inside though it runs a live stream from external cameras giving a seamless 360° view of space around the ship. With good software the system can even track one or two people in the space and alter the perspective as they get close to the wall if necessary.

  • $\begingroup$ The segmented windows making up the cupola are not dissimilar to the glass floor in the CN tower. And I;m not sure a screen has the same bragging rights aspect. $\endgroup$
    – Chris H
    Commented Jun 19, 2018 at 15:10
  • $\begingroup$ A screen looks the same from every angle, so it would definitely not look the same. Even with good head tracking for a single person, their depth perception would still be able to tell that the stars on the screen weren't "infinitely" far away. Plus, indeed, bragging rights. $\endgroup$
    – Thomas
    Commented Jun 19, 2018 at 15:20
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    $\begingroup$ @ChrisH I'll take your word for it, glass floors give me the heaves. No it doesn't give you the same bragging rights but you're more likely to live long enough to brag. $\endgroup$
    – Ash
    Commented Jun 19, 2018 at 15:20
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    $\begingroup$ @Thomas There are companies currently working on - and demonstrating - Integral Imaging multiscopic displays that passively display different images at different angles. There is even supposed to be a mobile phone with similar displays released later this year $\endgroup$ Commented Jun 19, 2018 at 16:28
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    $\begingroup$ @ChrisH A bit of cursory research revealed that...the CN Tower's glass floors are a full inch thicker than the thickest pane of glass on the ISS's copula! The ISS just has 4 panes stacked on top of each other for each window, so that if a crack forms, there isn't an immediate air leak. science.nasa.gov/science-news/science-at-nasa/2001/ast14mar_1 $\endgroup$ Commented Jun 19, 2018 at 16:43

Open the observation deck when viewing conditions are good.

Imagine you have a deck on the front of your ship. Passengers can stand there and enjoy the sunset, or watch the stars. But not right now, because you are trying to outrun a storm and there are high winds and occasional big waves out there.

So too your observation deck. When conditions are right, field generators produce a magnetic levitation effect that keeps in passengers and atmosphere and repels incoming charged particles and meteoroids.

The magnetic field does not stop electromagnetic radiation. If it were just the field, the sun would be fierce if you were within a solar system. You would get tan fast. Just the crewman going out on deck in the storm wears a coat and hat, persons using your observation deck near a star would need protective gear.

Another option for radiation protection would be a space within the magnetic field (2 fields?) containing a radiation absorbing vapor - mercury vapor or the like. This space could be flooded with vapor to a greater or lesser degree, allowing a sunshade type effect and absorbing / reflecting a proportion of incoming radiation.

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    $\begingroup$ I like the idea of vapor filled windows for radiation protection. Technically we already use gas filled windows all the time on earth for a similar affect against UV rays and heat. I would prefer not to require special suits to go out on the observation deck, but I really like the idea of maybe an artificial magnetosphere around the ship. It's starting to go in the energy field direction I was avoiding, but its something I can put into words scientifically so it might work for me. $\endgroup$ Commented Jun 19, 2018 at 13:20
  • $\begingroup$ @TitaniumTurtle, i completely understand you not wanting Handwavium, and it may seem "energy field direction" but it s fundamentally good by our understanding of physics. so at least its not handwavium at all, and a good solution to part of your problem. anyone could read your story and look it up and go, "wow that's actually real," that's the best part $\endgroup$ Commented Jun 19, 2018 at 15:35
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    $\begingroup$ "and enjoy the sunset" ...uh... $\endgroup$ Commented Jun 19, 2018 at 20:30
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    $\begingroup$ What about a plasma window? en.wikipedia.org/wiki/Plasma_window $\endgroup$
    – Efialtes
    Commented Jun 20, 2018 at 2:18
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    $\begingroup$ @MathieuGuindon: The first paragraph of the answer (with the sunset reference) is an analogy involving an ordinary (i.e. wet ocean) ship. $\endgroup$ Commented Jun 20, 2018 at 15:09

From an engineering perspective, the issue with your design isn't so much the windows themselves; it's the seams.

We learned (via the de Havilland Comet) that windows have to be planned very carefully in a pressure vessel. Your spaceship is a pressure vessel. Therefore, ANY windows, hatches, or holes of any kind you put in it have to be designed to compensate for the pressure issues the hole creates. Aeroplane windows are now rounded for that very reason.

Sure, there are 'strong' materials that can also help, and UV shielding will also protect your people, but the safest answer for your mob boss is actually virtual windows.

Imagine a large deck with high def video screens all around. These screens are attached to cameras mounted on the outside. The effect is the same as a window, but much safer. It also carries a number of other benefits...

Firstly, because it's a screen, stock market values, monthly takings by the pushers or enforcers, other other relevant business info can be superimposed over the view so your boss can review business AND enjoy the show.

Also, because there are no windows, police ships can't send recon drones over and note that the boss is in the observation room so now is a good time to strike. Realistically, the boss (if he's on board at all) could be anywhere in the ship, as could the observation deck. This is similar in concept to a Combat Information Centre (CIC) on an aircraft carrier or large military ship; there's no obvious 'bridge' to aim at for a critical strike.

Finally, the bulk of your ship can be built as a solid shell - not one piece per se as that generates other problems in a combat situation, but certainly from the outside it can appear seamless and therefore it can be more resistant to attack and more submarine like in shape without problems.

Of course, you could always go the other way and build the entire shell out of transparent aluminium or similar, but personally I think that's giving too much away.

  • $\begingroup$ Honestly in space if a drone came up to you you'd see it coming from thousands of kilometers and blast it before it got close... $\endgroup$
    – Efialtes
    Commented Jun 20, 2018 at 2:20
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    $\begingroup$ @Efialtes perhaps not; space isn't all that bright so if you can use a propulsion system that doesn't emit a bright jet of gas, all you really have to do is make it small and paint it black and you may get away with it. LADAR would be an issue but we've had questions on the site about stealth tech in space before and how to counteract it. It's an interesting topic, albeit out of scope for the OP. $\endgroup$
    – Tim B II
    Commented Jun 20, 2018 at 2:33

You wouldn't bother with windows. Windows add a structural weak point and in fact the new planes being designed no longer have windows. They've replaced them with cameras and screens.

see Planes of the future

Now for spacecraft, it's more important. You want the bridge in the safest spot in the craft which means right near the center of the ship which is also impossible to have windows.

Crew quarters would also be in the centre and the least important areas such as storage would be on the outside.

The outer hull of the ship is structural plus contains the radiation shielding and plating against micro meteors. You wouldn't want to cut holes in it for people to look out of.


In short, there are plenty of glass options available today. The glass we come into contact with daily is fragile because it is very thin. Thick glass can be as hard as concrete.

Some structural considerations:

  • Sufficiently thick glass will be safe enough. IIRC (from a tourist trip), a glass sheet that's 12cm thick is as strong as concrete. It is also quite heavy, but metal would be similarly heavy in either case.
  • Debris impacting the glass is an issue, but not more so than debris impacting the hull. The only additional consideration is that dirt/scratches is more annoying on glass than on metal, but fuctionally it doesn't matter. However you solve the debris problem for the hull (shield? reparative hull?), the solution can be the same for the glass.
  • In order to cope with pressure differences, deep sea vessels tend to bulge their glass windows outwards. Keep in mind that for your spaceship, you'd need to bulge the glass inwards (because the inside has a higher pressure than the outside, which is the opposite of a submarine).

However, there may be other defeating factors here, not just structural integrity.

There is no artificial gravity, so crew still uses simulated gravity through rotating rings (meaning no "gravity generator" or "gravity plates" BS).

This means that your ring/passengers will be spinning around at a fairly fast rate. If you put windows everywhere, they are going to see the stars and sun rotate really quickly as well.

This will inevitably lead to nausea and feeling imbalanced. I don't think you can swing having both open vieweing spaces and a fast rotating artificial gravity ring.

Humans would be better at coping with zero G than with the visual disturbance from spinning.


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