Bigelow Space Operations – B330 Space Station | Hacker News Reader

Bigelow Space Operations – B330 Space Station

bigelowspaceops.com

70 pointsChuckMcM34 comments

Can we attach a few of these units together, like 10 units, and then spin them up to create a rotating space station?

No kidding! Sadly it seems they don't plan this far ahead...so much potential: https://www.youtube.com/watch?v=TmLWxptFFYc&feature=share

Imagine a Context where you could invest in space companies using crypto tokens and then users or other entities with technical expertise could vote on product development ...

I do really hope we see something like it in the next 5-10 years.

https://blog.bigchaindb.com/starships-and-tokens-d8c32728a24...

I like how you could throw one of these up on a single Falcon Heavy launch. The lack of windows seems challenging to me, if you're going after tourists I would think this would be a priority feature.

I imagine that one could attach a "window section" to one of the docking ports. You could build those things up modularly kind of like the ISS.

I wonder how big one of these inflatable stations could get if your strap it on top of the BFR ^^'.

Any takers for a quick, back on the envelope calculation?

Although, come to think of it. One reason why the BFR has such a f* huge passenger capacity is because structure that would normally be dead weight and only used for payload packaging like the nose cone and adapter, are replaced by the spaceship itself.

Give me a few minutes, and I'll see if I can come up with a rough number.

Edit: got something, commented above.

Ok, I have a very rough number for the possible size if launched on a fully reusable BFR with payload based on a talk Elon gave in late 2017 [1]. I'm assuming that internal space scales roughly linearly and that deflated width isn't a factor when flying on the BFR, so I could be way off.

Here's the math:

Fully reusable BFR can do ~150,000 kg to LEO, Bigelow B330 weighs ~50,000 lbs or ~22,676 kg [2]

B330 has 330 m^3 of space [3], and the BFR could lift roughly 6.6 B330's

330 * 6.6 = 2,178 m^3

So, with my assumptions, a fully reusable BFR would be able to lift a Bigelow module with about 2,178 cubic meters of internal space. Of course, I'm probably forgetting something and my assumptions are probably off; however, I think that it's safe to assume that a fully reusable BFR could lift a very big module to LEO.

[1] http://www.spacex.com/sites/spacex/files/making_life_multipl...

[2] http://www.bigelowspaceops.com/b330.php

[3] https://en.wikipedia.org/wiki/B330

Edit: based on what @hughes said below, it looks like I did forget something: volume scales at a different rate than surface area. So it looks like the internal volume would be more like 5600 m^3.

Approximating the station as a hollow shell of constant thickness, the mass would scale with the surface area. The volume would scale proportional to the surface area to the power of 3/2.

So 6.6x the mass gets you 6.6x the surface area, which gets you about 17x the volume, or ~5600m^3

Ah, figured I was forgetting something. Editing my comment to reflect what you said. Thanks for the correction!

Even though volume grows with 3rd power of size and area with 2nd, you'd still better calculate volume here as 2nd power. The reason is that you usually want to have progressively thicker walls when the size of the object grows, and that - linear with diameter - growth of thickness reduces available weight, so the volume still grows as 2nd power.

But even then FH would deliver huge volumes on orbit.

Ok, here's the kicker!

I spun heh this a bit further, and imagined an inflatable torus with the same surface area and thus weight.

With an inner radius of 30m you get a comfy diameter of ~2.5m. [1]

If we throw this into spincalc [2] and ask it to compute the rotation rate of such a station to get mars gravity levels of 0.376g. Then we get ~3.2 revolutions per minute, which is well within human comfort levels according to this study [3]. (4 is the max)

So yeah this would basically allow you to shoot up a retrofuturistic rotating space station with comfortable gravity levels for future martians in one shot. Wow!

[1] http://www.wolframalpha.com/input/?i=outer+radius+of+a+torus...

[2] http://www.artificial-gravity.com/sw/SpinCalc/

[3] http://www.spacefuture.com/archive/artificial_gravity_and_th...

That is really cool. Outside of cool space stations, that could definitely be a useful addition for interplanetary spacecraft (like the spinning component of the Hermes from The Martian).

Yeah, but attaching two spacex interplanetary spaceships nose to nose via a tether and giving the pair spin with the maneuvering thrusters would probably give you a s*load more space with much more comfortable artificial gravity.

Still the scifi character of the ring is neat :D

If I remember correctly, the B330 is too big in terms of width to launch with the current fairing on a Falcon Heavy; although I think that Elon indicated at some point that they could do bigger fairings at customer request.

It'd definitely be awesome to see essentially an entire space station go up on top of one FH though.

It would be better to design the B330 to be its own fairing with just a launcher specific adapter ring at the base. That would provide a significant weight savings, reduce the volumetric constraints, and eliminate fairing separation mishaps.

Oh I like that idea. I'm not sure how it would expose the docking ports once in orbit though.

Fairings are an extremely tricky thing to design, and the B330 is not made out of materials that can survive a launch.

Falcon's fairing is about 5 m diameter, B330 is about 6 m diameter. Don't think B330 can't fit given that when not inflated it has smaller diameter.

It's actually the length of the fairing that's the issue. The Falcon fairing can only accommodate payloads 11.4m long. The BA 330 is 16.8m long, and that doesn't compress at all.

> The Falcon fairing can only accommodate payloads 11.4m long.

Are you sure? I was under impression I've read about 17 meters long fairing. Maybe for FH only.

Edit: "The fairing itself is 43 feet high and 17 feet wide, big enough, as the company points out, to hold a city bus." http://www.cleveland.com/science/index.ssf/2013/05/nasas_plu... So, 43 feet or 13,1 m. And this perhaps include nose part, which is conical rather than cylindrical.

OTOH Bigelow can definitely adjust the size. And from what I saw on the explanation video, B330 grows both in diameter and in length when deployed. So - ?

Yeah, here's a diagram showing the inner fairing dimensions:

https://marssettlement.files.wordpress.com/2013/05/falcon9fa...

"Fairing 2.0", which just flew yesterday for the first time, is larger but only by a few inches.

It would indeed be possible for the Heavy to have a larger fairing, but Musk has said he'll only do that if the BFR looks like it's going to take longer than he expects.

Note that Bigelow can choose any length they want. If they want to launch on ULA, their current plan is fine.

why have a fairing? couldn't you reinforce the station.

Or what about make the second stage a station/module itself.

You could attach something like the ISS Cupola module to it.

https://en.wikipedia.org/wiki/Cupola_(ISS_module)

> The lack of windows seems challenging to me

I think it actually has 4 windows along the torso (i.e., not just the end caps), albeit fairly small.

See the slides here

https://www.smithsonianmag.com/science-nature/robert-bigelow...

and the first image here

http://newsok.com/u.s.-company-plans-to-send-inflatable-hote...

Could they land something like this on the moon and build a quick habitat?

I think the real challenge would be getting it to the moon. A falcon heavy ought to be able to get it into orbit, but then you're still a lot of Delta-V away from a moon landing.

Neil Armstrong and Buzz Aldrin did it almost 50 years ago in a tin can, built from a box of scraps!

Landing this thing on the moon would be a dramatically bigger technical challenge than the Apollo Lunar Module.

The B330 supposedly has a mass of 50,000 lbs, which apparently doesn't include any significant propulsion mechanism. The LM was less than 10,000, including engines, and still required about 24,000 lbs of fuel for a round-trip. Even if you assume that you could just scale up the design by a factor of 5, you're still talking about something that's too big to launch on a Falcon Heavy.

Fueled LM had mass about 15 tons, empty second stage - 2 tons, second stage fuel - about 3 tons. So to land B330 with mass 50,000 lbs you'll need about 75,000 lbs of fuel (and then scale some more because you need to include tanks and engines).

Not trivial... but I think can be done with another launch of a boosting stage.

This would be my guess as well. Launch the habitat, and then launch the translunar tug/landing apparatus.

Ok, we need about 3.1 km/s for translunar injection, about 1 km/s to enter Moon orbit and then some 2.4 km/s to cancel orbital velocity (1.7 km/s) and land. Total is 6.5 km/s . For storable fuels with Isp of 3.5 km/s mass ratio becomes exp(6.5 / 3.5) = 6.4, so if you want to land 50,000 lbs mass on the Moon, you have to start from LEO having 320,000 lbs or 145 metric tons. More than Saturn V and more than twice FH. And here we don't even include tanks for fuel and engines which will get us to the Moon.

We can consider LOx/LH2 stage, which improve masses considerably. Wonder why SpaceX didn't buy XCOR yet?.. http://space-access.org/updates/sau148.html

So it's doable with at least one docking, and perhaps more. Maybe refueling should be involved as well.

Could they launch an extended second stage into orbit on a Falcon 9 and then use that second stage for TLI? Would that pencil out weight-wise?

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