Vast, a startup for quote: human habitation, first in LEO, and then beyond

[edzieba]

Because if your docking port’s center is even slightly misaligned with your axis of rotation, it will wobble around and make docking impractical. Better to offload that to the station side.

All currently flying vehicles that use the IDS standard have the docking port axis aligned with the axis of rotation: Dragon 2 - crew and cargo - Cygnus, and Starliner.
Dream chaser may or may not have CoM aligned with the port axis, but Shooting Star already has the port offset from the lifting-body axis so that may already be the case - it makes docking to 'stationary' targets easier anyway (uncouples translation from rotation) so already desirable, and makes the docking port and launch adapter ring concentric for balanced mounting on the launch vehicle, so doubly desirable.
HTV-X is CBM so rules itself out without an integrated adapter, at which point you can position the adapter along the axis of rotation.
HLS Starship mounts its proposed nose port along the axis of rotation.
That leaves non-HLS Starship as the odd one out, and nobody outside of SpaceX even knows whether it will host an IDS port, let alone where that port will be located (and those that do know likely also know how often that presence and position changes).

[JohnFornaro]

All currently flying vehicles that use the IDS standard have the docking port axis aligned with the axis of rotation.

Semantic confusion about a non-rotating hub aside, note that the ISS is, well, non-rotating.

There is no a priori reason or law of physics that IDS-II cannot be developed for the nose of Starship.  Starship could also rotate along its long axis to synchronize with the rotation of the space station.  The fans of this type of docking can work out the assymetric forces and assorted complexities involved.

Starship could also have a port mid-ship.  Then Starship would have to synchronize its rate of tumble with that of the space station. The fans of this type of docking can work out the assymetric forces and assorted complexities involved.

Starship could also have at its nose, a removable transfer craft which would be loaded, attach itself to the station, be unloaded and returned to Starship.  The fans of this type of docking can work out the assymetric forces and assorted complexities involved.

Starship could also have a pair of shuttle type bay doors midship, where the transfer vehicle could launch from.  Stop me if you've heard it before, but: The fans of this type of docking can work out the assymetric forces and assorted complexities involved.

[toren]

Maybe this back and forth on space station architecture deserves its own thread, since it's drifted far from the Vast PR prototype?

[Nomadd]

Because if your docking port’s center is even slightly misaligned with your axis of rotation, it will wobble around and make docking impractical. Better to offload that to the station side.

All currently flying vehicles that use the IDS standard have the docking port axis aligned with the axis of rotation: Dragon 2 - crew and cargo - Cygnus, and Starliner.
Dream chaser may or may not have CoM aligned with the port axis, but Shooting Star already has the port offset from the lifting-body axis so that may already be the case - it makes docking to 'stationary' targets easier anyway (uncouples translation from rotation) so already desirable, and makes the docking port and launch adapter ring concentric for balanced mounting on the launch vehicle, so doubly desirable.
HTV-X is CBM so rules itself out without an integrated adapter, at which point you can position the adapter along the axis of rotation.
HLS Starship mounts its proposed nose port along the axis of rotation.
That leaves non-HLS Starship as the odd one out, and nobody outside of SpaceX even knows whether it will host an IDS port, let alone where that port will be located (and those that do know likely also know how often that presence and position changes).

The axis of rotation will change with fuel and cargo. Maybe a couple of movable counterweights in the hub would keep everything balanced. In fact, you might need those to keep the whole station balanced anyhow.

[edzieba]

All currently flying vehicles that use the IDS standard have the docking port axis aligned with the axis of rotation.

Semantic confusion about a non-rotating hub aside, note that the ISS is, well, non-rotating.

The ISS rotates, just slowly (one per orbit when not actively reorienting).

[Robotbeat]

Because if your docking port’s center is even slightly misaligned with your axis of rotation, it will wobble around and make docking impractical. Better to offload that to the station side.

All currently flying vehicles that use the IDS standard have the docking port axis aligned with the axis of rotation: Dragon 2 - crew and cargo - Cygnus, and Starliner.
Dream chaser may or may not have CoM aligned with the port axis, but Shooting Star already has the port offset from the lifting-body axis so that may already be the case - it makes docking to 'stationary' targets easier anyway (uncouples translation from rotation) so already desirable, and makes the docking port and launch adapter ring concentric for balanced mounting on the launch vehicle, so doubly desirable.
HTV-X is CBM so rules itself out without an integrated adapter, at which point you can position the adapter along the axis of rotation.
HLS Starship mounts its proposed nose port along the axis of rotation.
That leaves non-HLS Starship as the odd one out, and nobody outside of SpaceX even knows whether it will host an IDS port, let alone where that port will be located (and those that do know likely also know how often that presence and position changes).

Starship (non-HLS) will need an IDS port for Project Polaris. Also, I kind of suspect they’ll reuse a lot of the HLS design for that mission.

[Twark_Main]

The axis of rotation will change with fuel and cargo. Maybe a couple of movable counterweights in the hub would keep everything balanced. I fact, you might need those to keep the whole station balanced anyhow.

Yes, this.

The movement will possibly be in the form of pumps and fluid tanks/bladders.

[Twark_Main]

I just mentioned in another thread that it's important to be working on the right "long pole" problem. But I haven't yet said what I think that is.

For Vast, I believe their long pole is cheap (possibly autonomous) reconfiguration of a modular space station. This lets them scale to arbitrary size without the costly conventional ISS approach.

How?

   • Each module is its own independently-maneuverable autonomous spaceship.

   • Each module is relatively cheap (serial batch production with extensive commonality between modules).

   • Critical inter-module connections automatically connect when joined (non-critical interfaces can still be done by hand). This means very early construction has the option to be 100% unmanned.

   • An incremental scaling approach that generates revenue along the way.

Want to build a big torus? Sure! All you do is gang together curving modules instead of parallel ones. The hull itself don't even need to be curved, you can just mount the docking ports at an angle and only curve the interior floors.

[Coastal Ron]

I just mentioned in another thread that it's important to be working on the right "long pole" problem. But I haven't yet said what I think that is.

For Vast, I believe their long pole is cheap (possibly autonomous) reconfiguration of a modular space station. This lets them scale to arbitrary size without the costly conventional ISS approach.

How?

   • Each module is its own independently-maneuverable autonomous spaceship.

That will make the overall design far more expensive, and that hardware becomes dead mass once all the modules are assembled. It would cost far less to just use a space tug to move the modules.

   • Each module is relatively cheap (serial batch production with extensive commonality between modules).

As one of the few people with manufacturing experience on NSF, I just want to point out that serial production does not automatically mean "cheap". It is the design that dictates cost, such as whether you add engines to every module or not (related to my comment above) instead of using a space tug to move the modules once they are in space.

Having a standardized design is another factor, regardless if the modules are made individually, in batches, or in serial production.

   • Critical inter-module connections automatically connect when joined (non-critical interfaces can still be done by hand). This means very early construction has the option to be 100% unmanned.

The first manufacturing company I worked for made electrical connectors. The big cylindrical ones you see on military equipment, and in space. There are varieties of those that can do blind connections (i.e. just push together the equipment), but insisting every connection be made this way is, in my opinion, going to cost more in the long run. Having one astronaut go through and hand connect everything won't take but a day, so I'm not sure why that would be perceived as something expensive or bad. Plus it costs more to make automated connections, so there is that too...

   • An incremental scaling approach that generates revenue along the way.

Which is something that everyone is always hoping to have, but it is tough to get. This is such an immature market that it is tough to understand which portion of the market to focus on first.

[Paul451]

   • Each module is its own independently-maneuverable autonomous spaceship.

I can't see anything on their website that even hints this.

Want to build a big torus? Sure! All you do is gang together curving modules instead of parallel ones.

You also need modules with extra ports to serve as junctions (to allow modules to be used as spokes, at right-angles to the torus), and a completely different type of module or modules to be used for the hub. And the forces on a docking/attachment system that hangs "vertically" in a baton is very different from the torque on modules that hang "horizontally" from each other.

(A wheel is a more complex beast than a stick. Who knew.)

[rsdavis9]

Your basic hexagon is really just 6+6 batons and a central hub.
6 batons around the outside.
6 batons making the spokes.
one central hub.

[electricdawn]

But you have to connect these "batons" at an angle, and in a three way direction, so you need an intermediate piece, which would complicate the construction quite a bit.

So you need a three-way connecting piece for the torus and a six-way hub in the middle. Probably not cheap and probably not the initial goal for Vast.

Could be something they MIGHT think of much later on. Could be.

[rsdavis9]

But you have to connect these "batons" at an angle, and in a three way direction, so you need an intermediate piece, which would complicate the construction quite a bit.

So you need a three-way connecting piece for the torus and a six-way hub in the middle. Probably not cheap and probably not the initial goal for Vast.

Could be something they MIGHT think of much later on. Could be.

Sort of when you have a single baton working whats the next step.

I also think that a "soft" connection to the single baton might be a good first step.
When the baton is not rotating and being outfitted then a hard dock.
But when the baton is rotating, a starship rotating next to it and vacuum transfer of stuff between the two might be required to not upset the rotation of the baton.
Hard to picture the forces when a starship almost as massive as the baton tries to dock while rotating at 4 rpm.

[Vultur]

Any idea of funding sources/investment or timeline for this?

[electricdawn]

Well, any "soft" connection would still be a straight line, unless you go for some flimsy... I don't know, I'm not a materials expert... canvas... thingy with three docking adapters built into it. That would just float around and knot themselves up.

Unless I completely misunderstand you.

So, I'm a total layman, but if you have a central hub that is rotating, and it has the central docking port for a space ship. Is it so impossible for - let's take for example Starship - Starship to rotate around its vertical axis at 4 rpm and actually synchronise it to the station?

Should be manageable to compute with a C-64... Unless there's mechanical stresses I'm not accounting for.

What am I overlooking?

[edzieba]

if you have a central hub that is rotating, and it has the central docking port for a space ship. Is it so impossible for - let's take for example Starship - Starship to rotate around its vertical axis at 4 rpm and actually synchronise it to the station?

No impossibility, just a minimum moment of inertia required for the station to avoid the instability issue due to the intermediate axis issue. Starship is big, so that minimum moment of inertia (and thus mass, essentially) is larger than for any other visiting vehicle, though other visiting vehicles do exist and so can be used when visiting smaller stations without the need for despin (or despun hubs with rotating gas type seals, or similar setups).

[JohnFornaro]

The ISS rotates, just slowly (one per orbit when not actively reorienting)[/url].

Good catch.  It also rotates around the Sun.

Edit.  And, [checks notes] around the center of the galaxy.

[bad_astra]

It's all kremlinology until we see something more substantial than a tiny image.

[Twark_Main]

The ISS rotates, just slowly (one per orbit when not actively reorienting).

Good catch.  It also rotates around the Sun.

It revolves around the Sun. Its rotation doesn't vary annnually, nor does its orbit around the Earth vary to compensate (eg SSO). That's why the ISS experiences high beta angle conditions at certain times of year.

By contrast, Vast's space station will likely need to precess their rotation axis around once per year, keeping the spin axis pointed at the Sun.


I suspect RSSs will eventually demand relatively tight aiming, with the Sun ~exactly on the spin axis. For early stations you can just cover the windows. For later stations though, imagine this video but 10x worse and with the added fun of motion sickness:



A high efficiency electric thruster, mounted on a gimbal at one or both ends, could easily precess the station around over 1 year. It could also, at the same time, reboost the station. It's simple vector addition, after all.

With an arcjet you could even use waste CO₂ and/or CH₄ from the ECLSS.

[Twark_Main]

It's all kremlinology until we see something more substantial than a tiny image.

Just personally, I wouldn't call a detailed 1600×790 image "tiny."

Also literally the first thing I said. 

They updated their website again, this time they have a picture!! Time for some Kremlinology...