The original note, as written at the time
A mask and tank drone-like module that is able to navigate rapidly to the point of need, say during the sudden depressurisation of a space ship or space chamber. It can also rapidly navigate to a stranded spacewalker. I am thinking we could also have mini orbs — a kind of all-encompassing suit-drone shaped like a sphere with a large glazed surface for 360 degree views. These modules should be abundant on a space ship.
Ongoing development
A mask-and-tank drone-like module that can navigate rapidly to the point of need — a sudden depressurisation of a ship or a chamber, or a stranded spacewalker. And spherical suit-drones with a large glazed surface, giving a 360-degree view, distributed abundantly through a ship.
The distribution is the design and the number is the point. A rescue device that must be fetched has a response time measured in the vehicle’s transit; a device that is already in every corridor has a response time measured in metres. In a depressurisation, the difference between thirty seconds and four minutes is the entire outcome.
The sphere is a good shape for this and not only for the view. A sphere has no preferred orientation, so a panicked person can enter it from any side, which matters enormously when the person is not thinking clearly and the air is leaving.
The 360-degree glazing is a psychological design decision as much as a practical one. A rescue capsule with a small window is a coffin you can breathe in. One you can see out of is a lifeboat.
Making them abundant changes the economics of the ship, and it should be argued as such: they are not equipment, they are structure, like a handrail. A ship that cannot afford enough rescue modules cannot afford the crew.
The design question worth adding: they should be usable without training, because the person who needs one will be breathless.
Anywhere a person can go, a rescue must already be there.