I am a post-human adapted for permanent life in vacuum and micro-gravity. How might my physiology and biochemistry overcome the following challenges?
Please note I have a strong cultural aversion to augmenting my body in order to help me survive: i.e. enclosing myself in artificially-constructed protective shells, etc.
At this stage, I look similar to an enormous shining pangolin with interlocking plates of keratin-analogue that are alloyed with steel to protect against ionizing radiation. My radically engineered DNA and its unparalleled checksum and repair functions keep the doctor away. I can move these plates to help dissipate heat and - just like a Terran pangolin - curl up in a protective ball to shield my more sensitive parts. I have a reactive outercoating that allows me to alter my pigmentation (which I typically set to polished silver in order to minimise heat loss).
Space is a tough place to live and its very big, so you could say my metabolism has multiple redundancies. I can eat comets and asteroid material, using the spinneret on my tail to swaddle them in cocoons before supping on the extracted organics and minerals. I sift small concentrations of hydrogen from the interplanetary medium for use as a metabolic catalyst, and I'm a radiotroph, with the outer layer of my armoured plates coated in a melanin that helps me capture energetic rays to power my body. Stick me near a magnetic field and I'll even generate power like a dynamo.
Part 4: Movement
As mentioned, I look very similar to a pangolin. However, my prehensile limbs are much longer, identical, in that they are all hands, and there are five of them - I have a manipulator at the tip of my dextrous tail-limb.
In "artificial" environments such as the vacuum cities where I live, architecture helps me move primarily through the use of my limbs. I might use my tail-limb to stabilise me against a tether or outcrop while I work, or throw out some silk (similar to the stuff I use to cocoon comets) to reach locations or retrieve objects in the medium distance.
However, I'd also like to be able to move greater distances in a reasonable time, although I can ratchet down my metabolism to a somnolent hibernation for long journeys.
I'm wondering whether my body could incorporate a kind of chemical thruster, perhaps a nuclear salt-water rocket? As far as I understand, the NSWR reactions would occur outside of my body, presumably meaning that I wouldn't have to worry about heat so much. As I'm a radiotroph, I'm also wondering whether I could incorporate this into my metabolic pathways.
How might I move at reasonable speeds over medium to long distances within the system?
Note that I do not need to go interstellar (yet...)