New Mars Forums

Images from the Vasa Museum in Stockholm.

Pictures from Upsalla.

Recent discussions on terraforming have focused on the production of nanorods for warming Mars.
https://www.nextbigfuture.com/2025/06/m … suits.html

These are far more potent, mass for mass, than any greenhouse gas we have discovered to date.  If Starship provides low cost launch capabilities to Earth orbit, then we can begin making nanorods on Earth and launching them to Mars. These rods do not need to soft land on Mars to be deployed.  If the delivery vehicle can slow their approach to say 1km/s, they could be deployed by exploding the vehicle in the atmosphere or by allowing it to impact the surface.

If nanorods can be delivered high into the atmosphere, then their effective atmospheric lifetime will be increased.  Any warming that they deliver will result in atmospheric pressure increase.  This would reduce surface radiation levels and would make it easier for astronauts to spend substantial time exploring the surface.

Starship is 9m in diameter and 52m long.
https://en.m.wikipedia.org/wiki/SpaceX_Starship

So any enclosure needs at least those dimensions.  A nubian vaulting technique may work best in this application.  With Starship already pressure rated, a layer of regolith 1-2m thick would be needed for radiation shielding.

It is building complexity and failure modes into applications that really don't need it.  It presupposes that you have an electronic device with you, that it is charged and working, that software problems don't screw it up.  In other words, it is a bad idea.  Much better simply to write the menu up on the wall, or print it and stick it to the wall.  If the menu can be conveyed using chalk written on a slab of stone, then that is the best solution.  The resources involved are miniscule.  The simplest solution is almost always the best.  There is an aesthetic elegance to it as well.

The concept examined in this post is the use of diamond cutting discs, imported from Earth, to shape Martian surface rocks into thin tiles or bricks.  These are then bonded using a native grout or epoxy glue to form parabolic domes using a timbrel vaulting technique.  The practicality of this idea depends upon the local abundance of suitably strong rocks.  Regolith will need to be excavated and grade seperated to extract rocks of the right size.  These would then be cut to shape using diamond saws.

The exact lifetime of a cutting disc is difficult to estimate, as it depends upon the hardness of the material being cut.  This site gives an estimate of 10 months, based upon 20 hours per week of cutting.  This amounts to an 800 hour life expectancy.
https://support.hisglassworks.com/hc/en … Disks-last

The amount of stone cut in this time, is again dependant on hardness.  This article examines cutting rates for rocks of different hardness.  Basalt has a hardness of 6-7 on the Mohs scale, which is comparable to granite.  This document examines cutting rates and wear for a number of rocks, including many granites.
https://www.nature.com/articles/s41598-024-54625-5.pdf

Cutting rates vary between 4.5-11.5m2/hr, with 8m2/hr being an approximate average.  A single disc will therefore cut 6400m2 of stone surface over an average 800 hour operating life.  I estimate that a single 300mm diameter disc will weigh 1.7kg, based upon this product and its specification.
https://www.toolstation.com/bosch-stone … 40807c63b0

Suppose we wanted to build a hemispherical dome some 30m in diameter.  How much cutting would be needed?  A strong timbrel domes could be built from three layers of tile or thinly sliced rock.  The surface area of a 30m diameter hemispherical dome is 1414m2.  All three layers would have 3x this surface area, or 4241m2.  A single diamond cutting disc, weighing 1.7kg could therefore cut enough stone to build a 30m diameter timbrel dome.  A 60m diameter dome would require some 4x as much cutting, or 16,965m2.  We would need 2.65 cutting discs, weighing 4.5kg, to cut sufficient stone for this.  Such a dome would provide some 56,549m3 of internal volume.  This is over 50x the Starship payload volume.

The dome will have high compressive strength, but would be relatively weak in tension.  To pressurise the dome, we must cover it with enough regolith such that external weight balances internal pressure.  As regolith is graded to provide coarse rocks, the lighter fractions will be compacted into a berm around the dome, that rises as the dome is constructed.  This provides a surface that robotic assemblers can use as a base as the dome is constructed.

The interior of the dome will be decked out and divided into compartments using a mixture of stone timbrel, adobe, rammed soil blocks and fine regolith mortar.

Cutting Starship upper stage into two parts strikes me as a good idea.  It is proving difficult for SpaceX to develop a fully reusable Starship upper stage.  The heat shield is likely to require extensive reservicing between missions even if they do get it to work.  Increased staging inevitably increases complexity, but relaxes dry weight requirements.  A 2.5 stage vehicle would involve a lower stage and a sub-orbital second stage, both of which are reusable.  The upper stage would be expendible (or repurposable and canibalised in orbit).  It would consist of a limited number of pressure fed engines, tankage and payload.  Control and manoevring systems would be stripped out in orbit and returned to Earth for reuse.  The pressure fed engines and fuselage would be raw materials upon reaching orbit.  Stuff we use for building space stations or grinding up and using for reaction mass.

Undersea pumped storage is under development in Germany.
https://youtu.be/essiSG3gED0

The only objection I have to this idea is that the pump and turbine must also be deep underwater or underground.  Undersea CAES using a trompe would have a lower maintenance burden.

It is a liquid core nuclear thermal rocket engine.  Not really a new idea.  The problem with it, in common with all NTR proposals is that fission products inevitably leak into the hydrogen exhaust.  Most will be blown away by solar wind.  But a small proportion will enter Earth atmosphere.  Enough for the lefty green lobby to spit their dummies out.

A fission-fusion micro-pellet pulsepropulsion system would give much better performance.  But the exhaust will be ionised, so fission products would be trapped in Earth's magnetic field.  If we are serious about colonising space, we need to take that hit.  Progress comes at a price.  It isn't a big problem.

Void, that is interesting.  One thing that surprised me (though probably should not) is the sheer size of the Hill's sphere for Kuiper belt objects.  Out beyond the orbit of Neptune, even small dwarf worlds can have gravitational influence over a vast region of space.  A body like Charon could be mined and used to build a swarm of habitats in Pluto orbit.  The barycentre between Pluto and Charon, could be one such conglomeration.

Most of the mass needed to build a space habitat is shielding.  This can be made from almost any material, including water ice.