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The vehicle design carries LOX for the rocket stage of the flight, and for deorbiting. I don't think the engine separates air for these purposes. It can run as a turbojet to an extremely high altitude by virtue of its cooler, but beyond that it runs basically as a normal rocket.
The previous design vehicle, of which the present one is a development, was called HOTOL and it didn't have the engines in separate nacelles, it was mounted in the back of the vehicle.
I have the impression that Spacex isn't really into learning from the experience of others. Design of pressure and vacuum vessels, including cryogenic equipment, is not a new subject. Making the same mistakes that others have made before you isn't the best way to progress.
Sabre engine, {if it can be made to work!} will solve many of the SSTO problems.
https://www.reactionengines.co.uk/news/ … conditions
Brilliant progress. Well done Spacenut.
That would be what would happen to get over a disaster, but the normal state of affairs would be to refuel and return all or almost all the landers if they are not write-offs, wouldn't it?
Welding a tank would be quite straightforward on Mars, if that is what you want to do. Type 301 stainless could be welded with sticks or wire feed which must be imported. I'm not sure, but I expect that shielding gas will not be required in the Mars atmosphere.
Weld spatter probably is bad for space suits.
Rubber tyres and a small watercourse. There are clues!
I believe that it is quite likely also, GW.
If chiral molecules are found with a very large preponderance of one hand over the other I would think this would be a clear indication of life. It won't say whether it is past or present, though.
I also think it quite likely that life on both planets will show a common origin, perhaps from a third place or perhaps from swapping rocks over the ages.
It would be possible to make both tile and substrate with tiny holes for transpiration. These wouldn't be a part of the pressure hull.
My question was whether it had been tried. If it has, how was it done?
Such tanks would probably be wound with locally produced mineral fibres (glass/ basalt/asbestos) and imported resin. For LCO they wouldn't need a liner but for LOX they probably would. This is to ensure that the optimum resin doesn't react with the oxygen. An explosion in this tank would be beyond embarrassing.
Have porous materials with coolant transpiration been tried for this kind of application?
I was involved in large industrial facilities, TAH. These tend to be built to order, not serial production. Faults mostly get corrected in commissioning before full production commences.
I was thinking about batch production of complex equipment when I suggested 1 percent. It would only be an order of kind of number for illustration.
The bathtub curve applies.
It may well weed out the sick and vulnerable if it gets to be a real pandemic. That includes old folks like a lot of the correspondents on this site including yrs truly!
Spacenut. Are you proposing a thousand miles of pipeline? That will need a number of compressor/pump stations (depends whether it is moving gas or air), pig launchers and traps and intermediate storage, just like pipelines on earth. That all involves a lot of power and a lot of mass.
You need the lightest possible, highly portable energy store and that means nuclear fission or a tank of fuel in current technology. Maybe big batteries in the near future. For Mars fuel you have to have oxidant as well.
Local power distribution can be by compressed gas, hydraulic pressure or electricity but for long distance energy transport I can't see anything other than portable systems coming into use for many years. When this does happen I expect it to be by HV DC overhead lines just like on Earth.
You are going to put an awful lot of fuel containers into orbit at 1 te of payload each, TAH. Will you try to recover them, fire them into the sun or deorbit them for burnup/ disposal in the ocean? With 1% chance of failure something bad is very likely to happen with the number required to fuel up a starship!
I think you need to be more ambitious with your payload, which means there will be less of them and more money can be spent on each to reduce the failure probability.
Use of CO2 for power would probably be by splitting it into CO and O2. These can be liquefied and stored, then boiled off and reacted together to recover the power required. Exhaust is CO2 which might be recovered or dumped to Atmosphere.
No novel technology here.
Earth moving equipment for grading/ clearing tracks and for piling regolith on top of shelters for radiation protection.
When the Chinese start launching men into interplanetary space, NASA will wake up.
Expect this virus to become a pandemic because of the ease with which it spreads. Make sure you are in the best physical condition you can contrive to be, with a good diet and a bit of exercise. This way you will be able to deal with the viral assault. Be thankful it doesn't look nearly as dangerous as the Spanish flu pandemic, let alone Yersinia!
So a prior mission is needed to put an MPS constellation in orbit. Maybe Falcon Heavy could do that. This constellation could also provide full comms coverage.
The pioneering mission has to locate specific resources and determine that they can be accessed and used, so it may have to hop around to find a good site. The best way of finding stuff is to employ a couple of field geologists and a couple of chemists with good equipment on the surface. A possible method might be to use remote operated equipment with a team in orbit to narrow the candidate site list, then excursions to the surface to finalise/confirm the choice of location. This team still has to come home using only what they took with them.
It won't be steel cable. It will be Dyneema or equivalent. Very high MW polyethylene. As strong as steel and with similar stretchability (ie not a lot), but about 15% of the weight.
The spiders have solved the problems of economical and efficient wrapping of objects. Study how they do it and benefit from hundreds of millions of years of selection.
So much more reliable with external percussion or rotary drill. I shall be surprised if anything comes from this device.
Well only a pioneering mission is going to find a good spot with the right resources and install a beacon in that area. That mission must be able to get itself home, so it is going to be a little one, possibly of short duration.
Ammonia is also a light molecule, Caliban. MW =17. However, I believe a vacuum is a better solution.
Admission of more propellant to the tube at higher elevations as the projectile passes injection points, is a possibility to improve performance. It has been tried in very large artillery pieces.
The cap can be a simple bursting disc. These are widely used in chemical and petroleum industries The outward dome pattern enables it to be made from friable material which is kept in compression by the external pressure. As the projectile shoots up the tube the residual gas will build up in front of it and blow the bursting disk away before it arrives at the tube exit.
I did consider such a boost device a long time ago, but mine was to have been supported by toroidal helium balloons. I decided it was unlikely to be practical due to atmospheric movement.
A slight issue with these designs is that the tube is filled with air that must also be accelerated out of the end. It isn't much of an issue with a regular gun barrel but we are talking about kilometre lengths.
Ideally we would evacuate the tube before firing and this might be done by purging it with anhydrous ammonia and fitting a burstable membrane over the end. A water spray would absorb the ammonia (it is very strongly absorbed by cold water) and deliver a partial vacuum in the tube. Pump the ammonia solution out and recover the gas for the next shot. The higher the outlet end of the tube is the lower the atmospheric pressure will be at the top and the lighter the cover can be. There may be other combinations of gas and solvent which would produce a better vacuum, or purging with steam and allowing it to condense after fitting a cover, might be considered. This would need a temperature regulated barrel to avoid formation of ice frost.
When the projectile exits the end of the tube in a cloud of hydrogen and ignites its engines, there might be some interesting pyrotechnic effects. This may well happen without the projectile igniting it as you may expect large static discharges, so I would suggest that we don't use hydrogen. Steam used as a propellant will require the barrel to be heated but there will be less of a fire/explosion risk.
In the gold mines on South Africa's rand there are shafts of large diameter with depths of three thousand metres and more. Obviously if you installed your system in one of these it is going to be simply vertical and not steerable. The floating tube may have recoil issues that would prevent accurate directional launching of the projectile.