PB666

I think we are taking the idea of a launch escape system way too far. Space is risky.

Easy, to repel gravity on Earth, here is what to do 1. drill a hole 6.4 Mm deep. 2. create a chamber about 100 cubic meters. 3. Place condensed antimatter (several million kilograms should do) 4. Drop a several million kilogram lead bullet down the hole. No more gravity. And on the bright side the moon will now be a dwarf planet with a rather unusual orbit. The ship you propose . . . . .its called the Start Trek's Enterprise . . .the drive you propose is called a warp drive . . . .and its space fantasy. https://en.wikipedia.org/wiki/Alcubierre_drive However, if you want to exit fantasy worlds and read up on what the problems are. There are complete lectures on general relativity online. General relativity is the limit of sciences knowledge on gravity at the moment, beyond which is a matter of conjecture. https://en.wikipedia.org/wiki/General_relativity https://en.wikipedia.org/wiki/File:Quantum_gravity.svg Note the big question mark surrounding quantum gravity. https://en.wikipedia.org/wiki/Graviton Gravitons appear to be a particles that travel at the speed of light. In fact their speed is what appears to determine the speed of light. They also are the structural basis of the Universe. While this is hard to fathom they also compose space. Space is not empty, it contains both gravitons (non-zero energy particles and other bosons) that compose space and create the spacetime field, the curvature of which you are familiar with as gravity. spacetime is curved by E = mc2. Despite the fact that these particles are traveling at C, the also simultaneously form 3-dimensional space in a process euphemistically cause the cosmic foam. Why we cannot alter the gravitational field? Actually we can, just not very much, we can move mass and energy from one place to the next. The problem is that Earth's graviational field is greater, the Earth has 1025 kg which produces a = 9.81 m/s2 at the surface. To negate the effect of gravity you need negative energy and negative mass. The problem is that in quantum systems, energy is always conserved (at least on the local scale). IOW the total of all potential and kinetic energy in a system remains constant indefinitely. Even space has energy, so called non-zero rest energy.

I thought X68 had been decommissioned.

SpaceX is trying also to reduce the time it takes to sign a contract to launch, they appear to be doing just that. Launches have to be contracted, you cannot design an PL/Launch interface otherwise. They don't have cushy govt set asides if that is what you are saying. The point being is that they are the interloper is going to make them a better and more competitive company . . . . they want to take the cush out of the govt set-asides and to that they need to make the recipients look poorly in comparison. Look here funding agency - We recycle our launch stage - We recycle our interstage fairing - We recycle our payload fairings - We deorbit our second stage and don't leave anyspace junk for our SLS garbage truck to need to pick up. We are the most environment friendly and a very cost efficient company, come launch on us. . . . .those other guys are wasteful Not to mention - We are buying up Methane (lowest greenhouse emissions of any fuel) from your drilling companies that are having to sell methane below cost. - We are going to have our next launch facility just 50 miles from South Texas Shale and not to terribly far from NASA, in case you are planning to launch from our new facility. They are also very good at building public support . . . . . .I'de be more worried about their next fantastic disaster than weather the purchasers are up at night wondering about the cost of trying to catch fairings. One of those captivating SpaceX launches is good avertising for the launch service as well as the launched.

That's not exactly true, if you contract with a launch service provider, particular if you have deposited money, then you want them to be there when you payload is ready to launch. If the company is offering you a low rate, but there is a good chance that they will be out-of-business (and you have to go to court to get a portion of your deposit back) then you might not choose to draw up a contract. Again as a satellite designer you need to fit your payload to the limits of the launch provider. This includes adapter limitations and fairing volume, cross-sectional area, and single dimension radial limits. Consequently once you contract you will be out of pocket if the provider cannot provide. Thus you do care whether the service is reputable, which means you also care if they are engaged in efficient business practices. And example of how this occurs is a satellite telecommunications company. For starters you are going to be launching many satellites. Each satellite is in a collective of similar satellites. In a launch service provider you want a consistent PL circumstance (i.e. the same fairing). If that PL configuration worked with one satellite it should work with all. Insurance may cover the loss of an investment, but there are intangible losses, like getting into a new market first and establishing dominance in that market before competitors. In this case you care very much about whether your launch provider can do it cheaply, repeatedly, reliably.

I graduated to PINE in 1989, VT102 was too cumbersome, the problem. Everyone thought that when W95 came out that the days of VT102 would be over. Nope, it was the USENET whose days as a relevant discussion that were numbered. The lesson that was learned is that with freedom come responsibility. Freedom of speech on the internet is an illusion, its basically freedom to be irresponsible. Fortunately I don't have kids or grandkids so there is no need for a device for handing out addictive content. If they could bring back the old Usenet and limit access only to NNTP proxies that where not attached to google or other mass consumption web applications (IOW individual pay by the year or graduate institutional accounts; repeat crossposters between desparately different groups would be banned and all post from anonymous remailers banned except in certain groups, political, and no-crossposting) that would be a cool thing, but it ain't going to happen. VT102 was not a bad thing, it was a good thing, it was insect repellent.

JWST has an active cooling system and will be deployed at ES L2 shield from considerable solar output and solar wind. Had JWST not done this it would have required two sun shields, one to block the intensity of the sun and the another to block the non-reflected heat from the first to the telescope. In addition to its heat shield its low temperature experiments required a cooler to drop the temperature to near CMBR. This will eventually limit the life of the telescope. https://en.wikipedia.org/wiki/MIRI_(Mid-Infrared_Instrument)#Cryocooler There are no simple answers in space, only inadequate solutions. Temperature is a function of the motion of particles. The motion of particles at a distance of earths orbit and factoring out Earths orbital motion (30 km/sec) is 250,000 --500,000 m/s. That constitutes as hot, if you remained in space for a long period of time your mummufied skin would eventually be charred. Comets detect this motion and begin degassing once they are approach the orbit of Mars, inside Mercury's orbit small comets disappear. If a human was placed in space they would feel cold, that is because of evaporative cooling, however once the temperature feel and most of the water was gone they would begin to heat up again. In fact its hot enough the temperature cannot be estimated for several reasons the first is variable temperature of particles coming from the sun as a result of its magnetic field. Therefore the solar wind is not constant even on a daily basis. The magnetic field is strong enough to be considered a MHD dynamo and considerable electric flow. If you happen to be in a focal point of one charged mass flows you would (irrespective of the insolance) feel the heat of current flow and protons and electrons try to neutralize themselves in a manner dependent on the charge of your body. There is an assumption that space is the same temperature as CMBR, but this really should be describe as the temperature of the intergalactic media because there are both hot and cold gas pockets and the solar system is currently moving through a cold gas pocket. If the temperature is not CMBR then what temperature is it. This can be ciphered from the temperature at which the solar wind begins to sublimated and extrapolated to distance this is the coldest component of space, dust. This roughly means that the particles are spread out enough that the particles are able to radiate their heat before other particles hit them. 165 K at 3.2 AU 200 K at 2.2 AU Inside the asteroid belt volatiles tend not to sublimate because the temperature is above the triple point of most gases (I posted recently on the triple points of those gases). This makes it difficult to deduce the temperature of space, the temperature of static gas pockets in space can be deduced. https://en.wikipedia.org/wiki/Van_Allen_radiation_belt; https://en.wikipedia.org/wiki/Ionospheric_dynamo_region This describes the motion of clouds of gas relative to the expected motion caused by the interaction of solar particles from space. So that if you were a small particle setting between the orbits of Earth and Venus what might your internal temperature be. A particle would not sit, it would fall, but a particle in a constant velocity spacetime energy isoquant would be moving ~35 km per second, and assuming all other particles would be moving the same. A reasonable guess of the temperature of space near Earth but outside of earths SOI is ~ 300K degrees (+/-50K and variable) for a dust particle of size similar size and reflectivity as one found in asteroid belt. 165K * SQRT(3.2) = 295 +/- 5 200K * SQRT(2.2) = 296 +/- 5 And that's what you should take the temperature to be. Again the data that support this is the average temperature of the Earth 288 K, the therma temperature of JWST main electronics array 300 K, etc. The temperature differences of the objects is the result of the difference in the composite forcing factors. On Earth the temperature is less because the Earth magnetic field shields Earth from the magnetic and electrical forces from the sun, the Van Allen Radiation belts are separated from the Earth and spread this radiation in space allowing it to be dissipated by radiation at distance from the Earth, just as the shield on JWST shields the telescope. If this were not the case the Earth might experience wider temperature variation, and in particular a higher compliment of radiation in the shorter wavelengths.

lol, but not that bad but still pretty invasive. http://www.astronomy.com/magazine/press-releases/2018/02/roadmap-to-radioresistance

https://www.frontiersin.org/articles/10.3389/fnhum.2018.00037/full

help us? help them. The LEO part is nothing compared to the Mars entry and landing.

The inner solar system is quite warm, remember it is capable of boiling sublimated gases off of asteroids. His company has at least a few patents and he is paying people to develop stuff. In terms of what he is doing, nothing new . . but that then leads to another question, if the technology has been in place for 50 years (the electronics at least from the 386 DX40) then why has it taken 30 years for just 1 member of the rocket industry to figure out how to recycle rockets. We know why that is. If he really really wants to go to Mars, his company will be inventing lots of new stuff, not to worry.

They are just fairings.

It has something like 4 turbo pumps, part of the fuel is ignited in one to run the pumps.

1. If the rocket has two side mounted boosters they operate close to Sea Level and the difference is trivial. Again assuming Vac ISP all the way up is deceptive. 2. In general you would not design any rocket to burn past 8500 dV since you can basically leave that for the second stage. (RL10b-2 or RL10-C which have ISPs of 466 or 452 and are much lighter. (for example you could use the remaining fuel to re-land your first stage). 3. Thrust RS68A = 3,140 kN (At Sea level) Thrust RS25 = 2,279 kN (At sea level) 4. Nozzle diameter RS68A = 2.43 m Nozzle diameter RS25 = 2.40 m Lets think really big, assuming an infinite hexogonal layout and minimum distance of 1/10th diameter between engines what is the Maximum unit force per area (pressure) when number of engines exceeds 2, which either engine can produce. P = T / (1.21d2*31/2) = RS68A = 266 kPa RS25 = 188 kPa This means that you can (with the most compact layout of engines) launch 42% more mass on a RS68A stack on average than on an RS25 Stack (of course you could use that stack to carry any dV you lost switching from RS25, but that would be dumb). By putting more thrust onto the core you lower the need for boosters and now you can be more flexible about the chosen boosters, for example F9 booster, which is relandable, has a higher ISP. Again your core should be relandable, which means you only want to burn to about 3500 m/s before MECO, and this means that the mass you launched with did not go into providing fuel for itself, but in providing weight for the second stage fuel mass and RL10C? or some variant of RL10 which would carry what. . . .300 t to Orbit. NASA can use RS25 if they want, my space agency would be using RS68 because the future of space exploration is about getting bulk into space.

the abilitiy to produuce lots of chaotropic agents in their circulatory system. The ability to use SO4 and NO2/3 and methane producers. Extremely slow metabolism. No mitochondria or equivalent, no chloroplast or equivalent.

Lets not talk about vaporware. I have asked here in threads for everyone to provide suitable example of fusion direct propulsion (and not the boiler plate big-bang machines). I just watched a lecture today about Liouvilles application to energy. The problem with energetic systems that have chaotic components is that the phase-space becomes convoluted and difficult to manage. This is so-true with fusion plasma generated propulsion, because you have to put energy into the system (its actually alot of energy for plasma) to keep the plasma ordered. The particulates like to dissociated and go their separate ways. If your machine is a heat machine, then as a heat machine you idealize the transformation of radiant heat into electric power. but once that is done you know what the efficiency is. We can model that with a fission reactor, with a lense pointing focused sunlight on a black body, whatever. If you are machine is a plasma machine then you idealize the plasma containment. I don't idealize either, a machine that does not exist is simply vaporware. But I can argue if you had fusion in space (and you will need it gathering in the outer solar system) then you also use it for ION drives, but fission does exist, and it simply would be feckless. So the question about fusion is will it work in space, maybe . . . .200-300 years from now. Without that dyson swarms are nothing more the heliocentric orbiting habitats. Follow the energy, always, if your are going to get in a discussion with me, tell me were the energy comes from . . .if its mass, tell me what energy that was used to derive the mass, if its propulsion, the same thing. If the source of energy goes undisclosed then there is no conversation to be had. If the mass is in the Mars-Pluto band, then mentioning solar is only going to prompt me to say where did you get the super lightweight super efficient panels from and how are you going to use these to carry the cubic kilometers of mass around?

Or raised by their desire to use the RS25. RS-68A 3 times more powerful. And BTW, those boosters are not safer, and yet SRBs are being used. If you have a 4 RS68A and you run into a problem with one of the engines, you can kill it, the three remaining will still probably take you to orbit. You can throttle them down. Its not a matter of 'if' a next SRB caused disaster will occur, its a matter of when.

Interplanetary transport can be broken down into two types of problems. 1. Bulk transport 2. Time sensitive transport. Getting bulks of Materials to Mars given the current launch structure is not hard it just requires patients and lots of planning. If you can get the material to LEO no 70 tons or so. To do this we need a construct. IN the construct we have a plate with mounts on both ends and a center that can mount 200s of tonnes. The plate itself and its engines might weight 20 tons, Another 20 tons for solar panels. There are tanks, they can hold several tons of hydrogen and oxygen. The plate empty is shipped to orbit. You can load the Bulk plate with cargo, this would take 3 shipments. So now the plate is full. Also you have tanks for Argon. Next you ship up and transfer the hydrolox fuels (the transport has a gas liquid recycler to recapture the blow off). The ship then burns to a highly elliptical orbit with its single 277 kg RL10b-2 engine. The ship however maintains about 1000 reserve dV of gas. Once there (using 0 as periapsis) it begins ION driven burns from -135' to 135 degrees with a slight retrograde burn at 180' to maintain the periapsis at ~ 6870 km. Once the last kick is initiated in burns the last 1000 dV of hydrolox placing it on a trajectory toward mars. The ship has however limited rentry capability. The next manuever it uses its ION drives to place it at S-M L1 and then it places itself in a highly eccentric orbit around mars using the martian atmosphere to break its speed, which at a certian point it circularlizes near the apoapsis and releases its payloads. This ship then returns to Earth on a long time frame using highly efficient ION power. Average round trip time 4 years, the transporter is considered fully depreciated after 5 trips and given interest rates its cost per trip is roughly 30% of the cost to build a new one, plus the cost of the argon, H2 and O2 shipments. There are two basic strategies 1. to aerobrake into Mars that part of the payload is liquid oxidant (NO2) and fuel, in which you use the atmosphere to decay to a certain point and then you burn back the remaining 3200 dV. There is basically no size limit, and you probably could bring in 200 tons, its just that you would only land about 50 tons (suitable for large items like nuclear reactors, drilling equipment or ISRU facilities) . The second strategy is to Aerobrake in parts. Basically instead of trying to land 200 tons you land 20 tons 10 times. (this is suitable for bulk goods like metal, food supplies, . . . .) Just to take care of the Mars dreamer argument, this will not build a city of a million, but you could build a decent science outpost on Mars. There is an additional, if one of the landers has enough fuel storage to return to orbit, then other landers could bring the fuel, it could be refueled on Mars, and if a crew quarter is attached it could carry crew back to LMO which other transporters could be used to get them back to Earth. One potential use of the tanks, for example aluminum tanks is that you could forge winglike fuel tanks, basically that fly at hypersonic speeds and finally turn high drag spoilers to slow the wind down and simply allow it to crash into the surface. The fuel is then gathered and the tanks aluminum is used as a raw material. Large enough wings could be made by have the wings launched in sections and assembled by robots in LMO. Time sensitive transport is a different issue (i.e. humans or precious liquefied gases) this probably would not be done well with ION drives and so the total tonnage is rather limited because of the mean ISP of the fuel. Essentially any of these systems SLS/Orion, BFR, Alt. FH could get a vehicle into LMO with proper support in LEO and proper reentry vectors around mars. A cycler could bring fuels to the vessels in LMO and they could land on Mars . . .but without support those ships will never leave Mars. So that unless there is a plan to send to mars the facilities and supplies (Not ISRU, but the actual resources) those who travel to mars on current technologies are doomed to die on Mars as those technologies eventually fail them. We have to separate the two missions, we currently are not used to the idea of bulk missions, because other than the ISS, we are not used to stockpiling large amounts of non-perishable materials in space. But if we abstractly think that this 'in space storage' is doable, and it simply represents the cost of getting bulk into LEO, and an aggregate of cost depreciated over time for slow transport then there is no reason to not consider a bulk material allocation around Mars. The way that you can model this is the intercoastal canal. As it was originally built is was for light (low draft ships) ships, barges and civilian and military use (deep enough for a destroyer but too shallow for a submarine). But over time given the canal, the low draft ships are gone, barges have evolved to carry 4, 8, double wide barges . . .almost as much cargo as a Ocean going ship with a fraction of the dedicated infrastructure. Then think of transporters of goods as everything that does not need to go along side of humans and that can just be loaded into any container. For example if its 100 days for humans, one set of clothes, minimal personal hygiene stuff, 100 days worth of air, water and food, no mass-expensive waste recycling. So that the design of a ship for bulk transport has fewer constraints than a crew rated or science rated vessel. because of this it can carry more.

Because the money would be better spent elsewhere. I supported the shuttle program, but at least it had a performance metric, this SLS program has none. Its seriously bad when the Europeans are calling out their own space agency asking them why they chose such 'questionable' contractors to work on a NASA service module. Who looses if its a mess up, ULA still get 1.3 billion dollars a year just waiting for some contractor in Europe to fail to meet a deadline. Musk has a clear advantage, 'hey dude, that part you were working on is way behind schedule, we need someone to relocate nuisance sand crabs at the Boca Chica facility, here's your tent'.

RS 68A is a better launch engine. No need to, there is already an RS68A, much more powerful engine capable of carrying a far bigger payload into space. They upgraded the nozzle on the RL10b it had a much longer and wider nozzel (thats what makes it so darn expensive) but it also difficult to place two RL10b-2 engines in most shells. The engine is reliable, its very simple design and probabily does not need to be man-rated in Pairs. But for vulcan progression they are going to ditch the 2-b and go with a smaller C so that 4 engines can be packed.

There is a trick to helping many metals (aluminum, copper, stainless steel, even galvanized). Take the metal when new, hit it very quickly with acid, say 0.01 M phosphoric with a trace of hydrocloric (10 ppm) (Iron and Aluminum will generate hydrogen gas in the presense of HCl and will pit so HCl is only trace, just enough to form monovalent anions to remove superficial metal salts). In the presence of nitrogen gas, helium or carbon dioxide rinse the metal free of the acid (or a solution sodium trace reducing agent and purged of all O2) and the briefly hit it with sodium bicarbonate to neutralize the acid (in this state the metal is extremely prone to corrosion so the next step must be performed rapidly. Rinse the bicarbonate off, get absolutely distilled water (No CO2) add denatured limestone (lime Cal, calcium oxide)...about a quarter teaspoon per gallon and allow the metal to soak in this solution while the metal is very fresh. Under basic conditions (like sea water) this will for short periods resist the corrosion. The calcium sticks like glue to the metal in a single layer, when it is exposed to the atmosphere CO2 binds the calcium forming a very thin layer of calcium carbonate that can only be removed with acid.

before the question mark as a comma and three more zeros. But you know if you build you facilities underground in tunnels potentially you can take care of 3 of the major mars problems at once, shielding, deep enough and its not to difficult to hold atmosphere, and also you are able to move freely laterally to transport. The only thing is you need from the start to be very good at forging drilling equipment.

You have to think about the thermodynamics, what you are trying to do is to move mass from where the structural mass comes from to the inner solar system. Remember Arthur starts most of his videos, if you have fusion power . . . . . So the principle problem of the dyson swarn is that enough is never enough. And at some point in his video he is talking about fusion H2-Fe, that is getting all the energy out of hydrogen, hydrogen that would be extracted from the sun with fusion power and structure being made with the fusion of hydrogen. But initially you have to convert mass into energy and then leverage that mass to move mass from the outer solar system (asteroid belt, kuiper belt, whatever) down to your dyson orbit. Since Fissile material is neither useful in construction and has a 4 fold lower energy/mass conversions ration as hydrogen, basically it increases the cost of moving things, so as things get harder and harder to move (further away and having less of the structural materials you want) they would theoretically become too expensive to move. Solar power will not move mass around, it can only provide the energy at the inverse square of the distance. Or to put this another way, a Dyson sphere is not about what it is, but what it does . . .its a function of growth, growth needs mass. There is an inadequate amount of fissile material in the innersolar system to provide the energy to acquire the mass. The problem is that based on what we know about nuclear conversions they are already 'theoretically' too expensive. For example, your basic thermonuclear engine with the maximum theoretical fuel has about 1/10th the dV required to move mass from the outer solar system, down into say a mercury/venus orbit and then return back to its station and do it again. The ion driven engines are more mass efficient, but the current limit to heat conversion in space is below 30% efficiency coupled with the ION drive efficiencies that is basically 21%, So if you need a million kw of power, you will produce 4 million kw of waste heat, and this adds weight. Take some time with a big long spread sheet and try to move a cubic kilometer of substrate from objects in the asteroid belt/outer solar system into the inner solar system, then construct an object, then return the ship back to the outer system (again with how much fuel) and gather the resource and move it again. You will find that it takes alot of dV.

https://en.wikipedia.org/wiki/Sun-synchronous_orbit

Because space-time propagates at the speed of light. Therefore the best approximation is always off be d/c. The way to solve the problem is to have magnetic interleaves between sections. But the reality is that best a Dyson sphere can ever be is a ring a few hundred kilometers wide. IMO even this would tap every available resource in the inner solar system that is not already deep in a gravity well . There is a saying learn to walk before learning to run. Dyson anything is way-way ahead of our technology or our ability to predict how likely it would be able to be done (.e.g will thermodynamics even transiently allow it).