Hannu2

I fear that authorities of local primate civilization may have problems with moar boosters to superheavy. Solid boosters are obsolete but 7 superheavies with asparagus staging would be nice next step, before hexagon of 19 stages. But I think that correct answer is "you began on too large planet with a species interested in too mundane things".

That is highly speculative option. SpaceX tried to make fuel tanks from composites and failed. It is clearly very non trivial task. No on knows how much development takes money or time and what results eventually are. Just take strenght of lightest composite and calculate some values is not very credible. But why we would not build two stage booster from those new advanced materials and get again benefits of multi stage rocket? There is already significant competition in small launches. There are small conventional rockets and rockets launched from plane. And there is also a threat that when huge starship begin to work as intended it takes markets because fully reusable huge craft may be cheaper than small expendable rocket. I am sure that those companies have investigates SSTO possibility but rejected it. It is like shuttle, many very advanced things are needed but no one knows how much it cost or take time to develop them. Governments may make overoptimistic decisions and keep programs running using loads of taxpayer's money even everything will not be realized as intended. But companies can not afford that.

The most realistic like options are probably boring for stories. But I think when (if) there are heavy battleships and warp missiles commonly used they have developed automated defenses against known weapons. Suitable defense weapon is always in readiness state and when missile is detected it is aimed and launched immediately. It is completely impossible to say. With you assumptions it is probably true but they seem to be very arbitrarily chosen combination of scifi and modern technology. If you use some other assumptions it may be very feasible to have battlecrafts with size of dwarf planet. Warp drives you described are so magic technology that we can not foresee what kind of detection, hiding, maneuvering or attack technology is available in that level. If spacetime can be manipulated maybe it is possible to form an event horizon around enemy ship and capture it. But maybe it is somehow possible defend by breaking that event horizon or even utilize it to harm attacker. Story can have whatever solution. All them may be criticized against reality but I think it is the whole idea of stories.

Also in Finland planks, nails and some other carpenter's materials are called by inch measurements. Everything is sold and official drawings is made in metric units according to European standards but inch is used in professional jargon and hobby carpenters too. Every store know to give you 98 x 48 mm plank if you ask "kakkosnelonen", which means 2 x 4 and packet of 75 mm nails if you ask 3".

Heading referenced to Earth surface is not defined. If you think in inertial coordinates heading is to east (I do not remember what definitions of zero and direction is used in this case). Orbit of standing object is very narrow ellipse and object is in apoapsis point. Inclination is equal to latitude and periapsis near the center of Earth. Or center of Earth if object sits on pole. Both coordinate systems are relevant in ascent. For example KSP changes from surface referenced frame to inertial frame during ascent (typically soon after 1000 m/s, I do not know if altitude or speed triggers the change). I did not check those values of Heading but they seem to be correct.

You can write some kind of administration over the whole operating area in your story. But even then there will be high risk operations. You may sell a cargo ship with monthly payment but probably want full prepayment for fighter ship if some pilot hero is going to conquer more solar systems from "bad aliens" to "our good civilization" or also for a research ship if some propellerhead claim that he has invented an ingenious new method to flee from behind an event horizon. Tracker and effective galactic police are pretty useless in such cases.

Answer is pretty obvious. SpaceX's bank account takes severe hit and metal workers get few months prolonged work contract. I think that only thing to do is to plan trajectory and building layout so that crashing rocket causes minimum damage to structures. It is impossible to save a rocket stage.

150 hours flight time is extremely overoptimistic. Electronic damage due to thermal cycling with low minimum, dust and wear in bearings or battery degradation is probable limits. Crashing due firmware error is also much more probable than motor damage (it was quite near already). Ingenuity's protection has not been done for months use. It will be good if it can do few scouting flights but I would not expect several months service life.

Of course barrier to activate massive destruction is high. But the larger number of people able to do so the higher probability is that worst happens. On Earth there are very few individuals who can begin massive nuclear attack from own initiative. Probably no one can, because all presidents have their inner circle who probably prevent such operation in case of psychosis. But if that artificial triggering of field collapse is possible, there will be more and more civilizations which can begin it. Every new increases probability and eventually, during billions of years, it happens. But it is very fictive speculation. I do not think it is ever possible if natural high energy phenomena, like black hole collisions or supernovae, have not enough bang for triggering.

If the universe is expanding as it seems to be, only finite part of it can interact due to finite light speed. Anything beyond observable universe can never affect to us. But even extremely small deviations (several orders on magnitude lower than observation limits) of known natural laws become very significant in such extreme extrapolations. Predictions to final fate of the universe are very speculative, even if they are based on best known science. Mass suicide works well as defensive weapon much like intercontinental nuclear missiles have worked decades on Earth. No one has realistic possibility to win in such situation. But if civilizations develop and many of them get ability to trigger collapse, risk that crazy dictator can launch it increases. It sounds that there will be work for action heroes in very far future.

I agree that honest competition is not very realistic option for states. But I hope that there is a little bit respect towards common effort to expand in space. Otherwise we get few military bases on Moon but no mining or significant science. I have heard those too. But I am quite sure that they are click bite topics and/or propaganda against those countries but government members do not really be stupid enough to believe that other superpowers disappear suddenly. There may be revolutions or other crisis in every country (also in western democracies) but usually they do not destroy states but just change leaders and redistribute property.

I think honest competition with respect to each other and rules (or good manners if there are not common rules, like in space investigation) is the best. If competitors feels each other enemies they use most resources to defenses and attacking instead of straightforward science and technology. For example nations use several orders of magnitude more money for their armies than for science. Military research produces sometimes usable things but most of the money goes to futile bureaucracy, practicing and display of power to enemies.

Higgs field have non-zero minimum energy. Some physicists have speculated that Higgs field may be in some kind on metastable state and it may be possible that it decays to lower energy state. I have understood that if such transition begins it expands at speed of light and nothing can stop it. It would change natural laws drastically and all current particles and their interactions would change. It would be impossible to know before it happens because there are not known ways to send information faster than light. Predicted probability of such event is be extremely low and it is not known is it really possible. Maybe you can write that some civilization (or cosmological level gangster boss) has a method to initiate such transition. I am surprised if no scifi author has already used it. https://en.wikipedia.org/wiki/False_vacuum_decay

Most of the cost of space probe is not from sensitive detectors but extreme reliability demand. Including huge test operations and redundancy of critical components. You could build Persevecance like rover for few millions (or tens of millions) if it were industrial instrument. Reason for all that redundancy has been cost and rarity of launches. If launch cost 200 millions per probe and there is one available at every transfer window it is very reasonable to put couple of hundreds of millions to reliability. But if you can send probe for few millions and there is practically unlimited launch capacity at every launch window you can build rovers with normal industrial standards and send tens of them with normal mission budget. Even half of them fail before beginning of mission and half of others before nominal end of mission you get much more scientific results with much less overall cost than now with one individual.

They save significant amount of money and time by using the same basic engine everywhere they can. They tried to develop much bigger engine. However, full staged combustion cycle has certain optimum size, which is not as large as they hoped. It is more advantageous to use large number of "small" engines.

So far it has not been a great motive. But now it begin to be very clear that environmental destruction has very high pricetag. Costs are usually not immediate and directly visible but modern science begin to understand mechanisms and most governments take environment things very seriously and are willing to pay huge amounts of money to develop new cleaner society. That is flawed logic. My logic can be used and will be used if someone actually invents perpetual motion. I did not say it is very fair to laugh those statements. They was very well justified based on information available at those times. As well as conservation of energy is for us. Development of science and technology was just unforeseeable then. Colonization or space industry is not possible for our generation but it begin to be somewhat foreseeable future. We know that there are almost unlimited resources available and our rocket technology is rapidly developing. Also awareness of severe consequences of reckless pollution and destroying nature is rapidly increasing and there is will to spend money to avoid it among people and governments, even among some businessmen. Utilization of space for mining and refining is very straightforward solution under those conditions even it will be very expensive to begin. It does not need any new science or natural phenomena, like perpetual motion machine. It is just politics, economy and engineering.

Everything you dump in atmosphere in the Gobi desert spread rapidly everywhere. You have to also mine everything which does not happen to be abundant in the desert from some other places on Earth with higher environmental value. Actually, I can not really say that desert nature has less value than some other areas with higher biodiversity. There are certainly many special species specialized to desert environments in all deserts on Earth. I do not believe that we will see space mining or industry. Except maybe some early experiments. But on the other hand, it is difficult to think that after couple of hundreds of years significant part of industrial production is not in space stations. It would need some catastrophic breakdown of development to prevent next logical step.

One thing is that as far as we know yet. We know that there is many more that 5 computers in the World and there is also very strong evidence that heavier than air aircrafts have flown. But nothing can prove that there will never be perpetual motion machine. We just do not know such natural laws yet. As far as I know, expanding universe has not time translation symmetry and therefore conservation of energy. Maybe some technomagic level civilization could utilize it. Almost certainly it never happens anywhere in the Universum, but it is impossible to prove impossible thing to be impossible (in nature, it may be possible in logical systems, like mathematics). But there is nothing against known natural laws in colonization of Solar system. It is only economy and engineering depending on political will. It does not produce profit in any reasonable schedule but it could be done as ideological project with our current scientific knowledge. Most of monumental projects in human history are ideological. Probably building and maintaining slowly (but exponentially) growing Mars colony few millennia would cost smaller percentage of US's, EU's or China's gross product than building of famous pyramids costed ancient Egyptians.

You are in prestigious gang with this statement. You must have heard for example: “heavier-than-air flying machines are impossible” from lord Kelvin in 1895 or "I think there is a world market for maybe five computers." from Thomas Watson, president of IBM, 1943 But if you are famous in your real life after couple of hundreds of years people will laugh to your statement. You are correct that those thing are not directly foreseeable at current tech level. And if you think our lifetime you are clearly right. But in longer periods there is no real obstacles. It is extremely expensive project to move mining and manufacturing industry to space but it can lead to almost infinite growth. There are many orders of magnitude more raw materials in space and no need to care pollution or other environmental aspects. Space will not be safe and comfort workplace for humans but there are always people who are willing to take risks if you pay well and there is probably not much need for human work. On the other hand, huge rotating space stations with gravity enough to keep people health may give orders on magnitude more living room for mankind. It would be interesting to se what happens to Earth at long run, when significant part of humans live in space or on other celestial bodies. Will it be exclusive natural paradise for rich people and average people live in space stations around the solar system? Or will rich people live in luxury space stations, average people in huge middle class stations and poor people on old fashioned Earth with all nasty natural problems? Will the Earth be some kind of natural preservation zone where lives some extreme conservative people in relatively primitive conditions? This is only apparent but not real fact. We can not use all land and resources because environment problems will be much more expensive than profits. We have already probably exceeded long term sustainable level of land using for our industrial and agriculture needs. Environmental problems and expensive countermeasures are already severe restriction for economic growth on Earth and will increase every decade in future.

It can be ideological objective in very far future. But it is hard to imagine as motivation for begin interplanetary living. It takes probably hundreds of years before colony could be enough self sufficient to work as backup and could not help in any case now living people. Probably curiosity is more important motivation at beginning phase. It is also very difficult to believe so extreme conditions that it would be easier to survive in space than anywhere on Earth.

Why not? Barge is probably so cheap that if there is reasonable possibility of hitting it it is worth trying. Especially if passive barge can be used. I do not know is it reasonable idea but if they decide to skip fabricating new SN17 does that license allow SN15 to fly again as SN17?

OK. I misunderstood your opinion. Sorry. As far as I know (based on my solid state physics courses) hydrogen is absorbed in regular palladium lattice and do not need defects. Wikipedia says that there can be 0.7 atoms of hydrogen per palladium atom at normal pressure. But you are right, impurities diffuse usually to suitable lattice defects in normal materials and small concentrations. Palladium's ability to absorb hydrogen in its lattice is exceptional. It may be that density of hydrogen atoms is highest near suitable defects in palladium and cold fusion theory is somehow based on it.

I disagree. Coulomb barrier for fusion between deuterium nuclei is about 400 keV. Chemical bonding energies of lattice defects are single or tens of eV per atom. There is a difference of at least 4 orders of magnitude. Also, distance of nuclei needed for probable fusion is extremely small compared to distances of nuclei in lattices. There is also no credible experimental evidence of cold fusion in palladium crystal (as far as I know). Also nuclei distances and energies in predicted metallic lattice is several orders of magnitude less than needed for fusion.

Fully mechanical robot is interesting idea. But the article did not tell anything about mechanical sensor technology. It is quite futile idea to make a rover which just run aimlessly until hits an obstacle. Sensors have to be electronic. Maybe some simple things, like temperature sensor and basic data processing would be possible mechanically but I can not imagine mechanical solution to analyze samples, see environment and react to it or receive commands from Earth.

Of course situations may vary. It is the reason why NASA wants to have more than one company capable of their operations. Final results will be clear in future when both ships have retired and replaced by newer ships. But so far Dragon has been clearly cheaper (If I remember correctly Boeing has been given much more money) and more productive.