-
Posts
653 -
Joined
-
Last visited
Reputation
468 ExcellentRecent Profile Visitors
The recent visitors block is disabled and is not being shown to other users.
-
What is problem here? Trajectory and safety zones have been set large enouhg that if some of those mentioned anomalies happen, it do not cause danger. They test those things and it is quite probable that something fails. It is enough that SpaceX knows what happened and try to fix problems. If every problem stays in designated safety areas and no one is hurt there is not any need for authorities to control the situation. They can be happy that they made a good job to demand enough safety measures and technical problems are SpaceX's problems, not anyone else's. Tower catch is not different thing. Public is far away and if catch fails only SpaceX's property is damaged. FAA's task is not to prevent engine anomalies, because it is impossible, but make sure that if anomaly happens, there is no severe danger. If something unexpected happens or debris drift out from safety zones then they begin investigation. It is exactly what happened after last flight because some debris falled to inhabited island out of safety zone. The want to make sure that even next ship explodes, debris falls to safe places.
-
I still do not understand this demand. Do you think that publication is some kind of legal punishment for breaking the rules? Is there really such an option in US laws? I do not believe that. If FAA finds something potentially dangerous it can demand fixing probelms or more investigations but it can not order any technical details to be public. It is SpaceX's desicion if it publish something. If that is the situation do not worry. I am sure that those better companies who obey industrial standards and practices will develop their own 250 t rockets very rapidly and sell them to customers already waiting eagerly with their fancy 250t satellites. Why do you care about one rogue company who do not understand their benefits? Did you invest your own money to SpaceX?
-
This is very ridiculous thought. If FAA suspect that something is not safe it may demand information from SpaceX or order some things to do but such investigations are never public. SpaceX do not have any obligation to give any data for public. Why do you care about flames? Even they seem quite wild (compared to size of booster) they seem not be significant issue and if they are, they can be fixed for production models. Starships so far are just test objects for company's ove product development. 4 mm steel plate can stand quite much heat and burning gas. You can weld a stove from much thinner non stainless steel (which is more prone to oxidation) and use it years to warm a building in cold climate.
-
Ammonia is seriosuly investigated as ship fuel. It can be made from air and water with renewable energy and it does not produce any carbon dioxide because NH3 does not contain carbon. Ship Diesel engines can use ammonia with relatively minor modifications. Negative things which need more development are toxicity, lower energy density than methane or diesel fuel and tendency to produce nitrogen oxides. https://spectrum.ieee.org/why-the-shipping-industry-is-betting-big-on-ammonia
-
It is very different, unfortunately. This kind of attitude that we should try things, take risks and accept losses, both money and lives, lacks completely in whole civilized world at these times. Now politicians calculate prestige and companies profits and porce of failura is set to ridiculous. Everyone knows that space industry would not be tecnomagic at all and it would increase production of everything by orders of magnitudes but investments are negligible. Couple of states build political pork systems and on eccentric billionaire try something. Most other companies just want to get their share of states' pork money. I think humans do not achieve any significant steps in space operations or industrial utilization before we get pioneering attitude of exploration era back. We should build ships and send heroic expeditions to almost hopeless missions until some come back with all the presitige for funders and data needed to make next operation more safely and productively. It do not work as business. It must be ideologically driven process. There will be huge business later but timescale and risks are so high that it is not good investment in modern quarter year economy.
-
What If We Could Weaken Or Stop Entropy Within A Scifi Field?
Hannu2 replied to Spacescifi's topic in Science & Spaceflight
Entropy is practically mathematical formulation for fact that probable things happen more often than improbable. Breaking it breaks all known natural laws and whole idea of causality. Yous have to define more conditions to think what could happen and I think almost anything. In my opinion knowledge and tech is not good or bad. Humans can be and they can use things to good or bad (intentionally or as unexpected side effect). So far humans have used everything preferably to generally bad things but after long suffering and learning process they have managed to do some partially good things too. Future inventions will work similarly. Ability to break all known natural laws, for example generating suddenly energy of couple of supernovas from nowhere, would maybe cause extinction before learning. -
Did we discover nuclear technology “too early”
Hannu2 replied to awsumguy76801's topic in Science & Spaceflight
I do not think it is true. Basic nature of humans do not change during centuries. New tech is laways used first for war, if it is possible (and nuclear technology certainly is). Then for enslave others and make profit without caring environment or health issues. We can think such tinghs and make reasonable regulation after severe problems and even after that there are people who want to abuse things criminally to bad purposes. If researchers invented fission now or 2300 research would be immediately prohibited for companies and civilian universities and investigated only in large state's military research departments and their contracted companies. There would be period of nuclear tests and heavy bomb building, severe accidents and probable small nuclear war before proper regulation and civil use as energy source. -
Is a revolutionary advance in spaceflight imminent?
Hannu2 replied to Exoscientist's topic in Science & Spaceflight
I do not believe that those hypersonic planes would be important in foreseeable future. They may get some very special application for example in military use but not massive commercial success. New rockets (Starship, New Glenn, Vulcan) will be next step and make new things possible but I would not say it revolutionary to send million cheap satellites for entertainment use. I do not believe any large scale manned operations in my lifetime (about 30-40 years). There are not real will and attitude needed for pioneering exploration anywhere in the world today. There will not be manned Mars trips or large operations on Moon before states and funders learn to handle failures, losses and deaths. There may be some short propaganda Moon operations from USA and China but not more. -
How sad that those who always know how things really are and what would be best to do never have power and money to build perfect world.
-
I would not like to see that flap melting through a ship window as a passenger. But it seems whatever was left after re-entry worked well enough.
-
There is another problem. The energy density of lithium batteries is about 1 MJ/kg. Energy density of carbohydrates is about 16 MJ/kg and fats over 30 MJ/kg. It would be much easier to bring food on desert than electricity. It is difficult to invent credible explanation why any natural lifeform on any planet conditions would develop such an ability. But maybe electric metabolism would fit to some superadvanced civilization who lives mainly in space stations and have practically unlimited energy supply but want to save material resources of their solar system for example for Dyson sphere.
-
Super Uranium... Would Physics Allow For It?
Hannu2 replied to Spacescifi's topic in Science & Spaceflight
https://en.wikipedia.org/wiki/Nuclear_binding_energy#Semiempirical_formula_for_nuclear_binding_energy If you look the graph of estimated nuclear binding energy per nucleon around Z 120-130 (where island of stability is expected to be) (about 6 MeV), it is not much smaller than binding energy of typical fissile elements of uranium or plutonium (about 7 MeV). Energy released in fission is from difference of binding energy of fissile nucleus and tighter bound daughter nucleii. Released energy per mass unit of superheavy elements would not be significantly larger than typical uranium or plutonium isotopes. I have read that estimated densities of those elements in metallic state is about 40000 kg/m^3. That would give somewhat smaller nuclear bomb cores but probably not anything like pocket size nukes. -
Super Uranium... Would Physics Allow For It?
Hannu2 replied to Spacescifi's topic in Science & Spaceflight
If such material was so radioactive or othervise dangerous and expensive, probably nothing generally significant would happen. As far as I know there are not applications in which low energy to mass ratio of normal fissile materials is bottleneck. It is easy to load enough uranium to reactor to run large ship few decades. Suitable cooling and safety systems and systems to convert heat to usable energy would be as large as now and there would not be nuclear planes, spacecrafts, cars etc. in near future. Mass of nuclear weapons are mostly chemical explosives to implode fissile material and safety systems so there would not be pocket sized atomic bombs. It is also hard to see than any army would be willing to take risks compared to modern suitcase atomic bombs. -
Aerobic metabolism is one option to get energy to join phosphate to ADP to return it ATP. ATP then gives energy to biological processes when it break to ADP and phosphate. There is also many anaerobic ways to get that energy but aerobic oxidation is by far the most effective known way and makes actively moving lifeforms possible. If that referenced study is true there seems to be a way to run that reaction cycle with electricity. Of course there is no known biological mechanism to do that and it is impossible to say can there be a working cell. Even then lifeform would need material (and special chemicals like vitamins) to grow and reproduce damaged things but eating for just energy would not be needed and food consumption of adult (or otherwise non growing or reproducing) individuals would be very small compared to humans.
-
Super Uranium... Would Physics Allow For It?
Hannu2 replied to Spacescifi's topic in Science & Spaceflight
As far as I know low utilization is practical thing. 4 % enriched uranium is cheap and there is no economic reason to use it effectively . It would be technically possible to build reactor to use higher enriched uranium and use larger part of it or even breed non fissile isotopes to fissile but such a tech is internationally and politically very problematic because it would give rapid way to build nuclear weapons. Used fuel is recycled and reprocessed to usable nuclear fuel (MOX fuel) in some countries. I do not know is it purely business thing or has it some military or political reasons.