Hannu2

OK. I read list in Spaceflightnow and it includes only two USSF missions. Now I found a complete list. But it still seems that communication satellite companies do not trust Falcon Heavy. There is only one such mission. Or don't they need more payload capacity?

This is guess but maybe another had some damage or technical problems and they decided to scrap it. There is also 2 unused booster set for Falcon Heavies. There are couple of space force missions in list which seem to slip always for future. Is there some known problems with Heavy or why it has so little use? As far as I know it is cheap compared to all other heavy rockets than Falcon 9 and has clean (but of course statistically not very significant) launch record.

This was also space race's Achilles' heel. Development of military missiles separated from orbital rockets during 60's. Military developed smaller nuclear bombs (in mass and volume) and wanted storage properties, hitting accuracy etc. instead of increased thrust and ISP space exploration needed. Missiles became simple solid propellant rockets which was easy to store in caves or submarines for decades and launch immediately after command. Saturn V with high energy hydrogen stages was clearly something military did not need. Therefore USA canceled 3 scientific Apollo missions and did not develop much space tech based on Apollo and moved to Shuttle, completely different spacecraft, which army thought to be useful in military operations.

Probably not. Nearby celestial bodies are known much better than ocean floors and all operations on deep oceans are extremely expensive and more dangerous for humans than space. Cost of space operations decrease all the time but there is no significant development in deep ocean operations (as far as I know). In addition to that there are environmental issues etc. against large scale industrial operations in oceans. I am quite sure that moving mining and refining, later also many assembling tasks, to space will be next generation's solution to environment problems on Earth.

It would be very useful for handling seasonal variations of many renewable energy production systems. Capacity would be unnecessarily large but if it would be possible to make 3000 TWh units probably it would be even easier to make 30 TWh units and distribute them on World's electric networks. Unlimited current is not reasonable idea under known natural laws but if maximum current would be extremely high there would certainly be military applications too.

Small amounts of methane can vaporize easier and form explosive mixtures with air. But I do not see significant difference in conditions of rocket explosion. Both are liquids which have to vaporize before chemical reactions. Temperature of methane is lower but heat of vaporization is larger. I think this kind of events are handled by orders of magnitude so explosion of Starship would be practically similar than explosion of N1. I am sure that authorities have thought the possibility of explosion, it would not be the first rocket exploded on pad after all, and accepted SpaceX's safety measures (when they will give the permission for launch). Launch pad would be destroyed but very probably no one is injured and damage of others property is small. If worst case happens maybe they finish those oil rig launchpads before continuing tests.

I lost couple of hours play because the game did not stop warp at Eve encounter. In most games there are automated autosaves at regular intervals and I have lost my routine to hit F5 after every laborious task. Is there a mod for KSP for that? Preferably it should use separate files with timestamps and keep at least few of them.

Do you allow any development? Or should every machine be something already built? If you think about rotating space stations you probably allow some development. I think that if we could build proper fission reactor for space (which is currently much more political issue than technical), we could accept high loss rate of missions and the fact that astronuts would get permanent injuries on their missions (for example radiation damage) and we used all possible resources we could make manned operations on all planets in few decades with current production rate. It would be nothing new. On expedition era kings and rich people sent ships and crews after another. Most of them were lost or just few participants came back without gold. But few successes made it profitable. I think current era of unrestricted capitalism without ideological objectives will end sometimes and then humankind (or strongest states or richest or mightiest persons) will have such objectives again. What could be better ideological objective for technical civilization than expanding to another bodies in their solar system (and maybe beyond if it will be possible) at any cost.

Let's hope that they release a new content DLC soon which give reason to investigate planets for others than science nerds who find a table of isotope contents interesting. Complete planet surface overhaul could add crazy geologic and weather effects, beautiful colors, scary lifeforms, including huge monsters, huge deposits of precious metals in pure form, etc. to all planets and moons.

I agree with orbiter probe to Uranus or Neptunus (planet scientists are probably better to decide which than I), if I was limited to somewhat realistic missions. But I am not sure how realistic they are without fission powered ion propulsion.

That contingency sampling would be a good idea. If fancy mechanic fails lander would just scoop a local dirt and put it in return capsule instead of bored stone samples. Is it easier or faster to make smaller and cheaper missions? It all political issues are taken into account?

Why do you thin that gel had greater density? Gel is made by adding some additive to liquid. If liquid is rocket propellant that additive stuff just takes room and makes it less dense. Why it would? Turbopumps need huge amount of power. Tens or hundreds of MW. The massive main engine of large cargo ship would struggle to run large rocket engines's fuel and oxidizer pumps. Gel would mean increased viscosity and increased power demand. On the other hand, I do not see immediately any benefits over liquid. If I was Elon Musk and you suggested a addition to make liquids less viscose I would buy a little bottle for testing but if you suggested some stuff which makes propellants harden in tanks you would be happy that it robot dog can not bite. Like what? You mean solid rocket fuel which would flow out of booster. If you combined oxidiser and fuel before burn chamber you had to pump all combined volume to chamber pressure. Highly viscose stuff would need more pumping power and get heated. It would also get heat from regeneratively cooled nozzle and chamber. Plumbing should be able to handle both chemicals. Only thing you would save is a dome between tanks and some parts from rocket engine. And spectacular and frequent anomalies, of course. If I remember correctly they have estimated that few tens of percents of rockets propellants take part in "explosion". And time needed to mix them slows the reaction significantly. Actually it is not even real explosion but some kind of flash (probably it has word in English). But mixed propellants would react immediately and burn completely.

It certainly is but it is extremely improbable that lander lands near specially interesting target if rovers need to drive kilometers to find them. Samples from those rocks will be much more valuable than bag of sand from random place. If we begin with "simple stupid" -class mission then researchers ask soon next level mission. Maybe on some idealistic level of thinking. Include funding bureaucracy, political issues, delays for various reasons, companies' and individuals' efforts to take personal advantage from every desicion etc. nasty real world stuff you get 4 billions and 10 years as a first (utterly optimistic) estimate. Then delays and budget overdrafts begin until after 20 years and 10 billions someone cancel the program.

Probably no. Water has more than 10 times higher heat of vaporization which is the most important energy absorbing phenomenon in cooling. Very cold nitrogen would also cause worse heat shocks and make many materials brittle. As far as I know one of the most important reason for use of stainless steel in rockets is its ability to keep its mechanical properties at -200 C. Nitrogen can be sold or be used to keep stored propellants cold. It is not much compared to overall costs of rocket launching but maybe they get back energy cost of liquefaction process.

ESA could be a very good idea but practical realization is even more political and much more poor than NASA. Every single country want to have orders and contracts for their companies more than they pay, which is naturally impossible before there is actual business in space. Maybe (a big maybe) it would work better if ESA was under EU level administration.

In Finland we had some discussions couple of years ago. Some politicians suggested space administration but it seemed to be just some political trick. Finland is some kind of restricted member in ESA. There are some companies which make spacecraft components for ESA and NASA but the State does not have any activities as far as I know. Fortunately it has probably been forgotten. It seems that Australian thing may be similar. Someone want a department with squadron of bureaucrats who has nothing real to do. In Australia it may be possible to launch rockets in future but there will certainly never be an orbital launch from Finland. The southest part is about at 59.5 N latitude and all trajectories to east should fly over Russian land. If some Finnish company want to use for example ESA's launchpad at South America ESA's and EU's bureaucracy is certainly enough. There is no need for Finnish government level in addition to that.

I counted cancelled or failed space missions due to bad weather delays. Travelers have commonly very limited periods they must fly for various reasons but space projects can adapt to delays for many reasons. Launch windows are usually weeks long and very many Mars projects have succeeded in spite of delay of 26 months to next window.

Unability to fly in bad weather is not a bad problem in current of foreseeable applications of space flight. Payloads which need to be launched at exact time are very exceptional. Most projects take years or even decades and delays of months or years are tolerable (and actually very common). That point to point passenger flight is such application but it does not seem to be very realistic idea at all. At least in next couple of decades. There is not only technical problems but legal and bureaucratic issues too which may be much more worse, if international aviation regulations must be changed.

I understood. But my English skills (which may be bad, I am not native) say that paper rocket is not suitable word for that phase. Paper rocket is rocket under planning. And if you think for example other companies and operators, rocket under flight test program (Starship) or under finalizing for first flight to orbit (SLS) are much more potential than rockets in early planning phase (for example manned Mars crafts or proposed nuclear stages). Probably every company and space organization take Starship into account and estimate benefits, risks and schedules when they plan their own projects in paper stage, even they would eventually decide that it is better to take one of current production models. But no one even think about possible nuclear rockets of far future. Of course Starship or SLS are not in operational work yet (i.e. "ready") and it is not guaranteed that they will ever be. And Proton clearly is because it has very long history and you can routinely buy a standard launch. But it is not definition of "paper rocket", at least in my opinion. It may be that someone uses that word differently. But in any case it causes confusion to call project in test and finishing phase as paper project. SpaceX's phenomenal pace of development is easy to forget because Musk gives always those "aspirationally" unrealistic schedules which slip years. But if you look history there are no many examples of such rapid development even in superpower's almost infinitely funded projects. But I am sure that NASA is not serious with that manned Moon landing in 2024. It is clearly impossible if they do not accept very high risk level and increase funding immediately by an order of magnitude.

What is the point of all this complaining? We know that you do not like SpaceX and do not believe they could achieve success. But they will absolutely surely not cancel their projects if someone in Internet do not like or believe them. Let them try whatever they want. I would mention also lion's share of global satellite markets and real attitude to try some real development instead of empty talks like national space organizations (except Chinese who also attempt to develop their space operations). I would not give applauds for Nasa, Esa or Roscosmos (or governments funding them) for activities in last 2 decades. Drag can also be controlled by orientation of craft. There is no need for large corrections in pinpoint landing. Controlled drag is needed for last minute change of landing area which is not needed in civilian space applications. Even spacecraft could do it and there would be another landing rig nearby such a major change of flight profile would need bureaucratic paperwork of months in normal conditions and be practically illegal.

There is a clear difference between funded project which building work has began and "paper project" which has not made any expensive building work yet. Of course there are unclear occasions (of example in my country building work of building has juridically began if I throw one shovel concrete on ground and let it harden but if I dig a trench for basement it has not began). But both SLS and Starship has many essential and very expensive components, like engines, ready or under flight test phase. Billions of dollars have invested for both projects. They are currently work in progress and if they were cancelled before finish they will be failed projects but they have very clearly passed paper rocket phase several years and billions of dollars ago. I would say that Moon lander version of Starship (and other suggested landers) and all published manned mars-operations are currently in paper phase. They have no significant hardware yet and will need several orders of magnitude more funding than already used to be severe projects under construction.

Your source assumes coplanar circular orbits. Under those assumptions ejection inclination is always zero. You should calculate more accurate trajectories and maneuvers by using all orbital elements. It is much more laborious (for both, computer and programmer) but not mathematically very difficult. You find formulas and algorithms with quite clear explanations from the link below. You can calculate inclination and LAN for parking orbit from ejection velocity vector and parameters of departing body. Improper gravity model of KSP may also cause errors, which can be (very) significant if you plan Moho transfers or transfers between Jool's moons. http://www.braeunig.us/space/index.htm

That may be true from some very abstract philosophical point of view. Like wars could be ended if no-one would kill or poverty could be ended if wealthy people would always help poor. But practically that is very false. If you are worker you use units your boss order to use. If you are boss or company owner you use units customers want to. If you are politician you know that any law can not overcome conservative attitude and traditions. Eventually you can not find an individual in real world who can avoid imperial and other strange units without significant trade offs in practical life. Situation is not perfect in countries or scientific community which use SI-system. There are many historical special units in most areas which stay alive during decades. For example ångströms (1 Å =100 pm) and 1/cm as unit of energy in spectroscopy.

There is no way. Most of those people are generally against lifestyle and culture of western civilization. It is futile to tell that expansion to space is the only way to maintain development in long periods if someone wants to shut down industrial production and return couple of hundreds of years backwards (usually without understanding that they would not be counts or princes but practically serfs without human rights in extreme poverty if they survived through some miracle when food production drop 90 % without modern machinery, chemicals and highly productive plant varieties). Religious people who think that their god want humans to stay on Earth are probably even harder to convince benefits of space technology. Third group are just nitwits who can not understand complex processes and long timescales. Pretty hopeless too.

Carbon fiber is not established in large rocket booster tanks. It is very special thing which needs special properties. If there are high pressure carbon fiber gas cylinders they are not straightly usable in rockets. That SpaceX's "trade" means failure. Their composite tanks were not good enough to heavy booster and they did not see way to achieve objectives in predictable time and costs. There are also no other companies who use such tanks in their large rockets. SpaceX use steel and Li-Al and others Li-Al. That 304L is not "ultra strong space steel with 10 % unobtainium and cost of million per kg" but very basic stainless steel used in very many industrial applications. Especially in food industry because it is very safe. Also usual kitchen stuff, like forks, spoons and pots, are made from such steel. They said their will develop material later phases and I do not know are new SNs still made from commercial 304L steel.