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About Hannu2

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    Junior Rocket Scientist

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  1. 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 c
  2. 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.
  3. 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 avai
  4. 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 t
  5. 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
  6. 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 extreme
  7. 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.
  8. 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?
  9. 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 i
  10. 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.
  11. 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.
  12. 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.
  13. Return to launch site needs delta-v but I think possibility of rapid reuse is more important than optimizing mass of single launch. It takes days to bring rocket from sea to launchpad and gives more restrictions if there is bad weather on sea.
  14. Why not? That exploding ship try to achieve new landing maneuver which can make far larger and cheaper ships possible. But first capsules was flown to orbit and back in 1960. There is nothing really new in Boeing's capsule. Dragon makes everything Starliner do but is much cheaper to operate. Certainly it do. But it is also certain that Starliner achieves never any milestones in manned or unmanned operation. It is second best tool for routine work, selected in addition to best tool because redundancy and political issues. Starship at least intends to achieve new things in b
  15. If I remember correctly this project began before routinely reuse of rocket boosters. It is clear that rapid and cheap reuse has destroyed most markets of these plane rockets. It may be practical to use standard 747 for some small rocket launches with special need of inclination but I can not believe that building and maintaining this kind of very special planes will be productive business.
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