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DDE

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Everything posted by DDE

  1. DDE
    There are significant doubts that a large rocket can be launched from an unprepared pad on Earth, or even landed on it. This killed the very similar ITHACUS proposal. Blast trenches are there for a reason. Research on transport rocketry concluded that it’s either a pad-to-pad affair or a one-way affair. Plus, it provides very little added value over a supply paradrop - indeed, “worry about recovering later” is the very definition of paradrops. Sure, if you’re willing to pay an exorbitant price for such mundane payloads. The situations where P2P’s supposed advantage in transit time is actually required are extremely few and far between - too far between to justify maintaining such a transport system. And if it can wait just a bit longer, the much cheaper freight jets win.
  2. DDE
    Everyone. I’m not sure how many people were phished by PwC to prepare one of their presentation, but they claimed a success rate of 100%. Other sources claim that at least 4% of those swindled get victimized again in under a year. Between the huge social media papertrails and the bank employees constantly selling data, no-one, and I mean no-one, is safe from social engineers. Tech-illiterate grannies are just the low-hanging fruit; even militaries can fall prey to convincing spear-phishes.
  3. DDE
    RD-171MV may up the ante a bit. Should make it to the test stand soonish. There’s also Energomash’s experimentation with an annular pulse-detonation engine. How do you even measure the chamber pressure in a spinning explosion?
  4. DDE
    A few millenia later...
  5. DDE
    My parents’ rationale as well.
  6. DDE
    Amen!
  7. DDE
    This bad boy can fit so many P2P hops in it!
  8. DDE
    Designed mission life. And it’s not particularly long... Rad-hardened electronics are a massive Achilles’ heel of ours.
  9. DDE
    You know the old blotting paper? Be sure to have some variant of tissues around, something like Kleenex. My pen leaks a bit, likely due to vibrations, so cleaning it is a practiced routine. Serious maintenance includes repeatedly filling and emptying the reservoir with watered-down vodka to thoroughly purge any dried ink build-up.
  10. DDE
    And this is where we get to the really awakwsrd part. Most of those people flew from point A to point B. There’s a pronounced shortage of desireable Points B in space. Thus we end up in a vicious cycle with BO’s thrillseeker-optimized suborbital trips breathing down our neck.
  11. DDE
    A very slim chance of military logistics use, a fair chance of use but by government agencies alone (and likey those more risk-tolerant than NASA), and straight-up nope, respectively.
  12. DDE
    I severely doubt anyone, be it SpaceX or the God-Emperor of Mankind, can bring the reliability of spaceflight down to airliner level. Ever. The hazards and energies involved are to a ridiculous degree greater than aircraft travel. Furthermore, it’s likely that the economic “sweet spot” for safety of human spaceflight is way, way, way below that of airliner travel because the tiny handful of humans that would ever venture off of Earth would be far more accepting of risk, so it’s economically irrational to ain for a lower chance than, say, 5% for a LOC event for an Earth-Mars flight. And don’t even try throwing historical parallels at me.
  13. DDE
    There is a five-stager. https://en.wikipedia.org/wiki/Augmented_Satellite_Launch_Vehicle Then there’s N-1 and Yenisei, if you include the lunar retromotor, N-1’s original Block D is a fifth stage, while Yenisei may take four stages just to get into LEO, and the lunar mission would be carried out using the fifth and sixth stages.
  14. DDE
    *If
  15. DDE
    Don’t drop that lOx dome... again.
  16. DDE
    It was done, but kind of a long time ago, in a Union far, far away. An elegant vehicle for a more... socialized age. Note the tiny separation between the boosters and the wings. The boosters would separate while still strapped together, and use a two-stage separation rocket to steer them clear of the wings, at a distance of 60 cm or less, without the exhaust hitting the TPS. And there was supposedly such a safety margin that it could still separate with either of the boosters having not expended their kerosene supply (there was a huge oxidizer dump valve to provide engine-out capability).
  17. DDE
    Don’t Indians have an SRB asparagus system?
  18. DDE
    It’s hapenn*gets drowned out by Raptor test fire* Final configuration appears to be: 4 x RD-171MV first stage, 2 x RD-171MV second stage, 1 x RD-180 third stage, all fired in parallel, and a smattering of hydrolox upper stages.
  19. DDE
    Interesting question: what’s better, ruggedized industrial laptops that are borderline-bulletproof, or sane maintenance practices?
  20. DDE
    In a way. Certain non-space-grade designs use blank shotgun cartridges or somesuch to pop the bolt.
  21. DDE
    It’s an attitude that gets missions cancelled over safety concerns. You probably don’t. Which is hardly surprising for a vehicle that gets most of its benefits by ditching certain aspects that added passive safety in most stages of flight, such as multiple-stage Mars orbiters.
  22. DDE
    The BFR is probably not at a point where the square-cube law avenges the notorious mass inefficiency of high-thrust pressure-fed rockets.
  23. DDE
    Well, great. This time our offic pulled out one of the 200 (and counting) winning tickets in today’s Fake Bomb Threat Lottery in Moscow. We’ve got a second office within walking distance, though. So I’m a working evacuee now.
  24. DDE
    I think he merely got infected with the utter schizophrenia of trying to run a national space program as a profit-making venture... while being chastised for not spending the taxpayer cash being sent his way.
  25. DDE
    Well, they don’t come with the car, let alone a car that’s older than my parents.
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