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Kryten

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Posts posted by Kryten

  1. 7 minutes ago, Mitchz95 said:

    Not much in the way of new information, but good to hear it's not related to the CRS-7 incident.

    That's only if you assume SpaceX's analysis of CRS-7 found the right cause, which NASA among others aren't certain of. It does seem to be something in oxygen tank helium system, so it would be consistent with the alternate explanations of the CRS-7 incident.

  2. 9 minutes ago, DDE said:

    This is quite surprising, since there's a huge push to retire the whole toxic family. It may be an interim design until the nativized, Proton-sized Zenit derivative takes over.

    Yes, it's supposedly an interim vehicle until Fenix/Sunkar takes over in 2024 or '25. It would not at all surprise me if it ends up lasting longer, though.

  3. The fire on south base is pretty much contained now, evacuation orders for communities outside the base have been lifted and specialists are starting to enter south base to evaluate the damage.

    The fire on north base (what they're calling the airport road fire) is now 250 acres. It's currently moving away from residential areas, and plenty of civilian facilities on north base are still open.

    The launch of WorldView 4 on the 26th has now formally been cancelled, although it was never likely. They're now looking at launch in 'early October,'.

  4. Another little thing for today; on September 21st 1992, formal authorisation was given to the 3-phase Chinese human spaceflight programme, which is consequently known as Project 921. Project 921-1 is development and initial testing of the crew vehicle, 921-2 testing with space labs (we're late in 921-2 right now) and 921-3 launch and commissioning of the modular space station. What comes after 921-3? Nothing that's formally been authorised, so your guess is as good as mine.

  5. One of the astronomers to be present at the conference has repeatedly been granted HST time to search for plumes, so that's almost certainly what it is. Particularly as he's had no less than four (one two three four) time grants for this search, for a total of 28 orbits-that's a lot of Hubble time, and they won't have given him it if nothing had turned up.

  6. It's rare in practice for rocket designs to be completely clean-sheet, especially in terms of engines. Take the Delta II, one of the most flown rockets in history; the first stage motor is an RS-27A, which was developed from the Saturn I's H-1 engine, which was developed from the S-3D for the Jupiter and Thor programmes, which was developed from the engine for the Navajo booster... and so on, right back to the V-2 engine. The upper stage motor is an AJ-10, which has a similarly convoluted heritage leading to the mid-40s Aerobee sounding rocket. Same for most engines today.

  7. 2 minutes ago, Rhomphaia said:

    The Black Arrow had three engines, one per stage.

    The first stage had 8 nozzles.

     

    It is a different matter to have multiple engines.

    Do you have a diagram showing this? I can't make out the gas generator/s in images of Gamma engines I can find, so I don't know if it really is one engine or multiple engines referred to as a single engine. The latter is quite common.

  8. 3 minutes ago, Scientia1423 said:

    Wow lol. The British black arrow rocket also had small engines, I think. The R1 and R3 were the only successful and R2 only just as it's payload Orba was sent to measure the upper atmosphere density by monitoring the decay of its orbit.

    Black Arrow had 11 engines, one of them a dependable solid. Nothing too bad with that with enough testing; Ariane 4 had many flights with a total of ten with very high reliability, and Falcon 9 also uses ten with reasonable reliability. N1 had 44, all liquid. To make it worse, most of the engines on N1 could only be fired once, meaning they couldn't test them before flight.

  9. 2 minutes ago, YNM said:

    I don't get it - Unless the rocket is full of gaseous air, it's going to be heavier than water right ? How in the hell they haven't think of that ? Even SLBMs can only get off water by some pushing mechanism (air) or engines, are they going to tow it on a boat fully laden ?

    Hydrolox is heavily biased towards liquid hydrogen, which is far less dense than water (70g/l v. 1,000g/l), so that bit at least checks out.

  10. 10 hours ago, Firedtm said:

    Expander cycle (Can be Open or Closed Cycle) most engines was open cycler till the 1990's when the Closed Cycle system was found out

     Almost all expander engines are closed-cycle, with the first being the RL-10 in the 60s. It was the open-cycle version (expander-bleed cycle) that was invented in the 90s, with the Japanese LE-5A, and the Japanese are still the only ones using this cycle. Closed-cycle expander has higher efficiency but a hard thrust limit of about 300kN (with hydrolox), which limits it to upper stages and very small vehicles, while expander-bleed allows enough thrust to be used in large booster stages.

  11. The one in the OP looks about as likely to launch something into orbit as I am.

    I mean, just look at their website; http://www.ripple-aerospace.no/

    There's almost no information, and the whole thing looks like engineering by design students. Major details are missing or are barely mentioned, like the fuel combo they intend to use; which, by the way, is hydrolox. How the hell is a sea-launched vehicle supposed to be filled with liquid hydrogen without turning into the world's largest ice lolly or wiping out all the payload mass with insulation?

  12. 17 minutes ago, RainDreamer said:

    Honestly though, I can't imagine a scenario where the military space race don't end up in trashing LEO and no one get to space anymore, even if it is between moon colonists and earth. So likely no one is planning to go do it, realistically. Doesn't mean we can't speculate though!

     Not much military infrastructure is in LEO right now, so this isn't necessarily true in a near-term scenario. It's limited to maybe a dozen his-res recon sats in the worst case (the US) and the Iridium constellation, and Iridium is low-throughput enough that it's probably not worth targeting.

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