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RCgothic

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Posts posted by RCgothic

  1. 3 hours ago, magnemoe said:

    Not much an fan of the whale mouth hatch. Prefer an side opening hatch. First the mouth make integrating payload harder as in how do you do it? You need to either remove the hatch or get payload above the starship and then tread it between nose and hatch and down to the adapter in the bottom. 
    It also limit deployment and will not work if you land on an surface. I also say it would make moving stuff between an cargo starship and an moonship cargo version harder. 

    As I understand satellite deployment with starship will be that you put your satellite in an container and the container will be opened in space an the satellite is released. 
    With the wale mouth its hard to release other direction than straight up after you tilted the container to clear the nose. 
    With an side door you can easier release multiple satellites. 

    Agreed, the whale mouth is a bit odd.

    Trans-shipping of cargo in space is also something they'll need to consider. 

  2. 44 minutes ago, JoeSchmuckatelli said:

    Okay - KSP question time:  Every single attempt at putting even a small spaceplane at the top of a large rocket ended up in horrible failure.  My 'best guess' to this is that I had wings way up high.  What is Starship doing IRL that keeps the 'wings' at the nose of the spacecraft from flipping the rocket during launch?

    IRL flight computers are much more capable and engine gimbal is capable of defeating quite substantial aerodynamic forces.

    E.g. Falcon 9 has no rear fins and a fairing that is larger than the main body. In KSP that's a no-no, but it's actually not that big a deal.

  3. 1 hour ago, Dr. Kerbal said:

    Can you please make this easier for me to understand. Think of me as an average Joe. I don’t understand what photons or wired math have to foe worth anything. Sorry, but please simplify so my brain can understand.

    It's a very complex subject, so explaining simply is hard.

    Basically, it's very hard to turn antimatter into useful work because it takes many metres of heavy material to absorb the energy released in the form of gamma radiation (which likes to go straight through things), and that's bad for rockets.

    Also the slightest percentage of energy transferred to the vehicle instead of the propellant requires vast radiators to dissipate, and those are heavy and so bad for rockets.

  4. 3 hours ago, tater said:

    Next Starlink launch in 3 days, lol.

    And if it launches on time it will shave I think 3 days off the fastest turnaround.

    Wikipedia says B1058 Demo-II to ANASIS-II was 1m 20d, but that month includes May 31st (51d).

    B1060 L11 to L14 would be 1m 18d but September was only 30d long, so 48d.

     

    At least until B1058 reclaims the title in November with CRS21!

  5. I propose:

     

    A planet is a gravitationally rounded body.

    major moon is a planet that orbits a barycentre inside a non-stellar primary.

    binary planet is a pair of planets orbiting a barycentre that is in free space at least some of the time.

     

    An asteroid is not gravitationally rounded.

    An asteroid orbiting a planet or planetoid is a natural satellite.

     

    A planetoid is a transitional form that is somewhat rounded by gravity. 

    A minor moon is a planetoid that orbits a planet.

     

    Therefore the moon is a major moon that is a planet. Later in its life cycle it will be a binary planet with Earth.

  6. Add me to the "we should have dozens of planets" caucus.

    Ceres was a planet before Pluto was.

    A planet should be defined by its shape and size, not by where it happens to be. By current definition a rogue gas giant could not be a planet because it's impossible to clear a hyperbolic orbit.

  7. 1 hour ago, Flying dutchman said:

    Only 4.9 km/s of dv? I really don't see Them doing point tot point with those nummers, or even getting tot Orbit with no payload when on top of super heavy.

     

    Edit: the prop load is twr limited in this case...

    Yes, SN8's propellant is limited by only having 3 engines and the requirement to get off the pad. Add 3 fixed thrust-optimised raptors instead of vacuum raptors blanks and that's another 750t of propellant (1150 total) it can carry.

    ~8km/s DV with 0 payload and 120t dry mass.

     

    That's ballpark P2P2Anywhere, but I'd expect any suborbital version to either *not* have range to anywhere on the planet, or to have more than six engines. Starship can comfortably fit nine sea level raptors.

  8. Assuming a TWR of 1.2 with 0 payload, 120t dry mass, 210t thrust per Raptor and an average ISP of 340:

    SN8 would have 395t of propellant and 4.9km/s of DV.

    F9 first stage with 15.8t payload and 116t second stage on top has about 3km/s DV.

     

    But I don't really think this is a test they'll actually perform!

  9. 20 minutes ago, cubinator said:

    Would SN8 be capable of a 100 km hop?

    I think so. Once you've got engine relight and the landing manoeuvre sorted the limiting factor becomes thermal protection.

    You'd need a heat shield for a return from LEO, but not from 100km straight up.

    I'd be willing to bet SN8 could come in faster and hotter than an F9 first stage.

  10. No, Pluto is a dwarf planet, or planetoid.

    That said, I think the *has cleared its orbit* criteria is rubbish.  If you transported Pluto to the inner solar system it would be a planet.

    That doesn't seem like a good definition to me.

  11. In Star Trek the Impulse Driver Coils envelop the ship in a low-grade subspace field that lowers the effective mass of the ship. Congratulations, now a miniscule quantity of propellant can propel a ship to high fractions of c.

    In Mass Effect a ship's drive core generates a negative mass effect field that actually lowers the vessel's mass. Same outcome.

     

    You've got a setting with warp drives and anti-gravity. Unless you've got a compelling story reason, hand-wave it.

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