5 ms·

Starship is ready for its 2nd test flight

62 points by alentred 3y ago

ansible 3y ago
The timing for the staging is interesting. On the one hand, you want to light the Starship engines (the 2nd stage) while the SuperHeavy (1st stage) is still accelerating the entire stack. This is to keep the propellants at the bottom of their respective tanks to prevent any bubbles going into the engines. The Starship then needs to be under sufficient thrust to accelerate just as the SH cuts its engines so that the two stages can separate safely. I'm sure it will be exciting. I just hope sufficient SH engines remain running long enough to try the staging event.
- panick21_ 3y ago
  Interesting how fast they switched to that.
  - ansible 3y ago
    The "spin the entire stack" was an interesting approach to staging as well. It is theoretically very simple and elegant, by just using the existing RCS thrusters for separating. It wasn't clear to me if this also obviates the need for a propellant settling burn on StarShip. I'd think it wouldn't, but I'm not sure. There is still a thin atmosphere at the staging altitude, so if StarShip is pointed in the right direction after separating, it should be de-accelerating slightly in the direction of travel.
    - LorenPechtel 3y ago
      Which would be the reverse of what you want, it would push the propellant away from the engines.
- greedo 3y ago
  Wouldn't the methane in Starship still be at the bottom of its tank due to the momentum imparted by the Booster regardless of whether it was still attached?
  - crgwbr 3y ago
    In a vacuum, maybe. But in any atmosphere, removing the thrust means negative acceleration due to drag. Thus the propellant could start to drift up/forward.
chasd00 3y ago
I thought for sure pad repairs would have taken longer than they did. I'll have to start getting back in the livestreams and get caught up on developments. I saw that the latest static fire was successful in that all engines ignited.
- MilStdJunkie 3y ago
  It's not the two months that was promised, but 6 mo is still astonishing. I keep wondering to myself, where is this money coming from?, but then I remember just how much cash we straight up torch in traditional mil-spec aerospace. Without anything to show for it, natch.
  - tekla 3y ago
    The US launched 90-90% of all objects into Space my # objects AND by mass. Lets see Europe launch their probes right now. Of course, they can't because they don't have a domestic launch vehicle and Russia is not available. That is where the aerospace money is going.
    - midasuni 3y ago
      There’s a vega launch next month
      - tekla 3y ago
        Vega is an infinitesimal blip on the launch industry and will continue to be a blip. It costs almost as much as a F9 with almost I believe less than a tenth of the performance. It only exists so that Europe can claim they have access to space as long as your payload is tiny
        midasuni 3y ago
        “ they don't have a domestic launch vehicle” So your claim was wrong
    - 3y ago
dmarcos 3y ago
Says not before middle of Sept. Would love to go. Anyone else trying to time a trip?
hackeraccount 3y ago
In this instance defeat has a single father and victory everyone minus one.

62 points by alentred 3y ago

The timing for the staging is interesting. On the one hand, you want to light the Starship engines (the 2nd stage) while the SuperHeavy (1st stage) is still accelerating the entire stack. This is to keep the propellants at the bottom of their respective tanks to prevent any bubbles going into the engines. The Starship then needs to be under sufficient thrust to accelerate just as the SH cuts its engines so that the two stages can separate safely. I'm sure it will be exciting. I just hope sufficient SH engines remain running long enough to try the staging event.

panick21_ 3y ago
Interesting how fast they switched to that.
- ansible 3y ago
  The "spin the entire stack" was an interesting approach to staging as well. It is theoretically very simple and elegant, by just using the existing RCS thrusters for separating. It wasn't clear to me if this also obviates the need for a propellant settling burn on StarShip. I'd think it wouldn't, but I'm not sure. There is still a thin atmosphere at the staging altitude, so if StarShip is pointed in the right direction after separating, it should be de-accelerating slightly in the direction of travel.
  - LorenPechtel 3y ago
    Which would be the reverse of what you want, it would push the propellant away from the engines.
greedo 3y ago
Wouldn't the methane in Starship still be at the bottom of its tank due to the momentum imparted by the Booster regardless of whether it was still attached?
- crgwbr 3y ago
  In a vacuum, maybe. But in any atmosphere, removing the thrust means negative acceleration due to drag. Thus the propellant could start to drift up/forward.

chasd00 3y ago

I thought for sure pad repairs would have taken longer than they did. I'll have to start getting back in the livestreams and get caught up on developments. I saw that the latest static fire was successful in that all engines ignited.

MilStdJunkie 3y ago
It's not the two months that was promised, but 6 mo is still astonishing. I keep wondering to myself, where is this money coming from?, but then I remember just how much cash we straight up torch in traditional mil-spec aerospace. Without anything to show for it, natch.
- tekla 3y ago
  The US launched 90-90% of all objects into Space my # objects AND by mass. Lets see Europe launch their probes right now. Of course, they can't because they don't have a domestic launch vehicle and Russia is not available. That is where the aerospace money is going.
  - midasuni 3y ago
    There’s a vega launch next month
    - tekla 3y ago
      Vega is an infinitesimal blip on the launch industry and will continue to be a blip. It costs almost as much as a F9 with almost I believe less than a tenth of the performance. It only exists so that Europe can claim they have access to space as long as your payload is tiny
      - midasuni 3y ago
        “ they don't have a domestic launch vehicle” So your claim was wrong
  - 3y ago

dmarcos 3y ago

Says not before middle of Sept. Would love to go. Anyone else trying to time a trip?

hackeraccount 3y ago

In this instance defeat has a single father and victory everyone minus one.