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I don't understand the term belly flop or rapidly reusable. Do You mean that it is becoming horizontal to reduce the falling speed rate to land on its belly?

I don't understand the term belly flop or rapidly reusable. Do You mean that it is becoming horizontal to reduce the falling speed rate to land on its belly? shuttle was reused and landed on wheels parallel to its belly.

gridspy 6y ago
Belly flop - https://youtu.be/vRPrLvVaQq8?t=145 https://youtu.be/vRPrLvVaQq8?t=145 (Yes, to reduce the falling speed. No, it lands vertically). Rapidly reusable - You can land it directly on (or next to) a launch platform, refuel it and launch it again the same day. Same as a regular aircraft. The Space shuttle had a disposable tank (which was lost on launch), recovered but basically destroyed solid rocket boosters (ditched into ocean) and finally on landing it had (potentially) damaged heat tiles which all needed inspection and which were all fragile and different.
- GizmoSwan 6y ago
  Does it use Nasa's pica heat shield. Nasa could have upgraded shuttle too to use their own tech so the shield tech is not material argument. The boosters were recovered. https://www.nasa.gov/centers/marshall/about/star/shuttle_110803.html https://www.nasa.gov/centers/marshall/about/star/shuttle_110...
  - gridspy 6y ago
    SpaceX Starship boosters are refueled after they land themselves using a pump. Shuttle solid rocket boosters have their shells fished out of the ocean by a boat. Then they return to the factory to be broken into sections and filled with a solid propellent. Different tech.
    - GizmoSwan 6y ago
      Yes but in real life they are not necessarily landing in the same spot the same day to be reused again. They could have multiple replacement boosters. Regardless, I have no problem with the booster return design unless it induces reckless danger to human life. The explosion is not a positive data.
      - gridspy 6y ago
        Given two options 1. People doing analysis and hoping to check everything through engineering rigor and (hopefully) good assumptions 2. Test early and often, learning along the way until many positive tests have proven the system I'd prefer 2. Look at systems like SLS to see the schedule results of (1). No people were put on Falcon launches until almost 100 successful launches. I imagine a similar situation for StarShip. For example NASA is funding in orbit refuelling experiments (unmanned) and also a StarShip moon landing (unmanned) which will help prove the system prior to human flight. Don't worry, plenty of people will carefully do analysis (1) later on. But the data they will review will include telemetry from real flights rather than just hopeful simulation / analysis results.
        GizmoSwan 6y ago
        Don't get your hopes up. Since it is rotating on an axis while moving and twice, it has a huge degree of freedom for failure. Even if successfully returns 100 times, any untested change to its payload can change the parameters which are apparently unknown because they have not used any fancy simulation. Good luck. I will be watching and ready to say I told you so. The staff could be absolute geniuses by they will not be able to foresee all the unexpected results.
        gridspy 6y ago
        The failures so far relate to the pressurization of the header tanks and the engine performance on re-light (hard problems). I imagine these will be well solved after 100 flights. The assumption that shifting payload is going to boggle the flight computers leading to loss of craft sounds unlikely. Both because the payload will be secured and the flight computers are more dynamic than that. Finally, the forces on the cargo shift from 1G towards the belly during the belly flop to a mix of gravity and pressure from the engines during the flip. While the view from the window would be "interesting" - the actual forces on the payload will remain a summed ~2G from these two axes (mostly from "down") during landing. This is similar to how the lift vector while rolling in an aircraft keeps you safely stuck to the floor (and not the walls) during jet flight. Anyone flying an aircraft or space vehicle who doesn't secure their loads is going to experience some shifting of cargo. Of course that's why you have a small cargo compartment which physically restricts the movement of potential cargo. See how 747s secure cargo in large bins within a dedicated cargo hold for reference.
Me1000 6y ago
Rapidly reusable means the goal is to have Starship (or at the very least the Super Heavy booster) fly multiple times a day. The Space Shuttle needed a new external fuel tank each flight, and the SRBs required significant refurbishment, to say nothing of the orbiter's own refurbishment. Also important to note that Starship is going to be an interplanetary vehicle. And that means it needs to be able to land in places with little to no atmosphere on a surface with no runway. The Space Shuttle was an impressive engineering marvel, especially for the time, but even if it could leave low earth orbit, there was no way it could land anywhere other than Earth.

gridspy 6y ago

Belly flop - https://youtu.be/vRPrLvVaQq8?t=145 https://youtu.be/vRPrLvVaQq8?t=145 (Yes, to reduce the falling speed. No, it lands vertically). Rapidly reusable - You can land it directly on (or next to) a launch platform, refuel it and launch it again the same day. Same as a regular aircraft. The Space shuttle had a disposable tank (which was lost on launch), recovered but basically destroyed solid rocket boosters (ditched into ocean) and finally on landing it had (potentially) damaged heat tiles which all needed inspection and which were all fragile and different.

GizmoSwan 6y ago
Does it use Nasa's pica heat shield. Nasa could have upgraded shuttle too to use their own tech so the shield tech is not material argument. The boosters were recovered. https://www.nasa.gov/centers/marshall/about/star/shuttle_110803.html https://www.nasa.gov/centers/marshall/about/star/shuttle_110...
- gridspy 6y ago
  SpaceX Starship boosters are refueled after they land themselves using a pump. Shuttle solid rocket boosters have their shells fished out of the ocean by a boat. Then they return to the factory to be broken into sections and filled with a solid propellent. Different tech.
  - GizmoSwan 6y ago
    Yes but in real life they are not necessarily landing in the same spot the same day to be reused again. They could have multiple replacement boosters. Regardless, I have no problem with the booster return design unless it induces reckless danger to human life. The explosion is not a positive data.
    - gridspy 6y ago
      Given two options 1. People doing analysis and hoping to check everything through engineering rigor and (hopefully) good assumptions 2. Test early and often, learning along the way until many positive tests have proven the system I'd prefer 2. Look at systems like SLS to see the schedule results of (1). No people were put on Falcon launches until almost 100 successful launches. I imagine a similar situation for StarShip. For example NASA is funding in orbit refuelling experiments (unmanned) and also a StarShip moon landing (unmanned) which will help prove the system prior to human flight. Don't worry, plenty of people will carefully do analysis (1) later on. But the data they will review will include telemetry from real flights rather than just hopeful simulation / analysis results.
      - GizmoSwan 6y ago
        Don't get your hopes up. Since it is rotating on an axis while moving and twice, it has a huge degree of freedom for failure. Even if successfully returns 100 times, any untested change to its payload can change the parameters which are apparently unknown because they have not used any fancy simulation. Good luck. I will be watching and ready to say I told you so. The staff could be absolute geniuses by they will not be able to foresee all the unexpected results.
        gridspy 6y ago
        The failures so far relate to the pressurization of the header tanks and the engine performance on re-light (hard problems). I imagine these will be well solved after 100 flights. The assumption that shifting payload is going to boggle the flight computers leading to loss of craft sounds unlikely. Both because the payload will be secured and the flight computers are more dynamic than that. Finally, the forces on the cargo shift from 1G towards the belly during the belly flop to a mix of gravity and pressure from the engines during the flip. While the view from the window would be "interesting" - the actual forces on the payload will remain a summed ~2G from these two axes (mostly from "down") during landing. This is similar to how the lift vector while rolling in an aircraft keeps you safely stuck to the floor (and not the walls) during jet flight. Anyone flying an aircraft or space vehicle who doesn't secure their loads is going to experience some shifting of cargo. Of course that's why you have a small cargo compartment which physically restricts the movement of potential cargo. See how 747s secure cargo in large bins within a dedicated cargo hold for reference.

Me1000 6y ago

Rapidly reusable means the goal is to have Starship (or at the very least the Super Heavy booster) fly multiple times a day. The Space Shuttle needed a new external fuel tank each flight, and the SRBs required significant refurbishment, to say nothing of the orbiter's own refurbishment. Also important to note that Starship is going to be an interplanetary vehicle. And that means it needs to be able to land in places with little to no atmosphere on a surface with no runway. The Space Shuttle was an impressive engineering marvel, especially for the time, but even if it could leave low earth orbit, there was no way it could land anywhere other than Earth.