4 ms·

Shuttle was fully reusable. The boosters came back down on parachutes.

by cma 6y ago

dnautics 6y ago
Main tank
NikolaeVarius 6y ago
Main tank is lost and side booster and shuttle required extensive refurbishing. It sorta counts, but against the point of reusability
- cma 6y ago
  Starship moved to tiles too, instead of transpirational cooling, it will likely require refurbishment. If shuttle had continued on tile inspection could have likely moved to machine vision based approaches, maybe they will be able to use something like that to keep refurb costs down on spacex's shuttle/starship.
  - NikolaeVarius 6y ago
    They are created with better materials and also do not require special one offs for every single tile, unlike the shuttle. Replacement is supposed to be "break it and attach a new one" without needing special glues, curing times which was the reason why shuttle heat shield refurbishment took so long at high cost.
    - cma 6y ago
      That sounds like an improvement, but not enough for passenger air travel replacement between the cost of coach and business class (New York to shanghai), promised for 7 years from now. They need many orders of magnitude of reliability improvements over shuttle for that, though it would be slightly suborbital reentry. The Dear Moon mission in a couple years will have full reentry at extreme speeds, assuming they weren't just ripping off that Japanese billionaire guy. I think they still planned transpirational cooling at that point? Dragon was supposed to have at least one mission to Mars every transfer period from 2020 onwards and that seems to have been scrapped.
      - NikolaeVarius 6y ago
        I dont understand where this comment is coming from. What sources are you using the make the cost claims you are making and/or the reliability requirements and/or heatshield requirements?
        cma 6y ago
        > Shotwell estimated the ticket cost would be somewhere between economy and business class on a plane — so, likely in the thousands of dollars for transoceanic travel. “But you do it in an hour.” https://www.vox.com/2018/4/11/17227036/flight-spacex-gwynne-shotwell-space-ted-conference-interview https://www.vox.com/2018/4/11/17227036/flight-spacex-gwynne-... I based reliability requirements on passenger jet travel and the risk people would be willing to take for non space-tourism transport. Also, I don't see how the tiles can be fully uniform except on the cylindrical part. The geometry of the nose part I don't think would allow it mathematically. Shuttle tiles often only differed in thickness based on needed heat withstanding, and could be generated by cnc processes automatically. Spacex may want something similar to optimize weight, especially since they are planning computer controlled install as well for most of them.
0x64 6y ago
The orbiter was reusable, the boosters were refurbishable, and the external tank basically crashed into the ocean.
- thedrbrian 6y ago
  Always thought it was a shame they didn’t push the main tank into orbit. Just think of an ISS made from a few of them rather than what we have now or the Ares from Red Mars.
  - jandrese 6y ago
    There were some orbital concepts that basically inflated a living space inside of an orange tank and stuck a few solar panels and radiators on the side. Shuttle trips were just too expensive to make it practical and with the ISS it would have been redundant.
  - NikolaeVarius 6y ago
    Alternative designs could have worked, but the Shuttle used the OMS after main engine cutoff, so keeping the tank would have eaten a ton of delta-vee
outworlder 6y ago
The shuttle required refurbishments on the thermal protection system. Every single one had to be inspected. The engines also required refurbishment. The boosters had to be fished out of the ocean. Those same boosters that used solid fuel and that could not (and cannot) be shutdown in case of issues. And the Shuttle happened to have two of them, with a decent moment arm on each, so a solid booster failure (even a partial one, with less thrust than expected) meant a mission failure. They had to be highly scrutinized. Given that the Shuttle was also a jobs program, they were built in segments, to allow for transport across long distances. So the o-ring seals were also problematic. All in all, the Shuttle was very brittle. If they could have been mass-produced, it would have probably been more economical to just throw them away on every flight and rely on economies of scale. At least, that way, one would only have to account for manufacturing issues, not every conceivable stress that could happen during a mission.

Shuttle was fully reusable. The boosters came back down on parachutes.

by cma 6y ago

Shuttle was fully reusable. The boosters came back down on parachutes.

dnautics 6y ago

Main tank

NikolaeVarius 6y ago

Main tank is lost and side booster and shuttle required extensive refurbishing. It sorta counts, but against the point of reusability

cma 6y ago
Starship moved to tiles too, instead of transpirational cooling, it will likely require refurbishment. If shuttle had continued on tile inspection could have likely moved to machine vision based approaches, maybe they will be able to use something like that to keep refurb costs down on spacex's shuttle/starship.
- NikolaeVarius 6y ago
  They are created with better materials and also do not require special one offs for every single tile, unlike the shuttle. Replacement is supposed to be "break it and attach a new one" without needing special glues, curing times which was the reason why shuttle heat shield refurbishment took so long at high cost.
  - cma 6y ago
    That sounds like an improvement, but not enough for passenger air travel replacement between the cost of coach and business class (New York to shanghai), promised for 7 years from now. They need many orders of magnitude of reliability improvements over shuttle for that, though it would be slightly suborbital reentry. The Dear Moon mission in a couple years will have full reentry at extreme speeds, assuming they weren't just ripping off that Japanese billionaire guy. I think they still planned transpirational cooling at that point? Dragon was supposed to have at least one mission to Mars every transfer period from 2020 onwards and that seems to have been scrapped.
    - NikolaeVarius 6y ago
      I dont understand where this comment is coming from. What sources are you using the make the cost claims you are making and/or the reliability requirements and/or heatshield requirements?
      - cma 6y ago
        > Shotwell estimated the ticket cost would be somewhere between economy and business class on a plane — so, likely in the thousands of dollars for transoceanic travel. “But you do it in an hour.” https://www.vox.com/2018/4/11/17227036/flight-spacex-gwynne-shotwell-space-ted-conference-interview https://www.vox.com/2018/4/11/17227036/flight-spacex-gwynne-... I based reliability requirements on passenger jet travel and the risk people would be willing to take for non space-tourism transport. Also, I don't see how the tiles can be fully uniform except on the cylindrical part. The geometry of the nose part I don't think would allow it mathematically. Shuttle tiles often only differed in thickness based on needed heat withstanding, and could be generated by cnc processes automatically. Spacex may want something similar to optimize weight, especially since they are planning computer controlled install as well for most of them.

0x64 6y ago

The orbiter was reusable, the boosters were refurbishable, and the external tank basically crashed into the ocean.

thedrbrian 6y ago
Always thought it was a shame they didn’t push the main tank into orbit. Just think of an ISS made from a few of them rather than what we have now or the Ares from Red Mars.
- jandrese 6y ago
  There were some orbital concepts that basically inflated a living space inside of an orange tank and stuck a few solar panels and radiators on the side. Shuttle trips were just too expensive to make it practical and with the ISS it would have been redundant.
- NikolaeVarius 6y ago
  Alternative designs could have worked, but the Shuttle used the OMS after main engine cutoff, so keeping the tank would have eaten a ton of delta-vee

outworlder 6y ago

The shuttle required refurbishments on the thermal protection system. Every single one had to be inspected. The engines also required refurbishment. The boosters had to be fished out of the ocean. Those same boosters that used solid fuel and that could not (and cannot) be shutdown in case of issues. And the Shuttle happened to have two of them, with a decent moment arm on each, so a solid booster failure (even a partial one, with less thrust than expected) meant a mission failure. They had to be highly scrutinized. Given that the Shuttle was also a jobs program, they were built in segments, to allow for transport across long distances. So the o-ring seals were also problematic. All in all, the Shuttle was very brittle. If they could have been mass-produced, it would have probably been more economical to just throw them away on every flight and rely on economies of scale. At least, that way, one would only have to account for manufacturing issues, not every conceivable stress that could happen during a mission.