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> There are still major risks with the Starship program To expand on this: I think it's reasonable to assume that the stack will reach orbit just fine and be a

> There are still major risks with the Starship program To expand on this: I think it's reasonable to assume that the stack will reach orbit just fine and be a functional rocket. The big risks are related to recovery. Starship will require in-orbit refueling to go to the moon, so (rapid) reusability is somewhat of a hard requirement. Superheavy (the first stage) is huge and will land directly on the launch tower instead of using landing legs - to reduce turnaround times. This is innovative and completely unproven. And a RUD would at the very least put the launch tower out of commission for a while. Starship (the second stage) will also have to survive the high velocity reentry in a good condition and nail the crazy landing maneuver. SpaceX heat shield tiles and the general aerodynamic and thermal properties of the rocket are an unknown for now. Musk recently said that Starship will probably require "many test flight" to achieve successful reentry and landing. On top there have been quite a few reliability issues with their new Raptor engine, which need to be ironed out. I'm sure SpaceX will figure it out, but there are a lot of risks lurking in the development program. All this makes the choice to go for SpaceX more impressive for the usually so cautious NASA. But the payoff would be enormous. If the re-usability works out, Starship can completely change the game for the launch market and lift capability.

simonh 6y ago
I'm getting very nervous about manned propulsive landings. I know it's been done before, e.g. the LEM, but that at least had an abort option available and the flip manoeuvre seems to introduce a lot of unpredictability into the process. I wouldn't be surprised if they take up a Crew Dragon with them in a cargo bay to bring the crew back down separately for the first manned flights, until they've demonstrated a strong track record of successful propulsive landings. As for Lunar Starship, it's massively overengineered for the Artemis requirements, capable of taking 100 tons to the Lunar surface. That's great for later missions to set up a base, but even then you'd likely need a crew version just for shuttling people back and forth. So I wouldn't be surprised to see the first version of that to be somewhat scaled down from the concept art. That should massively reduce the number of refuelling missions needed for the early Artemis flights.
- NortySpock 6y ago
  I agree, Crew Dragon (and maybe Orion and Boeing Starliner) are going to be the people-carriers of choice for Earth launch and re-entry for at least the next decade.
  - simonh 6y ago
    I don't really have concerns about launching people on Starship, it's the landing process that gives me the willies.
  - mlindner 6y ago
    I think people are really vastly underestimating how fast things are moving. I think you're completely wrong and Crew Dragon will be relegated to only fulling a remaining portion of a NASA contract after less than 5 years. Everyone else (private astronauts) will fly on Starship.
    - bdamm 6y ago
      Yeah, I really can't help but wonder if SpaceX is going to go after the long distance travel market. Starship can do suborbital hops without Superheavy.
      - simonh 6y ago
        Only comparatively short ones, with limited payload. Getting to a ballistic trajectory from one side of the planet to the other takes almost as much dV as going to orbit.
  - MPSimmons 6y ago
    A decade is a very long time. A decade ago, SpaceX only had 4 successful launches.
- nickik 6y ago
  > I'm getting very nervous about manned propulsive landings. Humans will land on earth in Orion capsule not Starship. So there will only be a tanker that has to do the flip. On the moon, there is no flip. The Appollo didn't have a abort option is parts of the flight, unless I am misinformed. > So I wouldn't be surprised to see the first version of that to be somewhat scaled down from the concept art. The problem is then about how you do the integration. All the tooling and processes are designed for one size of Starship, to change the whole design just to make it smaller is unlikely to be an efficient thing to do. Instead they could just fly part of it empty and take far less then the full 100t to the moon, rather then design a smaller version.
russdill 6y ago
Many of these risks don't apply to the lunar variant. The lunar variant won't be launching people from earth and won't be returning to earth. No re-entry, no landing flip, etc. As far as descent, it will do final touchdown with smaller engines higher up to avoid kicking up rocks. During landing, I think pretty much any one of the 6 raptor engines can be used to abort.
- the_duke 6y ago
  They somewhat apply because the lunar variant still needs to be fueled up in LEO with ~ 6 additional launches , all in relatively quick succession. This seems unfeasible without rapid reuse actually working.
  - russdill 6y ago
    True enough, they can't be throwing away tankers for each refuel.
    - garmaine 6y ago
      At the price NASA is willing to pay, they can. The tankers are only a few million dollars in raw materials.
  - themgt 6y ago
    In my opinion the way to think about SuperHeavy+Starship is a scaled up stainless steel Falcon 9. Currently Falcon 9's first stage booster (usually) lands and is quickly/cheaply refurbished/reused, while the second stage is completely thrown away except for partially successful attempts at fairing recovery. They've used this partially reusable system to do a large number of launches quite cost effectively. In SH+SS, the "Starship" part is the second stage, with the revolutionary goal that it can deliver a payload to orbit and then skydive back to earth and propulsively land itself. That has major risks and is unlikely to succeed the first number of attempts, with the loss of the stage and the 6 raptor engines. The "Superheavy" portion is very much equivalent to a scaled-up F9 booster, and the risks to landing it should be much lower (Elon's crazy catch ideas notwithstanding). tl;dr I think Starship system can mostly work if it's partially reusable to a similar extent as F9. Losing a half-dozen second stages to do a full orbital refueling for a Moon or Mars mission should still be a fraction of the cost of a single SLS launch, and they can continue working on full reusability while performing missions and cashing checks.
Denvercoder9 6y ago
> Starship will require in-orbit refueling to go to the moon, so (rapid) reusability is somewhat of a hard requirement. Is it though? The lunar starship itself doesn't depend on reusability. If SpaceX cannot get reusability down, they'll have to expend a few boosters and tankers to get it working. That'll cost them their profit, but it would fulfil the contract.
- mlindner 6y ago
  If they have to expend them, I doubt SpaceX would have any profit at all and they'd reneg on the contract.
  - bryanlarsen 6y ago
    Second stage tanker build costs are estimated at around $30M. Expending a dozen would thus cost $360M, about 15% of the contract. I highly doubt that SpaceX set their profit margin lower than 15%.
  - GoOnThenDoTell 6y ago
    Thry need to spend the R&D money anyway to get it working, why not let NASA subsidise it
pharke 6y ago
> Superheavy (the first stage) is huge and will land directly on the launch tower instead of using landing legs - to reduce turnaround times. This is innovative and completely unproven. And a RUD would at the very least put the launch tower out of commission for a while. I strongly suspect that they will be building many identical launch towers, it's pretty much their modus operandi and it makes sense. They've already had two Starships queued up at the launch pad for testing. Once they further improve the factory they'll probably need to build out more pads so they can keep the launch cadence up and free up space in the high bay. They're going to need to perfect that process if they are serious about eventually doing thousands of flights per year and sending hundreds of ships to Mars per conjunction. That's going to need a lot of Starships, a lot of launch pads, and probably several factories.
- madaxe_again 6y ago
  Well, they’ve got their two oil rigs, Phobos and Deimos, which I believe are to be the launch/catch facilities, so that’s two for starters. I don’t know if they’ll be doing it on land at all, or if the intent is to launch from one and catch with the other, allowing more downrange capability. We’ll see - it’s a blast (boom boom (boom boom!)) watching their development process.
- ChickeNES 6y ago
  SpaceX is asking the EPA for permission to build a second orbital pad and tower in Boca Chica, and I'd assume that we might hear something soon about the mothballed 39A Starship launch mount
Hypocritelefty 6y ago
Writes load of crap with out even reading the part that fan boys got lol

simonh 6y ago

I'm getting very nervous about manned propulsive landings. I know it's been done before, e.g. the LEM, but that at least had an abort option available and the flip manoeuvre seems to introduce a lot of unpredictability into the process. I wouldn't be surprised if they take up a Crew Dragon with them in a cargo bay to bring the crew back down separately for the first manned flights, until they've demonstrated a strong track record of successful propulsive landings. As for Lunar Starship, it's massively overengineered for the Artemis requirements, capable of taking 100 tons to the Lunar surface. That's great for later missions to set up a base, but even then you'd likely need a crew version just for shuttling people back and forth. So I wouldn't be surprised to see the first version of that to be somewhat scaled down from the concept art. That should massively reduce the number of refuelling missions needed for the early Artemis flights.

NortySpock 6y ago
I agree, Crew Dragon (and maybe Orion and Boeing Starliner) are going to be the people-carriers of choice for Earth launch and re-entry for at least the next decade.
- simonh 6y ago
  I don't really have concerns about launching people on Starship, it's the landing process that gives me the willies.
- mlindner 6y ago
  I think people are really vastly underestimating how fast things are moving. I think you're completely wrong and Crew Dragon will be relegated to only fulling a remaining portion of a NASA contract after less than 5 years. Everyone else (private astronauts) will fly on Starship.
  - bdamm 6y ago
    Yeah, I really can't help but wonder if SpaceX is going to go after the long distance travel market. Starship can do suborbital hops without Superheavy.
    - simonh 6y ago
      Only comparatively short ones, with limited payload. Getting to a ballistic trajectory from one side of the planet to the other takes almost as much dV as going to orbit.
- MPSimmons 6y ago
  A decade is a very long time. A decade ago, SpaceX only had 4 successful launches.
nickik 6y ago
> I'm getting very nervous about manned propulsive landings. Humans will land on earth in Orion capsule not Starship. So there will only be a tanker that has to do the flip. On the moon, there is no flip. The Appollo didn't have a abort option is parts of the flight, unless I am misinformed. > So I wouldn't be surprised to see the first version of that to be somewhat scaled down from the concept art. The problem is then about how you do the integration. All the tooling and processes are designed for one size of Starship, to change the whole design just to make it smaller is unlikely to be an efficient thing to do. Instead they could just fly part of it empty and take far less then the full 100t to the moon, rather then design a smaller version.

russdill 6y ago

Many of these risks don't apply to the lunar variant. The lunar variant won't be launching people from earth and won't be returning to earth. No re-entry, no landing flip, etc. As far as descent, it will do final touchdown with smaller engines higher up to avoid kicking up rocks. During landing, I think pretty much any one of the 6 raptor engines can be used to abort.

the_duke 6y ago
They somewhat apply because the lunar variant still needs to be fueled up in LEO with ~ 6 additional launches , all in relatively quick succession. This seems unfeasible without rapid reuse actually working.
- russdill 6y ago
  True enough, they can't be throwing away tankers for each refuel.
  - garmaine 6y ago
    At the price NASA is willing to pay, they can. The tankers are only a few million dollars in raw materials.
- themgt 6y ago
  In my opinion the way to think about SuperHeavy+Starship is a scaled up stainless steel Falcon 9. Currently Falcon 9's first stage booster (usually) lands and is quickly/cheaply refurbished/reused, while the second stage is completely thrown away except for partially successful attempts at fairing recovery. They've used this partially reusable system to do a large number of launches quite cost effectively. In SH+SS, the "Starship" part is the second stage, with the revolutionary goal that it can deliver a payload to orbit and then skydive back to earth and propulsively land itself. That has major risks and is unlikely to succeed the first number of attempts, with the loss of the stage and the 6 raptor engines. The "Superheavy" portion is very much equivalent to a scaled-up F9 booster, and the risks to landing it should be much lower (Elon's crazy catch ideas notwithstanding). tl;dr I think Starship system can mostly work if it's partially reusable to a similar extent as F9. Losing a half-dozen second stages to do a full orbital refueling for a Moon or Mars mission should still be a fraction of the cost of a single SLS launch, and they can continue working on full reusability while performing missions and cashing checks.

Denvercoder9 6y ago

> Starship will require in-orbit refueling to go to the moon, so (rapid) reusability is somewhat of a hard requirement. Is it though? The lunar starship itself doesn't depend on reusability. If SpaceX cannot get reusability down, they'll have to expend a few boosters and tankers to get it working. That'll cost them their profit, but it would fulfil the contract.

mlindner 6y ago
If they have to expend them, I doubt SpaceX would have any profit at all and they'd reneg on the contract.
- bryanlarsen 6y ago
  Second stage tanker build costs are estimated at around $30M. Expending a dozen would thus cost $360M, about 15% of the contract. I highly doubt that SpaceX set their profit margin lower than 15%.
- GoOnThenDoTell 6y ago
  Thry need to spend the R&D money anyway to get it working, why not let NASA subsidise it

pharke 6y ago

> Superheavy (the first stage) is huge and will land directly on the launch tower instead of using landing legs - to reduce turnaround times. This is innovative and completely unproven. And a RUD would at the very least put the launch tower out of commission for a while. I strongly suspect that they will be building many identical launch towers, it's pretty much their modus operandi and it makes sense. They've already had two Starships queued up at the launch pad for testing. Once they further improve the factory they'll probably need to build out more pads so they can keep the launch cadence up and free up space in the high bay. They're going to need to perfect that process if they are serious about eventually doing thousands of flights per year and sending hundreds of ships to Mars per conjunction. That's going to need a lot of Starships, a lot of launch pads, and probably several factories.

madaxe_again 6y ago
Well, they’ve got their two oil rigs, Phobos and Deimos, which I believe are to be the launch/catch facilities, so that’s two for starters. I don’t know if they’ll be doing it on land at all, or if the intent is to launch from one and catch with the other, allowing more downrange capability. We’ll see - it’s a blast (boom boom (boom boom!)) watching their development process.
ChickeNES 6y ago
SpaceX is asking the EPA for permission to build a second orbital pad and tower in Boca Chica, and I'd assume that we might hear something soon about the mothballed 39A Starship launch mount

Hypocritelefty 6y ago

Writes load of crap with out even reading the part that fan boys got lol