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Tim Dodd made a lovely point in his stream of the event. People keep asking why this is a big deal- we did this fifty years ago, right? It should be a lot easi

by mabbo 4y ago

Tim Dodd made a lovely point in his stream of the event. People keep asking why this is a big deal- we did this fifty years ago, right? It should be a lot easier now with modern tech. Yes, but now we're doing it safely. The Apollo program took risks that today's NASA never would allow. We're better at that now, but it's a lot more work.

pfdietz 4y ago
It's not a big deal, because it's so expensive it's a dead end. The problem has always been making human space flight cheap enough that it can lead to activities with positive return. The Apollo and Shuttle eras failed in that respect. SLS, by not reducing launch costs, continues in that sad and aggravating tradition.
- matheusmoreira 4y ago
  The massive cost comes from defeating gravity and getting stuff off of this planet. Cost reductions probably won't happen until the ISS turns into an orbital city with spacecraft manufacturing capabilities. The JWST engineers talked about the importance of building future telescopes and spacecrafts in space, it's a very important technological milestone for humanity. Mass drivers and orbital elevators are common in fiction but I don't know what the scientific consensus is on the viability of such structures.
  - pfdietz 4y ago
    Your argument is obviously wrong. If that were the case, all launch systems would have the same cost per kg, since they all are operating on the same planet with the same gravity. But in fact, the minimum cost imposed by gravity (the energy needed to get into space) is incredibly low. The minimum fuel cost is a very small fraction of the cost of launching with current launch vehicles. The costs come from expendability and manufacturing and non-fuel operating costs. None of these are dictated by gravity.
    - FPGAhacker 4y ago
      There is a cost in mass. Rockets today are essentially a giant fuel tank with a few engines connected to one side and cargo connected to the other side. Every kg of fuel is a kg of cargo you can’t launch. That’s the cost.
      - pfdietz 4y ago
        None of that justifies claiming the cost is due to gravity. The problem of getting to space is obviously affected by gravity, but the cost is dictated by other considerations. It's not like "oh well, gravity, we might as well give up because it's not possible to do much better."
        FPGAhacker 4y ago
        > None of that justifies claiming the cost is due to gravity. Where do you suppose the need for so much energy comes from?
        FeepingCreature 4y ago
        It's more that the cost in money doesn't come from the cost in energy.
        DarmokJalad1701 4y ago
        Congressional mandates forcing NASA to use Space Shuttle components for the SLS that are de facto non-competitive, single-source requirements assuring contracts to existing Shuttle suppliers is contributing significantly to the costs. For example, the NASA contract to Aerojet Rocketdyne to manufacture RS-25 engines is costing $146 million per engine. Each SLS launch will toss four of these engines in the ocean for a total cost $580 million. And that's just the engines of the core stage. For the cost of a single engine, they could have instead purchased an entire Falcon Heavy launch, which has two-thirds of the SLS lift capacity (and has to obey the same laws of physics as SLS). SLS is the price NASA had to pay to get Congress off its back.
  - Gwypaas 4y ago
    The Falcon 9 is ~500 tons of propellant for 25 tons to LEO. An A380 carries ~250 tons of fuel. In the Falcon 9 number the liquid oxygen is included. The RP-1 is a pretty much a cleaner diesel or jet fuel. The cost is like $1500 to $2000 per ton so like $500 000 to $1 000 000 in fuel costs for a launch. Fuel costs are still trivial compared to building and operating the rocket and is where huge reductions are possible.
- kunai 4y ago
  At the very least, Artemis is a functional space launch system with exceptional reliability and predictability despite its insane costs. The wasted billions are an embarrassment, but far less so now that we know a) the thing works, and works pretty darned well and b) it is, for now, the only game in town in its class. Starship is an interesting project with a lot of ambitious goals, but it is far behind schedule in terms of development and the Raptors are suffering from a lot of issues that Merlins didn't have due to SpaceX's inexperience with cryogenic fuels. So the question to be asked is: do we want an pricey but reliable and proven solution now, or do we hold out for years in the promise of some intangible futurist idea that will likely take far longer than anticipated to become a viable solution for crewed travel? If your answer is B, then it's fairly obvious you're less interested in the rapid progression of space travel writ large and more interested in ensuring a project you favor wins out. In a perfect world, SLS would be a rapidly reusable rocket with 5 RS-25s, an inflatable heatshield, F-1 derived liquid boosters, and landing legs. But that's not the world we live in, and something > nothing, in my opinion. And I also find it important to put the price of SLS/Artemis in context to other far more wasteful government projects that produce no surplus economic value for people, like the F-35 program or the B-21 (questionable benefit over existing defense systems). In that context, SLS is almost utilitarian, providing valuable scientific jobs to engineers and scientists, while propelling the way to the Moon for this generation's astronauts and explorers.
  - pfdietz 4y ago
    Exceptional reliability? How can you possibly claim that? Reliability comes from working out all the unknown unknowns, and that comes only from experience. Starship is not needed to condemn SLS. Falcon 9 and Falcon Heavy are sufficient to render SLS uncompetitive and unneeded. In a perfect world, SLS would have had a stake driven through its corrupt programmatic heart years ago.
    - zardo 4y ago
      In a perfect (space policy) world, SLS wouldn't have had major components determined by the legislature. It's extremely expensive because that's what the legislature asked for, a single use rocket built using super expensive engines designed for a reusable rocket.
- no_wizard 4y ago
  Isn't the true "ideal" a space elevator so you can continously deliver between the moon and the earth without having to burn lots of resources every single time? Shouldn't that be what we optimize for in the long run? Its the only way I can think of that space cargo becomes economical. Then you can ship raw material up to the Moon and build from there, launch from there etc. and vice versa. Maybe we'll see what Helium-3 can do for humans at that point
  - matheusmoreira 4y ago
    Yeah, a space elevator would be the most efficient way lift payloads to space where it's a lot easier to maneuver. Anyone knowledgeable about space elevators on HN? I wonder why it's never been attempted.
    - throwawaymaths 4y ago
      There are currently insurmountable materials science limitations, and even the materials that come close are not currently possible to manufacture at scale, or even assemble (one carbon nanotubes does not necessarily have the same properties of many carbon nanotubes) at scale into structures which will withstand the structural stresses. I believe this is not necessarily true for other celestial objects besides the earth
      - Smaug123 4y ago
        For example, Pluto and Charon is a pair that sometimes comes up; a space elevator connecting Pluto to Charon would very possibly just about be within our current civilisation's capabilities, if for some reason we cared to build one enough to sink the Earth's economic output into it. They're tidally locked. (https://en.wikipedia.org/wiki/Space_elevator https://en.wikipedia.org/wiki/Space_elevator has its section on "Extraterrestrial elevators".)
        actionfromafar 4y ago
        A space elevator for our own moon would be far more interesting to me. It could be built with known materials.
- LightG 4y ago
  Well, the US needed alternatives to Russian rockets, hence SpaceX and SLS. Now NASA need alternatives to Musk, so SLS is a good back up option. * canned laughter * (only semi joking considering his Ukraine starlink BS)
  - imglorp 4y ago
    Setting aside his BS, there's a chasm of difference between SpaceX and SLS: it's process. SLS designs ONE (mostly) disposable ship, per year, max, taking a decade to integrate and realize. Epic Waterfall. They have several concurrent pipelines. Meanwhile SpaceX designs a reusable ship factory. Scalable to as many a year as you can afford.
    - LightG 4y ago
      I know. But it's still space travel at the whim of a BS'er. Hence, the need for a back up or private competitor. Ideally as efficient. If not, then at almost any cost is the only alternative (NASA).
amelius 4y ago
Ok, but doesn't that mean we will be surpassed left and right by nations who don't care (as much) about safety?
- jackmott 4y ago
mytailorisrich 4y ago
The only 'big deal' is that NASA is planning to return to the Moon after a 50+ years hiatus. There's little that is groundbreaking.
Throwawayaerlei 4y ago
"now we're doing it safely." Mercury through Apollo really did not like the idea of using solid rocket boosters, you can't turn them off if things get out of hand, and of course they'll do that themselves in lots of failure modes. Suitable for a launch escape system ... and see the Shuttle for when these principles were turned on their head. Its SRBs, now being literally recycled for Artemis were low capital, high operating cost kludges that infamous killed one shuttle and its crew. In part because there was no provision made for escape aside from the pilots in the first couple of launches or so and that was rather limited, SR-71 technology with a pretty low max altitude. On the other hand the Orion crew capsule does have a tower escape system. So that old NASA you decry, they didn't lose a crew except on the ground due to a high pressure test with pure oxygen!?!?!! OK, that's a credible validation of that part of your thesis, see also Apollo 13 which was a close call. On the other hand does the Orion have a heavy shield for the astronauts to shelter behind in case of a solar storm (see Heinlein's Podkayne of Mars)? If not Apollo and the Artemis program are every bit as dangerous in what was a primary reason Nixon stopped Apollo before all its planned missions, program delays would have extended it into the change in the solar cycle. I would also note the start of this program many years ago was so badly designed the booster system's vibrations would have been lethal to humans. Springs in the crew capsule were part of the proposed solution to that, but going back to Shuttle diameter SRBs, only adding one segment, and all the mass of the tank and SSMEs should have fixed that. If my memory is correct that was a rocket powered by a single stack of SRBs, purely for sending crews out into space. But I'd like to know what happened after the Shuttle and it to make NASA take crew safety seriously. NASA was utterly callous about the known risk from the launch that killed the second shuttle and its crew. I finish by noting a bit of humility is warranted after just a single test mission success. That NASA and its contractors were able to pull it off is quite a feat, but as the Shuttle should have taught us bad designs can eventually catch up with you.
qbasic_forever 4y ago
It blew my mind to find out the first crewed mission to launch on the Saturn V (Apollo 8) flew all the way out and around the moon. No low earth orbit shakedown or anything, just straight to the moon (without landing). A few more launches tested they could dock with the LM and then Apollo 11 just went for it back to the moon and landing. The pace they went at is pretty unbelievable today.
- Aperocky 4y ago
  True YOLO moment. It's a miracle that everyone that went to the Moon returned unscathed.
- five82 4y ago
  I believe Apollo 8 was originally supposed to be a low earth orbit shakedown with the LEM. Because the LEM wasn’t ready, they decided to send them to the moon.
  - m4rtink 4y ago
    IIRC there might have been Soviets in a Zond capsule launched on a Proton beating US to the lunar orbit in play when changing the plans for Apollo 8.
pfdietz 4y ago
I have to dispute that doing it more safely is a worthwhile goal for SLS. It's useful to think about safety issues in terms of the statistical value of a human life. This is how much one should be willing to spend to save one expected life. It's a vital number for planning purposes. For example, should we install a guard rail at this corner? Is controlling this release of this chemical justifiable? Compute if the cost is less than the expected value of lives saved. If so, spend the money, if not, don't. The usual statistical value of a human life is around $10M. And you immediately see the problem: a rocket that costs $1B to launch is, in effect, killing 100 statistical people just by being launched. If the result of the launch is valuable enough to justify that mathematical carnage, wouldn't it also justify subjecting the astronauts to real risk? Conversely, if it's worth delaying a launch to reduce the risk to astronauts, is the launch really worth having spent all that money on at all? The space program has been caught in an internal contradiction, where the purported benefits are claimed to justify large expenditures, but not claimed to justify risking astronauts. And this makes no sense. To actually justify reducing astronaut risks, launch and mission costs must first be greatly reduced.
- matheusmoreira 4y ago
  Would people want to board a spacecraft built by people with this mindset?
  - pfdietz 4y ago
    Would people want to drive cars built by people with this mindset, on roads designed by people with this mindset, to get to airports to fly in aircraft built and regulated by people with this mindset? Trick question! Almost everyone does and doesn't see anything wrong with it. I would not want to get into an expensive risky rocket, since I don't see the benefit that would be commensurate with the enormous cost. If the cost were radically reduced, I might try it, and in that very much cheaper rocket the safety level would be much higher (or else the actual cost, including risk x value of my life, would swamp the ticket price.)
- toast0 4y ago
  I don't think the usual statistical value applies to an astronaut, especially an astronaut on a mission. At least, the loss to NASA will be much more. For one, they're going to spend a ton of money on investigagions. For another, it could significantly impact their future budget, and their ability to hire. It would depend on the details of the deadly incident though.
mr_toad 4y ago
> It should be a lot easier now with modern tech. The engine design is 41 years old. Older than many people reading this.
- m4rtink 4y ago
  41 years from the first flight, right ? So even older for the design and development of the engine.

by mabbo 4y ago

pfdietz 4y ago

It's not a big deal, because it's so expensive it's a dead end. The problem has always been making human space flight cheap enough that it can lead to activities with positive return. The Apollo and Shuttle eras failed in that respect. SLS, by not reducing launch costs, continues in that sad and aggravating tradition.

matheusmoreira 4y ago
The massive cost comes from defeating gravity and getting stuff off of this planet. Cost reductions probably won't happen until the ISS turns into an orbital city with spacecraft manufacturing capabilities. The JWST engineers talked about the importance of building future telescopes and spacecrafts in space, it's a very important technological milestone for humanity. Mass drivers and orbital elevators are common in fiction but I don't know what the scientific consensus is on the viability of such structures.
- pfdietz 4y ago
  Your argument is obviously wrong. If that were the case, all launch systems would have the same cost per kg, since they all are operating on the same planet with the same gravity. But in fact, the minimum cost imposed by gravity (the energy needed to get into space) is incredibly low. The minimum fuel cost is a very small fraction of the cost of launching with current launch vehicles. The costs come from expendability and manufacturing and non-fuel operating costs. None of these are dictated by gravity.
  - FPGAhacker 4y ago
    There is a cost in mass. Rockets today are essentially a giant fuel tank with a few engines connected to one side and cargo connected to the other side. Every kg of fuel is a kg of cargo you can’t launch. That’s the cost.
    - pfdietz 4y ago
      None of that justifies claiming the cost is due to gravity. The problem of getting to space is obviously affected by gravity, but the cost is dictated by other considerations. It's not like "oh well, gravity, we might as well give up because it's not possible to do much better."
      - FPGAhacker 4y ago
        > None of that justifies claiming the cost is due to gravity. Where do you suppose the need for so much energy comes from?
        FeepingCreature 4y ago
        It's more that the cost in money doesn't come from the cost in energy.
        DarmokJalad1701 4y ago
        Congressional mandates forcing NASA to use Space Shuttle components for the SLS that are de facto non-competitive, single-source requirements assuring contracts to existing Shuttle suppliers is contributing significantly to the costs. For example, the NASA contract to Aerojet Rocketdyne to manufacture RS-25 engines is costing $146 million per engine. Each SLS launch will toss four of these engines in the ocean for a total cost $580 million. And that's just the engines of the core stage. For the cost of a single engine, they could have instead purchased an entire Falcon Heavy launch, which has two-thirds of the SLS lift capacity (and has to obey the same laws of physics as SLS). SLS is the price NASA had to pay to get Congress off its back.
- Gwypaas 4y ago
  The Falcon 9 is ~500 tons of propellant for 25 tons to LEO. An A380 carries ~250 tons of fuel. In the Falcon 9 number the liquid oxygen is included. The RP-1 is a pretty much a cleaner diesel or jet fuel. The cost is like $1500 to $2000 per ton so like $500 000 to $1 000 000 in fuel costs for a launch. Fuel costs are still trivial compared to building and operating the rocket and is where huge reductions are possible.
kunai 4y ago
At the very least, Artemis is a functional space launch system with exceptional reliability and predictability despite its insane costs. The wasted billions are an embarrassment, but far less so now that we know a) the thing works, and works pretty darned well and b) it is, for now, the only game in town in its class. Starship is an interesting project with a lot of ambitious goals, but it is far behind schedule in terms of development and the Raptors are suffering from a lot of issues that Merlins didn't have due to SpaceX's inexperience with cryogenic fuels. So the question to be asked is: do we want an pricey but reliable and proven solution now, or do we hold out for years in the promise of some intangible futurist idea that will likely take far longer than anticipated to become a viable solution for crewed travel? If your answer is B, then it's fairly obvious you're less interested in the rapid progression of space travel writ large and more interested in ensuring a project you favor wins out. In a perfect world, SLS would be a rapidly reusable rocket with 5 RS-25s, an inflatable heatshield, F-1 derived liquid boosters, and landing legs. But that's not the world we live in, and something > nothing, in my opinion. And I also find it important to put the price of SLS/Artemis in context to other far more wasteful government projects that produce no surplus economic value for people, like the F-35 program or the B-21 (questionable benefit over existing defense systems). In that context, SLS is almost utilitarian, providing valuable scientific jobs to engineers and scientists, while propelling the way to the Moon for this generation's astronauts and explorers.
- pfdietz 4y ago
  Exceptional reliability? How can you possibly claim that? Reliability comes from working out all the unknown unknowns, and that comes only from experience. Starship is not needed to condemn SLS. Falcon 9 and Falcon Heavy are sufficient to render SLS uncompetitive and unneeded. In a perfect world, SLS would have had a stake driven through its corrupt programmatic heart years ago.
  - zardo 4y ago
    In a perfect (space policy) world, SLS wouldn't have had major components determined by the legislature. It's extremely expensive because that's what the legislature asked for, a single use rocket built using super expensive engines designed for a reusable rocket.
no_wizard 4y ago
Isn't the true "ideal" a space elevator so you can continously deliver between the moon and the earth without having to burn lots of resources every single time? Shouldn't that be what we optimize for in the long run? Its the only way I can think of that space cargo becomes economical. Then you can ship raw material up to the Moon and build from there, launch from there etc. and vice versa. Maybe we'll see what Helium-3 can do for humans at that point
- matheusmoreira 4y ago
  Yeah, a space elevator would be the most efficient way lift payloads to space where it's a lot easier to maneuver. Anyone knowledgeable about space elevators on HN? I wonder why it's never been attempted.
  - throwawaymaths 4y ago
    There are currently insurmountable materials science limitations, and even the materials that come close are not currently possible to manufacture at scale, or even assemble (one carbon nanotubes does not necessarily have the same properties of many carbon nanotubes) at scale into structures which will withstand the structural stresses. I believe this is not necessarily true for other celestial objects besides the earth
    - Smaug123 4y ago
      For example, Pluto and Charon is a pair that sometimes comes up; a space elevator connecting Pluto to Charon would very possibly just about be within our current civilisation's capabilities, if for some reason we cared to build one enough to sink the Earth's economic output into it. They're tidally locked. (https://en.wikipedia.org/wiki/Space_elevator https://en.wikipedia.org/wiki/Space_elevator has its section on "Extraterrestrial elevators".)
      - actionfromafar 4y ago
        A space elevator for our own moon would be far more interesting to me. It could be built with known materials.
LightG 4y ago
Well, the US needed alternatives to Russian rockets, hence SpaceX and SLS. Now NASA need alternatives to Musk, so SLS is a good back up option. * canned laughter * (only semi joking considering his Ukraine starlink BS)
- imglorp 4y ago
  Setting aside his BS, there's a chasm of difference between SpaceX and SLS: it's process. SLS designs ONE (mostly) disposable ship, per year, max, taking a decade to integrate and realize. Epic Waterfall. They have several concurrent pipelines. Meanwhile SpaceX designs a reusable ship factory. Scalable to as many a year as you can afford.
  - LightG 4y ago
    I know. But it's still space travel at the whim of a BS'er. Hence, the need for a back up or private competitor. Ideally as efficient. If not, then at almost any cost is the only alternative (NASA).

amelius 4y ago

Ok, but doesn't that mean we will be surpassed left and right by nations who don't care (as much) about safety?

jackmott 4y ago

mytailorisrich 4y ago

The only 'big deal' is that NASA is planning to return to the Moon after a 50+ years hiatus. There's little that is groundbreaking.

Throwawayaerlei 4y ago

"now we're doing it safely." Mercury through Apollo really did not like the idea of using solid rocket boosters, you can't turn them off if things get out of hand, and of course they'll do that themselves in lots of failure modes. Suitable for a launch escape system ... and see the Shuttle for when these principles were turned on their head. Its SRBs, now being literally recycled for Artemis were low capital, high operating cost kludges that infamous killed one shuttle and its crew. In part because there was no provision made for escape aside from the pilots in the first couple of launches or so and that was rather limited, SR-71 technology with a pretty low max altitude. On the other hand the Orion crew capsule does have a tower escape system. So that old NASA you decry, they didn't lose a crew except on the ground due to a high pressure test with pure oxygen!?!?!! OK, that's a credible validation of that part of your thesis, see also Apollo 13 which was a close call. On the other hand does the Orion have a heavy shield for the astronauts to shelter behind in case of a solar storm (see Heinlein's Podkayne of Mars)? If not Apollo and the Artemis program are every bit as dangerous in what was a primary reason Nixon stopped Apollo before all its planned missions, program delays would have extended it into the change in the solar cycle. I would also note the start of this program many years ago was so badly designed the booster system's vibrations would have been lethal to humans. Springs in the crew capsule were part of the proposed solution to that, but going back to Shuttle diameter SRBs, only adding one segment, and all the mass of the tank and SSMEs should have fixed that. If my memory is correct that was a rocket powered by a single stack of SRBs, purely for sending crews out into space. But I'd like to know what happened after the Shuttle and it to make NASA take crew safety seriously. NASA was utterly callous about the known risk from the launch that killed the second shuttle and its crew. I finish by noting a bit of humility is warranted after just a single test mission success. That NASA and its contractors were able to pull it off is quite a feat, but as the Shuttle should have taught us bad designs can eventually catch up with you.

qbasic_forever 4y ago

It blew my mind to find out the first crewed mission to launch on the Saturn V (Apollo 8) flew all the way out and around the moon. No low earth orbit shakedown or anything, just straight to the moon (without landing). A few more launches tested they could dock with the LM and then Apollo 11 just went for it back to the moon and landing. The pace they went at is pretty unbelievable today.

Aperocky 4y ago
True YOLO moment. It's a miracle that everyone that went to the Moon returned unscathed.
five82 4y ago
I believe Apollo 8 was originally supposed to be a low earth orbit shakedown with the LEM. Because the LEM wasn’t ready, they decided to send them to the moon.
- m4rtink 4y ago
  IIRC there might have been Soviets in a Zond capsule launched on a Proton beating US to the lunar orbit in play when changing the plans for Apollo 8.

pfdietz 4y ago

I have to dispute that doing it more safely is a worthwhile goal for SLS. It's useful to think about safety issues in terms of the statistical value of a human life. This is how much one should be willing to spend to save one expected life. It's a vital number for planning purposes. For example, should we install a guard rail at this corner? Is controlling this release of this chemical justifiable? Compute if the cost is less than the expected value of lives saved. If so, spend the money, if not, don't. The usual statistical value of a human life is around $10M. And you immediately see the problem: a rocket that costs $1B to launch is, in effect, killing 100 statistical people just by being launched. If the result of the launch is valuable enough to justify that mathematical carnage, wouldn't it also justify subjecting the astronauts to real risk? Conversely, if it's worth delaying a launch to reduce the risk to astronauts, is the launch really worth having spent all that money on at all? The space program has been caught in an internal contradiction, where the purported benefits are claimed to justify large expenditures, but not claimed to justify risking astronauts. And this makes no sense. To actually justify reducing astronaut risks, launch and mission costs must first be greatly reduced.

matheusmoreira 4y ago
Would people want to board a spacecraft built by people with this mindset?
- pfdietz 4y ago
  Would people want to drive cars built by people with this mindset, on roads designed by people with this mindset, to get to airports to fly in aircraft built and regulated by people with this mindset? Trick question! Almost everyone does and doesn't see anything wrong with it. I would not want to get into an expensive risky rocket, since I don't see the benefit that would be commensurate with the enormous cost. If the cost were radically reduced, I might try it, and in that very much cheaper rocket the safety level would be much higher (or else the actual cost, including risk x value of my life, would swamp the ticket price.)
toast0 4y ago
I don't think the usual statistical value applies to an astronaut, especially an astronaut on a mission. At least, the loss to NASA will be much more. For one, they're going to spend a ton of money on investigagions. For another, it could significantly impact their future budget, and their ability to hire. It would depend on the details of the deadly incident though.

mr_toad 4y ago

> It should be a lot easier now with modern tech. The engine design is 41 years old. Older than many people reading this.

m4rtink 4y ago
41 years from the first flight, right ? So even older for the design and development of the engine.