Of Earth, Mars, and the moon, the moon is the body that requires the most propellant to land on. All your delta-v must be done via rocket propulsion. Both Earth and Mars landings can be performed with ~600 m/s of propulsive delta-v, the remainder being handled by atmospheric braking, no parachutes required.
Apart from the immense costs of your pipeline proposal, relying on such a thing for your water supply would be incredibly risky, and still limits you to locations along the pipeline and activities that can be supplied sufficient amounts via the pipeline.
Landing on the moon takes more propulsive delta-v than landing on Mars, so payloads are more limited and costs of moving material are higher. The lunar ice is going to be in the form of icy regolith instead of deposits of nearly pure water ice, and the moon has a shortage of carbon and nitrogen, much harsher thermal and radiation environments, and a very difficult power situation with its 2-week night periods...you are going to need to ship enormous amounts of batteries to keep solar powered facilities running through the night.
The geology of the moon is also largely unprocessed igneous rock: Mars has a wide variety of minerals that have been separated and concentrated by liquid water and wind: the Spirit rover got stuck in a patch of iron sulfate powder, for example. It'll be a lot easier to find useful mineral deposits nearby on Mars.
No, it's as Kjella said: CRS missions are not satellite launches. On top of the rocket launch, you get a spacecraft rated for human occupation while in orbit and cargo delivery services to and from a manned space station. All that doesn't come free.
No, they're just flying at a higher angle of attack to do more maneuvering aerodynamically instead of with propulsion. They tried parachutes and soft-landing in the water...parachutes couldn't even keep the stage intact through reentry, and even the softest splashdowns led to stages breaking up either when they toppled over or because of waves afterward. Even if the stage remained mostly intact, at best they'd be able to salvage some pieces of hardware.
The goal is rapid reuse, with little more than a quick inspection, re-stacking with second stage and payload, and refilling expended fluids. No parachutes, no fishing waterlogged hardware out of the ocean. In fact, Musk has talked about possibly refueling the stages on the barge and flying them back
There's nothing stopping them putting the Tesla on the shake table for vibration testing. I do expect that they've had to make modifications. Stripping out or draining/purging things like the brake system, applying copious amounts of epoxy and the occasional weld to fix things in place, etc.
There's a slight difference in circumstances between the two cases. For one, when they launched the first Dragon, they didn't have an already-operating launch system that has just done 18 launches in one year. For another, this is a more expensive manned capsule and a much more complicated and risky launch vehicle.
Additionally, the Dragon will operate almost exclusively on the Falcon 9 under considerably different flight conditions, not the Heavy, and the Heavy will operate almost exclusively with fairing-encapsulated payloads, not Dragons. Performing an abort test would also prevent them from doing a full test flight of the Heavy, on top of likely making core recovery impossible. Such a test would be expensive, high risk, and afterward they'd still need to do a Dragon abort test on the Falcon 9 and a full test flight of the Falcon Heavy.
There's a long list of reasons *not* to do this. Where's one reason to do it?
Not in 2017. The accident was a ground equipment failure on a test stand during a test of a single engine that didn't even involve a complete rocket stage, let alone any payload.
They're already going to do an in-flight abort test, they're just not going to risk an expensive Dragon capsule and critical test milestone on an untested rocket to do it.
No, better to put the resources to something less risky. Spending millions on interplanetary comms, power systems, thermal control, etc. and putting the result on an experimental rocket that has a good chance of destroying it all would just be foolish.
Using a low-value payload is not unusual. The Saturn SA-1 payload was a bunch of Florida beach sand.
Asteroids. Solar orbit's already filled with more junk than SpaceX will ever launch, and most of it's gone millions to billions of years without encountering anything else. It's not crowded out there.
There's almost always a tradeoff somewhere. Could be efficiency, could be complexity, could be some other emissions that get increased. In automotive ICEs, for example, there is a direct tradeoff between efficiency increases (and CO2 reduction) via increased compression ratio and combustion temperature, and the increase in nitrogen oxide emissions that results.
"Every little bit helps" is an incredibly wasteful way to approach things, prone to generating unnecessary additional costs while achieving less. There are things the time and energy can be far more productively put to than reducing the already-negligible CO2 emissions of rockets. What Musk has done in electrifying cars far outweighs what his rockets will emit, for example.
SpaceX's Mars plans involve transit trajectories that are far higher energy than a Hohmann transfer. They're aiming for average transit times of 115 days, more to deal with the microgravity and radiation hazards than due to the supply requirements.
They are also targeting locations with accessible water resources. That and the atmosphere mean they don't need a perfectly closed life support system on the surface, they mostly need to import food and can easily augment supplies with fresh produce from greenhouses.
SA-5, the first Saturn 1 orbital flight, flew with a payload of about 11 metric tons of Florida sand. Even the Saturn V you cite used a Block 1 CSM, a version of the craft only intended for testing. And the lunar module itself was just a dummy. It is in fact very frequent to use dummy "satellites" that are no more than engineering hardware or even just mass simulators instead of actual hardware.
There were unmanned landers even before that. They presumably built some testbeds on Earth to develop the technology rather than just throwing it together and hoping it worked when it got to the moon.
However, it's not landing a rocket that's the big deal. Armadillo Aerospace was able to fly and land rocket vehicles with an absurdly low budget. The big deal is landing the first stage of an orbital launch vehicle (with the scales and mass fractions that implies) for reflight, and doing so without making the system so ridiculously complex and expensive to operate that you'd be better off with expendable rockets.
There's also the fact that they've doubled the payload capacity of the single-core Falcon 9, and can now use it for many payloads originally planned for the Heavy. Combine that with the fact that reuse makes 3x as big a difference for Heavy launches, and it's perfectly clear why they prioritized getting Falcon 9 optimized and re-flying over the Falcon Heavy. Getting stuff into orbit is the goal, not launching the Falcon Heavy.
Yes, they're way behind their original estimated launch dates. They adapted their plans in response to what they learned. In an industry that spent 30 years flying a vehicle known to be badly flawed and a complete failure at its goals of reducing cost of space access, this is something that is badly needed.
Also, as for the subsidies SpaceX has received, from that same article:
"The state put up more than $15 million in subsidies and infrastructure spending to help SpaceX build a launch pad in rural Cameron County at the southern tip of Texas. Local governments contributed an additional $5 million."
That's it. It's not even Federal money, or being handed directly to SpaceX...a lot of it is stuff like road improvements.
That claim was messed up in several different ways. Most cold fusion schemes used pure deuterium fuel. The problem with cold fusion is simply that cold fusion doesn't work. The notion that fusion is a scam if it can't produce more tritium than it consumes is an odd one too...the goal is power production, not tritium production. Fuels are typically consumed, tritium is unusual in that the process that consumes it can also produce it.
And finally, D-T fusion can actually produce excess tritium by breeding it from Li-7, which reacts with a high energy neutron (>2.466 MeV, D-T fusion producing 14.1 MeV neutrons) to produce tritium and a lower energy neutron which can go on to produce more tritium. And even the Li-6 reaction would reduce the overall tritium requirements.
Try actually reading about it. Apart from the fact that pure alumina is unlikely to be a practical electrolyte for aluminum production and that most research has been based on iron rich basalt rock similar to that easily available on Mars and the moon, with electrolysis temperatures of around 1600 C, pouring liquid aluminum (or iron, as is the case in the actual research projects being done) is hardly a major technical hurdle to overcome.
This is isn't some poorly thought out idea of what might be technically possible: physical hardware has been built and operated. The inputs are literally just ore (in some cases just crushed volcanic rock as a lunar regolith simulant) and electricity.
It truly is a bad combination. Seriously, do some research before bragging about teaching on a subject you clearly know nothing about. Just because you're familiar with one particular way of doing things does not mean it is the only possible approach.
Yes, the temperatures are high. Guess what, the people developing these systems figured that out pretty early on, and electricity turns out to be pretty good at heating things to high temperatures, with several experimental designs being heated by the current used for electrolysis. The material difficulties with the electrodes and crucibles are also areas of current research, but workable solutions already exist. The fact is that molten oxide electrolysis can produce large quantities of reduced metal and oxygen with the only inputs being oxides (typically a mix of silicates and metal oxides, as in molten basalt rock) and electricity. No reducing agents required.
Those metals are not "incredibly expensive". Energy intensive, yes, but...oh, what was it I said you needed?
And yes, the specific aluminum process widely used here on Earth uses consumable carbon electrodes, but that is a matter of convenience rather than a necessary part of the process, the actual process is driven by electrochemistry. The only thing required to extract oxygen and reduced metals from rock is in fact energy, in the form of electricity.
Look, this is not a difficult to understand set of reactions. If you'd do a few minutes of research on the subject, you'd see how foolish your stubborn refusal to admit this makes you appear...it's fundamentally no different from electrolyzing water for hydrogen and oxygen. There is no reducing agent required, anywhere, and when done with oxides, oxygen is a direct product of the process.
The Falcon Heavy is $90 million, they've given cost figures for quite some time now. And Musk points out that the $300 million difference exceeds the average cost of the satellites. Some are more expensive, but many others are cheaper, even government satellites.
And SpaceX already has a backlog of more than 50 payloads waiting to launch over the next several years, including over a dozen government launches. Musk might just have some idea what his customers want.
The transit spacecraft carries several times its mass in cargo, serves as the spacecraft for bringing that cargo to orbit and delivering them to the surface of Mars, and is built for rapid and complete reuse, with spacecraft only needing to be mated together on the pad and loaded for another launch.
Your suggested alternative greatly increases propellant requirements to allow for braking into orbit instead of doing a direct entry and landing. That requires more launches per mission, every one of those launches requiring an expendable vehicle to be constructed and transported to the launch site for every launch. And you haven't even dealt with the issue of landing on Mars and returning vehicles to Earth...how do you get your orbital spacecraft refueled for return? Ship expendable tanker launchers to Mars?
You aren't gaining anything with that approach, you certainly aren't cutting the costs by 2/3.
Slashdot Mirror
Of Earth, Mars, and the moon, the moon is the body that requires the most propellant to land on. All your delta-v must be done via rocket propulsion. Both Earth and Mars landings can be performed with ~600 m/s of propulsive delta-v, the remainder being handled by atmospheric braking, no parachutes required.
Apart from the immense costs of your pipeline proposal, relying on such a thing for your water supply would be incredibly risky, and still limits you to locations along the pipeline and activities that can be supplied sufficient amounts via the pipeline.
Landing on the moon takes more propulsive delta-v than landing on Mars, so payloads are more limited and costs of moving material are higher. The lunar ice is going to be in the form of icy regolith instead of deposits of nearly pure water ice, and the moon has a shortage of carbon and nitrogen, much harsher thermal and radiation environments, and a very difficult power situation with its 2-week night periods...you are going to need to ship enormous amounts of batteries to keep solar powered facilities running through the night.
The geology of the moon is also largely unprocessed igneous rock: Mars has a wide variety of minerals that have been separated and concentrated by liquid water and wind: the Spirit rover got stuck in a patch of iron sulfate powder, for example. It'll be a lot easier to find useful mineral deposits nearby on Mars.
No, it's as Kjella said: CRS missions are not satellite launches. On top of the rocket launch, you get a spacecraft rated for human occupation while in orbit and cargo delivery services to and from a manned space station. All that doesn't come free.
The AMOS incident happened in 2016. The only explosion significant enough to reach the news this year was that engine test.
No, they're just flying at a higher angle of attack to do more maneuvering aerodynamically instead of with propulsion. They tried parachutes and soft-landing in the water...parachutes couldn't even keep the stage intact through reentry, and even the softest splashdowns led to stages breaking up either when they toppled over or because of waves afterward. Even if the stage remained mostly intact, at best they'd be able to salvage some pieces of hardware.
The goal is rapid reuse, with little more than a quick inspection, re-stacking with second stage and payload, and refilling expended fluids. No parachutes, no fishing waterlogged hardware out of the ocean. In fact, Musk has talked about possibly refueling the stages on the barge and flying them back
There's nothing stopping them putting the Tesla on the shake table for vibration testing. I do expect that they've had to make modifications. Stripping out or draining/purging things like the brake system, applying copious amounts of epoxy and the occasional weld to fix things in place, etc.
There's a slight difference in circumstances between the two cases. For one, when they launched the first Dragon, they didn't have an already-operating launch system that has just done 18 launches in one year. For another, this is a more expensive manned capsule and a much more complicated and risky launch vehicle.
Additionally, the Dragon will operate almost exclusively on the Falcon 9 under considerably different flight conditions, not the Heavy, and the Heavy will operate almost exclusively with fairing-encapsulated payloads, not Dragons. Performing an abort test would also prevent them from doing a full test flight of the Heavy, on top of likely making core recovery impossible. Such a test would be expensive, high risk, and afterward they'd still need to do a Dragon abort test on the Falcon 9 and a full test flight of the Falcon Heavy.
There's a long list of reasons *not* to do this. Where's one reason to do it?
Not in 2017. The accident was a ground equipment failure on a test stand during a test of a single engine that didn't even involve a complete rocket stage, let alone any payload.
They're already going to do an in-flight abort test, they're just not going to risk an expensive Dragon capsule and critical test milestone on an untested rocket to do it.
No, better to put the resources to something less risky. Spending millions on interplanetary comms, power systems, thermal control, etc. and putting the result on an experimental rocket that has a good chance of destroying it all would just be foolish.
Using a low-value payload is not unusual. The Saturn SA-1 payload was a bunch of Florida beach sand.
Asteroids.
Solar orbit's already filled with more junk than SpaceX will ever launch, and most of it's gone millions to billions of years without encountering anything else. It's not crowded out there.
https://www.nasa.gov/sites/def...
Wind doesn't produce branching riverbeds filled with rounded stones.
There's almost always a tradeoff somewhere. Could be efficiency, could be complexity, could be some other emissions that get increased. In automotive ICEs, for example, there is a direct tradeoff between efficiency increases (and CO2 reduction) via increased compression ratio and combustion temperature, and the increase in nitrogen oxide emissions that results.
"Every little bit helps" is an incredibly wasteful way to approach things, prone to generating unnecessary additional costs while achieving less. There are things the time and energy can be far more productively put to than reducing the already-negligible CO2 emissions of rockets. What Musk has done in electrifying cars far outweighs what his rockets will emit, for example.
SpaceX's Mars plans involve transit trajectories that are far higher energy than a Hohmann transfer. They're aiming for average transit times of 115 days, more to deal with the microgravity and radiation hazards than due to the supply requirements.
They are also targeting locations with accessible water resources. That and the atmosphere mean they don't need a perfectly closed life support system on the surface, they mostly need to import food and can easily augment supplies with fresh produce from greenhouses.
SA-5, the first Saturn 1 orbital flight, flew with a payload of about 11 metric tons of Florida sand. Even the Saturn V you cite used a Block 1 CSM, a version of the craft only intended for testing. And the lunar module itself was just a dummy. It is in fact very frequent to use dummy "satellites" that are no more than engineering hardware or even just mass simulators instead of actual hardware.
There's a reason they posted as Anonymous Coward...
There were unmanned landers even before that. They presumably built some testbeds on Earth to develop the technology rather than just throwing it together and hoping it worked when it got to the moon.
However, it's not landing a rocket that's the big deal. Armadillo Aerospace was able to fly and land rocket vehicles with an absurdly low budget. The big deal is landing the first stage of an orbital launch vehicle (with the scales and mass fractions that implies) for reflight, and doing so without making the system so ridiculously complex and expensive to operate that you'd be better off with expendable rockets.
There's also the fact that they've doubled the payload capacity of the single-core Falcon 9, and can now use it for many payloads originally planned for the Heavy. Combine that with the fact that reuse makes 3x as big a difference for Heavy launches, and it's perfectly clear why they prioritized getting Falcon 9 optimized and re-flying over the Falcon Heavy. Getting stuff into orbit is the goal, not launching the Falcon Heavy.
Yes, they're way behind their original estimated launch dates. They adapted their plans in response to what they learned. In an industry that spent 30 years flying a vehicle known to be badly flawed and a complete failure at its goals of reducing cost of space access, this is something that is badly needed.
Also, as for the subsidies SpaceX has received, from that same article:
"The state put up more than $15 million in subsidies and infrastructure spending to help SpaceX build a launch pad in rural Cameron County at the southern tip of Texas. Local governments contributed an additional $5 million."
That's it. It's not even Federal money, or being handed directly to SpaceX...a lot of it is stuff like road improvements.
That claim was messed up in several different ways. Most cold fusion schemes used pure deuterium fuel. The problem with cold fusion is simply that cold fusion doesn't work. The notion that fusion is a scam if it can't produce more tritium than it consumes is an odd one too...the goal is power production, not tritium production. Fuels are typically consumed, tritium is unusual in that the process that consumes it can also produce it.
And finally, D-T fusion can actually produce excess tritium by breeding it from Li-7, which reacts with a high energy neutron (>2.466 MeV, D-T fusion producing 14.1 MeV neutrons) to produce tritium and a lower energy neutron which can go on to produce more tritium. And even the Li-6 reaction would reduce the overall tritium requirements.
Try actually reading about it. Apart from the fact that pure alumina is unlikely to be a practical electrolyte for aluminum production and that most research has been based on iron rich basalt rock similar to that easily available on Mars and the moon, with electrolysis temperatures of around 1600 C, pouring liquid aluminum (or iron, as is the case in the actual research projects being done) is hardly a major technical hurdle to overcome.
This is isn't some poorly thought out idea of what might be technically possible: physical hardware has been built and operated. The inputs are literally just ore (in some cases just crushed volcanic rock as a lunar regolith simulant) and electricity.
It truly is a bad combination. Seriously, do some research before bragging about teaching on a subject you clearly know nothing about. Just because you're familiar with one particular way of doing things does not mean it is the only possible approach.
Yes, the temperatures are high. Guess what, the people developing these systems figured that out pretty early on, and electricity turns out to be pretty good at heating things to high temperatures, with several experimental designs being heated by the current used for electrolysis. The material difficulties with the electrodes and crucibles are also areas of current research, but workable solutions already exist. The fact is that molten oxide electrolysis can produce large quantities of reduced metal and oxygen with the only inputs being oxides (typically a mix of silicates and metal oxides, as in molten basalt rock) and electricity. No reducing agents required.
Those metals are not "incredibly expensive". Energy intensive, yes, but...oh, what was it I said you needed?
And yes, the specific aluminum process widely used here on Earth uses consumable carbon electrodes, but that is a matter of convenience rather than a necessary part of the process, the actual process is driven by electrochemistry. The only thing required to extract oxygen and reduced metals from rock is in fact energy, in the form of electricity.
http://lmgtfy.com/?q=molten+ox...
Look, this is not a difficult to understand set of reactions. If you'd do a few minutes of research on the subject, you'd see how foolish your stubborn refusal to admit this makes you appear...it's fundamentally no different from electrolyzing water for hydrogen and oxygen. There is no reducing agent required, anywhere, and when done with oxides, oxygen is a direct product of the process.
The Falcon Heavy is $90 million, they've given cost figures for quite some time now. And Musk points out that the $300 million difference exceeds the average cost of the satellites. Some are more expensive, but many others are cheaper, even government satellites.
And SpaceX already has a backlog of more than 50 payloads waiting to launch over the next several years, including over a dozen government launches. Musk might just have some idea what his customers want.
The transit spacecraft carries several times its mass in cargo, serves as the spacecraft for bringing that cargo to orbit and delivering them to the surface of Mars, and is built for rapid and complete reuse, with spacecraft only needing to be mated together on the pad and loaded for another launch.
Your suggested alternative greatly increases propellant requirements to allow for braking into orbit instead of doing a direct entry and landing. That requires more launches per mission, every one of those launches requiring an expendable vehicle to be constructed and transported to the launch site for every launch. And you haven't even dealt with the issue of landing on Mars and returning vehicles to Earth...how do you get your orbital spacecraft refueled for return? Ship expendable tanker launchers to Mars?
You aren't gaining anything with that approach, you certainly aren't cutting the costs by 2/3.