Just a huge check list for Musk to go through such as its questionable with the dates he is giving. Hell I wish I was Joe Rogan asking him a series of questions.
Feel free to correct me below.
- Demonstrate that they can send a 100-150 ton payload to Mars, which I suppose is the weight estimates of the starship. ITS tankers I have looked at (he proposes 5 for interplanetary mission) weigh 380 tonnes, interplanetary spaceship with cargo and passengers is estimated at 450 tonnes per trip to Mars. The only time I remember such heavy weight proposals was by the UR-900 to UR-700 rockets which have been cancelled by the Soviets. So if this does turn out successful than congrats for their company on setting new world records of heavy payload launches to space that surpass Saturn V, but a successful Mars mission is another story.
- Demonstrate that orbital refueling works which of course we have yet to see.
- I believe there are 4 tankers required for the Mars mission shown in the image I have looked at and they have to do some kind of maneuver with the starship which of course we have to see a demonstration that this works.
- Land I suppose a 100-150 ton object into Mars and NASA has had great difficulty trying to land at least a 1 ton rover. Space X has to demonstrate this.
- Musk has presented heat tiles with temperatures of 1560 kelvin in his tweet video regarding a re-entry profile, while Berkeley labs has said the re-entry heat load to Mars is 4000 degrees Fahrenheit. re-entry heat loads for earth are even higher. So is he making it sound like he is expecting that these tiles can survive the wear and tear of entering either Mars or earth without the whole crew dying?
- His stainless steel rocket design has criticism of its own because an atlas rocket crumpled from its own weight. The stainless steel he presented is 310S which corrodes at 2,000 degrees Fahrenheit and melts at 2,400 degrees Fahrenheit.
- Has presented a cooling method to blood rocket fuel from tiny holes of rocket ship. Microscopic pores however can be easily clogged especially entering Mars.
- He is going to use solar cells to power a plant to harness Martian subsurface ice, electrolyte it into H2 and O2, then liquefy and store it as rocket fuels. We have frozen water at our planets poles and to my knowledge, no-one makes rocket fuel this way or has even proposed that so that is another hurdle. So before he goes stakes the lives of his crew, I would recommend him demonstrating a group of people in astronaut suits doing this on earth and how long it takes to have the supposed required amount of fuel before leaving Mars atmosphere back to Earth.
- Russians have said a trip to Mars they would need a spaceship with several meters of lead or create some better radiation absorbing material that weighs less than lead. Space X has yet to demonstrate that, suits that can demonstrate that. Says 115 days to Mars on average, than once the crew lands I wonder how long it will take them to go mine in Mars before returning to earth with said amount of time.
- What is the cost of all of this? and what is the failure rate before making such an investment on Space X?
After he gets the Space ship to leave orbit what percentage % in progress is he done in getting to Mars with a human crew?
A few points:
1. Starship is 100-120 tonnes; the payload is an additional ~100 tonnes; so long as the payload is secured properly this shouldn't present too much of an issue. The vehicle certainly has more than enough thrust to launch and land with that kind of payload.
2. True for cryogenic propellants, though there's been successful demonstrations in the past of transferring liquids between spacecraft; the only fundamental difference is that you just have to be more careful about valves seizing with cryogenics. Either way we'll hopefully see them demonstrate this next year.
3. Something like that; it'll depend on what optimisations they make for tankers, what payloads they intend to deliver to Mars, how much weight they can cut from Starship, etc. Refuelling should be fairly simple; it's just docking with quick-disconnects.
4. To some extent that's what they're doing now; the timing of manoeuvres and length of burns will be different, but the landing process is the same on both Mars and Earth.
5. The tiles are based on TUFROC which has been demonstrated to handle Earth re-entry very well via the X-37B and sample tiles on Dragon capsules. Heat loads for Mars will definitely get hotter than re-entering from LEO, but the temperatures that tiles reach is highly variable depending on the aerocapture and/or re-entry profile.
6. Earlier Starships were built from 301, not 310; current prototypes are using 304L and they're moving towards (or may already be using on prototypes being built today) proprietary 30X alloys optimised for the job. Crumpling is also purely a matter of structural design, not the material - yes aluminium-lithium, etc alloys can be lighter and therefore thicker / more reinforced, reducing the chance of buckling, but that doesn't work at the re-entry temperatures that Starship needs to survive.
7. Transpiration cooling might possibly be used in select areas, but they don't plan on using it if they don't have to. The specific areas where it might be needed (flap hinges) are ones where any pores don't need to be tiny either, because you can simply spray liquid methane from a more conventional nozzle to wet the internal-facing hinge surface.
8. They're using the Sabatier reaction to produce CH4 and LOX from atmospheric CO2 and mined ice; it's a reaction that was first demonstrated >100 years ago and is well understood today. The only reason we don't use it on Earth is because it's energy intensive and therefore uneconomical when CH4 can instead just be obtained from natural gas deposits and LOX can just be produced via condensing / liquifying atmospheric O2 (SpaceX is actually constructing an O2 production plant right next to their Boca Chica construction yard right now). On Mars there's no real alternative than using the Sabatier reaction, so the plan is to simply deploy a massive solar panel farm to power it, get some atmospheric compressors running and (the most challenging part) mine some ice for providing the hydrogen for the process (a short-term alternative is delivering just pure hydrogen on some Starships, or delivering an excess of water [which might be a good idea for life-support regardless in case a water shipment or two from Earth fails to land]).
9. For the majority (or potentially entirety) of the transit you won't need anything close to metres of lead. For solar radiation Starship can keep its tail pointed to the sun, putting propellant and several angled layers of steel between the crew and space. For cosmic radiation it's actually better to have shields made out of lighter elements, so things like HDPE, lithium metal hydrides, water (potable and/or grey being stored and cycled through the life support system) can be used to protect the cabin and a purpose-made radiation bunker for any major radiation events.
For stays on Mars itself the general intent is to use Martian regolith (either via homes dug underground, or potentially by using nearby ex-volcanic tubes and caves) to protect colonists from radiation, with the Starship they rode in on being a temporary home.
10. Starships themselves are quite cheap; Raptor engines are in the ballpark of just $1m each, stainless steel is cheap and in many ways easier to work with than carbon composites or aluminium alloys (TIG welding plasma-cut and folded sheet steel rather than trying to mill out giant slabs of aluminium, press them into shape and then friction-stir weld). I've previously estimated that in terms of engines, avionics, steel and labor they're only paying something like $10m per vehicle; there'll be extra money involved for tooling and equipment hire, even more if you include things like land-purchases, facility construction costs, off-site R&D, etc, but either way this is no SLS. Starship is also an investment by SpaceX into creating a full reusable launch vehicle that theoretically should be cheaper per launch than Falcon 9 while having a significantly larger payload capacity. This not only helps with the general launch market, but it allows SpaceX to launch Starlink satellites for significantly less. Starlink in turn is intended to fund Starship's continued development and Martian colonisation projects. Then finally, Elon himself sees Starship and Mars colonisation as his primary pet projects, and as such, has previously stated that he's gathering wealth (via his shares in Tesla, etc) in order to help personally fund a colonisation effort.
Elon's timelines are almost always unrealistically optimistic, but I do think we'll see an orbital launch this year so long as there isn't a major problem like the orbital launch pad (under construction) blowing up, or the integration tower (required to stack Starship onto SuperHeavy) being destroyed (or constructed far slower than expected). Then once they're getting Starships into orbit they'll want to immediately start using it for Starlink launches. Between those, they'll want to also test orbital refuelling ASAP next year as its critical to Starship's architecture and any potential NASA Artemis HLS contracts. SpaceX also wants to launch dearMoon in 2023 which would potentially be Starship's first manned mission and the first commercial space mission beyond LEO; for that they need to prototype and test a crewed variant of Starship, including an unmanned trip around the Moon to test extra high-speed re-entry and how things like the ambitious panoramic window holds up under the varied loads and temperatures. I expect dearMoon to get delayed to something like 2025, but we'll just have to wait and see. In 2022 and 2024 I also expect SpaceX to launch (assuming in-orbit refuelling is demonstrated) some unmanned Starships to Mars, primarily to gather test data, but also potentially to deliver cheap but useful payloads like water. There's potential then for a manned launch in 2027, but even if it gets delayed to after 2030 it'll be far ahead of the timeline where NASA would have the funding to get us there.