Elon Musk To Unveil Mars Spacecraft Later This Year, For 2025 Flight (foxnews.com)

frank249 writes: Fox News is reporting that Space X and Tesla CEO Elon Musk expects to unveil plans for the spacecraft that would send humans to Mars within a decade. Speaking at an event in Hong Kong, Musk said he was 'hoping to describe the architecture' of the spacecraft at the International Astronautical Conference in Mexico in late September. "That will be quite exciting," Musk said. 'In terms of the first flight to Mars, we are hoping to do that around 2025.' As for his plans to go into space, Musk said he was hoping to reach the International Space Station 'four or five years from now.'

Comments

Timothy!!!

[qbast]

The whole page of submissions from 'timothy'. What the hell?

Re:Timothy!!!

[myster0n]

He's the only one sober enough to submit stories.

Re:Timothy!!!

[lhowaf]

There are new editors. They've eaten Timmay and are submitting stories under his account.

Safely???

[Alomex]

I have no doubt than in ten years he can build a rocket powerful enough to reach Mars. Then if he wishes to do it safely, he would have to send several unmanned missions (I'm thinking three) before he can get a safe certification for the one year (wo)manned journey.

A hell of a lot of things can go wrong in a year, as the ISS proves, and that is within the protective realm of the earth's magnetic field.

Re:Safely???

[ravenspear]

The rocket is not in question.

Right now the long pole in manned Mars surface missions is not rocket launch technology, it is Mars surface survival.

What kind of structure will people live in on Mars? How will it land? Heavy large structures that would be required for human habitation have not been landed on Mars to date and that is quite tricky.

How will the people live there? What kind of suits and structures will they use for radiation protection? For oxygen and water generation? For food production?

Obviously all of these problems have been addressed on ISS but only in the sense of solutions that can be relatively quickly resupplied from earth which won't be the case with a Mars surface mission.

Re:Safely???

[Rolgar]

Earth is moving about 20% faster than Mars. What this means is that the optimal time to launch from Earth to Mars is when Earth is behind Mars. The space ship will continue to have a speed advantage which will have to be negated. Now, the travel time from Earth to Mars is so long that Earth will long pass Mars by the time the spacecraft reaches Mars. Now, since the Earth will be ahead and getting farther away, to catch the Earth before it goes around the Sun, the space craft would have to speed up the difference plus even more to actually catch up. Fuel efficiency wise, the mission will have to last about half a year before the astronauts have an opportunity to launch and head fly on an intercept course with Earth.

Re:The Musk factor

[cytg.net]

Ill take 2034 over ???? though.

Re:Musk needs to get a grip

[Rei]

So for the CEO of a rocket company, making a rocket is "outside his sphere"? Interesting.

Mars Colonial Transporter

[frank249]

The first demo flight of the 27 engine Falcon Heavy is in April. SpaceX announced in May 2015 that they are positioning Dragon V2 spacecraft variants—in conjunction with the Falcon Heavy launch vehicle—to transport science payloads across much of the solar system, in cislunar and inner solar system regions such as the Moon and Mars as well as to outer solar system destinations such as Jupiter's moon Europa. Details include that SpaceX expects to be able to transport 2,000–4,000 kg (4,400–8,800 lb) to the surface of Mars, including a soft retropropulsive landing using SuperDraco thrusters following a limited atmospheric deceleration. When the destination has no atmosphere, the Dragon variant would dispense with the parachute and heat shield and add additional propellant.

SpaceX began development of the large Raptor rocket engine for the Mars Colonial Transport before 2014, but the MCT will not be operational earlier than the mid-2020s. SpaceX have not yet publicly released details of the space mission architecture nor all the system components of the MCT, nor a timeline for earliest MCT missions to Mars. Elon Musk hopes to unveil the space mission architecture at the International Astronautical Congress in September 2016.

The super-heavy lift launch vehicle for MCT is intended to be fully-reusable. Mars Colonial Transporter has been notionally described as a large interplanetary spacecraft capable of taking 100 people or 100 tonnes of cargo at a time to Mars.

Sounds far fetched but based on Musk's track record, I would not be surprised if he goes for it.

Re:Mars Colonial Transporter

[frank249]

Th US Air Force has just given SpaceX a $33m contract to develop the Raptor Engine. Raptor is the first member of a family of cryogenic methane-fueled rocket engines under development by SpaceX. It is specifically intended to power high performance lower and upper stages for SpaceX super-heavy launch vehicles. The engine will be powered by liquid methane and liquid oxygen (LOX), rather than the RP-1 kerosene and LOX used in all previous Falcon 9 rockets, which use Merlin 1C & D engines. Methane rocket engines have higher performance than kerosene/RP-1 and lower than hydrogen, with significantly fewer problems for long-term, multi-start engine designs than kerosene—methane is cleaner burning—and significantly lower cost than hydrogen, coupled with the ability to "live off land" and produce methane directly from extraterrestrial sources such as the surface of Mars.

The Raptor engine will have over six times the thrust of the Merlin 1D vacuum engine that powers the second stage of the current Falcon 9, the Falcon 9 v1.1.

The broader Raptor concept is a highly reusable methane staged-combustion engine that will power the next generation of SpaceX launch vehicles designed for the exploration and colonization of Mars." According to Elon Musk, this design will be able to achieve full reusability (all rocket stages), and as a result, "a two order of magnitude reduction in the cost of spaceflight.

Re:Mars Colonial Transporter

[Rei]

Meh. CH4, H2 and RP1 are all clean, cheap fuels - the levels of pollution and fuel costs are practically non-issues here. ISP, thrust and density are what matter. Methane simply lies on the curve between RP-1 and H2 in terms of thrust, density and ISP (significantly closer to RP-1 than H2). H2 is easier to produce on Mars than methane, which is in turn easier to produce than RP-1 - in this regard, methane is closer to H2 than RP-1 (the mass fractions of current hydrocarbon synthesis from CO2 and H2 tend to produce more methane than heavier hydrocarbons, although the ratios depend on the catalyst, and new catalysts could change this, and you could always do subsequent steps to combine light hydrocarbons)

Methane probably is a good balance for Mars if you want local propellant production. And really, since Mars round trips are so far down the rocket equation chain, you pretty much have to either use extremely high ISP fuels, or go with local propellant production. SpaceX has chosen the latter.

Re:Mars Colonial Transporter

[rasmusbr]

This is all very impressive, but the reason why USAF wants better rockets is probably nothing to do with Mars. They probably want cheaper and better satellites and the ability to put heavy weaponry in space, such as tungsten rods with retrorockets and guidance. That old cold war idea.

The Mars trip will happen when there is a compelling reason for people to go there, like if someone other than the US tries to get there first.

Re:Mars Colonial Transporter

[gman003]

CH4 has a specific impulse much closer to LH2 than RP1. CH4 is 1 carbon per 4 hydrogen atoms, RP1 is about 1 carbon per 2 hydrogen atoms.

At vehicle scale, CH4 might be even more efficient than LH2. LH2 is a deep cryogenic fuel - boiling point at 20K. The mass of insulation needed it pretty severe, particularly when you account for its low density. CH4 boils at a much, much more reasonable 110K, making it just barely thermally compatible with LOX at 90K - this is significant for interplanetary flights, where the temperatures of the fuel and oxidizer will eventually equalize without intervention. That's one reason most interplanetary probes use hydrazine for maneuvering once past Earth orbit - they can just regulate the entire spacecraft to one temperature, not worry about boiling their fuel. MCT will have to cool its propellant but at least it's not too cold, nor do they need to insulate one propellant from the other.

Also, natural methane has been detected on Mars. If we can determine the source, it may be possible to use it simply by condensing it, which will be even easier than producing LH2. Other planets/moons may be even easier.

Re:Mars Colonial Transporter

[Rei]

CH4 has a specific impulse much closer to LH2 than RP1

False. But don't just take my word for it, take CEA2's. Parameters: all chamber pressures set to identical 204.08, pi/pe set to give a constant 100:1 expansion ratio, mdot=2223.8 (same as the SSME). All fuels burned with LOX at a stoichiometric ratio. All chemicals at their boiling point except the RP1, which is set to 300K. RP1 simulated by dodecane.

ISP:
H2: 436,9
CH4: 365,6
C12H26: 360,6

Seriously, have you never looked at an ISP table before?

The mass of insulation needed it pretty severe, particularly when you account for its low density.

Nope. As is typical, it made up about 7% of the shuttle ET's mass. Nowhere near comparable to such an ISP difference.

CH4 boils at a much, much more reasonable 110K, making it just barely thermally compatible with LOX at 90K

Nope, CH4 freezes solid at 90,7K (versus LOX boiling at 90,2K). And it becomes way too viscous as it approaches its freezing point. That doesn't mean that they can't share a common bulkhead, but it does complicate it for long-term storage (aka, Mars missions)

That's one reason most interplanetary probes use hydrazine for maneuvering once past Earth orbit

That and because it's hypergolic and requires only trivial, lightweight engines - which isn't applicable to CH4.

Also, natural methane has been detected on Mars. If we can determine the source...

This is pure fantasy. Mars's atmospheric concentration is 10ppb - in an atmosphere that's only 0,7% the pressure of Earth's to begin with. Earth's is 1700 ppb at two orders of magnitude higher pressure, and the concept of condensing methane out of the atmosphere at "rich spots" is ridiculous even here - where we have extremely detailed global surface-level data on where "rich spots" are. Lastly, as much as I'd love a detailed surface-level whole-planet geological resource survey of Mars, that's just not going to happen anytime remotely soon - if in our lifetimes at all.

Realistic missions involve using as little speculative technology or speculative data-finds as possible. Even the concept of producing hydrogen from water on Mars is looked at with hesitation (O2 from CO2 is trusted more; the feedstock is much more pure and predictable - the Mars 2020 rover will be testing that one out, hopefully it will go well). Even for O2 we still need to demonstrate a reliable, deliverable system for local storage (as well as industrial-scale production rather than tiny lab-scale production).

Re:Mars Colonial Transporter

[AJWM]

Meh. CH4, H2 and RP1 are all clean, cheap fuels - the levels of pollution and fuel costs are practically non-issues here. ISP, thrust and density are what matter. Methane simply lies on the curve between RP-1 and H2 in terms of thrust, density and ISP.

Mostly right. Two out of three for clean: RP-1 has a tendency to coke up and can foul injectors or lead to hot-spots in the cooling tubes if you're re-using the engines. (Merlin's pintle injectors are probably not as prone to coke fouling, and all of this is going to depend on dozens of specific design decisions in the engine.) (The cleanliness of the exhaust is, as you also implied, irrelevant. Expecially compared to storable and/or hypergolic fuels.)

Isp is what matters above a certain altitude, below that what matters it thrust. All the Isp in the world won't help you get off the ground if your thrust to weight ratio is less than one. We've tested nuclear rockets with Isps in the 900s (three times better than LOX-H2) but they were too heavy to get off the ground. (Ion engines have the same problem in spades, but we're not talking about those.) Methane (and RP-1) will give you higher thrust than a comparable LH2 engine. Again, there are tradeoffs -- you could run LH2/LO2 engines O2-rich for higher thrust during part of the launch (although superheated O2 isn't the most benign environment for your pad, or the engine nozzles.)

Glad you brought up density. Many people forget about how this affects rocket performance. For any given mass of fuel (or oxidizer), the denser it is the smaller you can make the fuel tanks. The smaller the tanks, the less dead-weight you're lifting. I believe the latest Falcon-9 super-cools the LOX (making it denser) to take advantage of this. Methane also allows for considerably smaller tanks than LH2, making up some of the Isp disadvantage (the reduced insulation needs and simplified handling also help). (Some of Gary Hudson's old Phoenix SSTO proposals considered using densified (slush) hydrogen to get tankage weight down, but we still have hardly any experience with that stuff, and it's still barely 1/5 density of LCH4).

Re:Mars Colonial Transporter

[Rei]

My impression when they wrote "clean" was "clean from an environmental perspective". :)

Thrust is strongly correlated with density (as how fast you can burn a fuel depends on how fast your turbopumps can pump it into the chambers), so one can get a good sense of how good a fuel will be from a thrust perspective by its density. Which is why hydrogen makes for lousy first stages ;) Still, methane's reduced density definitely loses out over RP1. But I'm sure the thrust level will be fine.

You're correct about the "super-cooling" (they refer to it as densification, to avoid being mistaken for the phenomenon "supercooling"), which gives more thrust and lets them store more propellant - at a cost of additional complexity (mainly on the ground). I imagine they're probably not going to want to have to deal with that sort of complexity on Mars... but who knows?

You mention slush... slush and gel propellants provide an additional interest possibility, which is the ability to incorporate metal dusts into the burn. Aluminum offers a huge improvement to hydrocarbons and small improvement to LOX/LH in terms of ISP; it also provides a density boost. Lithium provides an even bigger boost to all cases, although obviously it poses additional handling difficulties. The most efficient chemical rocket engine ever tested dispensed with that altogether and burned molten lithium with hydrogen and fluorine (triprop... the hydrogen is there as a working gas, it doesn't contribute to the reaction). Got 542 sec ISP ;) According to CEA sims it's still a killer mix even if you use LOX instead of LF2... although it still depends on how much one is willing to hazard working with lithium. But that's all sort of a side point... if they use gel or slush propellants, particularly with hydrocarbons, they can really benefit by incorporating aluminum powder, which is quite safe and offers excellent density. Aluminum also tends to even out the burn and reduce vibration.

Re:Musk needs to get a grip

[ColdWetDog]

Everybody knows rockets are cylinders, not spheres (unless, of course, you are a rocket physicist).

Re:Unveiling?

[ColdWetDog]

He's got a better chance to get it off the ground than does NASA. He runs a dictatorship and is not beholden to the kleptocracy that is the US Congress.

Bet he gets there before NASA.

Re:You mean Space Coffin

[catchblue22]

This monster is going to get people killed in the name of profit.

Imagine if the above intrepid poster typified decision makers in sixteenth century. They would never have sent out explorers such as Sir Francis Drake or Ferdinand Magellan on their great voyages to map the world. Hell, if all humans were all like this poster (and those who modded him up), these great explorers would never have existed. Judging by many of the comments on this article, we are turning into a society of Statler and Waldorfs who criticize from the sidelines while offering little of substance. So grow a pair, and remember that all of us are going to die. What are you going to do with your life?

Re:Beyond Rockets

[solartear]

Reducing cost to orbit is precisely what Musk has been working on for the last 15 years. SpaceX has been reducing the cost, and looks to do it even more with re-use of its current rockets. And it is developing a much larger, cheaper launcher, to be completely re-used, since the vast majority of the cost is in building the things. The Shape Shuttle became a bad design because of politics, not because re-use of chemical rockets cannot work well.