SpaceX Wants To Go To Mars — and Has a Plan To Get There
mknewman writes with an article at NASA SpaceFlight which lays out the details of a plan from SpaceX to send a craft to Mars, using an in-development engine ("Raptor") along with the company's Super Heavy Lift Launch Vehicle. "Additionally, Mr. Musk also introduced the mysterious MCT project, which he later revealed to be an acronym for Mars Colonial Transport. This system would be capable of transporting 100 colonists at a time to Mars, and would be fully reusable. Article is technically dense but he does seem to follow through on his promises!"
This is an endeavor that's been on Elon Musk's mind for a while.
SpaceX, more than any other of the "private" space companies, has shown a compentencey for building rockets.
My Ass Is Blue, or whatever the pipe dream that Jeff Bezos is dumping money into, is not a player, not just for Mars, but for any real space flight.
Orbital Sciences and SpaceX are the real players.
If you want news from today, you have to come back tomorrow.
Groovy ... but before I care, SpaceX needs to first have humans in space.
Then I'll give a quid about their plans for space travel.
I mean, if they haven't done a manned space flight to outside the atmosphere, it is far-fetched to be running before you can walk or even stand.
The end.
Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
Seattle has Centurylink DSL (12Mbps where I live, better or worse depending on your distance from the infrastructure), cable (I don't know what they'll tell you speed-wise, I hate Comcast, but faster than the DSL), Clear WiMax (~10Mbps, last I checked), CondoInternet (specific buildings only, but it's at least 100Mbps), and a few other various options (including LTE from all of the Big 4). The eastside (and possibly other suburbs) can get FiOS from Frontier (I think they have 40+Mbps), and down south there are some other fiber options as well, or so I've heard.
Now, out in the boonies, yeah it's going to suck. Sticking near the major metropolitan areas though, you can definitely get good service.
There's no place I could be, since I've found Serenity...
Sorry for the dupe, I forgot to login.
Oh, the reason is very technical. The short story is that CH4/LOX is the best on full flow staged combustion. Exactly the most difficult and expensive cycle that nobody wanted to do. And if they do, since handling a new propellent is a new development in itself, they rather do with the propellents that they know.
In the staged combustion level, CH4 is slightly better than RP-1/LOX, if you have Russian efficiency, else RP-1 is better. But if you have an hydrogen/LOX upper stage is inferior. And since it need 27% more volume than RP-1/LOX, if you are volume limited (like everybody usually is, due to road or train transport limitations), RP-1/LOX is better. And for reusability, it depends on the parameters. Hydrogen can work, and NASA, Rocketdyne, P&W and Aerojet (now, all the same company), had a lot more experience in H2 and might be a better choice for Shuttle like applications. And if you compare to hypergolics (think Proton, Long March, etc.), hydrogen or kerosene, it is more difficult to start.
And again, all this for a first stage, space applications might have different requirements.
So, methane is king for a first full flow reusable engine. Which should be the pinnacle of performance, but nobody had boldly gone there.
I imagine it has something to do with the fact that It takes considerably less energy to escape Earth entirely than to go into even a low orbit, and what is to be gained by stopping in orbit? The craft you transfer to will have had to already make the trip up itself, you may as well just put your passengers in it and save the stop. Our rocket technology is mostly not terribly dependent on whether it's operating in air or vacuum, and for a reusable craft you have to be able to land on Mars and take off again with minimal planet-side infrastructure anyway, so any potential strength and weight reductions for an craft unsuitable for an Earth launch would be severely limited - most of the benefit could likely be gained from a breakaway 1st stage that just handles getting the rocket to a Mars-surface equivalent gravity-well "depth".
Moreover, the vast majority of the craft weight is fuel and tanks which will need to be landed to refuel anyway - no sense adding a bunch of fuel-hauling longboats if you can gracefully land the gas tanks rocket on their tail. The reason the moon missions used a lander were probably twofold: control systems were not yet advanced enough to land a full rocket on it's tail, and fuel for the entire mission had to be carried from Earth. If you could refuel on the Moon then it might well have made more sense to land the whole, potentially much smaller, EarthMoon rocket and refuel it.
Where space-only vessels become useful is once you have multiple "ports" with their own "longboat" / space elevator infrastructure already in place to allow cargo/passenger transfer and refueling. After all surface-to-orbit is the most expensive part of the trip, and much can be gained by not needing to include the capacity to handle that, but only if it doesn't mean hauling along a completely second vessel for the ride.
Alternately if ion drives were mature enough to propel the interplanetary stage, but not yet powerful enough for a surface launch, then the massive efficiency boost might make it worth having it a separate landing vehicle - no sense dropping a large useless ion drive into a gravity well and hauling it up again. Since most of the weight is the drive rather than the fuel as with rockets it changes the dynamics of the situation.
--- Most topics have many sides worth arguing, allow me to take one opposite you.