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SpaceX Shows Off Its Interplanetary Transport System in New Video (techcrunch.com)
Elon Musk's SpaceX plans to send humans to Mars with a ship called the Interplanetary Transport System, the company announced today in a video, revealing how the ITS will actually work. The ITS will be capable of carrying up to 100 tons of cargo -- people and supplies -- and it will utilize a slew of different power sources en route to Mars. From a report on TechCrunch: SpaceX has released a new video showing a CG concept of its Interplanetary Transport System, the rocket and spacecraft combo it plans to use to colonize Mars. The video depicts a reusable rocket that can get the interplanetary spacecraft beyond Earth's orbit, and a craft that uses solar sails to coast on its way to a Mars entry. The booster returns to Earth after separating from the shuttlecraft to pick up a booster tank full of fuel, which it then returns to orbit to fuel up the waiting spaceship. The booster craft then also returns to Earth under its own power, presumably also for re-use. The solar arrays that the spacecraft employs provide 200 kW of power, according to captions in the video.The Verge is live blogging SpaceX's conference, and has details on specs.
They show the spaceship being launched first, to be refueled by a drone tanker. Shouldn't the tanker be launched first? Unlike the spaceship, it can wait indefinitely in orbit if the second launch is delayed.
I agree. There's no way to land a man on the moon, and I can't understand why anybody would be crazy enough to even try.
And that's different from NASA/Energia how? Both burnt hundreds of billions of dollars and killed over a dozen astronauts/cosmonauts, and hundreds of workers/civilians in the process. The only difference with private spaceflight (non-cost plus) will be that it will cost a LOT less and things will improve drastically with every launch instead of the snails pace we've become accustomed to. It should also be noted that neither of SpaceX's failures would have resulted in the loss of a hypothetical crew, the Dragon cargo capsule survived the first failure and continued transmitting until it hit the ocean (an actual crew would have overrode the computer and deployed the parachutes) and the second failure would never have had a crew on-board during a engine test and even if they were the LAS would have carried them away from the Falcon 9.
For example, the Saturn V used two different kinds of fuel: LOX with RP-1 and liquid hydrogen. This optimized performance for the 1st stage booster vs the upper stages. This increased the cost and complexity of the ground support. SpaceX uses only one kind of fuel for all stages. This reduces complexity and cost.
If you build a booster stage that is robust enough to return with only aerobreaking, it is going to weigh more and be more complex. You pay for that extra weight for every launch. Note that some of the structure is only used for re-entry and is dead weight on the way up. Breaking with the engines means they are used both on the way up and the way down.
As Musk points out in his presentation, fuel is the cheapest component of the launch system. Therefor it makes economic sense to use more fuel to land the launch stages, which are the expensive components.
The people at SpaceX are not dumb. They came up with a different solution because they framed the problem differently. Rockets are hard, and there is not a single best way to build them. There are a lot of projects that use vertical powered landing: McDonald-Douglas DC-X and Blue Origin New Shepard are examples and NASA funded various prototypes. Aerobreaking is not the only reasonable option.
Why is Snark Required?
Sure, you can do it, but if you rely on your rocket engines entirely to decelerate (as the video clearly shows), you would need roughly double the fuel.
Agreed, but the real question is what are they replacing the expended fuel with? I mean, so that the landing mass is roughly the same as the launch mass. Because that's the only way you would need roughly double the fuel.
On a more serious note, they've already been landing boosters this way. In Earth gravity. Furthermore, how the fuck are your parachutes going to help land on a planet with little-to-no atmosphere?
You play KSP, so it's totally reasonable to expect that you know better than an entire company full of rocket scientists.
Chuuch. Preach. Tabernacle.
They are cutting corners with safety to make their death trap cheap. They should be stopped before they start killing people.
Because SpaceX is a private effort, you have no way of doing that. You will have to be satisfied with getting your lawyers to kill off government infrastructure projects instead.
The problem is if you miss landing on a barge, you lose the booster. If you miss landing and hit a giant fuel tank, you lose a lot more.