Nibb31

We can't even fix climate change on our own planet. What makes you think we could terraform Mars ?

There's this thing called suspension of disbelief. You have to use it to watch just about anything on TV. If a few small liberties with physics ruins your enjoyment of The Expanse, then you shouldn't be able to enjoy any TV show, book, or movie at all.

I think it's mostly for piece of mind. Any workplace needs contingency plans and NASA's job, as an employer, is to provide a decent effort to secure the workplace. You need an evacuation plan in any workplace, especially in an environment where there are hazardous materials. This isn't just for the crew, but for any workers who will be working in the white room facility at the top of the tower. So yes, even though most mishaps involving rockets wouldn't allow time to evacuate, you still have to plan for those that do. Failure to do so would be a huge liability.

The concept is for the ITS to land into a cradle, which is supposed to dispense of needing legs. It's a crazy idea, and like many of their other ideas, might be scrapped when it starts flying. The booster doesn't reach orbit and certainly doesn't come back from orbit. If it launches anything else, that thing is going to need an upper stage. What market is there for a larger payload ?

There was a Russian concept for a military version of Soyuz (Soyuz VI) that used RTGs instead of solar panels. The RTGs dangled off the side in their own reentry capsules and could be recovered after the mission. Interestingly, they were oriented to use shadow shielding to protect the crew from radiation:

And you don't unload 10 000 tons in a field either. People tote the "unprepared terrain" argument for airships, but handling thousands of tons of cargo requires infrastructure, trucks, cranes, depots, and those things are going to need a prepared terrain anyway.

They enter the hatch in the orbital module and climb down into the descent module. There is an adjacent hatch in the fairing of course.

What is the future of food? Apples, oranges, or pineapple?

A mix of all that. There is no 'single future'. The question is pointless.

Such smart people can do better.

What some people call "bureaucracy" is what other people call "traceability" and "quality". We do things a lot differently today than we did several decades ago. Most of the design work is done through iterations of specifications, iterations of CAD designs, and iterations of simulation. Much of the paperwork is because systems are far more complex, components are sourced from different suppliers, and everything has to work together straight away. Each component has to rely on an approved interface with the other components. The only way to agree on specifications is to write them down. For example: To design Concorde, there was a team of a few dozen engineers. The team had a global view of the entire plane, so they could easily communicate with each other and perform changes in their area of expertise without impacting other parts of the design. The majority of the workforce was an army draftsmen to iterate the drawings, carpenters who built several iterations of wood mockups and die-cast models for wind tunnel testing, and factory workers who built 4 prototypes and 2 test aircraft (that's 50% of the total number of actual production aircraft). The result was a great design, but no market. To design the A350, there was an army of engineers, market studies, purchase commitments, lots of specification documents and computer simulation, supplier selection and certification. Most of the construction work is down to contractors who don't necessarily have direct communication with R&D. So the documentation is the only way for different teams to communicate with each other. The development cost of the A350 was probably much higher than the cost of the Concorde and yet there was hardly any prototyping involved. The first A350 flew exactly as planned. The only reason it wasn't sold to a customer was because certification requires destructive testing. The second one was delivered to a customer. The reason there was no prototyping was because all that paperwork had certified pretty much every component beforehand. And because the costs are so high, organizations require risk mitigation. The regulatory and legal pressure is much higher today, and the paper trail is a requirement. There are probably more lawyers working at Airbus today than there were R&D engineers back in 1960s. As for probes like Beagle 2, Philae, or Schiaparelli, they actually are prototypes. They are special cases where there is very little data to perform proper simulation, so every science mission is a test to see if it can be done. The chances are high that something doesn't work as planned, and the only way to find out exactly what went wrong is to follow the paper trail back to each component. It's the only way to learn from your mistakes.

This is what Berlin Tempelhof Airfield looked like during WW2: The planes would follow the semi-circular taxiway and just take off in whatever direction suited them best.

No, you're right. I don't believe in this plan more than I believe in any of the DRMs or Zubrin-powered wet dreams. Mars has always been "20 years in the future" since the 1940s, and the trend continues. It probably just means that we are simply not ready for it yet.

That's how airfields used to be pre-WW2: a big flat field with no marked runways and a big sign with the name of the airfield. Just land in the direction of the windsock and try not to hit another plane.

Yeah, well, we get new Mars DRMs every couple of years, I doubt that such a plan will stick. That's 10 launches to construct two vehicles, plus at least half a dozen crewed launches to go with it. It's not realistic.

The DSH *is* the Mars Transport Vehicle. It's the smallest possible habitation for 4 crew members that can sustain long duration manned flights in deep space. All it needs is the SEP tug and it becomes your ride to Mars. So the plan is to build the DSH, send crews back and forth on Orion, and then attach a SEP tug module.

ISRU has yet to be proven. If you want lives to rely on it, it's going to take several design iterations. With a synod every 2 years and no resources assigned to it at this point, there is little chance of it reaching maturity in the next decade. Nobody suggests it should be a simulation, but it would be a proving ground. There are still many similarities: low gravity, lack of atmosphere, cosmic radiation. In some areas, the Moon is harsher than Mars, so if we can develop technologies to stay alive there, then we can live anywhere. To prove those technologies, we can't afford to wait for every 2 year synod and a 6 month journey to get the results. Using the Moon as a proving ground accelerates the development cycle dramatically. Besides, the Moon is our back yard. We need to learn to survive in our back yard before we can cross the ocean. I really doubt those numbers when a single F9 launch costs $60 million and is the cheapest way to get a meaningful payload into LEO, let alone Mars. Most of Zubrin's budget estimates are totally unrealistic. No it hasn't. Long term life support, ISRU, shielding, propulsion, landing large payloads... None of that is "proven". They are theorized at best, but none of the engineering has been done. There are no prototypes. None of it has been tested in the field. You need a TRL of around 8 or 9 in order to send humans. Those techs are at a TRL of 2 or 3 at best, they are far from "proven".

Yes, and it's a load of rubbish. Not if you want to come back. On the return trip of the journey, it's supposedly easier to insert your MTV into EML-2 or lunar DRO than into LEO. You RV at the gateway with an Orion and ferry your crew home.

There's nothing similar. The AAP Venus flyby vehicle was a wet-tank S-IVB hab with an Apollo docked to it. The crew was supposed to dock to the S-IVB, burn into the flyby trajectory, then purge the tanks and setup the hab during the flight. The DSH is an EML-2 station based on ISS modules, with an optional SEP tug to take it to Mars. The Orion is going nowhere.

No it didn't. It originated from the urban legend about sending a manhole cover into space: http://io9.gizmodo.com/no-a-nuclear-explosion-did-not-launch-a-manhole-cover-1715340946 No degree of good engineering would allow a modern ship to survive a nuclear warhead going off inside the hull.

That's the old wet-tank Apollo Venus flyby vehicle. It has nothing to do with DSH. What's your point ?

The point of the DSH is to provide a destination for Orion. Orion was designed for cislunar space and because there is no lander, the DSH is only place where Orion can reasonably go. Orion is never going to Mars. In any Mars expedition plan, the MTV is assembled at the DSH (the DSH might even become the hab module for an MTV). On its return trip from Mars, the MTV inserts itself into EML-2 and the Orion ferries people back and forth.

Have you ever seen a Nimrod MRA4 or a Short 330 ?

I didn't say transporting large volumes of liquid was impossible (there are such things as tanker aircraft). I said a swimming pool is impractical. Thanks for illustrating my point.

A swimming pool is still impractical. It's not so much roll that would cause spillage, but pitch. You can't take off or land without pitching up or down and centrifugal force won't prevent your pool from spilling over. Once the spillage starts, you get a massive transfer of weight that would be catastrophic.