Nibb31

Metaphor is right. It's more efficient to launch a single SLS with a 130 ton payload than 10 Falcon 9s with a 13 ton payload. However, there are practical limits to building bigger rockets. You need bigger factories to build the bigger stages, you need a bigger VAB to assemble the rocket, and you need logistics to transport all those bigger parts around. So as you get bigger, there is a point where you start losing economical efficiency. For the US, anything bigger than SLS would require extension work on the VAB and at Michoud, new crawlers, larger capacity propellant facilities, and bigger barges to ferry the stages from Michoud to the Cape. Basically, you would need to redesign and rebuild the entire Cape Canaveral infrastructure and several factories around the country, which would cost billions more than just designing the SLS. For Russia, there are no waterways to ferry rocket stages to the launch sites, so they are limited to railroad capacity for large stages. This is why the N1 was basically built on-site in sheds at Baikonour in very rudimentary conditions, which was the main cause of the failure of the program. Designing rockets isn't just about assembling tanks and engines. It's also about railroads, ships, cranes, roads, industrial facilities, chemical handling and some very very large buildings.

Just about everything we have these days comes from China, including top-brand quality stuff. They can make cheap knockoff stuff too. You get what you pay for, they cater for all markets.

Space: 1999

This has been suggested and rejected like hundreds of times since KSP exists. That's not how Lagrange points work, so it would be pointless.

You can't have two orbits in phase at different altitudes. Orbital speed is a function of orbital altitude.

There are no Lagrange points in KSP.

Well, he's not getting an SLS. The SLS is only available for government launches and NASA isn't interested in doing a flyby stunt.

Citation needed. The current record seems to be 53km for a balloon launched in Japan. Not NASA, and not 1,000km. That would be twice the altitude of the ISS! And of course, reaching orbit is about speed, not altitude. Unless you accelerate your balloon to 27000km/h, it will only come down, and none of these high-altitude balloons have enough payload to carry a rocket with 7500m/s of delta-V.

Just set rescaleFactor to 1.1 in all the part config files. Then it can take 2.5m modules (Fustek) as a tight fit.

What would be the point of even going there if you could do it in VR? You could send robots with high-resolution sensors and reproduce the exact same sensorial experience as if you were actually there.

Those technologies need research and development, not validation. There isn't enough time between now and 2018 to bring all of them to the appropriate TRL for manned spaceflight, especially on private funds. Apollo 7 and 8 were validation flights for actual flight hardware. At the time they were launched, all the pieces were practically in place for the moon landing. A flyby in 2018, as proposed by Tito, wouldn't validate any actual hardware that would be used for an actual mission. It's supposed to be a Dragon on a Falcon Heavy, maybe with a small inflatable in the trunk, but that's it. There would need to be a closed-loop ECLSS plus 2 years of supplies on board. The clock has probably already run out on that anyway with only 4 years to launch and no hardware being built. I agree that the engineering aspect is important. However, I disagree that little effort is spent on engineering... Since Constellation (and even before), NASA has spent much of its resources designing new vehicles but never flying them simply because they lacked a mission, ie. the focus is on engineering shiny new rockets, but the actual motivation for the mission is simply non-existant. Unfortunately, the only reason for funding a public space program is either national prestige (for which there are more affordable means) or science. The only reason for finding a private space program is either to achieve a return on investment or to send a billionnaire with too much money on a joyride. Neither are really sustainable at this time. How is that relevant for a flyby ?

What's the point of sending a ground penetrating radar just to do a single flyby? Because you need at least a small rationale for spending billions of dollars to do something. The only other reason would be for billionnaire's joyride, which won't serve much of a purpose to Mankind. However, it would still be a cruise where you don't get to see anything because it's night time. If you're going to watch the flyby on a night-vision LCD monitor, then it takes a lot of joy out of the joyride. What do you mean by support? If it means actually contributing billions of taxpayer dollars, then sorry, but I wouldn't support it. If it's a private effort to send a billionnaire on a stunt, then I don't see why he would need my support. And it wouldn't be a stepping stone at all. Very little of the technology for a flyby would be of any value for an actual manned mission to the surface of Mars.

The cycler concept is only useful for hab space really, which is only a small fraction of the total mission. Any consumables or experiments need to go up and down with the shuttle craft, so you really won't be reusing much for each mission. You still need to rendez-vous with the cycler, which is on an interplanetary trajectory, which means that the shuttle craft needs to have enough delta-v to get itself into that interplanetary trajectory itself. It also needs to carry the crew, the supplies for 2 years, the equipment, and the propellant for the cycler ship and the lander. Basically, the shuttle-vehicle needs to have the same mass as a conventional Mars Transfer Vehicle (ie. Copernicus), minus the hab module. If you're reusing the Mars lander, then it will also have to inject itself into the cycler's orbit in order to rendez-vous, so you are going to need a really massive SSTO lander. When you look at the details, you don't save much mass at all by using an Aldrin cycler.

It is absolutely pointless from any scientific perspective. You couldn't make any useful observations and you wouldn't have to time to teleoperate any useful experiments on the ground. If all you want is the experience of watching a Mars sunrise and sunset through a 20cm porthole, then you could reproduce that with an IMAX projector for a fraction of the cost.

There are pharmaceutical solutions to bone decay. They are being experimented and refined in long term stays on the ISS. Artificial Gravity is a technology that we know nothing about. It will take decades and lots of experimentation to get it to a TRL compatible with a manned interplanetary mission.

I'm pretty certain we will be able to use this sort of hi-fidelity VR technology to explore virtual worlds way before we ever (if ever) get to see actual interstellar exploration. It's also why I don't think space tourism will ever become a mass industry. Who would want to risk their lives and spend months travelling to Mars if you can live exactly the same experience with a VR machine ?

Additionally, these flyby trajectories put your approach on the dark side of Mars, meaning that you won't see anything, which makes the whole idea of a manned 500-day trip pointless.

The .tga file sizes are crazy. 65MB for some of them ! There really isn't much point in having 4096x4096 resolution on textures. Even if someone has a 4096 pixel display, it would be overkill ! I had to reduce the textures to 512x512 to even load the mod in KSP.

Launching manned add several orders of magnitude in terms on complexity, and you probably won't be able to man-rate everything before we are flattened by the asteroid. If your trying something new, it's better to send a robotic mission.

The payload and satellite bus are part of the total project cost. I'm not talking about just the launch cost, I'm talking about what it costs a customer to get a satellite in orbit to do a specific job. Together they count as two fifths, because the operational payload (instruments, transponders, whatever) is usually expensive, but of course, it's only a quick estimation of how much a space program costs. My point is that savings on the launch vehicle won't impact payload, ground station, transport, testing, infrastructure, etc... and therefore only has a marginal impact on the total program cost for the customer. And if they reuse a stage 10 times, that doesn't make it cost ten times less, because there will be overhead. We are talking about commercial or institutional satellites launches here. NASA doesn't want reused hardware for ISS Dragon trips. They will be free to reuse the hardware from NASA launches, but only for commercial launches, if they can actually find customers for 7t launches to LEO. It's a misconception that STS was "rebuilt each time". The engines were removed and rotated, which limited the downtime, systems were checked, fluids were purged... Most of the parts that were taken out were actually rotated between the orbiters to keep up with the schedule. The Shuttles weren't totally ripped apart between each flight, but it was a very complex machine. SpaceX is aiming for rapid turnaround, but there are only so many corners you can cut. They are still going to have to perform extensive verification of the stages before stacking them again. They are still going to have to purge fluid circuits and test the engines. The tanks especially are going to need intensive verification, because they are going to be subject to all sorts of loads and they are usualy made of thin sheets of metal. Any cracks or bends, and the structure can fail during the next launch. It certainly won't be land-refuel-launch without any tests or verification, and there will be quite some manpower involved in the refurbishing work. I disagree. They are trying lots of stuff that hasn't been tried before. There is lots of innovation going on in that company. The idea is that some ideas might fail, others might stick technically and economically. SpaceX is about as bleeding edge as it gets...

Air hose would just displace the dust. You would still bog up filters. Due to the lack of erosion, each particle of moon dust has tiny sharp edges, like glass shards, making it extremely abrasive. Not safe to breath either. It's also very fine and static, which makes it get into every little nook and cranny, which can cause big trouble on moving parts. Future missions will use suitports to avoid contaminating the interior of the vehicle. Basically, the suit has a rear hatch that attaches to the airlock. The suit stays outside and the astronauts climb into it.

Yes, I missed that. The Cassiope first stage did successfully retro-fire the Merlins in the supersonic airflow. But I don't think it splashed down intact. My understanding is that the engines flamed out way before due to the centrifugation. Not bad for a first attempt though, and nothing that can't be fixed.

That's what it does. It flies a more vertical profile than a conventional launch, which causes some of the payload capacity penalty, but minimizes the horizontal delta-v to turn around. Then it separates with some fuel left in the tank, and performs a "kick back manoeuver". The delta-v required to turn around is much lower when you are going the slowest, which is when you are at apogee. Reusing the upper stage is orders of magnitude more complicated, and only a notional concept right now. The upper stage goes much faster and requires a heavy TPS, which also eats into the payload capacity. The mass penalty of the extra fuel and landing gear is more severe on the upper stage, and on a normal profile it's suborbital, so it would also need an extra boost to make a full orbit.

Look at how filthy they were! Dealing with lunar dust is one of the big challenges of any future missions. It might even be the cause of the Chang'e 3 rover problems...