Nibb31

You will be way beyond the 10% mass penalty. Wings are one thing, but you need control surfaces and landing gear, which need hydraulics, some way to maintain pressure in those hydraulics (an APU or a propulsion unit). At Mach 7, you're also going to need some sort of TPS, so your wings can't be made solely of composites. And of course, your structure is going to need to be much heavier because it has to handle all sorts of dynamic loads instead of just containing fuel in vertical position.

But what exactly are you backing up by sending a few hundred people to Mars ? Not our gene pool, our culture, our civilization, our biodiversity, our environment, our thousands of years of history... The only thing you're saving is a few hundred people, and they will be in a much more precarious situation than the rest of Humanity ever was. Those things aren't replaceable, so they can't be "backed up". It would be like backing up your computer by saving a couple of files on a flaky old 5.25" floppy, and then storing that floppy on top of a loud speaker. That's a rubbish backup strategy, just as a Mars colony is a rubbish way of preventing extinction. If you want to save those things that aren't replaceable, then your prime responsibility, is to spend as much as you can to protect them because they are unique. Then, you might want to make records of them and store those copies in a vault somewhere as a secondary measure, but you don't need a Mars colony for that.

My point was that statistics say that your kid has much more chances of dying while climbing Mount Everest than if your whole family stays safely at home. Especially if you buy a fire alarm and a fire extinguisher. See, the problem is that a Mars colony is a solution looking for a problem. You're taking the outcome that you want for some romantic vision of a bright future, and they trying to justify it by finding a problem that it might solve. But when you look at the problem independently, either the problem is non-existent or it can be solved by much more trivial means without your complicated solution. You're free to go and climb the Himalaya for the big adrenaline rush, but saying that you're doing it so that you will be a backup to your family's gene pool if the family house burns down, is rubbish. The idea of a Mars colony as a backup for humanity is rubbish. If all life on Earth is destroyed, there's no bringing Humanity back, and there won't be anyone left to be sad that we're gone, so it ultimately won't matter to anyone.

In what way is a Mars colony a backup of anything ? You don't backup your household by sending one of your kids to climb Mount Everest. If your house burns down and you all die, then the surviving kid won't bring you, your family, or the house back. On the other hand, the risk of your kid dying in the Himalayas is much higher than your house burning down in the first place.

Ok! Got it But in a hypothetical CRS-3 (2024-2028), that would still look something like a joint SNC/ESA proposal including a barter element, which would be competing against Orbital Cygnus, SpaceX and ULA... I don't think it's likely to be acceptable in NASA's procurement process and would be considered unfair by the other proponents. ISS partnership agreements between national government agencies and NASA's procurement for commercial services happen on very different and independent levels.

I didn't say it didn't have 4 legs, I said the legs had a pantograph structure, which looks stronger and more capable of handling a vertical load.

I was talking about the second landing attempt (CRS-6), which was a bit of a hard landing, where the rocket also tipped over. The hard landing was the reason of the failure, but a sturdier design for the landing legs might have saved the rocket.

It's in the middle of Kazakhstan, not exactly a place with major touristic appeal.

Not crazy, but not possible. NASA's contract with SNC covers the service of getting X amount cargo to the ISS for X dollars. Since SNC doesn't have its own launcher, SNC has to purchase a launch from a launch provider to fulfill its contract. The cost of that is incurred by SNC, not NASA, so there is no place for a barter agreement between NASA and ESA. It seems like ESA is running out of barter chips at this stage, unless NASA agrees to order a few more Orion SMs... Beyond that, there really isn't much use for ESA's ATV technology. I really wish ESA would come up with a program of its own, otherwise all that spacecraft technology is just going to waste.

I was talking about the Apollo LM, so Moon landing only. 3 RCS quads would have made manual control more complicated and lacked redundancy and efficiency. It would have been a bad idea.

They don't have a rocket to fly on. Energia is as long gone as Saturn V is. The tooling and parts supply chain is gone, so you'd need to redesign a whole new rocket. Since most of Buran's components are obsolete too, there really isn't much worth reinstating at all. Also "better" is subjective. The main purpose of the US STS was to bring back the crew and the very expensive main engines. Buran could fly unmanned, and the engines were expendable. As such, it didn't make much sense at all.

Wikipedia says that there have been studies done in 2007 and 2014 with more recent atmospheric models, which basically confirm the "winter" theory: https://en.wikipedia.org/wiki/Nuclear_winter#Recent_modeling

It looks like maybe the legs didn't have time to latch into place. The legs deploy really at the last second (if that!), so maybe deploying slightly earlier might fix the problem. This is the second time they have a landing gear failure. On the previous barge landing attempt, it looked like one of the legs failed because the rocket landed with some lateral motion. Something's wrong with the design.

Three legs is the minimum for stability. The Apollo LM designers considered both 3 and 4 leg configurations, but the 4 legged version offer more tolerance to landing on a slope. It also provided an easier arrangement regarding RCS thrusters. In a 3 legged arrangement with 4 RCS quads, one of the legs would have been too close to a thruster. I don't think they ever considered more legs because weight was the main concern. The same is true for rockets. I think four legs is the optimal arrangement, but I think that a pantograph system like the New Shepard vehicle or the LT-05 landing strut in KSP might offer better strength. I also think that VTVL first stages should be designed from scratch for landing. The Falcon 9 booster is a conventional booster with landing equipment bolted on as an afterthought. In the future, VTVL booster designs should probably be shorter and wider with an integrated landing gear, like the old SASSTO or ROMBUS designs.

The extent of the deal with ESA is that ESA is giving SNC one IDS docking adapter for it. These are expendable BTW. Any more will have to be purchased by SNC. Cargo DC on Ariane might happen if SNC purchases flights, but ESA will never buy anything from SNC because it's against their policy to spend money in non-member countries. Manned DC on Ariane will never happen, because Kourou is simply not equipped for manned spaceflight (they can launch Soyuz rockets from Kourou, but they can't process Soyuz or Progress spacecraft). Also because Ariane 5 is scheduled to be replaced by Ariane 6 so it makes no sense to man-rate it at this stage.

Apollo had an Attitude Controller and a Translation Controller.

Thanks for the news. We discussed these pictures several months ago: http://forum.kerbalspaceprogram.com/index.php?/topic/112148-rare-photos-of-survived-burans/

I think they need to redesign that leg system.

If they have a successful landing in these conditions, they can land any where!

It's not NASA's to sell. The ISS is a joint international project where components are owned by different countries with different laws regarding transfer of government-owned assets to the private sector. The Colombus module alone belongs to ESA, which would require all ESA member countries to agree, which would cause endless debates in each country. The paperwork to transfer the ISS to a private company would be impossible.

A Lagrange point is better for a telescope: no atmosphere, 360° field of view, and permanent communication with the ground with (relatively) low latency. If it had to be supported on ground, the far side of the Moon would be much easier than Mars.

That is not the reason. We deorbit dead hardware so that it doesn't become a hazard for future spaceflight. The ISS has a shelf life which is determined by: solar panels, structural fatigue, seals, filters, fluids, insulation, paint, etc... and also obsolescence. It needs to be actively controlled, which costs money. If you turn off the environmental control, bacteria, fungus, and mold will take over, rendering it uninhabitable. If you turn off MMOD avoidance, it will eventually get hit and break up. If you turn off attitutude control, it will start tumbling. It might settle down into a gravity gradient, but drag and gravity will pull and push it around, causing stress on the structure. If you power it down, it will be only a matter of time before it vents its atmosphere, leaks, and breaks up up. Without maintenance, paint and insulation will flake off a create a cloud of debris around it. Basically, once it's turned off, there will be no fixing it or bringing it back to life. It's dead.

I don't think perchlorate salts will make a very good wine.

You're sounding like a fanboy. Musk says a lot of things. He does some of what he says (generally much later than announced) and there is also a whole lot of stuff that he gives up and forgets: reusable upper stages, telecom constellation, hyperloop, etc... Also Tesla loses $200 million every year and SolarCity isn't too healthy either. Elon Musk isn't God. He's a human being like everybody else, and he screws up just as often as we all do.

Because the author wanted an epic story where humanity pulls together to build big space ships. So he came up for a reason for humanity to pull together and build big space ships.