Nibb31

Musk "only" has a personal fortune of $14 billion. To put it into perspective, $14 billion is peanuts when it comes to aerospace projects. It's pretty much what it cost Airbus to develop the A350, which is a rather conventional aircraft based on an existing design. But that money is tied up in his companies. He can't spend any of his fortune, because he would have to sell his shares, which would crash the companies and he would lose billions. For example, SpaceX is valued at $2.5 billion. If he wanted to sell $1 billion in shares, the value of the company would crash and he'd be in deep trouble. This is why, like most billionnaires, Musk lives on credit. As for other investors, they put money into the business because they expect a return on investment. And so do the banks who lend him money. Without the MCT, the BFR suffers from the same problem as SLS. There are no large payloads to launch. You need to be financially viable, otherwise you're going nowhere. Even though he's a billionnaire, Musk can't just throw his money away. SpaceX is a business and has to generate revenue in order to survive. He needs to at least break even, which requires some sort of business plan.

Nope, the CRV was X-38 (or rather X-38 was to become the CRV). The CRV was only an emergency lifeboat that would be taken to the station in the Shuttle's payload bay and would stay attached to the station until needed. It wasn't to be launched manned. The X-38 flew several glide tests before being cancelled. HL20 was an early 90's paper study for a crew transfer vehicle that predated CRV and would have launched on top of a rocket with a crew like DC. No hardware was built.

The DOD has zero interest in cargo resupply vehicles.

Both DreamChaser and the CRV were based on the HL20, which was based on the Russian BOR spaceplane.

Electric propulsion ?

Wow, so DreamChaser is finally going to have its chance to fly. I'm not a fan of putting wings and landing gear on a capsule, but that's good news for SNC.

Why colonization again ? Can't we just settle for something that could actually happen in our lifetime, like a small outpost or even just a manned landing? It's way too early to think about colonization. We hardly know anything about these places. Lets land a rover on Titan or drop a drone-blimp on Venus and see what those places are like before we even start hypothesizing about science fiction silliness.

I'd like to see a bright future as much as anyone else here, but I'm realistic. My opinions are fueled by my observations and my experience of how the world works. Being realistic only makes the small achievements more awesome. I was blown away by New Horizon's flyby or Philae landing on a comet. I'm blown away by the ISS. I'd be blown away by a new Moon landing, even if it is just a rehash of Apollo. I've learnt not that we should be modest. Space is hard, and progress is made by accomplishing smaller goals that are actually achievable rather than dreaming about goals that are unrealistic.

A 6 month long flight on an A380 with supplies for the journey would cost way more than $500000.

Read it again, it was perfectly correct English.

Can the Falcon upper stage loiter for 3 days ?

NASA is a government organization. Its return on investment is dictated by political goals: prestige, diplomatic bargaining chips, and subsidizing the districts of prominent congress members. It's a research and soft-power organization. Colonization is not part of its mandate. Where is the political and social push to spend government money on colonizing Mars? Where are the ground-roots social movements who want taxpayer money to fund off-world settlements? Where are the politicians who have added it as part of their platform ? What benefit would any government expect from building a self-sufficient colony? Protecting the planet includes surveying and alleviating cosmic threats, which is still much cheaper than building colonies on other planets. Besides, there aren't any credible cosmic threats that would leave less survivors on Earth than a colony on Mars. Even if you wipe out 99.9% of the World's population, there will still be more survivors than a Mars colony could ever support. If we have the technology to build self-sufficient habitats on Mars, then we can also build self-sufficient habitats on a scorched Earth. Having a colony on Mars has no effect on our chances of survival as a species. There is no backup. If we lose Earth, we lose everything, and there won't be anybody left to be sad about it, so it won't really matter anyway.

Survival of the species has nothing to do with it. If that's what you're worried about, then the best way to protect our species is to protect our planet. You can't make a "backup of humanity" by colonizing Mars any more than you can duplicate your computer by saving a few files to an old floppy disk. What has NASA got to do with it?

Again, launches and/or spacecraft to Mars is not a proper business plan. It's a bridge to nowhere. It would be like setting up daily 747 flights to South Georgia Island and expecting thousands of people to want to emigrate there. The only thing that would change my mind is if someone could come up with an actual business plan that justifies the cost of sending populations to Mars to stay. The barriers are not technological. When the need arises to send people to Mars, I have no doubt that we will figure out how to do it. In fact, that's the easy part. The real problems are social, economical, and political. There currently is no reason to colonize Mars. Proponents of Mars colonization are grasping at straws trying find justification for their science-fiction pipe dreams.

Mars is not America. The colonists that went to America did so escape persecution or poverty. They left because they were miserable and expected a better life for themselves and their families. They also expected to get rich(er) by growing/hunting/mining goods that would have a trade value, including with the home country. None of that applies to Mars. You won't find a better life. It will be dull, dangerous, and uncomfortable, unsuitable for raising kids, and there is nothing to trade. If you have $500000, then you are likely not part of the population that is oppressed, persecuted, and poor. With that amount of start-up money, you could emigrate to a variety of nicer places than Mars and provide your children a decent education in a fairly comfortable environment. So, Musk's business case for a Mars colony doesn't work. And that ticket price is unrealistically optimistic. It's very unlikely that he can bring the cost down to that level, even with reusable rockets. Mostly wishful thinking and kiddy-talk. TL;DR

Not gonna happen. There are simply no reasons for society to spend billions on a Mars colony. The MCT is a bridge to nowhere. I think the business case won't close and Elon will be sad.

They'd have to: Agree that there is a problem Agree to participate in a conference Agree to do something about the problem Agree on what to do Agree on who does what Agree on what sacrifices have to be made That's a lot of things to disagree about. Even if you get to #3 (which is pretty much where we are on the subject of Global Warming after 20 years of debate), #4 and #5 are far from. Country A might think that the best course of action is brace for the impact and ride it out (dig bunkers. Country B might want to nuke it, Country C might prefer to ablate it with lasers... and there might not be enough money to try all 3 of those solutions, so maybe they'd need to divert resources from other parts of the economy and you'd also have to get people to agree on what sacrifices need to be made in order to reach those goals.

And a one-off vehicle without a market isn't going to be cheap and economic. Skylon is only viable if a huge market for daily flights of small payloads to LEO suddenly appears out of nowhere.

Events like Tunguska and Chelyabinsk are rare, and not really worth spending huge amounts of money on. The chances of them doing any significant damage (other than breaking some windows) are low. It's not worth spending billions to divert an asteroid that would only break a few windows.

The Rafale and Eurofighter also have 2 engines and are much more modern and probably cheaper than old F-15s. The choice of the aircraft depends on the role. Although both are multirole aircraft, the Eurofighter is slightly biased towards the interceptor role, whereas the Rafale is a better all-rounder.

Did you even read the thread before replying? The UN has nothing to do with space exploration. Even if a Mars landing was collaborative effort, it wouldn't have anything to do with UN organization.

Colonization is a silly idea, and way too premature. There is absolutely no social, political, or economical push for colonizing other planets, and no rational reason to do so. Therefore, any discussion about which planet is best to colonize is going to end up being based on conjecture, or worse, on flawed analogies about historical colonies. A more realistic goal would be to build a small research outpost or just manned exploration.

I think they are still reviewing options. The Rafale has been mentioned, but there are probably others.

Then add a heat shield, avionics, landing gear, power, RCS, and you'll have pretty much zero payload fraction, if any. Something like DC-X makes sense as a first stage. Its profile would be similar to the F9 first stage, but it would be optimised for the reentry and landing instead of bolting stuff onto a conventional stage like SpaceX does.

It's supposed to serve as a base camp for BEO exploration as well as something that you can tug along with you for long duration flights or become the main hab module of a larger exploration vehicle.