Relatively ancient and inactive
1. Actually you were quite ignoring your common knowledge of the elements. This is what we learn in our school- US included. Lets put the fact together.
Heat resistance is due to the material's lack of free electrons, which are responsible for transmitting heat and electricity. It is they that define a 'metal'- which gives a metal the tint, strength (free electrons are attracted to protons of other particles, which bind and give them more durability and strength.), and most its characteristics.
But to have a material which has both heat resistance and strength would require them to 'not have' alot of free electrons- but has to compensate with more mass to give it more strength (more molecular mass means more attraction for each molecule, giving the material more strength. refer to gravitation.) But then to put a greater mass up in space and to attempt a reentry? I am sorry but that just doesn't work like that. (refer to gravitation again) More force would be required to slow down the craft. Now these complications makes breakthroughs easy.
Brilliant. Then again, you already answered this...
If you've learned chemistry, we're nearly hitting the limit on how many possible elements there can be- and alot of materials we havent found out- seems like they usually have a half-life of less then a second. Which means we turn to composite alloys, which provide us with more options (as alloys provide more diverse characteristics then single elements). Plus, if we're talking about going to other planets- then we would already have a technology viable for a controlled reentry.
Additionally, there are other work arounds, such as having a ship which changes from meteriorite-resistant to heat-resistant by putting one plate of one above one of another as the need arises. When you're going back into the atmosphere, for instance. Will it make it heavier? Yes. However, the heat-resistant plates don't weigh that much.
Um, all of this is well and good, but have you guys considered communication on such a massive scale? How are you supposed to talk to those far off colonies? It'll take enormous amounts of time to send and recieve messages, not to mention enormous amounts of money, and we don't even have a reliable system for sending messages like that. What will we do, build a massive line of sattelites to each and every planet so they can speak to the people that sent them to colonize the planets confidentially (It'd be pretty easy to just intercept messages moving across those huge distances)?
Sure. Build satellites, and
encode the messages.
Is it really profitable to send these ships back and forth? I mean, to get those resources means sending the ships, but those ships need to be massive, bigger than anything we have right now, to give us anything in the way of the resources we need, and they'd have to be coming at regular intervals during the year, not just once every 5 or so.
Yes. When it becomes an option, different companies will start innovating and coming up with nice new technologies for really big spaceships. It should happen eventually. It'll be hard, but if its profitable, it's possible.
Edit: Once they become self sustaining, why would they give us their hard earned resources?
Because they're employees of company X, because they're self-sustaining in food and all but we provide luxuries like computers, and because we'll kick their ass if they don't.
None.