[separate launch "taxi"]That means you have two spacecraft to design from the start rather than one, but that's certainly an option.
First, it won't be just a few missions. Probably all the missions for the first couple decades. There will be many exploration missions with just a small crew before they can possibly think about actual colonization with large numbers of colonists. You have to explore various potential location looking for a promising site with favorable conditions for a colony. Then you have to test out the new systems which the colony will use, and test out resource collection, etc. Not to mention I think it highly likely NASA would jump in bed with them as soon as it were to look likley they could land people on Mars. They'll provide fund which will be beneficial for SpaceX, but they'll have their own agenda of places they want to go too. And you can only fly out every 2 years. So, after maybe 20 years of Mars mission, you are ready to put 100 colonists on an MCT, what do you do then?That's the question.
Why wouldn't a Mars escape trajectory arc over some? Do you wait until Mars rotates exactly towards Earth and then launch? I'm being a little facetious, but you get the idea, you need to turn anyway, so why not reduce gravity losses while you are doing it.
Hans Koenigsmann .... "but at least 100 times is our goal."
http://www.iflscience.com/space/huge-spacex-announcement-coming-soon-could-be-mars-missionOk Chris, you knew we were going to get ahold of this eventually. First question: Bigger than a Breadbox?
Quote from: guckyfan on 07/25/2015 05:43 amHans Koenigsmann .... "but at least 100 times is our goal."Should have asked earlier - assume it's BFR here due to thread. Is that right? (MCT can only launch every 18 months, so 100 uses is over 50 years)
Quote from: GregA on 10/08/2015 03:45 amQuote from: guckyfan on 07/25/2015 05:43 amHans Koenigsmann .... "but at least 100 times is our goal."Should have asked earlier - assume it's BFR here due to thread. Is that right? (MCT can only launch every 18 months, so 100 uses is over 50 years)One MCT launch to Mars requires a minimum of 3-4 launches. Each synod needs at least 2 MCT to maintain a station, more to expand it, say at least 3. That's 9-12 launches every synod of 26 months. That's a bare minimum. I am quite sure there will be more.
Not that it matters I guess, but ... my question doesn't matter. It MUST be the BFR.(Your answer generalises it to the Mars Colonial Transport system. Which means BFR and tankers etc)
If the goal is for the MCT component that goes to Mars to be reused 100 times, and that component launches once every synod, but Koenigsmann doesn't think it'll last 30 years, then obviously he's talking about something else. If 2 or 10 MCTs launch that's not the same as a single MCT being reused 2 or 10 times.... but it would reuse the BFR.
(I'll have a listen to the speech and see if there was something else)
My take on the statement was that he meant it will not fly daily for 30 years which would be over 10,000 uses.
It is in german and there was not much else in it for us space fans. It was an interview in a general news magazine.
I think Mr Musk was quite clear that he would do all possible for the MCT to return to Earth during the same synod. This would enable the same MCT to be serviced and reused during the next synod. Possible or not that is the goal.
You are still not getting what I'm trying to say.
It has to be a separate spacecraft, or it can't operate as a escape vehicle. Such a double-vehicle would become hideously complex.
Quote from: Lobo on 10/08/2015 12:20 am[separate launch "taxi"]That means you have two spacecraft to design from the start rather than one, but that's certainly an option.But you propose two spacecraft in one. The LAS you propose is a separate spacecraft, according to you capable of full EDL. But it must also be integrated back into the MCT in a way that doesn't just allow it to break away as a LAS, doesn't just require it to be integrated tightly enough to handle re-entry while acting as the nose of the MCT (while still being able to break-away instantly), but its engines must also be able to serve as the landing engines for the whole MCT, both on Mars and on Earth.(Plus you want another non-LAS "explorer" MCT for smaller crews. Plus yet another MCT design for cargo. So four spacecraft.)I can't fathom how you think that is going to be somehow easier to nest two spacecraft inside each other like matryoshka dolls than to build them independently.To use an analogy, do you think is would be cheaper/easier to design a car whose drivers-side wheels, seat and side panels split off to become a motorbike, or to just design a normal car and a separate normal motorbike?
You are assuming the major risk is in the cruise phase. I assume it is during launch, TMI and landing