Quote from: meekGee on 06/11/2012 11:01 pm but can only happen in 6 years, whereas a minimally-modified one can be launched in 2. No, that is my point, they can't do it in 4 years much less two.
but can only happen in 6 years, whereas a minimally-modified one can be launched in 2.
SpaceX listed on a stock market may find that a long term mission with little profit is unpopular with its shareholders. Fortunately there is an easy way for Elon Musk to solve this problem - set up MarsX. MarsX can contract SpaceX to build and launch the spacecraft.
Quote from: Mongo62 on 06/11/2012 09:22 pmwhether a Red Dragon style mission should use a near-stock Dragon or a Dragon-derived Mars lander probably comes down to cost vs benefit. So cost to them is more than just $. The incremental cost of another rocket or another capsule, especially when they are masters of their own schedule, is going to be a lot lower.
whether a Red Dragon style mission should use a near-stock Dragon or a Dragon-derived Mars lander probably comes down to cost vs benefit.
I've already said that I think an untouched Dragon is a poor choice. My (amateur) thoughts about what a Dragon derived design could be like would be:1. Keep the current Dragon heat shield and mold line2. Use the current thrusters and Super Dracos for an all propulsive landing3. Get rid of the pressure vessel and have a backshell which separates4. Jettison the heat shield before braking to reduce landing mass and allow the super Dracos to point straight down5. Replace the trunk with a cruise stage.This means essentially a new spacecraft, but it means the payload is exposed to the Martian environment on landing and can be offloaded if required.
If they have an assembly line pushing out 20-40 cores per year (the have stated that they want to achieve this in the next few years) then there my occasionally be a time when they have some extra hardware laying around without a customer.
I don't know. But just about every type of factory occasionally has surplus inventor to deal with. Cars, toys, furniture...It sounds like this is the production model for SpaceX, though I'm not saying I know for sure either way.
Quote from: go4mars on 06/12/2012 01:28 pmI don't know. But just about every type of factory occasionally has surplus inventor to deal with. Cars, toys, furniture...It sounds like this is the production model for SpaceX, though I'm not saying I know for sure either way.No, production is order based.
In modern facilities, correct. But the production capacity is there. So the incremental cost to make one more article for internal consumption is low, especially when flex-scheduled to a time when orders are low.
Which is applicable to any production facility, which is meaningless since it still doesn't mean it will happen. The cost will still be too high.
but useful only when the producer is also the consumer,
Quote from: meekGee on 06/12/2012 04:51 pm but useful only when the producer is also the consumer,They are no more the consumer than ULA is for Atlas or Delta
Quote from: go4mars on 06/12/2012 01:28 pmI don't know. But just about every type of factory occasionally has surplus inventor to deal with. Cars, toys, furniture...It sounds like this is the production model for SpaceX, though I'm not saying I know for sure either way.>Another thing to consider is that, if SpaceX becomes publicly owned, it will have a Board of Directors that has to approve funding for projects (in a broad sense). If there's no return on money spent flying to Mars, then why would they approve it?
SpaceX has enough on their plates right now with redesigning F9, meeting CRS obligations, and competing for CCDev on its "anything-but-even" playing field.
if SpaceX becomes publicly owned, it will have a Board of Directors that has to approve funding for projects (in a broad sense).
Quote from: go4mars on 06/12/2012 01:28 pmjust about every type of factory occasionally has surplus inventory to deal with... It sounds like this is the production model for SpaceX.Maybe for the "pieces-parts" makers if they have order cancellations, but not for a systems integrator.
just about every type of factory occasionally has surplus inventory to deal with... It sounds like this is the production model for SpaceX.
Very interesting this morning presentations by John Karcz from Nasa Ames (min 32:00) and M. Rover? from JPL (min 42:24) on Dragon missions to Mars.Looks I'm not the only one that thinks Dragon looks promising as a delivery platform to Mars, at least for medium sized scientific missions.I'd like to highlight a few points (words taken from the video between colons, the rest is mine):- About Falcon Heavy and Dragon mods needed to launch to Mars "there are some changes we should have to be made but ... they aren't too bad, they're pretty straightforward" (min 35:40).- As we know Dragon needs to prove a number of its [yet] theoretical capabilities, but my personal impression about the Nasa personnel doing the presentations is that they are non as skeptical as some over here ... - As currently planned Ice-Dragon would land a 1 mT payload at an altitude of -3 km (MOLA ref.), but "should be able to deliver quite more than that" (min 41:10). And it could also land that tonne as high as -1.3 km (min 49:15), and achieve a 10 km accuracy (using MSL guidance techniques).- Supersonic retro propulsion is now just TRL 2 and is the main worry for the mission planning (min 50:40).- Dragons heat-shield is expected to be able to endure a 6 km/s entry into the martian atmosphere.- Red Dragon's ballistic coefficient will be 450 kg/m2 (min 48:06) (add entry mass 7.2 km/s and diameter 3.7 m, and that gives an hypersonic Cd of ~1.5).- The SuperDraco engines will start only 800 m from the surface, while the capsule is doing 2.24 km/s. Deceleration will reach 7 g.- For payload deployment the three apertures of a Dragon capsule (instrument bay included) should suffice for many things but if that's not enough, and given that the shell of the capsule was designed for containing the pressure of a full atmosphere and for these mission that's not a worry, it should be possible to "put significant holes in that capsule with fairings over them ..." (min 01:25:40).- Dragon's propellant capacity "is modular and they have the capacity to put quite a bit of propellant in the vehicle ...". By now they are considering 1.9 mT and that's enough for the missions considered (01:28:10).- The superDracos "have a very, very wide [throttling] range" (01:29:00) (according to the previous presentation at least 5%-100%).And there wer more interesting things, but that's enough for one post.