Lunar Big Falcon Rocket


#21

Why artists and art? I thought at first. Well it’s probably the best and wise way to bring more excitement. To change people’s way of thinking. To show for peoples where we are, who we are and where we should go. And why.
Maybe It’s the best Way.
p.s. lets vote for the Tim Dodd :slight_smile:


#22

Crew of Apollo 13 (which because of the accident only flew around the Moon) became humans who moved the longest distance from Earth. Elon said at the conference that they were going to fly very close to the Moon, so it’s likely that the lunar orbit is highly elliptical and the BFR will move away from the Earth even further than Apollo 13. And at the beginning and middle of the conference Yusaku Maezawa almost repeated Kennedy’s words saying “I choose to go to the Moon”.

So here my guess about the first words of Maezawa after landing: “If i flew further than others, it is by standing upon the soudlers of giants” (this is a slightly modified words of Isaac Newton). And we even know the name of one of these giants, yes guys?)


#23

Something curious I noticed, that I have not seen mention anywhere. There seems to me to be is a slight discrepancy in the number of people for the mission. MZ says that he would be inviting 6-8 artists on the mission. That would make a total of 9 maximum. Yet, Musk keeps mentioning a dozen ie 12 which would mean that 3 people are unaccounted for. So who are these 3 people? would like to hear thoughts on this. Some possibilities I thought of. 1) They are just not used by MZ, he just likes the numbers 6-8 (he is an artist after all ,and they are crazy, and he is rich) 2) the 3 are Crew 3) The 3-5 are special guests of MZ like family or close friends. I am just reading too much into it ?


#24

I’m going to assume they are crew. It’s almost certain that these untrained and not necessarily especially fit people aren’t going to go up alone. They’ll probably have at the very least 1 person to run the ship and make sure people get strapped in when needed. But I’d think a medic and another technical person on board in case something breaks would be desired…


#25

FITorion is right. You need professionals on board.


#26

I think Elon has Tweeted that there would be a least a couple of trained astronauts onboard.


#27


#28

I wonder what the passenger capacity is for this iteration of the BFS?


#29

You know what’s been missing in every iteration of the BFS … heat radiators.


#30

Well it has an extra 100+ m3 of space in the cargo section. I would think that they will not exceed 100 and maybe limit it to 50 or less but give them a lot more facilities and there maybe space for a small centrifuge, like one that was being developed for use in LEO. I wonder if some of these changes have anything to do with the “secret” Mars meeting SpaceX hosted?


#31

I think there has been a substantial space increase in the cargo volume. As far as i know its been increased from 800 cubic meters to 1100 cubic meters. So much more space for passengers. … I think this is mainly designed for the city to city transport function … but it would also make it generally more comfortable for passengers to Mars … of course.


#32

Well having had a few days for my excitement to calm, I had another look at the presentation, especially the “everyday astronaut” question :smile:.

So one of the statements from Elon was that if they switch the sealevel engines to Vacuum you would get a “significant” increase in cargo capacity.

So I did some maths regarding the switching out of the Sea Level to the Vacuum optimized engines and I was very surprised !!

if you switch out 4 then the cargo weight capacity goes up from 100 tons to 165 tons !!!
if you switch out all 7 then the cargo weight goes to 250 ton !!! Of course I could be mistaken in my Maths … but gosh it makes much more sense now why they increased the cargo volume capacity from 800 cubic meters to 1100 cubic meters !! The carrying capacity increase sure is “significant” !!


#33

Is Elon, Ray in the Field of Dreams … YouTube


#34

The BFS iteration 1 refueled each other side-by-side while in orbit. Iteration 2 refueled each other rear-to-rear. I wonder how Iteration 3 would refuel each other with the swept-back control surfaces on the aft of the vehicles?


#35

Probably still read to rear, but with a staggered conformation:


#36

Some thoughts about the payload development of the Big Falcon Rocket (BFR):

So the payload of the BFR fell considerably from 300 metric tons (2016) to 150 metric tons (2017) to now ‘only’ 100 metric tons (2018). Does that mean the BFR will be less capable than the Saturn V which could lift 135 metric tons to Low Earth Orbit (LEO)?

The short answer would be a resounding ‘NO!’ and to illustrate why, you can simply look at the thrust which is 60.8 Meganewtons in the current BFR as compared to 35 Meganewtons for the Saturn V.

As for the seemingly smaller payload, that needs some explaining. Payload capacity is always a question of ‘where to’ as a frame of reference, but in reusable rockets it’s also a question of the mode (payload in expendable mode as compared to reusable mode):

The BFR is DESIGNED to launch 100 tons to Low Earth Orbit in one go in fully reusable mode which is less than the 135 tons the Saturn V could lift to LEO, but if you wanted to use the BFR Platform (that is the first stage called Big Falcon Booster) to lift as much mass as possible you could probably easily lift 150 tons or more to LEO in a expendable mode - as demonstrated by the bigger thrust. Its just not designed with that task in mind.

Also, since the BFR will be refuelled in orbit by several other BFR launches, a fully fueled BFR will then be able to deliver 100 tons of payload all the way to the Moon and even Mars. That actually blows the Saturn V right out off the water.

Consider this: Yeah, the Saturn V could lift a nominal 135 tons to Low Earth Orbit but off that, less than 50 tons went into a Trans Lunar Injection. And of those about 50 tons, only about 30 tons arrived at the Moon orbit; about 15 tons for the Service and Command Module that stayed in orbit and about 15 tons for the Lunar Excursion Module that actually landed on the Moon. Of those 15 tons, most was the vehicle and its fuel. Net payload is actually more like 600 kilogramms: 2 astronauts (say 150 kilos), the ‘Apollo Lunar Surface Experiments Package’ (about 150 kilos), a Lunar Rover in Apollo 17 (a bit over 200 kilos), then an estimated 50 kilos of food, water and oxygen and another 50 kilos for the spacesuits and other personal stuff.

So actually the term ‘payload’ can mean a whole lot of things depending of what you mean by it. If you define ‘payload’ in the narrowest possible term, Saturn V could deliver a payload of 600 kilos (including the 2 astronauts) to the Moon’s surface and it could bring back 350 kilos from the Moon to Earth (they left the experiments and rover up on the Moon but could take in excess of 100 kilos of rock and regolith samples back).

The BFR in contrast could take 100 tons, including 100 people DOWN AND UP to the surface of the Moon or even Mars - if you take into account running the system in a reusable mode, use orbital refulling at Earth and local fuel production and/or storage at the destination.

So yeah, if you peel back the onion that is ‘payload’ capacity, keeping in mind that comparing the fully expendable Saturn V with the fully reusable BFR is really comparing apples with oranges, then you see that on a whole, as an entire system consisting of the Big Falcon Booster (1st stage), the Big Falcon Spaceship (manned 2nd stage) and the Big Falcon Tanker (unmanned 2nd stage), the BFR is WAAAY more capable than Saturn V / Apollo.