SpaceX Tuesday...
Discussion
The Dragon 2 can carry up to 7 people - though for a longer mission like one around the moon I suspect it won't be filled to capacity so as to allow more living space. So far all they have announced is that there will be two paying passengers aboard but no mention of the total crew numbers - I expect the total could be as high as five
I presume it boils down to the lifting capability of the Falcon 9 Heavy and how much weight it can push out towards the moon.
A Saturn V could place 30 tons in lunar orbit. That 30 tons consisted of Command/Service Module and Lunar Module together with the fuel needed to place the assembly into lunar orbit plus the fuel to get the Lunar Module down onto and back up from the lunar surface together with the fuel to accelerate the Command Service Module out of lunar orbit.
This Dragon flight has no Lunar Module type vehicle attached nor will it be entering lunar orbit, just swinging around the moon and back to earth - what is called a free-return trajectory. That eliminates quite a bit of weight. So, how much weight is a fully manned Dragon capsule with provisions for a week long mission?
A Saturn V could place 30 tons in lunar orbit. That 30 tons consisted of Command/Service Module and Lunar Module together with the fuel needed to place the assembly into lunar orbit plus the fuel to get the Lunar Module down onto and back up from the lunar surface together with the fuel to accelerate the Command Service Module out of lunar orbit.
This Dragon flight has no Lunar Module type vehicle attached nor will it be entering lunar orbit, just swinging around the moon and back to earth - what is called a free-return trajectory. That eliminates quite a bit of weight. So, how much weight is a fully manned Dragon capsule with provisions for a week long mission?
It wouldn't have made much difference in that they would have used less fuel to power the whole thing in the first place. They operated Apollo missions to the margins needed and didn't have much spare capacity over and above what was absolutely necessary.
The Saturn V didn't quite accelerate the assembly to full earth escape velocity. It didn't need to. At the point the top stage of the Saturn V (the S1B) fired up to lessen the grip of the earth's gravitational pull, it increased the overall speed of the combined mass to around 25,000 mph - but not quite enough to fully escape earth's gravity.
What it did do was allow the Apollo Command-Service Module/Lunar Module combination to freewheel towards the moon, all the time gradually slowing down. By the time it had reached about 2/3 distance to the moon, the velocity had dropped to around 5,000 mph. If there was no moon, the speed would have fallen right down to zero, at which point the craft would start falling "downhill" back to earth, gradually accelerating all the time.
Of course, there was a moon and at 2/3 distance the moon's gravity started to pull on the craft and it began picking up speed again as it fell towards the moon.
Using this technique, they could use their fuel much more efficiently.
The lightest Apollo lunar mission would have been Apollo 8 which didn't carry a Lunar Module.
The Saturn V didn't quite accelerate the assembly to full earth escape velocity. It didn't need to. At the point the top stage of the Saturn V (the S1B) fired up to lessen the grip of the earth's gravitational pull, it increased the overall speed of the combined mass to around 25,000 mph - but not quite enough to fully escape earth's gravity.
What it did do was allow the Apollo Command-Service Module/Lunar Module combination to freewheel towards the moon, all the time gradually slowing down. By the time it had reached about 2/3 distance to the moon, the velocity had dropped to around 5,000 mph. If there was no moon, the speed would have fallen right down to zero, at which point the craft would start falling "downhill" back to earth, gradually accelerating all the time.
Of course, there was a moon and at 2/3 distance the moon's gravity started to pull on the craft and it began picking up speed again as it fell towards the moon.
Using this technique, they could use their fuel much more efficiently.
The lightest Apollo lunar mission would have been Apollo 8 which didn't carry a Lunar Module.
XM5ER said:
p1stonhead said:
This is going to be live in HD - probably the whole trip. Im so bloody excited to see it.
Hopefully they will do a fly by of one of the Lunar lander locations and shut all the Moon truthers up forever.Ample photographic recent images have been captured of the Apollo sites by the LRO mission but they still twitter on.
With people like that, there is no persuasion - so let them stew in their imbecilic notions.
SystemParanoia said:
Eric Mc said:
a week long mission?
Without all the extra equipment the Apollo's carried... could the mission time be shorter due to the craft being much faster ?Edited by MartG on Tuesday 28th February 12:31
MartG said:
SystemParanoia said:
Eric Mc said:
a week long mission?
Without all the extra equipment the Apollo's carried... could the mission time be shorter due to the craft being much faster ?Edited by MartG on Tuesday 28th February 12:31
durbster said:
Dr Jekyll said:
Zoobeef said:
The news this morning reported they had paid £250k each. Either thats supposed to be £250m or its heavily discounted as itll be experimental and used rockets etc.
That'll just be the deposit.
Eric Mc said:
No such luck.
Ample photographic recent images have been captured of the Apollo sites by the LRO mission but they still twitter on.
With people like that, there is no persuasion - so let them stew in their imbecilic notions.
True enough. The internet is both a blessing and a curse.Ample photographic recent images have been captured of the Apollo sites by the LRO mission but they still twitter on.
With people like that, there is no persuasion - so let them stew in their imbecilic notions.
Agree a free return trajectory makes sense on this mission.
For those that don't not know you basically aim ahead of the moons orbit, close enough so that you get pulled into its gravity well (technically we already are, but it has greater affect the closer you get) this will speed up the craft and you do a 'flyby' you don't actually orbit it all the way round, this increased momentum put you on escape velocity speeds and you come flying back to earth. There will likely be a few adjustment manoeuvres on the way there and back but these will be very minor and used with the same inert gas they use on the falcon stage recovery (those jets that look like a fire extinguisher going off)
If you were to plot the course of the craft it would actually look like a figure 8 with the Earth in the lower circle and moon in the upper circle. I.e. They will orbit Earth west to east, but orbit the moon east to west!
For those that don't not know you basically aim ahead of the moons orbit, close enough so that you get pulled into its gravity well (technically we already are, but it has greater affect the closer you get) this will speed up the craft and you do a 'flyby' you don't actually orbit it all the way round, this increased momentum put you on escape velocity speeds and you come flying back to earth. There will likely be a few adjustment manoeuvres on the way there and back but these will be very minor and used with the same inert gas they use on the falcon stage recovery (those jets that look like a fire extinguisher going off)
If you were to plot the course of the craft it would actually look like a figure 8 with the Earth in the lower circle and moon in the upper circle. I.e. They will orbit Earth west to east, but orbit the moon east to west!
Eric Mc said:
It wouldn't have made much difference in that they would have used less fuel to power the whole thing in the first place. They operated Apollo missions to the margins needed and didn't have much spare capacity over and above what was absolutely necessary.
The Saturn V didn't quite accelerate the assembly to full earth escape velocity. It didn't need to. At the point the top stage of the Saturn V (the S1B) fired up to lessen the grip of the earth's gravitational pull, it increased the overall speed of the combined mass to around 25,000 mph - but not quite enough to fully escape earth's gravity.
What it did do was allow the Apollo Command-Service Module/Lunar Module combination to freewheel towards the moon, all the time gradually slowing down. By the time it had reached about 2/3 distance to the moon, the velocity had dropped to around 5,000 mph. If there was no moon, the speed would have fallen right down to zero, at which point the craft would start falling "downhill" back to earth, gradually accelerating all the time.
Of course, there was a moon and at 2/3 distance the moon's gravity started to pull on the craft and it began picking up speed again as it fell towards the moon.
Using this technique, they could use their fuel much more efficiently.
The lightest Apollo lunar mission would have been Apollo 8 which didn't carry a Lunar Module.
Looking at the Apollo 11 flight plan (apart from the Saturn V rocket) the rest of them were left with about 60% of the fuel to spare if all went to plan. not a bad redundancy.The Saturn V didn't quite accelerate the assembly to full earth escape velocity. It didn't need to. At the point the top stage of the Saturn V (the S1B) fired up to lessen the grip of the earth's gravitational pull, it increased the overall speed of the combined mass to around 25,000 mph - but not quite enough to fully escape earth's gravity.
What it did do was allow the Apollo Command-Service Module/Lunar Module combination to freewheel towards the moon, all the time gradually slowing down. By the time it had reached about 2/3 distance to the moon, the velocity had dropped to around 5,000 mph. If there was no moon, the speed would have fallen right down to zero, at which point the craft would start falling "downhill" back to earth, gradually accelerating all the time.
Of course, there was a moon and at 2/3 distance the moon's gravity started to pull on the craft and it began picking up speed again as it fell towards the moon.
Using this technique, they could use their fuel much more efficiently.
The lightest Apollo lunar mission would have been Apollo 8 which didn't carry a Lunar Module.
OK, a couple of things I'm thinking about with this.
If they've paid $250k, then in my mind, that is peanuts and certainly not "a significant deposit" as stated in the press release, when you consider how much this is likely to cost. I can't see it being less than $100m per person. If it is just $250k, I don't think it's likely to happen, hence such a small deposit, who ever they are can cearly afford to lose that money. Sadly. I would, like everyone else, love to see this happen.
Secondly, has SpaceX practically rendered Virgin Galactic redundant? Surely Virgin, has the money to do what SpaceX are doing, yet they're mucking about focussing on getting a few people to experience micro-G for a few minutes, while SpaceX are talking about getting to Mars eventually and doing serious development on better and better systems to achieve that goal. I just don't think there can be that much future in Virgin Galactic at the moment.
However, other than the above, I think this is magnificent!!
If they've paid $250k, then in my mind, that is peanuts and certainly not "a significant deposit" as stated in the press release, when you consider how much this is likely to cost. I can't see it being less than $100m per person. If it is just $250k, I don't think it's likely to happen, hence such a small deposit, who ever they are can cearly afford to lose that money. Sadly.
I would, like everyone else, love to see this happen.Secondly, has SpaceX practically rendered Virgin Galactic redundant? Surely Virgin, has the money to do what SpaceX are doing, yet they're mucking about focussing on getting a few people to experience micro-G for a few minutes, while SpaceX are talking about getting to Mars eventually and doing serious development on better and better systems to achieve that goal. I just don't think there can be that much future in Virgin Galactic at the moment.
However, other than the above, I think this is magnificent!!
Virgin Galactic and even Blue Origin) are both in danger of appearing old hat with talk of sending paying passengers around the moon.
The big BUT is that nobody has done anything yet so we shall just have to wait and see which of these projects gets to do what they say it will do first.
The big BUT is that nobody has done anything yet so we shall just have to wait and see which of these projects gets to do what they say it will do first.
Eric Mc said:
It was the use of the fuel in the Saturn V I was specifically referring to. The rocket itself was loaded with the PRECISE amount of fuel; to get the SIVB and LM and CM on their way to the moon as described above. There were no meaningful reserves in the booster.
I think it has the loads etc in the flight plan. it is like you said then. I can have a look at exact figures when im next home. Unless you already know/not bothered etc.
Zoobeef said:
Eric Mc said:
It was the use of the fuel in the Saturn V I was specifically referring to. The rocket itself was loaded with the PRECISE amount of fuel; to get the SIVB and LM and CM on their way to the moon as described above. There were no meaningful reserves in the booster.
I think it has the loads etc in the flight plan. it is like you said then. I can have a look at exact figures when im next home. Unless you already know/not bothered etc.Gassing Station | Science! | Top of Page | What's New | My Stuff