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11 minutes ago, kerbiloid said:

Usually  empty cans are to be dropped in space rather than kept inside the capsule, increasing the pressurized and heat-protected volume.
Saving, say, 100 kg of a tank, they add, say, 200 kg of the ship hull.
I hoped that I was wrong and they just drop the tanks with... trunk.

I believe the fuel tanks are not inside the pressure shell of the capsule. They are inside the aerodynamic shielding you see but not pressurised. You are also savings engines, which are rather expensive.

12 minutes ago, kerbiloid said:

5x5 km for nowadays parachute landing from orbit.

Which is not precise enough to avoid being forced to land in a large, remote area with no one nearby you can accidentally land on. Propulsive landing allows landing much closer to processing facilities so that money isn't wasted on recovery. Small savings but makes sense in the long run. 

15 minutes ago, kerbiloid said:

Just put a new parachute. It's exactly not more expensive than a single use trunk and second stage.

I don't know if you've heard, but the second stage tends to be discarded in ALL rockets. Plus, most manned vehicles tend to discard a service module which has expensive engines, propellant tanks, and life support equipment inside, whereas Dragon just discards an aluminium shell with some solar cell sheets on it...

17 minutes ago, kerbiloid said:

If CST-100 counted with cargo and service module (i.e. launch mass), why Dragon is empty and without trunk?

If you again bothered to actually pay attention to what I wrote, you would see that Dragon dry mass is listed (i.e. empty of fuel) and I then ADDED the mass of propellant - I do not know if the mass of the trunk is included or not but it will not make a great deal of difference considering it is, as already said what seems like a thousand times, an empty shell. 

5 minutes ago, Emperor of the Titan Squid said:

this has nothing to do with the mars mission really. i personally believe that the first mars landing will be done by an IMRS like mission, with international colaboration, and commercial construction of parts.

You're right, this has got rather off topic. I'm not sure I can see an international collaboration like that actually happening given the sheer scale of it (I can't really see any political motivation for that at the moment), but it is probably our best chance of getting people to Mars within the next half century. SpaceX's vision seems somewhat too optimistic - I can't imagine a private company like them amassing the funds to pull it off, but who knows, it might happen (if several years/decades behind schedule)

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8 hours ago, Nibb31 said:

You don't like the decisions that are made at the UN? Then vote to change the folks who represent your country at the UN.

When did you, or any of us for that matter, vote for a representative for the UN? Can you even name our representative to the UN? Such representatives are appointed, not elected. We even had Shirley Temple once lol. I have all of this matter from high authority, an authority higher even than the UN itself ... it's call The International Court Of Justice, at the Hague ... Tommy Buergenthal, and old family friend.

 

8 hours ago, Nibb31 said:

SpaceX's finances are private and pretty confidential.

SpaceX has announced its IPO, so that data is forthcoming. Soon enough.

3 hours ago, Bill Phil said:

Musk isn't a miracle worker. All he's doing is using his fame to show off cool ideas that other people had. Still good that they're gettng attention, but Musk is just a famous rich guy that shows the ideas off.

My assessment of him as well - 'a brilliant blow-hard'.

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2 hours ago, Emperor of the Titan Squid said:

i feel that the UAE should start a space program

It does. It even has a budding Mars program.

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5 hours ago, benjee10 said:

I believe the fuel tanks are not inside the pressure shell of the capsule. They are inside the aerodynamic shielding you see but not pressurised. 

Pressurized hull is several millimeters thick. Heat protection usually - several centimeters. Its definitely inside the heat protection.

5 hours ago, benjee10 said:

You are also savings engines, which are rather expensive.

Presuming that lifespan is 10 flights (as in all other projects I've read about, except spaceplanes - which are usually 100), they spend 8 engines per 10 flights (0.8 per flight), instead of 1 engine per flight
And those engines and tanks make to spend more powerful rocket engines. So, unlikely this is more expensive.

5 hours ago, benjee10 said:

Which is not precise enough to avoid being forced to land in a large, remote area with no one nearby you can accidentally land on. Propulsive landing allows landing much closer to processing facilities so that money isn't wasted on recovery. Small savings but makes sense in the long run. 

When deorbiting, both Dragon and non-Dragon should have more or less the same precision.

After the aerobrake - your can easily calculate that the side maneuver of the Dragon when it's already on 20 km height is limited by several kilometers. I.e. a parachute ship sits down somewhere in 5x5 km area, while Dragon can select place inside it.

5 hours ago, benjee10 said:

I don't know if you've heard, but the second stage tends to be discarded in ALL rockets.

Btw, original plans were included reusable 2nd, but that doesn't matter, It anyway spends 20$ of total cost per flight, which anyway means that every 5 flights resusable Falcon shoul spend its total cost.

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9 hours ago, kerbiloid said:

Usually  empty cans are to be dropped in space rather than kept inside the capsule, increasing the pressurized and heat-protected volume.

The Dragon's tanks and engines are inside the Dragon capsule, not the trunk.

If the tanks were jettisoned with the trunk, where would the propellant for landing come from?

9 hours ago, kerbiloid said:

This looks like buy a diesel truck instead of a light pickup to return empty plastic bottles.

It only empties the bottles in the last seconds of flight.

9 hours ago, kerbiloid said:

Just put a new parachute. It's exactly not more expensive than a single use trunk and second stage.

What has the parachute got to do with the trunk and second stage?

The trunk is needed for abort, power supply, cooling, and to transport unpressurized cargo. Dragon can't fly in space without the trunk.

The second stage is needed to reach orbit.

The parachutes are needed for abort mode landing and for redundancy if the SDs fail.

9 hours ago, kerbiloid said:

5x5 km for nowadays parachute landing from orbit.
In any case they use toxic hyperholic fuel and probably need to wait for the rescue team.

Probably. But that's true for every spacecraft returning from orbit. 

9 hours ago, kerbiloid said:

The less acceleration - the more fuel to be spent (and launched). Two seconds of discomfort vs several tonnes of payload.
Btw, 1500 of toxic and flammable hyperholic propellant just near the cabin look not like an additional comfort factor.

The tanks are outside of the pressure vessel.

9 hours ago, kerbiloid said:

If CST-100 counted with cargo and service module (i.e. launch mass), why Dragon is empty and without trunk?

Chutes weight 100-200 kg (as you can read above), and yet nobody have told they cost too much that 8 engines will be cheaper.

Chutes have to be repacked and replaced each time, with new pyrotechnics, covers, etc... They are not cheap, and not fast turnaround.

The engines are reused.

 

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6 hours ago, LordFerret said:

When did you, or any of us for that matter, vote for a representative for the UN? Can you even name our representative to the UN? Such representatives are appointed, not elected. We even had Shirley Temple once lol. I have all of this matter from high authority, an authority higher even than the UN itself ... it's call The International Court Of Justice, at the Hague ... Tommy Buergenthal, and old family friend.

Your country's foreign policy (including appointment of ambassadors and the US stance at the UN and other international institutions) is decided by the folks that you elected. The delegation that represents your country at the UN answers 100% to your administration. Anything that the US delegation says or votes for at the UN comes directly from the President and the Foreign Secretary.

The same is true for NASA, the military, or pretty much any other government activity. You don't get to vote on anything they do,  you don't get to vote on the people who are appointed to run those government agencies, and you don't get to vote directly on laws and regulations, because that's how representative democracy works.

So if anything needs to be reformed, it's probably representative democracy itself, not just the UN.

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SpaceX has announced its IPO, so that data is forthcoming. Soon enough.

Has it? A while ago, Musk was claiming that he would only IPO SpaceX once his Mars ambitions are accomplished.

If he does IPO SpaceX, then he'll lose control over his dream. When an actual board of directors starts running the company, they will they will lose all interest in sending Musk to die on Mars.

 

Edited by Nibb31

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17 minutes ago, Nibb31 said:

If he does IPO SpaceX, then he'll lose control over his dream. When an actual board of directors starts running the company, they will they will lose all interest in sending Musk to die on Mars.

This is sounding more and more like a Heinlein story. I hope I'm still alive on the day he hires a couple space jockeys to take him there right before his death.

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7 hours ago, Nibb31 said:

Has it? A while ago, Musk was claiming that he would only IPO SpaceX once his Mars ambitions are accomplished.

Well he's got Google and Fidelity onboard already. Google I can understand, but Fidelity is the one that's got me scratching my head - and apparently I'm not alone.

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15 hours ago, LordFerret said:

SpaceX has announced its IPO, so that data is forthcoming. Soon enough.

Yes when they reach Mars. Which will be in 2025 according to Elon with people.  So the IPO is at least 9 years away so no it is not forthcoming.

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1 hour ago, LordFerret said:

Well he's got Google and Fidelity onboard already. Google I can understand, but Fidelity is the one that's got me scratching my head - and apparently I'm not alone.

Fidelity is an investment fund. Their job is to invest in stuff they believe will make money. Not sure what's head-scratching about that.

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17 hours ago, LordFerret said:

SpaceX has announced its IPO, so that data is forthcoming. Soon enough.

Wait, wut? Doesn't that pretty much doom his Mars plans, since if he actually ends up spending the cash needed to send people to Mars, investors would try to stop him in fear of SpaceX losing too much money on unprofitable endeavors? Wasn't that the point to not announcing an IPO in the first place?

20 hours ago, Emperor of the Titan Squid said:

i feel that the UAE should start a space program

https://en.wikipedia.org/wiki/United_Arab_Emirates_Space_Agency

They already have one, and a Mars mission to boot. I think starting with Mars is a little ambitious, but let's see how they go.

10 hours ago, 5thHorseman said:

This is sounding more and more like a Heinlein story. I hope I'm still alive on the day he hires a couple space jockeys to take him there right before his death.

I don't get it?

15 hours ago, Ten Key said:

I'm not sure if it really works that way. I happened on this article this afternoon, thought it might be relevant. . .

http://fortune.com/2016/06/06/space-startup-moon-express/

Spoiler: It doesn't. Just because you own a piece of land, doesn't make you the supreme ruler of it, you still need to comply to the govn't. Ever heard of property taxes?

On 2016-06-06 at 6:19 AM, PB666 said:

Lets stop badmouthing the UN, ok, my little report post finger is getting twitchy, and it has next to nothing to do with ELon Musk going to Mars. Elon could do whatever he likes and Noone can say anything until after the fact. Or would you have international bodies beurocratizing what you put on your hobby rocket or KSP forum cubesat?

Yeah, he's right. This is off topic as hell. Elon probably doesn't have to deal with the UN, NASA didn't have to to make the ISS, last time I checked.

On 2016-06-06 at 5:40 AM, PB666 said:

You like after you stuck your fat political foot right in the middle of it. 

Wow, way to be a freaking amazing person for no freaking reason.

"You know, let's attack the person, not the argument!" Because that's the best debate strategy, ever.

I hope you're happy.

 

On 2016-06-06 at 6:08 AM, LordFerret said:

I have very little confidence or faith in Musk's ability to pull off a Mars mission, even less a simple mass transit tube system.

Hyperloop is NOT "simple". It is literally the opposite of "simple" (and also likely, "cheap").

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5 minutes ago, fredinno said:

I don't get it?

Read The Man Who Sold The Moon and then Requiem. Or, read below

Spoiler

 

In the Heinlein story The Man Who Sold The Moon, the main character basically built up an entire space agency that eventually put the first man on the moon, specifically so he could go there some day. He was judged too important to risk, though, and later in life too old.

In the story Requiem, he hitches a ride and then dies on the moon, presumably happy that he finally made it.

 

 

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On 2016-06-06 at 8:33 AM, Nibb31 said:

Musk clearly has a reality distortion field

That would look awesome.

I wish he actually had one :(

On 2016-06-06 at 8:02 AM, CptRichardson said:

I'm not sure why everyone thinks that a failure in Tesla or Solar City would impact SpaceX. The whole point of these things called 'corporations' is that such failures don't effect the other ones even if all of them are owned by the same entity. There's also the fact that SpaceX is generating a McDuckian silo of money that Musk can swim in thanks to actually being the best launch provider in the world at the moment and getting better all the time.

 

Furthermore, as I've said before, the pessimissm over SpaceX is getting really old. Yes, they've had delays, but generally barring superceding the need for something, they've actually delivered or are on track for delivering their technological promises with one exception (second stage landing). Heck, even their delays in the FH are because they keep managing to improve the F9 and have had to go back and adjust how they're building the FH several times to account for higher thrust in the component cores, not because it's actually too hard for them. That, and because they really haven't needed it yet, but will before too long when they get ahold of the alphabet soup agency contracts. There wasn't much point in having it earlier because other than those agencies there isn't anyone on the market at the moment who really NEED 50 tons to LEO (seriously, good god).  The same goes with their BFR. We know they've at least had their engines working for it for at least a year, and they've been busy designing the other hardware for the system for some time. Given how the FH has been delayed by improving the F9, it's not hard to see that the BFR has almost certainly been getting massively improved by advancements being taken from the F9, but is still approaching a completion state of design.

 

I mean, seriously, how many technological miracles does Musk have to pull out of his hat before you stop badmouthing him? The whole point of SpaceX is going space-core over mars, and  Musk has made sure that one way or another nobody can tell him no. Maybe not '2024', but they will get to Mars barring total nuclear war.

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There wasn't much point in having it earlier because other than those agencies there isn't anyone on the market at the moment who really NEED 50 tons to LEO (seriously, good god).

"Those agencies" as in one- NASA (and maybe DOD in the very unlikely case we get a "Star Wars: The Force Awakens" program.)

And SpaceX was unable to compete for heavy GTO missions, where there is a market (look: Ariane 5, Proton, Delta IV Heavy).

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.  The same goes with their BFR. We know they've at least had their engines working for it for at least a year, and they've been busy designing the other hardware for the system for some time.

Source? Other than Brownsville, and engines (which have apparently shrunk to "upper stage" size), I don't know any part of BFR that is under development.

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Heck, even their delays in the FH are because they keep managing to improve the F9 and have had to go back and adjust how they're building the FH several times to account for higher thrust in the component cores, not because it's actually too hard for them. That, and because they really haven't needed it yet, but will before too long when they get ahold of the alphabet soup agency contracts.

They already have them- and in any case, a F9 expendable can get the vast majority of them already, barring Atlas 551 and Delta IV Heavy contracts.

FH could have been made faster if SpaceX held back making the F9 FT until after it was launching, as doing so would have allowed them to compete directly with ArianeSpace in the GTO market, much faster (and time is $$).

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I'm not sure why everyone thinks that a failure in Tesla or Solar City would impact SpaceX. The whole point of these things called 'corporations' is that such failures don't effect the other ones even if all of them are owned by the same entity. There's also the fact that SpaceX is generating a McDuckian silo of money that Musk can swim in thanks to actually being the best launch provider in the world at the moment and getting better all the time.

SOurce? Else, it's just speculation.

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Furthermore, as I've said before, the pessimissm over SpaceX is getting really old. Yes, they've had delays, but generally barring superceding the need for something, they've actually delivered or are on track for delivering their technological promises with one exception (second stage landing).

Except, you know, the satellite constellation. Or F5 and F1 reuse. Or a whole other number of things.

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I mean, seriously, how many technological miracles does Musk have to pull out of his hat before you stop badmouthing him? The whole point of SpaceX is going space-core over mars, and  Musk has made sure that one way or another nobody can tell him no. Maybe not '2024', but they will get to Mars barring total nuclear war.

Or you know. He dies before he goes to Mars, or SpaceX goes bust with a collapsing satellite market. Or any other number of things. And Musk has not done "miracles", when all that stuff is based off economics and science. Is star formation a "miracle?"

20 hours ago, Emperor of the Titan Squid said:

this has nothing to do with the mars mission really. i personally believe that the first mars landing will be done by an IMRS like mission, with international colaboration, and commercial construction of parts.

WE all hope so too.

On 2016-06-06 at 8:37 AM, kerbiloid said:

Unplanned Rapid Events.

Currently they have a 12-t single use launch vehicle and a cargo capsule. The same was in 1960s.

How is the reuse of F9 stages a "Unplanned Rapid Event"? It was planned since the beginning!

Well, to be fair, the Titan IIIC wasn't going to be reusable in a few months.

On 2016-06-06 at 10:28 AM, benjee10 said:

SpaceX will suffer delays, there will be setbacks, but ultimately I see no reason that they can't achieve their goals given their track record, and to suggest that they are anything other than innovative and pushing boundaries of space technology is frankly plain rude. 

READ:

https://en.wikipedia.org/wiki/SpaceX_satellite_development_facility

https://en.wikipedia.org/wiki/Falcon_1#Reusability

http://space.stackexchange.com/questions/10391/how-does-spacex-plan-to-achieve-reusability-of-the-falcon-9-second-stage

Not everything SpaceX plans ended up in results.

23 hours ago, linuxgurugamer said:

parachutes are heavy.  Desert is sandy.  Imagine sand in a rocket engine?  Also, in order to land in a desert, would require launching over land, something no one really wants to do

Actually, it has to do more on the lines of "There's no desert near the Cape", and "Kistler tried the same thing with chutes but failed miserably".

Sand isn't that big of a deal- the thrust on a final landing burn pushes sand out of the engines.

Also, launching over land isn't that huge a deal in the middle of nowhere, and not using any toxic materials in a rocket- not to mention if the rockets are intended to be reused. Kistler wanted to do the same in Nevada and Australia.

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27 minutes ago, fredinno said:

Wait, wut? Doesn't that pretty much doom his Mars plans, since if he actually ends up spending the cash needed to send people to Mars, investors would try to stop him in fear of SpaceX losing too much money on unprofitable endeavors? Wasn't that the point to not announcing an IPO in the first place?

Initially announced in like 2012 or somewhere around there, it didn't go anywhere. This past year however, after SpaceX permitted Google and Fidelity to 'invest', it had announced plans to make an IPO in '2016'. Now, I can see Google investing, but as I stated before, I wonder about Fidelity (and yes, I know who and what Fidelity is, I do, er, ah, 'business' with them). Fidelity's buy-in this year tells me (perhaps just me) that something's afoot for 2016. If SpaceX does go public, despite what some argue, Musk could still retain control and direction over where it goes and what it does. Going public could also give it the funding it needs. SpaceX also has an up and coming competitor to be aware of ... Moon Express, who are closer to receiving mission approval than SpaceX (according to the Wall Street Journal, and other sources). Granted, Moon Express isn't looking at Mars (yet), but a foot in the door is a foot in the door.

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23 hours ago, benjee10 said:

Strange as it may seem, yes, parachutes are heavier than landing gear. The 8 engines are going to be there parachute or not so that's irrelevant. The amount of propellant used in landing burn is very little considering that the rocket is almost entirely empty. Landing legs are designed to be as lightweight as possible. The parachutes required for a booster this size would be ridiculously huge and incredibly heavy; the shuttle SRB parachutes (which would be of a comparable size) mass around 3510kg; the mass of the landing legs of Falcon 9 is around 2000kg. 

As for CAPSULES landing in sand, they are CAPSULES not ROCKET BOOSTERS, so they land on a blunt heat shield. Rockets coming down in sand sounds like a terrible idea; if the terrain is not flat the sand will slide and they may tip or sink into it. Deserts also have the unfortunate habit of being in the complete middle of nowhere, which isn't a huge problem for a small space capsule which could conceivably be airlifted away by helicopter, but is rather a large inconvenience when dealing with a very large first stage. Plus, capsules are returning from an orbital flight so can choose their landing zone, whereas the booster must be recovered suborbital, which places it over the ocean, which would be even worse considering salt water corrodes rocket engines (cost of SRB refurbishment was higher than building new ones during the shuttle program because salt water corroded the casings). 

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The parachutes required for a booster this size would be ridiculously huge and incredibly heavy; the shuttle SRB parachutes (which would be of a comparable size) mass around 3510kg; the mass of the landing legs of Falcon 9 is around 2000kg. 

In a desert reuse scheme, landing legs are always needed no matter what anyways. :P

http://space.stackexchange.com/questions/12381/is-it-possible-for-the-space-shuttle-solid-rocket-boosters-srb-to-hit-the-spac

http://spaceflight101.com/spacerockets/falcon-9-ft/

Shuttle SRB dry mass:~83T

F9 1st stage dry mass: ~22T.

No, F9 chutes would be far smaller. And a final landing burn may be done to slow the rocket down if needed, right before landing.

The bigger question is actually fuel savings. That is a lot more relevant, because every gram of fuel saved for landing adds to the dry mass!

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whereas the booster must be recovered suborbital, which places it over the ocean, which would be even worse considering salt water corrodes rocket engines (cost of SRB refurbishment was higher than building new ones during the shuttle program because salt water corroded the casings). 

Wasn't the SRB reuse being bad more because the SRBs themselves required disassembly and reassembly anyways to be reused?

H-1 engines were dunked and restarted from seawater. Granted, refurbishment was needed, because H-1s were never intended to fire more than once, but the concept was proven that it could work. The extra performance of doing so may be cheaper than not doing so.

23 hours ago, linuxgurugamer said:

They land on sand, but aren't reusable.

CST-100 is.

23 hours ago, benjee10 said:

 I'm not clear on whether smaller emergency parachutes would still be included.

They would, otherwise, an aborting Dragon Capsule would be screwed.

6 minutes ago, LordFerret said:

Initially announced in like 2012 or somewhere around there, it didn't go anywhere. This past year however, after SpaceX permitted Google and Fidelity to 'invest', it had announced plans to make an IPO in '2016'. Now, I can see Google investing, but as I stated before, I wonder about Fidelity (and yes, I know who and what Fidelity is, I do, er, ah, 'business' with them). Fidelity's buy-in this year tells me (perhaps just me) that something's afoot for 2016. If SpaceX does go public, despite what some argue, Musk could still retain control and direction over where it goes and what it does. Going public could also give it the funding it needs. SpaceX also has an up and coming competitor to be aware of ... Moon Express, who are closer to receiving mission approval than SpaceX (according to the Wall Street Journal, and other sources). Granted, Moon Express isn't looking at Mars (yet), but a foot in the door is a foot in the door.

:D Moon Express isn't planning on any manned missions to anywhere. Try again.

Also, there is still the problem of investors dumping stock in fear, which WILL impact SpaceX's plans significantly. No longer can Elon do whatever he wants with his company.

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3 minutes ago, fredinno said:

Moon Express isn't planning on any manned missions to anywhere. Try again.

Maybe you don't understand what I wrote?

4 minutes ago, fredinno said:

Granted, Moon Express isn't looking at Mars (yet), but a foot in the door is a foot in the door.

 

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22 hours ago, benjee10 said:

Most recently it was used to carry the BEAM to the ISS. As you can see, minus cargo, it looks pretty empty. It's basically a fairing. You can also see in this pic how in the final Dragon V2 it will have little fins to aid with aerodynamics (I'm assuming that the aero is not so much of a concern in a mocked-up pad abort since the vehicle is not already supersonic, hence the simple mass-mockup of the trunk in the abort test):

I wonder how this fins would work well when they are covered in Solar panels? Also, isn't exposing the panels potentially a hazard (like if a bird hits)

23 hours ago, benjee10 said:

 

Only two of the engines are fired at any one time on orbit solving the TWR issue. 4 are used for landing. All 8 for abort.

It's still OP for orbital maneuvers...

23 hours ago, kerbiloid said:

Add refurbishing procedures cost, damaged equipment replacement - and you get that reusable Falcon shall lose 100% of cost in ~3 flights.
As Dragon's dead weight - tanks and engines - drops this value 1.5-2 times more, this means that Falcon will hardly save more than one launch cost per its lifespan.

That's not how reuse works... There's something called "diminishing returns".

22 hours ago, benjee10 said:

Those several tonnes would be lifted to orbit regardless if they were built into the capsule or not. An orbital spacecraft requires fuel tanks and engines. Whether they're on the capsule or on a service module they will still be lifted into orbit. The same propellant is being used for abort as would be used for OMS and/or landing (depending on whether reserve is kept or parachute is used) so ultimately there is no unnecessary mass here.

But you need to build a bigger heat shield to house all that, increasing mass. That's why the Soyuz has 3 modules, all jettisoned before reentry- it's a lot more mass-efficient to do that than what NASA did with the Apollo CSM.

22 hours ago, benjee10 said:

PLUS, from what I can find, it weighs less than CST-100 does! 6,400kg dry + 1,688kg propellant = 8,088kg total for Dragon V2 instead of 13,000kg for CST-100! You whole argument that it weight double what it should is pretty much entirely irrelevant since the other way of doing pretty much exactly the same thing (minus external payload capability, minus pin-point landings, minus recovery of all significant non-structural elements except the solar cells) weighs more! Even if it costs Falcon 9 some reusability (which I'm not entirely convinced of), it is still far more efficient than it's nearest rival, and launches on a rocket which is far less expensive. I'm not getting all the doom and gloom vibes you seem to be getting here.

Dragon V2's interior is a lot more mass-efficient than CST-100's. Also, CST-100 uses a less mass-efficient capsule shape.

22 hours ago, kerbiloid said:

If it anyway carries parachute (not too heavy thing - just ~0.2-0.3 t) and is not destroyed using it, why carry 6 engines more and a cystern of fuel inside the capsule?

Probably because SpaceX wants to reuse it. A purely mass-efficient solution would drop the LES, the fuel tanks, solar panels, etc. not needed for reentry. However, Dragon does not need to be mass-efficient, F9 provides plentiful payload margin.

22 hours ago, kerbiloid said:

~1-2 tonnes less would be lifted if use chute (or 1-2 additional tonnes of cargo) - and see above about hull mass due to increased volume.
If count this increased hull mass, even worse: 3-4 tonnes of the rocket payload are just spent.

The F9 has more than enough fuel for Dragon, even RTLS reuse. No need to worry about that side of the equation, much.

21 hours ago, kerbiloid said:

Just put a new parachute. It's exactly not more expensive than a single use trunk and second stage.

 

15 minutes ago, LordFerret said:

Maybe you don't understand what I wrote?

 

It's still a very long shot..

21 hours ago, kerbiloid said:
22 hours ago, benjee10 said:

 

Just put a new parachute. It's exactly not more expensive than a single use trunk and second stage.

They need a new second stage anyways- and same with the trunk. And chutes are expensive.

Quote

It only empties the bottles in the last seconds of flight.

Why? isn't that likely to cause an explosion due to the extra burst of fuel?

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1 hour ago, fredinno said:

How is the reuse of F9 stages a "Unplanned Rapid Event"?

I just proposed a neutral term for "miracle". Not necessary for SpaceX theme.

1 hour ago, fredinno said:

The F9 has more than enough fuel for Dragon, even RTLS reuse.

That's not about "whether F9 can lift Dragon".
That's about: F9 has a limited amount of launches (as any device), and every useless tonne of Dragon wastes it. 
Say, if Dragon were 2 times lighter, it would require 2 times less F9 launches, F9 would fly 2 times more.
And F9 launches limit looks miserable even without Dragon.

 

1 hour ago, fredinno said:

And chutes are expensive.

Indeed?

 

 

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20 hours ago, LordFerret said:

SpaceX has announced its IPO, so that data is forthcoming. Soon enough.

Source?

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3 hours ago, fredinno said:

Wow, way to be a freaking amazing person for no freaking reason. "You know, let's attack the person, not the argument!" Because that's the best debate strategy, ever. I hope you're happy.

I'm just wondering who gave you the overdose of caffeine in your espresso.

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2 hours ago, kerbiloid said:

I just proposed a neutral term for "miracle". Not necessary for SpaceX theme.

But it

2 hours ago, PB666 said:

I'm just wondering who gave you the overdose of caffeine in your espresso.

I don't want to start an argument, so let's stop trying to liquid each other off. Deal?

2 hours ago, kerbiloid said:

I just proposed a neutral term for "miracle". Not necessary for SpaceX theme.

That's not about "whether F9 can lift Dragon".
That's about: F9 has a limited amount of launches (as any device), and every useless tonne of Dragon wastes it. 
Say, if Dragon were 2 times lighter, it would require 2 times less F9 launches, F9 would fly 2 times more.
And F9 launches limit looks miserable even without Dragon.

 

Indeed?

 

 

Quote

That's not about "whether F9 can lift Dragon".
That's about: F9 has a limited amount of launches (as any device), and every useless tonne of Dragon wastes it. 
Say, if Dragon were 2 times lighter, it would require 2 times less F9 launches, F9 would fly 2 times more.
And F9 launches limit looks miserable even without Dragon.

REALLY?:rolleyes:

If SpaceX had a "Falcon 5", reducing Dragon Mass would be worth it. However, as it stands, reducing Dragon Mass does not have many benefits, aside from maybe fitting a small 100kg satellite out the back of the trunk (however, the trunk is space-limited, so only a few satellites will fit- and only of the smallsat-type. F9's main market is GTO and the "big satellite" market, so the reduction in F9 launches from a smaller Dragon is minimal.

Plus, Dragon v2 launches only 1 time a year (the launches need to be shared with Boeing).

Quote

Indeed?

 

I'm not Russian. How do you expect me to watch that?

Quote

I just proposed a neutral term for "miracle". Not necessary for SpaceX theme.

It's just as inaccurate, and 100% more awkward.

Edited by fredinno

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On June 6, 2016 at 1:04 PM, fredinno said:

Well, I didn't start it...

You were the one who said the UN was bad. If you didn't want a liquid response you should watch who you point  your liquification unit at.

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3 hours ago, Robotengineer said:

Source?

There are many sources which speculate on this, which you can Google.

I will throw this up however,

Quote

In 2012, an initial public offering (IPO) was perceived as possible by the end of 2013,[38] but then Musk stated in June 2013 that he planned to hold off any potential IPO until after the "Mars Colonial Transporter is flying regularly,"[39] and this was reiterated in 2015 indicating that it would be many years before SpaceX would become a publicly traded company,[40][41] where Musk stated that "I just don’t want [SpaceX] to be controlled by some private equity firm that would milk it for near-term revenue"[42]  - https://en.wikipedia.org/wiki/SpaceX

...which is very interesting, to me, because Fidelity IS a 'private equity firm'.

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