Jump to content

NASA SLS/Orion/Payloads

_Augustus_

By _Augustus_
in Science & Spaceflight

 Share

Recommended Posts

PB666

PB666

Posted
Posted (edited)

This is known, I actually took Falcon Heavies flight apart and broke it into pieces, added different fuels etc. Falcon Actually needs a much more efficient second stage to compete with SLS. The second stage engine is heavy and gets 3400 Ve . The proposed 4 RL10C-x that are going to end up on the EUS are supposed to be in the 420 ish range, not great for RL10 but good considering they power density and weight for a expansion cycle cryogenic (They could theoretically replace all 4 with and RS25E and have power to boot). In fact, I found it 'strained' just to get 63t into LEO using his setup (although I did not test this with block 5).

This is what Ellison was talking about last month, FH does great compared to DeltaIV heavy until it gets about half the dV to orbit, then its competitiveness starts to wane, by the time in reaches TLI values most of the advantage is lost.

Musk seems to be flexible with the second stage, he could contract to the Russians for a Second stage full cryogenic engine and get those number up. I think the reason they wouldn't is that the Merlin 1-D-vacuum is cheap and fast to make, and since no-one is recycling the second stage he doesn't want to go there. Musk is willing to step up the cost on anything, as long as the customer demands it and is willing to pay, but right now he has --> 150 flights to take care of so that resources will be going into turnover.

What he could do is contract with a third party to build a circulator for LEO to DSG that is cryogenic and just ship cryogenic fuels to the circulator (complete with its own H2 recycling pump). In this situation

1. Falcon heavy carries a circulator with enough mono to run its control systems in Orbit.
2. Falcon heavies carry sufficient oxygen to the circulator.
3. Falcon heavy finally brings payload and liquid hydrogen to the circulator.
4. Once full the circulator goes to DSG, dumps it PL and returns to LEO (and alternative is that it uses Solar panels and ION drive to return it to LEO).

The business he is engaged in is volume, to be successful he has to put a reusable uniform factor rocket into space with PL and then land successful. Repetition here is where the profit is, and there is very little repetition in servicing NASA's DSG.

How much money Musk spends on FH evolution really depends on interest, if by the end of the year there are a dozen scheduled flights, the may relook at the second stage, but so far FH has a luke-warm response (since the FH launch only 2 more contracts have been added so  . . . ).

 

Edited by PB666
Link to comment
Share on other sites
tater

tater

Posted
Posted

I think they transition to requiring FH for any launch that otherwise requires an expendable F9. Throwing perfectly good boosters away is insane. They'll expend boosters from their remaining stock of used boosters, then only after that for EOL boosters to get rid of them.

FH as an SLS replacement has always made little sense to me, it's not big enough, and the only mass limited payload is propellant. The only use for FH (to me) is 100% booster recovery GEO missions, and as a cheap vehicle for things like space probes where you can immediately do a transfer burn, maximizing what the mass to LEO actually is---propellant.

Link to comment
Share on other sites
Canopus

Canopus

Posted
Posted

FH would be Great for the NRO, launching something like a big Keyhole into polar low earth orbit. Although it is speculated that they are going to switch to much smaller optical satellites already.

Link to comment
Share on other sites
PB666

PB666

Posted
Posted (edited)
3 hours ago, tater said:

I think they transition to requiring FH for any launch that otherwise requires an expendable F9. Throwing perfectly good boosters away is insane. They'll expend boosters from their remaining stock of used boosters, then only after that for EOL boosters to get rid of them.

FH as an SLS replacement has always made little sense to me, it's not big enough, and the only mass limited payload is propellant. The only use for FH (to me) is 100% booster recovery GEO missions, and as a cheap vehicle for things like space probes where you can immediately do a transfer burn, maximizing what the mass to LEO actually is---propellant.

They could dabble in SLS range, SLS achieves the higher PL to TMI because they are using some of the most expensive first and second stage engines out there, not of them will be recycled and boosters that were designed to be recycles but will essentially be trashed. There is room on the F9 core to add two more boosters, and stagger the separation of the two pairs so that essentially the core shuts down sooner and runs at minimal thrust until the second pair is separated. But even that is troubled by the fact that the second stage is nowhere near as efficient at EUS.

I think from an economic point of view, unless they are getting a honey-deal like ULA, there would be no competitive reason to go that direction.

Before I say impossible, I would sure like to see what the Block 5 FH telemetry looks like.

Edited by PB666
Link to comment
Share on other sites
Mitchz95

Mitchz95

Posted
Posted
4 hours ago, tater said:

Throwing perfectly good boosters away is insane.

Does anyone else remember when statements like these were hypothetical?

We are already taking first-stage reuse for granted. :D

Link to comment
Share on other sites
Ultimate Steve

Ultimate Steve

Posted
Posted
3 minutes ago, sh1pman said:

Doubt it. F9 expendable might be cheaper than FH reusable.

Assuming a total cost per F9 launch is 62 million...

F9E - 1 booster, 1 s2, 2 fairings (not counting them for reusability just yet). 40M, 16M, 6M. 62M.

F9HE - 3 boosters, s2, 2 fairings. 120M, 16M, 6M. 142M.

But if we reuse the FH and say that refurb costs 1/4 of the manufacturing cost (and with block 5 it should be less), then the boosters only are 10M each, meaning 30M, 16M, 6M. 52M.

 

Even if it is not cheaper, it should help with launch cadance, and SpaceX has a pretty big backlog to get through.

 

Link to comment
Share on other sites
sh1pman

sh1pman

Posted
Posted
10 minutes ago, Ultimate Steve said:

Assuming a total cost per F9 launch is 62 million...

F9E - 1 booster, 1 s2, 2 fairings (not counting them for reusability just yet). 40M, 16M, 6M. 62M.

F9HE - 3 boosters, s2, 2 fairings. 120M, 16M, 6M. 142M.

But if we reuse the FH and say that refurb costs 1/4 of the manufacturing cost (and with block 5 it should be less), then the boosters only are 10M each, meaning 30M, 16M, 6M. 52M.

 

Even if it is not cheaper, it should help with launch cadance, and SpaceX has a pretty big backlog to get through.

 

I’m talking about the price tag. If I’m a customer, I’d choose the cheapest option available. FH launch is going to cost me 90M for the fully reusable configuration. F9 is 62M for a launch with booster recovery, and there is no official price for F9 expendable launch. I don’t think it’s higher than 90M.

Link to comment
Share on other sites
Ultimate Steve

Ultimate Steve

Posted
Posted (edited)
8 minutes ago, sh1pman said:

I’m talking about the price tag. If I’m a customer, I’d choose the cheapest option available. FH launch is going to cost me 90M for the fully reusable configuration. F9 is 62M for a launch with booster recovery, and there is no official price for F9 expendable launch. I don’t think it’s higher than 90M.

I'm not quite sure what the actual price/cost is (/r/SpaceX had several discussions and hasn't yet come to a concrete conclusion) but each contract probably varies a lot...

Also

https://twitter.com/elonmusk/status/963094533830426624

Elon has said that 95M is only "slightly" higher than the cost of an expendable F9 (and that's expending one FH core), but that doesn't really line up with the advertised 90M/62M prices, so they may be outdated. The price we see on the website is also very rarely the price the customer pays, at least based on the transactions that have been made public.

Edited by Ultimate Steve
Link to comment
Share on other sites
sevenperforce

sevenperforce

Posted
Posted
7 minutes ago, sh1pman said:

I’m talking about the price tag. If I’m a customer, I’d choose the cheapest option available. FH launch is going to cost me 90M for the fully reusable configuration. F9 is 62M for a launch with booster recovery, and there is no official price for F9 expendable launch. I don’t think it’s higher than 90M.

F9 expendable launch is $92 million. FH is $90 million.

Interestingly enough, Elon quoted FH with the core expended at $95-97 million, suggesting per-booster operating costs of only $2.5 million per flight in comparison to the cost of an expendable Falcon 9. But obviously there is some scale-sliding for marketing and business purposes here.

Link to comment
Share on other sites
sh1pman

sh1pman

Posted
Posted (edited)
4 minutes ago, sevenperforce said:

F9 expendable launch is $92 million

Source? 

If single rooster recovery cuts the price by 30M, then partially recoverable FH should cost 120M. And Musk said it’s 95M.

edit: yeah, this discussion should probably be moved to SX thread

Edited by sh1pman
Link to comment
Share on other sites
KSK

KSK

Posted
Posted
2 hours ago, sh1pman said:

Source? 

If single rooster recovery cuts the price by 30M, then partially recoverable FH should cost 120M. And Musk said it’s 95M.

edit: yeah, this discussion should probably be moved to SX thread

Single rooster recovery nets you some cash but to be honest it's pretty much chickenfeed in the overall scheme of things.

Sorry...

Link to comment
Share on other sites
sh1pman

sh1pman

Posted
Posted
2 minutes ago, KSK said:

Single rooster recovery nets you some cash but to be honest it's pretty much chickenfeed in the overall scheme of things.

Sorry...

Phones and their autocorrects... :)

Link to comment
Share on other sites
wumpus

wumpus

Posted
Posted
10 hours ago, tater said:

Read the comment in the first image. LOL. Sad, but true.

Where is the surprise in all this?  Congress is uninterested in going to the Moon.  They *are* interested in funneling money to SLS.  If NASA wants any funding to go to the Moon, they have to use SLS.  There's probably some grumbling from Congress not already on the SLS bandwagon wanting some reason for funding the thing (and maintaining NASA's budget at all), so NASA is scrambling to find a mission for it.

I don't think SLS is eating the rest of NASA's budget.  I'd say that the rest of it is disappearing and NASA is scrambling to protect what they can keep (SLS).  The piper has to play what the guys paying the bills want to hear.

Is lunar orbit even a good place for such a base?  It might make sense if you need to get somebody on/off the surface (radiation, solar flare, whatnot) but it seems kind of unlikely.  I'd expect that a Lagrange point makes much more sense (don't try explaining it to a Congressman).

 

Link to comment
Share on other sites
Canopus

Canopus

Posted
Posted
6 minutes ago, wumpus said:

Is lunar orbit even a good place for such a base?  It might make sense if you need to get somebody on/off the surface (radiation, solar flare, whatnot) but it seems kind of unlikely.  I'd expect that a Lagrange point makes much more sense (don't try explaining it to a Congressman).

 

Lagrange points would make more sense if the Gateway was used as the staging point of a Mars mission, like originally intended, but since the focus has shifted to the moon the NRHO offers two advantages. The first is  a small advantage in DeltaV needed to get to the surface, the second is that the gateway, with its Apolune high over the south pole, would have long line of sight to a mission taking place down there and could act as a relay.

Link to comment
Share on other sites
PB666

PB666

Posted
Posted
19 hours ago, Canopus said:

Lagrange points would make more sense if the Gateway was used as the staging point of a Mars mission, like originally intended, but since the focus has shifted to the moon the NRHO offers two advantages. The first is  a small advantage in DeltaV needed to get to the surface, the second is that the gateway, with its Apolune high over the south pole, would have long line of sight to a mission taking place down there and could act as a relay.

La grange points make sense if your intent is to circulate ships between LEO and Lx (x = 1 or 2) and circulate ships between Lx and other points in the solar system. The dV advantage of burning all the way to your destination is overriding other strategies in most cases, but if the circulator is ION driven, then in makes sense to burn to L2 and back with a conventional and perishable fuel like H2/O2. Probably if you just use the H2/O2 as a final boost out of LEO from an ION drive, its going to work out better. But you have to keep the cryogenics fresh until the ION drive has prepared the last kick out.

There are two basic strategies for Mars, getting humans there and getting supplies there, provided an adequate intial orbit ION drive can negotiate the supply run by themselves but Humans require special condsideration. L2 is just to far to be useful for human transfers and the DSG is probably a good place to store fuels for transfer.

Again the point made above, what is NASA going to use this for . . . . . .IDK.

Link to comment
Share on other sites
_Augustus_

_Augustus_

Posted
  • Author
Posted (edited)

NASA can't figure out what they want PPB to be.

http://spacenews.com/nasa-considers-acquiring-more-than-one-gateway-propulsion-module/

Is it a station service module or a full-on SEP tug? Make up your minds......

Meanwhile, Zubrin is pushing Moon Direct. I mean, the dude could just wait for BFR, but this idea is still far more compelling than SLS/Orion.

http://spacenews.com/op-ed-moon-direct-how-to-build-a-moonbase-in-four-years/

I think this quote sums up DSG:
 

Quote

 

[NASA] is proposing the build a lunar orbiting space station dubbed the Deep Space Gateway. This boondoggle will cost several tens of billions of dollars, at least, and serve no useful purpose whatsoever – except perhaps to provide a launch manifest for the Space Launch System. We do not need a lunar-orbiting station to go to the moon. We do not need such a station to go to Mars. We do not need it to go to near-Earth asteroids. We do not need it to go anywhere. If we do waste our time and money building it, we won’t go anywhere.

 

 

Edited by _Augustus_
Link to comment
Share on other sites
Guest
This topic is now closed to further replies.
 Share
Go to topic listing
×
×
  • Create New...