_Augustus_

NASA SLS/Orion/Payloads

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1 hour ago, RCgothic said:

Did someone just use "not-econimical" as an argument against an SLS competitor? :o

No i‘m just sick of the meme that SpaceX has proven airplane like reusability in Launch vehicles. Because they have not. 

1 hour ago, Xd the great said:

I would like to see that myth. Any links?

https://en.m.wikipedia.org/wiki/Space_Shuttle

So no, SpaceX has not ”done the impossible“ when they land part of a rocket and reuse it two or three times.

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58 minutes ago, _Augustus_ said:

When BFR flies in a couple years, I'll be sure to remind you of this.

It took 5 years and a national effort to develop and fly the first Saturn V. No expense spared. And you think little, itty bitty, SpaceX is going to have flying a bigger and much, much, more complicated BFR in a "couple years?"

There's going to be a whole lotta fanboy eating crow in a couple years.

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1 hour ago, Kerbal7 said:

It took 5 years and a national effort to develop and fly the first Saturn V. No expense spared. And you think little, itty bitty, SpaceX is going to have flying a bigger and much, much, more complicated BFR in a "couple years?"

 

How long does it take to design a new computer that is vastly more capable than a computer from 1967?

Part of the reason modern companies can build better spacecraft is that so very much is now well-understood, and off the shelf. New engines are a long pole, but control systems are vastly superior to the 1960s. Every one of us here has more computing power in his/her pocket than existed on Earth during the entire space race (combined). This also allows designs to be tested before they are even built, something impossible back in the day.

There are more options than "SpaceX is snake oil, and SLS/Orion is the best rocket/spacecraft ever!" and "SpaceX will destroy the lousy SLS/Orion porkfest!" There's a lot of gray in the real world.

SLS is an old-space project (though badly run compared to most old-space projects as far as I can tell). SpaceX and BO have different cultures. Both can succeed, they are not mutually exclusive.

Edited by tater

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7 minutes ago, Xd the great said:

Yeah, space shuttle glided. Falcon 9 did a supersonic retropropulsion on the flames on its engine.

Nothing new, Apollo LM did that first.

And then there was DC-X.

And then New Shepard.

/s

Edited by sh1pman

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15 minutes ago, Xd the great said:

Yeah, space shuttle glided. Falcon 9 did a supersonic retropropulsion on the flames on its engine.

You were talking about reusing a launch vehicle and that the Shuttle did, more than the Falcon 9. So nothing impossible about it. 

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DC-X and the LM did not do supersonic retropropulsion. The former never got going that fast in any direction, the latter was not in a medium with a speed of sound.

NASA contractors have talked about VTVL for what, 55+ years? Landing boosters was/is a non-trivial accomplishment. I have a copy of Bono and Gatland's Frontiers of Space (1969). All their predictions/suggestions are based upon technology they were comfortable with in 1969. They say in the introduction:

Quote

As we enter the age of the space rocket much remains to be done before it can take its place alongside more conventional means of transportation. The rocket boosters of today are not recovered for re-use; they are allowed to burn up while penetrating Earth's atmosphere or to splash down wastefully into the sea. No other method of transportation could long survive the extravagance associated with disposal of the carrier vehicle after only one use. Truly efficient space exploration awaits the day when launching can be accomplished by a booster which can be recovered and re-used repeatedly.

This was true in 1969, and before that when many of the Bono designs were first drafted years before he wrote the book quoted above. It's still true now.

39 minutes ago, Canopus said:

You were talking about reusing a launch vehicle and that the Shuttle did, more than the Falcon 9. So nothing impossible about it. 

On-topic, the SSMEs are being reused AGAIN for SLS!

They apparently cost ~40M$ new, yet each reused engine on SLS is apparently costing us 127 M$.

Does reusing the engines on a 777 cost more than the engines cost new each flight? Shuttle was more "rebuilt" each flight than reused. The early concepts assumed a far more aircraft-like turn around. Nothing remotely close to that ever happened with Shuttle, sadly.

 

Edited by tater

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4 minutes ago, tater said:

On-topic, the SSMEs are being reused AGAIN for SLS!

They apparently cost ~40M$ new, yet each reused engine on SLS is apparently costing us 127 M$.

Does reusing the engines on a 777 cost more than the engines cost new each flight? Shuttle was more "rebuilt" each flight than reused. The early concepts assumed a far more aircraft-like turn around. Nothing remotely close to that ever happened with Shuttle, sadly.

 

There is no arguing that, The Shuttle made little sense as a reusable launch vehicle and certainly wasn‘t cheaper than any other disposable launch vehicle they could have build during that time. 

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2 minutes ago, Canopus said:

There is no arguing that, The Shuttle made little sense as a reusable launch vehicle and certainly wasn‘t cheaper than any other disposable launch vehicle they could have build during that time. 

I wish the SLS program wasn't so, well, awful.

Human spaceflight is a stunt---but it's a stunt I dearly love. I want human spaceflight to succeed, and indeed flourish. If I thought SLS was the path to that, I'd be all-in for SLS. They're making it hard for anyone rational to really root for SLS, though. Shuttle was not my favorite in many ways, but I still loved to watch it fly. Even space fans will forget SLS exists in the dead time between launches, lol.

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If BFR doesn't beat SLS, it will be New Glenn. SLS is an atrociously managed project from start to finish.

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NG certainly has utility for the Gateway, assuming a different paradigm of cislunar operations. NG could loft substantial Gateway elements, but they can't co-manifest with a crew vehicle, so they'd need to develop a pretty robust tug vehicle (ULA ACES?).

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8 hours ago, sh1pman said:

Nothing new, Apollo LM did that first.

And then there was DC-X.

And then New Shepard.

/s

Yeah, but their TWR can be less than 1, which means it is less suicidal in landing those.

Edited by Xd the great

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On 11/7/2018 at 9:24 AM, Canopus said:

https://www.nasaspaceflight.com/2018/11/northrop-grumman-synergy-omega-sls-solid-boosters/

So we might after all see something of a Block 2 using a more advanced solid rocket motor.

I predict that EUS will be permanently scrapped and we'll see the original Block IA come back.

The Remote-Controlled Vampire Cat: NASA releases new ...

Eureka: El rompecabezas del cohete gigante SLS

Eventually, maybe a J2X-based upper stage like the original Block II.

On 11/7/2018 at 11:26 AM, tater said:

NG certainly has utility for the Gateway, assuming a different paradigm of cislunar operations. NG could loft substantial Gateway elements, but they can't co-manifest with a crew vehicle, so they'd need to develop a pretty robust tug vehicle (ULA ACES?).

NG S2 is planned to have some kind of on-orbit reusability eventually, so it might be able to act as its own tug.

Actually, NG can just barely get Orion to the Gateway (people have done it in RO), and that's assuming the engines don't improve over time like Merlin and Glenn itself doesn't get bigger. 

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Anything that would make Orion more LV agnostic could only help the spacecraft, it's pretty useless right now given the abysmal (theoretical) flight rate.

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On 10/11/2018 at 2:51 PM, MinimumSky5 said:

I've often wondered why NASA were told to use the RS25's, surely using RS68's would make more sense. Yes they don't have the same efficiency, but they're cheap and expendable. 

Apparently, man-rating those things would have been even more expensive. The question obviously came up when Orion flew on a Delta IV.

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2 minutes ago, DDE said:

Apparently, man-rating those things would have been even more expensive. The question obviously came up when Orion flew on a Delta IV.

More than the 2 B$ they are spending on refurbing 16 engines?

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On 11/7/2018 at 2:29 PM, Xd the great said:

I would like to see that myth. Any links?

The launch cost of falcon 9 is 60 million for 6 tonnes to ISS, lower than that of a soyuz, and much much lower than that of a space shuttle.

“To ISS” is far more than that. And that’s on the equivalent of the Progress. 

https://arstechnica.com/science/2018/04/nasa-to-pay-more-for-less-cargo-delivery-to-the-space-station/

Also note that SpaceX advertised per-launch costs are for reuse whereas payload values are for expendable flights.

1 minute ago, tater said:

More than the 2 B$ they are spending on refurbing 16 engines?

“Hold my latte!”

It’s the same people, after all.

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Wow, for a lander, the dry mass can only be 27% of the full mass assuming a hydrolox (450s) or 15% assuming some hypergolic (315s). That's down from 41% hydrolox and 27% hypergolic.

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Future lunar landing vehicles that support a hypothetical ice extraction enterprise won‘t begin their journey from LLO anyway. Might aswell build one now that is up to the task and can be adapted for future uses.

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4 hours ago, Canopus said:

Future lunar landing vehicles that support a hypothetical ice extraction enterprise won‘t begin their journey from LLO anyway

[citation needed]

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3 hours ago, sh1pman said:

[citation needed]

Who would put a fuel depot in low lunar orbit?

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You'd need a frozen orbit at the very least for a depot. Im not sure what's best for thermal management, having full shade half the time, or never.

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