The "Real Aerospace" Thread

Discussion regarding the Outsider webcomic, science, technology and science fiction.

Moderator: Outsider Moderators

Post Reply
User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

The "Real Aerospace" Thread

Post by Arioch »

Really good article at Ars Technica on how NASA is investigating a redesigned Saturn V F-1 main engine as a booster engine for the new SLS.

http://arstechnica.com/science/2013/04/ ... k-to-life/

Essentially, they had to disassemble and reverse-engineer a 40-year-old F-1 to figure out how it works. Not sure what that says about the current state of our aerospace industry.

The F-1 is a monster, though... the largest working single-chamber liquid fueled rocket engine ever (the Russian N1 exploded all four times it was launched). "The power output of the Saturn first stage was 60 gigawatts. This happens to be very similar to the peak electricity demand of the United Kingdom."

The SLS, if it ends up using the F-1B (instead of solid rocket boosters), would have 4 space shuttle RS-25 engines on the main stage, and 4 F-1B engines on each of two booster stages.

User avatar
Mr Bojangles
Posts: 283
Joined: Sat Mar 03, 2012 1:12 am

Re: The "Real Spacecraft" Thread

Post by Mr Bojangles »

That was a great article. There's a follow-up to it:

The F-1B

Not only did NASA reverse-engineer the engine, one of the companies in the Advanced Booster Competition is using that data to create the F-1's successor, the F-1B. Same beast, modern tech. Fun times. :twisted:

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Spacecraft" Thread

Post by Arioch »

Yes, just got through reading the second article. A good discussion of the reasons behind using kerosene in booster stages for the energy density, and liquid hydrogen in the upper stages for the efficiency.

User avatar
Mr Bojangles
Posts: 283
Joined: Sat Mar 03, 2012 1:12 am

Re: The "Real Spacecraft" Thread

Post by Mr Bojangles »

Rocketry is a fascinating topic. It seems so simple: get some fuel and oxidizer, put them in a tube with a nozzle on one end and light it off. But, it's so much more difficult than that. So many things to balance, so many tradeoffs to be made. The author's analogy of the rocket being "hammered" through the atmosphere is very appropriate.

And, I don't know about you, but I found this article to have the best description of specific impulse I've seen to date.

User avatar
Trantor
Posts: 780
Joined: Sun Mar 06, 2011 1:52 pm
Location: Hamburg, Germany

Re: The "Real Spacecraft" Thread

Post by Trantor »

Arioch wrote:Essentially, they had to disassemble and reverse-engineer a 40-year-old F-1 to figure out how it works. Not sure what that says about the current state of our aerospace industry.
Nothing, because that´s only relevant for historians/museums.
Today we must make engines with todays standard of tech (laser- vs rodwelding, 5-axis CAM-tools vs handdrilling etc pp).
Or were you insinuating that they even don´t understand basic rocket tech anymore? :mrgreen:

Arioch wrote:The F-1 is a monster, though... the largest working single-chamber liquid fueled rocket engine ever (the Russian N1 exploded all four times it was launched).
That´s kinda vague since the N1 had 30 engines vs Saturn 5s 5 F-1.
One F-1 has a thrust of IIRC 6.7 Meganewton, but the russian RP-170 has 8 Meganewton. Since it is Energijas mainengine and has made two succesful flights (100% successrate, like the F-1) it is the world strongest Rocketengine.
The WHOLE Saturn-ROCKET has more thrust, yes, but not the single engine.
As i always say - don´t fall for your own PR...

;)
sapere aude.

User avatar
Trantor
Posts: 780
Joined: Sun Mar 06, 2011 1:52 pm
Location: Hamburg, Germany

Re: The "Real Spacecraft" Thread

Post by Trantor »

Mr Bojangles wrote:That was a great article. There's a follow-up to it:

The F-1B

Not only did NASA reverse-engineer the engine, one of the companies in the Advanced Booster Competition is using that data to create the F-1's successor, the F-1B. Same beast, modern tech. Fun times. :twisted:
Honestly? That´s a dead end.
That F1-B thingy is everything but "modern". It´s a joke.
It´s the piss poor performance parallel in rockettech to the ever recurring undead Winchester 73 zombie clones in gun tech. Yawn, good night, America...

Plus it´s prone to be a failure since those scholar-smartasses "optimized" all safety margins away. Moneyquote: "Because they didn't have the analytical tools we have today for minimizing weight, everything was very robust,..."
Yeah, sure, buddy. What could POSSIBLY go WRONG??


Ok, oldschkoool engineers like me could rant for hours about that.
So let´s better offer some constructive criticism (tm). :mrgreen:

How does a really modern engine look like? Well, if you don´t want to burn Trillions of tax money until those students´ smartasses learning curve starts to rise, you could simply buy RD-170s.
Or, which is to be preffered, leave it to the Germans.

So how would we make it? "Smartass Students"(tm) would say, we need 8 Meganewtons per unit.

So my humble little self would utter sth like "O RLY?" then. :mrgreen:

Because, let´s have a look at the basics first: Saturn Vs mass was 3000tons (so roughly 600tons per F-1), and it deployed only 43tons to the moon, about 1.4 percent or 1/70.
This is a lousy number.
Why so?
Because the Big V lacked boosters.

According to Tsiolkowskis calculations (i made an excelsheet once to play around with stagemasses and different fuels) there´s more possible. With the right fuels and the right massrelations between the stages up to 2.2% or 1/45.
Also, with todays materials we don´t need 43tons to the moon. Let´s be conservative, and say 35 tons at a rate of 1/50 is sufficient (lot´s of safety margin here).
That makes 1750 tons, or about 60% of Big Vs mass.

And since we have boosters now we split our need of first stage engines into six units (two under each barrel), which have to lift slightly less than 300tons each, compared to Big Vs 600t/each.
Makes roghly 3.3 Meganewton per unit, which really eases work on them.

Ok, what wonderfuel (sic!) do we use? Well, liquid methane and LOX.
Why so?
There are a lot of reasons, but the two most important are specific impulse (30% more than RP-1) and then physical characteristics: Almost same density AND temperature as LOX! No need for two different technologies anymore, same pumps, plumbing, sealings, dimensions whatever in both systems.
Makes it less complex and much much more compact, which again saves construction weight and in iteration overall weight and so on.

Why doesn´t somebody use Liquid Methane yet? Well, that was a political decision by some oil-sponsored white collar cretin in Washington, DC...
And the russians? Well, that´s more complicated, but it has to do with a lot of personal quirks and jealousy among the shanghaied german engineers and the russian ones at the bginning (after WW2), and later on with a lot of more complications. Or in other words: SNAFU.
...

Ok, now we have our target power output and our fuel, and since we´re Germans and not smartass blockheads, we will make an engine that pretty much will look like a 50% upscaled version of the SSME. Bang.

That means staged combustion, maybe even full-flow staged combustion if that will work at this size, to get the absolute maximum.
The F1B-dud OTOH would rely on a simple exhaust gas generator design, giving away ANOTHER 15% of specific thrust... (insert rolleyes here :mrgreen: )

Very probably these engines would be reusable, coming back from the 1st- and boosterstages via parachute and airbags. 10 or 20 launches per unit should drastically reduce cost.

Oh, and BTW, 300tons of thrust is a smart number, which can be arranged/combined into a lot of useful rockets for all purposes, from heavyweight LEO via GEO to planet missions. I can elaborate further on that once i find my papers and that exceltool.

...

Ok, but enough german brilli^H^H^H^arrogance for now, i´m pretty sure you all have questions? ;)
sapere aude.

User avatar
Mr Bojangles
Posts: 283
Joined: Sat Mar 03, 2012 1:12 am

Re: The "Real Spacecraft" Thread

Post by Mr Bojangles »

Trantor -

Did you even read the linked articles? They're not looking at it because it's the most efficient, most advanced, most powerful rocket engine. They're looking at the F-1 because it works. It's proven technology that has never had a mission-scrubbing incident. Never once did one explode on the launch pad, or experience an issue that lead to abort of a launch.

All the work that the two articles described was done to see what those "old school" engineers did right (because they did do something right). Some of those engineers were even involved in this project! The idea being that the engines can be improved using modern materials and techniques. Does this mean there will be absolutely no problems? Of course not; anyone that's serious about rockets knows how spectacularly they can fail (Americans, Russians, even Germans). However, building upon proven technology is usually not by default a "bad thing."

The overall idea behind the SLS is "if it works, go with it." So, it'll likely use several RS-25s (of which there are many still around), and either the Shuttle SRBs, or maybe F-1B liquid-fueled boosters. This will allow NASA to leverage its existing knowledge and capacities, and with the addition of a growing private space launch capacity, this seems a good path to follow.

Also, Arioch isn't wrong about the F-1 being the most powerful single-chamber liquid-fueled rocket engine built and flown to-date; it is. The RD-170 had four chambers.

User avatar
Trantor
Posts: 780
Joined: Sun Mar 06, 2011 1:52 pm
Location: Hamburg, Germany

Re: The "Real Spacecraft" Thread

Post by Trantor »

Mr Bojangles wrote:Trantor -

Did you even read the linked articles?
Sure, or where do you think the quote comes from?

Mr Bojangles wrote:They're not looking at it because it's the most efficient, most advanced, most powerful rocket engine.
Nothing of that except the power. It´s an inefficient dinosaur.
A breaktrough then, yes. But history today.

Mr Bojangles wrote:They're looking at the F-1 because it works. It's proven technology that has never had a mission-scrubbing incident. Never once did one explode on the launch pad, or experience an issue that lead to abort of a launch.
So what? That´s like saying "Horses never burnt because of a leaking tank. Let´s not develope cars, stick to the horse!!1!"

Mr Bojangles wrote:The idea being that the engines can be improved using modern materials and techniques.
AAAAAAAAAAAAAND zhis iss ze werry WRONG approach.

No sane person would adapt modern tech/materials to an old (and crappy) design.

Mr Bojangles wrote:This will allow NASA to leverage its existing knowledge and capacities, and with the addition of a growing private space launch capacity, this seems a good path to follow.
This is a dead end and will result in trillions of wasted tax money. Leave it to ze Germans:
Image

Mr Bojangles wrote:Also, Arioch isn't wrong about the F-1 being the most powerful single-chamber liquid-fueled rocket engine built and flown to-date; it is. The RD-170 had four chambers.
Splitting hairs... :roll:
sapere aude.

Absalom
Posts: 718
Joined: Sat Sep 24, 2011 4:33 am

Re: The "Real Spacecraft" Thread

Post by Absalom »

Arioch wrote:Essentially, they had to disassemble and reverse-engineer a 40-year-old F-1 to figure out how it works. Not sure what that says about the current state of our aerospace industry.
Probably says that the documentation was either shoddy, or just not clear enough for what they were doing. I won't explain my source, but I know that a major long-lived IT product from a major corporation (most of you have probably never heard of it, yet directly benefited from it) needed to have critical pieces reverse-engineered a few times because the engineers who knew to use component W from company X instead of almost identical component Y from company Z had retired. I don't know it for a fact (my information source has since moved to other pastures) but I've heard it implied that they had to do it again in the last few years (yes, I'm talking about a currently available product).

There's also the fact that book-learning isn't reliably a way to make knowledge "real". Actually seeing the equipment and how it fits together can do a lot to cement that high-level knowledge, potentially even better than VR (though admittedly, I'm not certain anyone has managed definitive studies yet).
Trantor wrote:
Mr Bojangles wrote:They're not looking at it because it's the most efficient, most advanced, most powerful rocket engine.
Nothing of that except the power. It´s an inefficient dinosaur.
A breaktrough then, yes. But history today.
Do you keep track of NASA at all? ESPECIALLY with their track record, better something Ok now, than something Great never.
Trantor wrote:
Mr Bojangles wrote:They're looking at the F-1 because it works. It's proven technology that has never had a mission-scrubbing incident. Never once did one explode on the launch pad, or experience an issue that lead to abort of a launch.
So what? That´s like saying "Horses never burnt because of a leaking tank. Let´s not develope cars, stick to the horse!!1!"
At the current rate, if NASA tried to design a car it would result in an Edsel would get 4 miles per tank if not for the fact that it would never leave the drawing board.
Trantor wrote:
Mr Bojangles wrote:This will allow NASA to leverage its existing knowledge and capacities, and with the addition of a growing private space launch capacity, this seems a good path to follow.
This is a dead end and will result in trillions of wasted tax money. Leave it to ze Germans:
Image
If you want to build a new rocket, then get the EU to fund it.

Quite frankly, if I were a member of congress then around when the space shuttle was retired, I would have pushed for the entire Saturn 5 to be temporarily reactivated for precisely the "we already know it works" principle. Two successful test flights (or maybe even one) would likely be enough reverse-engineering iteration to nail down what needed to be done to build them in a "usable for unmanned launch" state.

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Spacecraft" Thread

Post by Arioch »

[post deleted] Trantor, if you can't post in a civil manner, then don't post here. If I have to delete another flame post or close another thread because of you, I will simply ban you from the forum. There will not be another warning.

Karst45
Posts: 785
Joined: Sat Mar 05, 2011 4:03 pm
Location: Quebec, Canada
Contact:

Re: The "Real Spacecraft" Thread

Post by Karst45 »

Mr Bojangles wrote:Rocketry is a fascinating topic. It seems so simple: get some fuel and oxidizer, put them in a tube with a nozzle on one end and light it off. But, it's so much more difficult than that. So many things to balance, so many tradeoffs to be made.
Tell me about it *Kerbal rocket exploding behind him* What did go wrong this time!

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Spacecraft" Thread

Post by Nemo »

Exploded? Add struts and more rockets.

Image

User avatar
Hālian
Posts: 766
Joined: Fri Sep 30, 2011 4:28 am
Location: Central Florida
Contact:

Re: The "Real Spacecraft" Thread

Post by Hālian »

Arioch wrote:[post deleted] Trantor, if you can't post in a civil manner, then don't post here. If I have to delete another flame post or close another thread because of you, I will simply ban you from the forum. There will not be another warning.
What'd he do?
Image
Don't delay, join today!

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Spacecraft" Thread

Post by Arioch »

CJ Miller wrote:What'd he do?
He went a flame too far. The matter has been dealt with, so let's not gum up the thread with it. You can PM me if you have concerns, but there's really nothing to be concerned about.
Nemo wrote:Exploded? Add struts and more rockets.
I take it then that KSP still doesn't appreciably model atmospheric drag. :D

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Spacecraft" Thread

Post by Nemo »

I appreciate the modeled cherry red glow of the burning air wrapping around my stock parts ship during the ascent. I also appreciate the copious amounts of duct tape which easily over comes it.


Honestly though, only real affect I can think of is youll break off your solar panels if you extend them prior to launch, but only because you cant duct tape (strut) them. Otherwise its just a fuel efficiency issue, which is just a fancy way of saying you didnt strap on enough rockets.

Karst45
Posts: 785
Joined: Sat Mar 05, 2011 4:03 pm
Location: Quebec, Canada
Contact:

Re: The "Real Spacecraft" Thread

Post by Karst45 »

Arioch wrote:
CJ Miller wrote:What'd he do?
He went a flame too far. The matter has been dealt with, so let's not gum up the thread with it. You can PM me if you have concerns, but there's really nothing to be concerned about.
Nemo wrote:Exploded? Add struts and more rockets.
I take it then that KSP still doesn't appreciably model atmospheric drag. :D

Nope that in update .20 or .21 (we are at .19)

But they did add atmospheric effect. With 2 other mods you could add a lots more realism.

Deadly reentry (do i need to explain?)
http://www.youtube.com/watch?v=8ovbMe6Sboo
and
Ferram Aerospace Research that add a lab to test aerodynamic and add the said effect on it
http://www.youtube.com/watch?v=VKX22RhqC60

Yes i like how Scott Manley do is test and youtube video, always adding some interesting space trivial.

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Spacecraft" Thread

Post by Arioch »

I like the RCS animations.

User avatar
Mr Bojangles
Posts: 283
Joined: Sat Mar 03, 2012 1:12 am

Re: The "Real Spacecraft" Thread

Post by Mr Bojangles »

Karst45 wrote:
Mr Bojangles wrote:Rocketry is a fascinating topic. It seems so simple: get some fuel and oxidizer, put them in a tube with a nozzle on one end and light it off. But, it's so much more difficult than that. So many things to balance, so many tradeoffs to be made.
Tell me about it *Kerbal rocket exploding behind him* What did go wrong this time!
Between Kerbal and actual models, I have sent many a rocket to its fiery doom. :D
Nemo wrote:Exploded? Add struts and more rockets.

<image snipped for brevity>
I am dying of laughter! Simply amazing. :lol:

User avatar
anticarrot
Posts: 43
Joined: Sat Apr 02, 2011 8:45 pm

Re: The "Real Spacecraft" Thread

Post by anticarrot »

Unfortunately Saturn V and SLS are also very silly rockets. The former was built to win a race (very well built as it happens, but it's still a silly optimisation metric) and the latter is being built to maintain NASA's work force (concentrated, incidentally, in two politically powerful states) which has historically been it's biggest defense against major programme cancellation. No one wants to sack 20,000 people in Florida and Texas when a major elections are always less than two years away.

There are many ways to give NASA more capability, but almost none of them require the LC-39 launch complex that those 20,000 jobs revolve around. It's been twenty sodding years since NASA has allowed itself to imagine a future (DC-X/X-33 in 1994) that required genuine institutional reform and didn't depend on a facility built for the needs of 1960s America. This has had the unfortunate effect of crippling NASA's ambitions. Forty years ago its major ambitions were building a space plane, building a space station, and going to mars, and there has been almost no change or growth in its long term goals since then.

If you want a modern version of the F-1 engine, the closest you'll get is the Merlin engine, which is actually flying, and evolving towards the D varient. If (and it's looking more like when) Falcon 9H flies, and if (and again, it's looking more like when) Space X solves the reusability problems, then Merlin-D will be as close as we ever want to get to the F-1. 8-)

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Spacecraft" Thread

Post by Arioch »

What is it specifically that you think is silly about SLS? If you want to put large payloads in orbit, then you need some kind of reliable, low-cost heavy lift rocket. Neither a spaceplane nor a DC-Y could fulfill this role. What's your alternative to something like the SLS?

I'm as sad as anyone about the abandonment of the DC-Y, but it was intended to lift relatively modest payloads around 9,000 kg, whereas the SLS is intended to lift payloads of between 70,000 to 130,000 kg. It's hard to build space stations or interplanetary exploration vehicles 9 tonnes at a time.

Post Reply