Space Things

[Dadhawk]

Originally Posted by Irace86.2.0

Firing up the engines is not an easy process. Musk was basically saying it is a delicate orchestra of pressure, temperature and timing in a sequence that needs to play out like a ballet. Convo starts at 9:20. I guess we will have to wait for the findings when they get released.

And there-in lies my concerns about StarShip as a launch vehicle from the Moon's surface. The LEM used hypergolic fuel, so as long as the fuel flowed there was going to be thrust. StarShip, like the booster, is dependent on the "orchestra" of too many parts in my opinion. But, like I said I'm no rocket scientist, I just know which rocket I'd rather be riding.

[Spuds]

Originally Posted by Unplugem

Finally, someone in this thread who can at least discern a sliver of truth.
Elon Musk literally means "scent of God." His name is blasphemous. He was born "privileged" to bloodline parents. His father was a pedo. His whole life is scripted; if you don't believe me, look into the book "Project Mars: A Technical Tale," written by satanic Nazi occultist and founding member of NASA, Werner von Braun. In the book, he writes that a man named "Elon" will lead humanity in colonizing Mars.
Now Werner von Braun was an initiated Freemason/Jesuit, who helped direct the fake moon landing. The man was not stupid; he was very well informed of the scripted plans that were being executed in order to brainwash the public into believing in "outer space;" Just look at what he had written on his tombstone when he died.
Elon Musk, aka Lone Skum, is a puppet, who follows the script given to him by his superiors.

Can't you just make your own thread and stop trolling in everyone else's?

[Spuds]

Originally Posted by ZDan

He has a bachelor of *arts* in "physics". I.e., he ain't any kind of physicist. And he's certainly not an engineer either. I am an aerospace engineer and I have *some* knowledge of materials and IMO he isn't any kind of expert there either. What he is great at is exploiting others to advance himself. He is also a tyrant and it is well known that he has handlers to keep him from interacting with the people actually doing the hard work because he might fire them for disagreeing with his idiotic "ideas".

To be fair, my mom has a bachelor of arts in computer science. And she's a fine (retired) engineer.

Musks superpower is that his daddy is rich and he has rich friends. If a sucker is born every minute, a 1%-er sucker is born every 2 hours, which still leaves a lot of rich suckers.

[Dadhawk]

Originally Posted by Spuds

To be fair, my mom has a bachelor of arts in computer science. And she's a fine (retired) engineer.

I have a bachelor of science in Philosophy, the last time I checked the only one ever granted by my undergrad school. I took enough math and science courses as electives to qualify.

I always thought having a B.S. in Philosophy seemed totally appropriate.

[bcj]

Originally Posted by Irace86.2.0

It would be nice to be accelerating the whole time, which is the fastest way to get there, but that would be miserable for the crew. If we had the fuel to do that then the trip would be shorter, but half the time would be positive acceleration and then half the time with negative acceleration (deceleration). Imagine pulling g's or having a steady acceleration for weeks just to shorten the trip from six months to days or weeks. It would be terrible.

We're coping with this 24/7 right here in this gravity sink. WTF?
There's fuel available without dinking around with the moon or Marz.

[Dadhawk]

Originally Posted by Irace86.2.0

...Imagine pulling g's or having a steady acceleration for weeks just to shorten the trip from six months to days or weeks. It would be terrible.

Actually if you could accelerate the ship at 1g or less constantly it would feel like Earth and potentially provide "artificial" gravity wouldn't it?

At an acceleration of 1G you can reach the speed of light (in theory) in about one year with minimal effect.

When there is no acceleration (you are coasting) you are experiencing zero g which is just about as bad to me.

[Irace86.2.0]

Originally Posted by Dadhawk

And there-in lies my concerns about StarShip as a launch vehicle from the Moon's surface. The LEM used hypergolic fuel, so as long as the fuel flowed there was going to be thrust. StarShip, like the booster, is dependent on the "orchestra" of too many parts in my opinion. But, like I said I'm no rocket scientist, I just know which rocket I'd rather be riding.

They have their reasons. There is a lot of good reasons discussed here:

https://everydayastronaut.com/abort-towers/

[Irace86.2.0]

Originally Posted by ZDan

He has a bachelor of *arts* in "physics". I.e., he ain't any kind of physicist. And he's certainly not an engineer either. I am an aerospace engineer and I have *some* knowledge of materials and IMO he isn't any kind of expert there either. What he is great at is exploiting others to advance himself. He is also a tyrant and it is well known that he has handlers to keep him from interacting with the people actually doing the hard work because he might fire them for disagreeing with his idiotic "ideas".

Again, I didn't say he was an engineer, and also, I didn't say he was a physicist. He has a degree in physics is all I said, and I said he clearly carries a passion for engineering. I said he clearly is knowledgable about the specifics beyond what your typical CEO would know. I'm not saying he is the same as, but I am saying he talks like someone who is a project level manager. Typically when presenting a car or a product, the CEOs barely give much depth about the specifics. They leave that to others to know, but he either has a significant interest in the subject matter, so he wants to know, or he is involved in decision making processes, so he needs to know. Regardless of the reasons, I'm personally impressed with his level of knowledge of the systems and components and engineering requirements of the cars, batteries, rockets, engines, etc of his companies, especially for someone who is not an engineer, who is not a physicist, who has a BA degree and who is a rich, spoiled brat. What those videos I posted, and he doesn't sound like Billy Madison, which is who you paint him out to be.

We can agree to disagree on the subject.

[Irace86.2.0]

Originally Posted by bcj

We're coping with this 24/7 right here in this gravity sink. WTF?
There's fuel available without dinking around with the moon or Marz.

Is English a second language for you? I ask because you seem to speak in unintelligible ways. That's not a dig. I'm just curious because your sentences are incomplete and indirect. We're coping with what? This what? With gravity? With fuel payload constraints?

Yes, we have plenty of fuel here, but we need it up there, so we can go to Mars and back easier. The Starship is 90% fuel with 4600 T of propellant, but only has a payload of 100-250 T depending on whether the rocket will be reused or not. That is because, as you put it, we live in this [large] gravity sink, and most of that propellant is used to escape earth's gravity. The energy needed to escape the moon's gravity is far less, so suddenly that payload gets much larger, or refueling Starship means there is a lot of unspent fuel that can be used on a mission to mars.

Let's put it this way: Say you want to drive around the equator at 25,000 miles, but you couldn't refuel; at 25 mpg, that is about 1000 gallons or having a fuel tank that weighs 8,000 pounds; probably need a bigger vehicle, and now it probably doesn't get 25 mpg; wouldn't it be easier to refuel along the way instead?

Option A) we can build an even bigger rocket than Starship to have enough fuel to escape earth's gravity, that can accelerate in space to mars, can decelerate to land on mars and then launch to escape Mar's velocity and have enough fuel to accelerate to earth and decelerate to land, but we must remember that 90% of the rocket is already propellant, so how big would this rocket be?

Option B) we can launch a bunch of payloads of fuel to orbit, launch a final large rocket to space and refuel before going to mars and back.

Option C) we can launch less payloads of fuel to orbit, launch a final rocket into space that doesn't need to be as big, refuel before going to mars, and then refuel on mars before heading back to earth.

Option D) we could refuel in space, go to the moon, refuel before going to mars, refuel on mars then head back to the moon and go back to earth.

Say we could do Option D): would we have enough fuel to reach higher velocities, so we could cut the time to mars shorter? Probably. It is the best chance to get there faster, if the procession of the planets allow a faster route, but going back to what I was saying before, we don't have a ship large enough that holds enough fuel such that we could flat out accelerate half the distance to mars and decelerate the second half of the distance. Our best scenario is refueling on the moon or in orbit around the moon, so Starship is full when it leaves the moons gravity, and then it will burn the rockets to about 50% fuel (minus burnoff), and then it will coast for weeks to months before igniting the burners to slow the rocket before landing on Mars, where it will then refuel, launch into space with refueling payloads, return to refuel, and then leave from space refueled.

Is refueling in space and the back and forth costing more time than saving time with a slower straight shot? Probably not. Average velocity would go up and trip time would decrease going faster. This is like doing a cannonball run from NY to LA and saying, 'wouldn't it be better traveling 65 mph and stopping less to refuel because you get better gas mileage than traveling at 110 mph and needing to refuel more often?" For a trip from NY to LA, that speed differential is a difference of saving 12 hours, but the refueling time is not 12 hours, so the extra few stops is entirely worth it.

[Irace86.2.0]

Originally Posted by Dadhawk

Actually if you could accelerate the ship at 1g or less constantly it would feel like Earth and potentially provide "artificial" gravity wouldn't it?

At an acceleration of 1G you can reach the speed of light (in theory) in about one year with minimal effect.

When there is no acceleration (you are coasting) you are experiencing zero g which is just about as bad to me.

Yeah, 1G would be ideal, for sure. Maximum g's in a rocket is around 3g. Less ideal. Angular acceleration is a better mechanism for inducing gravity.

Obviously we can't reach the speed of light, but I get what you mean.

My point isn't a practical one; it was more of a theoretical one that the fastest a rocket with unlimited potential to accelerate would necessarily have to spend half its time decelerating too. Such a hypothetical "fastest trip" would be miserable, accelerating at levels of G that would crush a human. As you pointed out, even at 1G the ship would accelerate to the speed of light in a year. As it stands, we don't have the ship size with enough thrust power and energy to go at or beyond G for very long, so this isn't an issue. We are talking second/minutes, not hours or days or weeks. At best we can hope to reach a faster coasting velocity that could shorten the trip considerably, but I don't know the math on what we could do with rockets at the thrust and scale of the ones we have with the need to decelerate and land at the end of a long trip when we have burnoff too.

Where is Bob Lazar with a gravity machine?

[NoHaveMSG]

Originally Posted by Irace86.2.0

Is English a second language for you? I ask because you seem to speak in unintelligible ways. That's not a dig. I'm just curious because your sentences are incomplete and indirect. We're coping with what? This what? With gravity? With fuel payload constraints?

You are too literal. Not everyone speaks directly, accounting for every qualifier a statement may infer the way you do. We have had misunderstandings in the past due to this.

As Dadhawk already said, I always thought the idea behind the 1g acceleration/deceleration was for gravity simulation

[Dadhawk]

Originally Posted by Irace86.2.0

They have their reasons. There is a lot of good reasons discussed here:

https://everydayastronaut.com/abort-towers/

This is talking about using liquid fueled and "built in" escape rockets instead of the solid fuel rocket towers used previously. there was some discussion of hypergolic engines but it was mostly positive other than the fuels are toxic to handle.

The situation I'm talking about is not the emergency situation but the ascent from the Moon. Maybe Starship's size is what requires more standard liquid fuels, but it does introduce an ignition risk.

[Irace86.2.0]

Originally Posted by NoHaveMSG

You are too literal. Not everyone speaks directly, accounting for every qualifier a statement may infer the way you do. We have had misunderstandings in the past due to this.

As Dadhawk already said, I always thought the idea behind the 1g acceleration/deceleration was for gravity simulation

In a practical sense, it can't be done linearly. It can only be done with angular acceleration.

[NoHaveMSG]

Originally Posted by Irace86.2.0

In a practical sense, it can't be done linearly. It can only be done with angular acceleration.

I wasn't talking about practicality, I just explained my understanding of what I thought the primary reason for the accel/decel idea behind long distance space travel was. There are quite a few obstacles to it, I thought it was neat as opposed to just rotating the craft.