First US lunar lander in more than 50 years rockets toward moon with commercial deliveries

submitted by neolib from apnews.com

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[–]SMCAB 3 insightful - 2 fun3 insightful - 1 fun4 insightful - 2 fun -  (16 children)

The last time the U.S. launched a moon-landing mission was in December 1972. Apollo 17’s Gene Cernan and Harrison Schmitt became the 11th and 12th men to walk on the moon, closing out an era that has remained NASA’s pinnacle.

Yet they threw away all the data and info or lost it all? A mother keeps her little rascals kindergarten paperwork in a tote for eternity, yet NASA lost all the data pertaining to its "pinnacle." I think their pinnacle is swindling 71 million dollars a day from you.

I'll bet anything those aren't private companies either. Friends of the program I say.

Edit: They now have engine problems and have the solar panels facing the wrong way? For fucks sake. Why would the propulsion system of the lander have anything to do with this? The lander isn't flying the rocket is.

[–]Tom_Bombadil 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 1 fun -  (15 children)

They now have engine problems and have the solar panels facing the wrong way? For fucks sake. Why would the propulsion system of the lander have anything to do with this? The lander isn't flying the rocket is.

You're spot on.

Have you seen the evidence proving rockets can't function in space?
Rocket [exhaust] thrust pushes off of the atmosphere, and that's why they use second stage rockets. Analogous to a jet ski impeller forcing water out into/against a lake (body of water), etc.

The second stage rockets diffusers are tuned for efficiency the lower pressure environment of the upper atmosphere.

Zero atmospheric pressure in space = zero rocket efficiency. Period.

An inescapable fact of rocket propulsion.

I'm curious about the solar panel as they relate to engines. Maybe they have ion engines, or another tech. But probably not.

Like you said, They'll hoax away for $70 million a day (paraphrased).

[–]Alienhunter 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 1 fun -  (9 children)

Newton's third law of motion.

You are confusing a jet engine which indeed requires air to run with a true rocket engine, that just blasts out matter at high velocity to produce thrust according to Newton's third law.

It's the same phenomenon as when you sit on a cart and throw baseballs. You'll move backwards as a result of the force of your throw. No atmosphere necessary.

[–]Tom_Bombadil 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (8 children)

No atmosphere necessary.

Apply this concept to a jet ski. It uses an impeller to force a jet of water out the back and push against the body of water to propel it forward.

Now take a jet ski out of the water, and assume an infinite supply of water jetting out of the back into the air.

Do you believe the jet ski will be propelled forward, by high density water in the air? It still has the equal and opposite reaction.

Rocket exhaust works on the atmosphere in the same way that the water jet works against a body of water.

It's the exact same principle.

[–]Alienhunter 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 1 fun -  (7 children)

Assuming the Jetski has an infinite amount of water, it would work in space as there's minimal friction to overcome, merely on the third law principal.

A Jetski also would be propelled forward in air as well however this thrust is simply insufficient to counter both gravity and friction.

We tend to visualize this as a push against something in terrestrial situations but it isn't how it actually works. Think about how if you use a water hose at high pressure you can feel the push back before the stream is in contact with anything. Or for a more extreme situation, a gun.

You could easily use a gun to propel yourself in space same as throwing a rock or just pissing would also produce thrust. It's just not going to be very effective when compared to a rocket.

The rockets used in a vacuum do need to be designed differently than ones used in atmosphere for practical purposes. (You can't light a firework in space for example because there's no oxygen to combust) this is solved in space rocket designs by having the reaction take place in a chamber that has the necessary agents for combustion already prepared.

Essentially you bring your own air to "push off against".

[–]Tom_Bombadil 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (6 children)

A Jetski also would be propelled forward in air as well however this thrust is simply insufficient to counter both gravity and friction

The actual work done to move the jetski in water is not produced by the equal and opposite push from the water jet.

Be honest about this. The propulsion of a water jet on air vs water jet in water is incomparable. The amount of work done (force x distance) in the air is literally negligible.

This same principle applies in space, where the is literally nothing to push against. Zero work can be done on the vacuum of space. It literally vacuums the exhaust gases out of the rocket as quickly as they are produced.

Literally vacuumed out.

Also, Gravity doesn't disappear in space. The Earth's radius is 7000 miles, and the atmosphere is 100 miles max.
The rocket is still feeling 95% of gravity's effects continuously.

Meanwhile, the rocket gases are vacuumed out of the rocket engine.

Bro. Every bit of interplanetary space travel is 110% impossible with rocket propulsion.

It's horrid reality. But it's the actual factual truth of physics.

[–]Alienhunter 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 1 fun -  (5 children)

The actual work done to move the jetski in water is not produced by the equal and opposite push from the water jet.

That's how it would work in a vacuum though. And that's how rockets work.

If you've got unlimited rocks you could just build a space vehicle that consists of a catapult, hurling rocks into the black to push you forward. Slowly and surely. Doesn't matter what the shit is, you take some mass and expell it in the opposite direction of where you want to go.

The problem in real world examples is we don't have unlimited fuel, fuel is heavy and it's very difficult to carry enough of it to go to wherever you want since you need to accelerate to about 40,000 kph to escape velocity.

Low Earth orbit is like 30,000 kph for example so you're already 3/4ths of the way there with that. Gravitational pull at orbital velocities really is less about overcoming the pull and more about shaping your orbital vector.

[–]Tom_Bombadil 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (4 children)

That's how it would work in a vacuum though. And that's how rockets work.

Then why wouldn't it work with water in air on a jet ski? It's the identical principle.

And liftoff consumes the 1st stage rocket in mid atmosphere less than 25 miles.

There's more than 200,000 more miles to the moon with the second stage rocket, and maybe the main unit rocket.

You think they can travel another 100,000 miles directly against 95% gravity? The Earth's radius is 7000 miles.

The rocket leaves the atmosphere at 7100 miles from Earth's center of G. The inverse square law of gravity doesn't shrink significantly for a huge distance.

It's easily 8-9 newton's of constant gravity, with a seriously diminished propulsion; assuming your model theory. Hopefully, we're at least in agreement about this.

In reality, the vacuum of space would draw out the rocket exhaust as quickly as it's produced.

The foundational propulsion mechanism between a rocket and a jet engine is the same.

The method of generating thrust differs, one is strictly combustion.
The other is a positive feedback loop of compressing ambient air (oxygen source) in a turbine, and mixing in fuel for enhanced combustion, which generates increased airflow and compression, [in positive feedback loop] until the sufficient thrust is generated.

Both depend upon high velocity gaseous exhaust applying force against the atmospheric environment.

I realize you attribute the equal and opposite concept in space, but that can't happen.

Pressure requires a surface to compress against. The atmosphere is compressed against the Earth's surface and gravity.

There's no opposing compression surface in a rocket nozzle cone. The vacuum draws it out without resistance.
Zero compression. Zero thrust.

[–]Alienhunter 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 1 fun -  (3 children)

Again you are simply misunderstanding the third law of motion. No atmosphere is necessary to push against. A jet engine would work fine in a vacuum as a source of thrust assuming you brought your own air to use. (In reality since a Jet engine needs to suck in air from the surrounding atmosphere to work it won't work in space) rockets simply bring everything with them they need to function in space.

You also aren't fighting directly against Earth gravity. Once you achieve orbital velocity which in terms of energy needed is absolutely the biggest hurdle, then you need relatively little energy and thrust to make course corrections as you're in a vacuum condition with no air resistance and therefore no drag. In an orbital velocity that 95% of normal ground level acceleration works to keep you in an orbit and also can be used to gravitationally slingshot you out further if you are smart about how you go about it.

Keep in mind that you are at about 75% of escape velocity in low earth orbit. The amount of energy you need to escape from low earth orbit is far lower than the amount of energy you need to reach low earth orbit in the first place. The amount you need to reach the moon is even less than that as the moon is still in earth orbit.

It's one of the counter intuitive peculiarities of orbital physics we don't consider in terrestrial situations. Same as how the energy required to leave the solar system entirely is much lower than the energy required to go to the sun despite the fact the sun is much closer. If you wished to send a probe to impact the sun you'd have to work against the Earth's velocity to place the probe in an orbit that had the probe lose most of its relative velocity against the sun which is much harder to do than get the probe a bit more velocity to do a slingshot maneuver around the sun and achieve a parabolic orbit that will see it fly out uncontrollably into the void.

[–]Tom_Bombadil 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (2 children)

Again you are simply misunderstanding the third law of motion. No atmosphere is necessary to push against.

Your premise assumes that the equal and opposite reaction in the third law will apply force in a vacuum.

For a gas to apply force, it has to apply pressure. But had molecules can only apply pressure to one another if they're contained.

The atmosphere functions at a container with back pressure at 14 lbs/(in2).

The inertia of atmosphere (resistance to gaseous expansion), applies back pressure to the exhaust gases, which applies back pressure against the rocket surfaces, and the equal and opposite sequence does work on the rocket and it's is moved.

Combustion in a vaccine doesn't have an enclosure of atmosphere.

In a vacuum, as soon as the molecules ignite and expand they are forced into empty space without resistance.

No inertia of gases in the atmosphere to create back pressure. The gases expand without resistance into the vacuum of space.

No back pressure, and no compression of gases, and no build up of pressure against the surface of the rocket.

No work applied to the rocket. No movement.

There's no way around this reality. The rocket exhaust won't build up back pressure (thrust), which means there's no efficiency.

Bro. This is physical reality. I don't like it either, but there's nothing for it.

[–]SMCAB 2 insightful - 2 fun2 insightful - 1 fun3 insightful - 2 fun -  (1 child)

I absolutely have. A rocket engine, or air propulsion cannot work in a vacuum. There is zero resistance to push anything forward. It's so crazy. I've seen all of the videos of true vacuums built and propulsion inside that can't even move a flag. Everything NASA(US Defense Dept) tells you dies under the weight of its own details.

It just baffles me how Mr. Pettit stands on a stage to this day and claims they can't solve the "Tyranny of the Rocket Equation", which is how to carry enough fuel for their payloads, and that we can't leave "low earth orbit", and yet here we are going to the moon again. It's astounding.

[–]Tom_Bombadil 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (0 children)

"Tyranny of the Rocket Equation", which is how to carry enough fuel for their payloads, and that we can't leave "low earth orbit", and yet here we are going to the moon again. It's astounding.

This.

And they're completely omitting the zero propulsion in space detail.

[–]SMCAB 2 insightful - 2 fun2 insightful - 1 fun3 insightful - 2 fun -  (2 children)

Look into Hubble if you haven't. Just a couple quick notes. The specs of the Hubble telescope, match the specs of the telescope on the plane they call SOFIA. That plane flies in our atmosphere. Some believe that this is what's actually taking the pictures thay claim the Hubble is taking. In fact, they have both released pictures on the same day that match eachother. That makes no sense.

If you study Orbital Degredation, the math says that the Hubble should have plummeted into our oceans years ago, yet they keep "pushing it" back into place. They do not fly missions there to reload the "propulsion" that supposedly keeps it in place. Yet somehow they are able to just push it back into place, without it flying away perpetually, which is exactly why they tell you a voyager type probe keeps flying away perpetually is possible. They push it and it just keeps going because there is nothing to stop it. Yet they fly so close to planets, but never get caught in orbit, but they have no propulsion to get out of orbit.

It's all bullshit.

[–]Tom_Bombadil 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (0 children)

It's all bullshit.

99%.

Near earth orbit is possible. They can launch satellites into orbit.

They can slingshot it out of the atmosphere.

[–]Alienhunter 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (0 children)

Once you are in orbit you don't need that much fuel to maintain the orbit. Over long periods of time gravitational irregularities and atmospheric drag do cause low earth orbit satellites to fall out of orbit and burn up but these effects are minimal and only build up over time, so long as you keep things high enough and prevent them from dipping back into the atmosphere they can maintain an orbit for many years on a small amount of fuel.

The voyager probes were able to go past all those planets without falling into an orbit essentially because they were going way to fast. The point of the voyager probes was essentially to fly them out as quickly as possible during a planetary conjunction that allowed for relatively easy access so they could snap pictures. The consequence of sending them out quickly is that they are going too fast to stop afterwards so they just fly past. It was the same with the recent probe to Pluto, in order to get the probe there in a reasonable amount of time, which is still more than a decade, they need to fly it so fast that it's prohibitively expensive to slow it down and insert it into an orbit on the other end.