Atmospheric re-entry has always been the most interesting part of space flight to me. I didn't even know her occupation existed until seeing this video but that would be a dream job for me. Ever since I saw Apollo 13 and how it showed the re-entry in an awesome display of the hardest part that we have to deal with.
Isn't it the pressure wave in front of the heat shield that forms ionized plasma which creates the highest amount of heat compared to the lower altitude which has more friction, but less heating issues due to the speed being reduced from the higher altitudes? If I remember correctly, the craft will go through a aerobraking maneuver to slow down in the upper atmosphere and then fall back to earth after the velocity is bled off? Similar to the Apollo capsule?
Just reading some of the comments here. You guys need to keep in mind the shape of the heat shield. It makes an oblique shock wave at a large angle, which ends up dumping most of its energy in the air itself and makes a huge amount of wave drag (drag as a result of the shock wave pressure jump). This is great for reentry, and the physical shield itself can take the rest of the energy that came from stagnating the flow up to itself for the amount of time the capsule is at huge speeds. So the benefits are less weight, less fuel since less maneuvering is needed (less weight), and a simpler design. This is why Apollo was pretty much the same design, and it's why supersonic aircraft have sharp edges; sharp edges help make the wave angle lower, which reduces wave drag (it doesn't exactly affect whether it's a strong or weak shock, that's another story, but it's usually a weak shock in nature). "But then more energy heats up the aircraft", yes, it does, but remember most supersonic aircraft in service don't cruise over mach 3.
One thing i don't understand in the return logic is why not flip the ship in reverse and have a controlled burn to slow it. Considering it will be a discard, having a special tank just for that sole purpose would probably be much more efficient than having a very high speed at return landing since it could mean a possible failure. A successful mission is managing your odds. You cut here to add there, add here cutting there. Of course cost wise it would be extra fuel both up and back since extra weight means more fuel for liftoff but in the end it pays off in the sense that you don't have to expose the craft to high speed return except for an emergency case. Meh just a ramble/rant.
Rok Adamlje I already took that to note, didn't you read? Even so, if that's the concern for you, then note that fuel would be taken to orbit on a different rocket than the one that they would strap Orion to. Sigh.
Sorry, I guess I didnt see the expand button to see the whole post On the other hand, PICA is rated for higher temperatures, but supposedly has harder application in large heatshields.
But if it is slowed down, how will they know that the heat shield will work when they arrive from/to Mars. Because interplanetary travel involves traveling very fast. So this is a test to see whether the heat shield will hold for when they travel back to Earth.
I was wondering if these heat shields could be used or slightly modified and used under a landing pad to deflect hot rocket exhaust plume heat & gases, reducing the big dust clouds appearing upon landing/reentry?
heat shields are deteriorative, they lose material upon being used so it would have to be replaced constantly and the expelled material would be the dust clouds so probably not.
what is the module attached to Orion at the end ? A marina deep space module ? moon landing ? thanks for the answer. It would be great to have an actual plan for Orion.
If it goes much faster than the Apollo missions, the G force will be higher for astronauts. Can't we think of a better way to lower the speed ? Like orbital maneuvers or rendez vous with an orbital station ? Or just extra thrust power to slow the craft, the weight ratio vs the heat shield would be better this way. When the Eagle landed on the moon they didn't use any shield after all.
They would aerobrake, or do a aerocapture and try reentering the atmosphere after an orbit. This can mitigate the G loads put on the craft and the astronauts. When Apollo reentered the Earths atmosphere, it wasn't a ballistic curve, but it actually used the air-frame to create some lift and bleed off speed by leaning forward some. Kind of like a rock skipping on the water. It slows down enough before dropping down at a safe speed. Pertaining to "extra thrust power", what ever energy used to get up, you'll have to experience the same amount of energy going down. So, the amount of fuel you'll need to slow down to get into orbit or reenter the atmosphere at a slower speed would require much much more fuel and thus a much much bigger rocket. This isn't efficient and could quite possibly cause more problems. When the Eagle, or LEM (Lunar Excursion Module), landed on the moon, there were was no atmosphere to slow down the craft, so there were no need for a heat shield. Instead, the Command Module used its engines to put itself and the LEM into a lunar orbit around the moon. To land, the LEM had just the right amount of fuel to counter the gravity and horizontal velocity to land safely. Being how light the LEM is and how low the Moon's gravity is, not as much fuel would be needed as if they wanted to land a craft like that onto Earth. Also, the LEM splits into two after their mission on the moon was complete leaving the bottom half (descent stage) on the moon while the upper stage returned to lunar orbit to meet up with the Command Module and head back home. I hope this answers your questions.
While it is possible to reduce the speed with engines before hitting the atmo, the dV required would be very high (in other-words, would require loads of fuel, too much to carry with it). It would take as much force (dV for the rockety folk) to slow it down as it did to make it depart in the first place (kinda), but simply doubling the fuel won't do, because of the law of diminishing returns (basically means to lift even a little more fuel into orbit would require a massively larger rocket at launch) They could do a couple passes through the upper atmo to slow it down a bit, but a) narrow margin for error (to low, burns up; too high; flung back into a solar orbit), b) the craft would still be on a very wide orbit after the first pass, perhaps taking days between passes (so again, more onboard resources would be needed, more weight to lift initially). They didn't need a heat shield when landing on the moon as there is no atmo, so the craft doesn't generate friction as it descends. But the command module the astronauts returned to Earth in did have a head shield, but it didn't need to be as strong as Orions because a Lunar return won't be traveling as fast as a return from another planet. Basically, play KSP! Then you'll get a ruff idea of the problems involved!
the slowing effect of the atmosphere is too great not to use, although there definitely can be something to slow it a bit so the G forces arent too high.
Responding to your and other comments on the Orion heat shield (RUclips doesn't give me a reply tab on your comments...) Regarding an (additional) retro-thruster. To do that, you'd have to add a thruster built for it, fuel etc. Probably would increase the weight by a third, and be disposable, cost millions. Vs. heavily tested tech. In other words no chance. The video makes it sound like new tech, whereas it's just an upgrade. Some posts regarding this test on most websites make reference to Space-X et. al. They are still planning to test crew delivery systems for Low Earth Orbit, delivery to the ISS. there is no comparison to the tech needed for Orion. For more on this there are several "how high up are they" illustrations showing the relative highlights of the ISS, you average satellite and the orbital heights of the Apollo missions...again, no comparison.
Extreme Tutorials Yes she is - and smart too. When I look in the mirror I see someone who is not as pretty and nowhere near as smart, but I can do a good impression of Maurice Chevalier singing "Thank heaven... for NASA engineers... for engineers go further into space everyday..."
"I saw worse crimes committed by Americans in the Iraq war after 9/11, is President Bush in Prison for war crimes? And shaking hands with Prime Minister Johnson should punished by death! (By Heaven of course)!" May God save the humans left after Armageddon!" - Jesimiel Millar Fernåndez - 87
Atmospheric re-entry has always been the most interesting part of space flight to me. I didn't even know her occupation existed until seeing this video but that would be a dream job for me. Ever since I saw Apollo 13 and how it showed the re-entry in an awesome display of the hardest part that we have to deal with.
Isn't it the pressure wave in front of the heat shield that forms ionized plasma which creates the highest amount of heat compared to the lower altitude which has more friction, but less heating issues due to the speed being reduced from the higher altitudes? If I remember correctly, the craft will go through a aerobraking maneuver to slow down in the upper atmosphere and then fall back to earth after the velocity is bled off? Similar to the Apollo capsule?
Just reading some of the comments here. You guys need to keep in mind the shape of the heat shield. It makes an oblique shock wave at a large angle, which ends up dumping most of its energy in the air itself and makes a huge amount of wave drag (drag as a result of the shock wave pressure jump). This is great for reentry, and the physical shield itself can take the rest of the energy that came from stagnating the flow up to itself for the amount of time the capsule is at huge speeds.
So the benefits are less weight, less fuel since less maneuvering is needed (less weight), and a simpler design. This is why Apollo was pretty much the same design, and it's why supersonic aircraft have sharp edges; sharp edges help make the wave angle lower, which reduces wave drag (it doesn't exactly affect whether it's a strong or weak shock, that's another story, but it's usually a weak shock in nature). "But then more energy heats up the aircraft", yes, it does, but remember most supersonic aircraft in service don't cruise over mach 3.
Isn't the heat from friction neglectable, compared to the pressure heat from PV=nRT?
Orion is not the only thing that needs a heat shield, dang Molly...
Keep ur arnold palmer zipped up pervy.
So hot! And the shield too...
Antonio Santos nice
What are the similarities and differences between the Apollo ablative materials and the Orion ablative materials?
What are the inner material properties of this shield ? i am very curious.
Whoa cool but how do you make a heat sheid?
I agree. The friction slowes the spacecraft as well as heating it. It's physics.
question: why is there a black paint job near the windows?
Will the shield break if you use it once?
One thing i don't understand in the return logic is why not flip the ship in reverse and have a controlled burn to slow it. Considering it will be a discard, having a special tank just for that sole purpose would probably be much more efficient than having a very high speed at return landing since it could mean a possible failure.
A successful mission is managing your odds. You cut here to add there, add here cutting there.
Of course cost wise it would be extra fuel both up and back since extra weight means more fuel for liftoff but in the end it pays off in the sense that you don't have to expose the craft to high speed return except for an emergency case.
Meh just a ramble/rant.
Fuel is heavy...
Rok Adamlje I already took that to note, didn't you read? Even so, if that's the concern for you, then note that fuel would be taken to orbit on a different rocket than the one that they would strap Orion to.
Sigh.
Sorry, I guess I didnt see the expand button to see the whole post
On the other hand, PICA is rated for higher temperatures, but supposedly has harder application in large heatshields.
But if it is slowed down, how will they know that the heat shield will work when they arrive from/to Mars. Because interplanetary travel involves traveling very fast. So this is a test to see whether the heat shield will hold for when they travel back to Earth.
aserta *nods*
Very beautiful inginer!
It helps to have lots of hot girls working in the heat shield team, your colleagues need to know how to cooldown :-)
I was wondering if these heat shields could be used or slightly modified and used under a landing pad to deflect hot rocket exhaust plume heat & gases, reducing the big dust clouds appearing upon landing/reentry?
heat shields are deteriorative, they lose material upon being used so it would have to be replaced constantly and the expelled material would be the dust clouds so probably not.
what is the module attached to Orion at the end ? A marina deep space module ? moon landing ? thanks for the answer. It would be great to have an actual plan for Orion.
That would be a Delta Cryogenic Second Stage, and a European-made service module which is based on that of the ATV.
If it goes much faster than the Apollo missions, the G force will be higher for astronauts. Can't we think of a better way to lower the speed ? Like orbital maneuvers or rendez vous with an orbital station ?
Or just extra thrust power to slow the craft, the weight ratio vs the heat shield would be better this way. When the Eagle landed on the moon they didn't use any shield after all.
They would aerobrake, or do a aerocapture and try reentering the atmosphere after an orbit. This can mitigate the G loads put on the craft and the astronauts. When Apollo reentered the Earths atmosphere, it wasn't a ballistic curve, but it actually used the air-frame to create some lift and bleed off speed by leaning forward some. Kind of like a rock skipping on the water. It slows down enough before dropping down at a safe speed.
Pertaining to "extra thrust power", what ever energy used to get up, you'll have to experience the same amount of energy going down. So, the amount of fuel you'll need to slow down to get into orbit or reenter the atmosphere at a slower speed would require much much more fuel and thus a much much bigger rocket. This isn't efficient and could quite possibly cause more problems.
When the Eagle, or LEM (Lunar Excursion Module), landed on the moon, there were was no atmosphere to slow down the craft, so there were no need for a heat shield. Instead, the Command Module used its engines to put itself and the LEM into a lunar orbit around the moon. To land, the LEM had just the right amount of fuel to counter the gravity and horizontal velocity to land safely. Being how light the LEM is and how low the Moon's gravity is, not as much fuel would be needed as if they wanted to land a craft like that onto Earth. Also, the LEM splits into two after their mission on the moon was complete leaving the bottom half (descent stage) on the moon while the upper stage returned to lunar orbit to meet up with the Command Module and head back home.
I hope this answers your questions.
While it is possible to reduce the speed with engines before hitting the atmo, the dV required would be very high (in other-words, would require loads of fuel, too much to carry with it). It would take as much force (dV for the rockety folk) to slow it down as it did to make it depart in the first place (kinda), but simply doubling the fuel won't do, because of the law of diminishing returns (basically means to lift even a little more fuel into orbit would require a massively larger rocket at launch)
They could do a couple passes through the upper atmo to slow it down a bit, but a) narrow margin for error (to low, burns up; too high; flung back into a solar orbit), b) the craft would still be on a very wide orbit after the first pass, perhaps taking days between passes (so again, more onboard resources would be needed, more weight to lift initially).
They didn't need a heat shield when landing on the moon as there is no atmo, so the craft doesn't generate friction as it descends. But the command module the astronauts returned to Earth in did have a head shield, but it didn't need to be as strong as Orions because a Lunar return won't be traveling as fast as a return from another planet.
Basically, play KSP! Then you'll get a ruff idea of the problems involved!
the slowing effect of the atmosphere is too great not to use, although there definitely can be something to slow it a bit so the G forces arent too high.
Responding to your and other comments on the Orion heat shield (RUclips doesn't give me a reply tab on your comments...) Regarding an (additional) retro-thruster.
To do that, you'd have to add a thruster built for it, fuel etc. Probably would increase the weight by a third, and be disposable, cost millions. Vs. heavily tested tech.
In other words no chance. The video makes it sound like new tech, whereas it's just an upgrade.
Some posts regarding this test on most websites make reference to Space-X et. al.
They are still planning to test crew delivery systems for Low Earth Orbit, delivery to the ISS. there is no comparison to the tech needed for Orion. For more on this there are several "how high up are they" illustrations showing the relative highlights of the ISS, you average satellite and the orbital heights of the Apollo missions...again, no comparison.
I think she means "farther" since it's literal and not figurative. Nonetheless, she's way smarter than I'll ever be.
oooo Molly, i'm thinking about friction alright
how do the Russian Cosmonauts train for increased Gs during launching and reentry proceedures to and from the ISS. I know how the US does it.
I'm very interested
In first orian sounded like Oreos or because I’m craving them rightnow
Forgot the boosters...
Kaiip įdomu stebėti savo atvirumo klaidas emocijų atžvilgiu....
Smart and hot... As soon as she start talking I totally forgot about Orion xD
She is DAMN good looking.
Extreme Tutorials Yes she is - and smart too. When I look in the mirror I see someone who is not as pretty and nowhere near as smart, but I can do a good impression of Maurice Chevalier singing "Thank heaven... for NASA engineers... for engineers go further into space everyday..."
Stop ozone depletion.
Yes. Really.. really hot
Hi
"I saw worse crimes committed by Americans in the Iraq war after 9/11, is President Bush in Prison for war crimes? And shaking hands with Prime Minister Johnson should punished by death! (By Heaven of course)!" May God save the humans left after Armageddon!"
- Jesimiel Millar Fernåndez
- 87
I HATE THESE 2 MIN VIDS FROM NASA...THEY ARE FOR A SIMPLETON...THEY NEED TO BE MORE DETAILED