Experience 7 mins of terror as the latests Mars Rover lands on Mars.

I too wish it well, had already seen the video doing the rounds.
Smashing it into the surface is gonna make NASA cry though seeing as it cost ~$2.5 billion

reply to post by detachedindividual


I totally agree with your post.

We are so many getting a "hard on" regarding this mission it's crazy !
I had not seen this new video yet thanks a lot.
Waiting is going to be tough...

Originally posted by IamMe14
reply to post by nobodysavedme

 

The video explains why they can't land the whole thing, the amount of dust that would be kicked up would damage components - hence the lowering by rope part of it.

Dust?

Really?

All that 10000 fold increase in complexity for a bit of dust?

the spirit/opportunity rovers did quite well in spite of the dust.

That can be easily solved by using shaping it largely without horizontal surfaces or covering the rover in thin foil and the arm would tear the foil off after the dust settles or the foil simply tears off as the rover moves.

thin foil tears very easily.

We already have mature technologies for removing dust one is called electrostatics and is used routinely in car manufacture to attract or repel spray paint by altering the polarity and dust is also effected by electrostatics.


the sky crane is really stupid and an example of over engineering when simpler solutions would have done.

SEE... this is very technical and critical 'stuff' they are dealing with here. And they have the best experts in that particular field to get the job done correctly!

My question is - why don't we have this type of correlation between the U.S. economy and the people at the wheel. We should have experts navigating our country, not incompetent, greedy, content liars (politicians). I hate when common sense gets misplaced.

Yes, I understand everything is clouded by the almighty $/NWO/eugenists/banks/9 families but damn we are so far off of the right track.

Originally posted by six67seven
...My question is - why don't we have this type of correlation between the U.S. economy and the people at the wheel. We should have experts navigating our country, not incompetent, greedy, content liars (politicians). I hate when common sense gets misplaced...

Economics is a far, far less predictable science than physics.

Dealing with gravity and force vectors is simple compared to trying to predict how the economy will manifest itself.

youtu.be...

...Now why wasn't a 'sky crane' used to lower Armstrong to the surface of the Moon? If dust is such a problem for this thing, it had to be a problem for the Lunar Module. Yeah yeah, Mars and the Moon aren't the same...duh, but they're both covered in dust, yet no dust cloud was shown in any film on the Moon Landings.

Not to mention the moon has even less atmosphere than the Moon...where's all of this applied physics during any of the moon landings?

Originally posted by Xterrain
youtu.be...

...Now why wasn't a 'sky crane' used to lower Armstrong to the surface of the Moon? If dust is such a problem for this thing, it had to be a problem for the Lunar Module. Yeah yeah, Mars and the Moon aren't the same...duh, but they're both covered in dust, yet no dust cloud was shown in any film on the Moon Landings.

Not to mention the moon has even less atmosphere than the Moon...where's all of this applied physics during any of the moon landings?

Have you tried answering those questions yourself? I mean, are you really looking for answers to those questions, or are you really just looking to spread the questions around?

Because, surely, if you tried, you could come up with....something. Even if you couldn't arrive at a complete answer, you might, if you tried, get part of one.

My point is that I have absolutely no problem with people who have lots of questions regarding space travel, and if my limited knowledge can answer their questions then I am happy do so, or if I can't answer the questions, I will crack the books and learn right along with them. I do however get annoyed when people with agendas masquerade as people expressing curiosity.

If you're not one of those, my apologies for being....well, suspicious.

Originally posted by Xterrain
youtu.be...

...Now why wasn't a 'sky crane' used to lower Armstrong to the surface of the Moon? If dust is such a problem for this thing, it had to be a problem for the Lunar Module. Yeah yeah, Mars and the Moon aren't the same...duh, but they're both covered in dust, yet no dust cloud was shown in any film on the Moon Landings.

Not to mention the moon has even less atmosphere than the Moon...where's all of this applied physics during any of the moon landings?

First of all, wanting to protect the rover from dust is not the main reason for using the sky crane. It may be "a" reason, but not "the" reason. Other Mars probes have used more direct methods of landing before, such as the Viking landers and the Phoenix probe. The more complex nature of the MSL Curiosity rover may have contributed in not wanting dust kicked up around it.

However, as I mentioned above, the main reason for the sky crane is weight-savings. If you put the engines under the rover, the rover would need to be set aboard a platform. That platform would need a ramp so the rover could roll off of this landing platform onto the surface of Mars. Those things would add weight.

Secondly, there was dust kicked up by the Apollo LEM. You can see it in this video from about 3:50 to about 4:15. At about 3:50, Armstrong even says "picking up some dust here":


However, there would be no "dust cloud" on the moon. The moon has no atmosphere, so there would be no air in which the dust could hang around in the form of a cloud. Any dust kicked up on the moon would fall directly back down to the moon in a parabolic path. No atmosphere = no dust cloud.

The Apollo LEM also shut off its engines when it was 4 or 5 feet off the surface. The LEM landing pads had contact probes that were 5 feet long. When that probe made contact to the surface, the engine was shut off, and the Apollo LEM basically "fell" the rest of the way. This was done because there was not much space between the engine nozzle and the ground, and they didn't want the engines burning so close to the ground if the ground was uneven (such as a big mound under the engine nozzle).

Gravity on the moon is only 1/6 that of the earth, so Apollo engineers felt it was acceptable for the LEM engine to shut down prior to actually being on the ground. They felt they could safely "drop" that last 4 or 5 feet without thrust.

Gravity on Mars is a bit higher -- 38% that of Earth. A spacecraft may not be able to turn off it's thrusters so early, and thus more dust would be kicked up. That dust may form into a bit pf a cloud in Mars; atmosphere, but it wouldn't be much of a cloud, because the Martian atmosphere is still very thin.

But again, the main reason for the sky crane over a direct landing is NOT dust, but rather weight. A rover AND a landing platform under the rover with engines attached to that platform would be a lot of weight landing on Mars. Granted, this sky crane weighs something, also, and it needs to stay relatively still while lowering the Rover, but the precision required to land all that additional heavy equipment (the rover AND that engine platform) on Mars would require a lot more of a precisely controlled landing than the sky crane does.

-

...



"""But again, the main reason for the sky crane over a direct landing is NOT dust, but rather weight. A rover a landing platform under the rover with engines attached to that platform would be a lot of weight landing on Mars. Granted, this sky crane weighs something, also, and it needs to stay relatively still while lowering the Rover, but the precision required to land all that additional heavy equipment (the rover AND that engine platform) on Mars would require a lot more of a precisely controlled landing than the sky crane does"""



you are totally wrong,


the sky crane has weight and is expending fuel while it HOVERS.

hovering REQUIRES FUEL.

A LOT OF FUEL.

it has to support it self and rover for 30 seconds to a minute while the rover goes down on ropes.then it has to cut the ropes. fly away peter ,fly away paul so that it does not fall on the rover.

that is a lot of fuel being expended.

all the nasa morons had to do was put the rover in a box which had 4 thrusters attached to it a few inches above the lower edges of the box at each corner.

land the box.

then one side of the box falls away and acts as ramp.

simple.

the sky crane stupidity has put a huge amount of unnecessary landing risk.

if it fails i will definitely say I TOLD YOU SO.


Ask any VSTOL Harrier pilot how tricky it is to balance a harrier plane on 4 hot jet exhausts going downwards EVEN with with outriggers pipes on the wings blowing more compressed air to balance it in the air.

also the number of accidents.

in this case you are compounding the problem by hanging a 1 ton rover underneath while it goes down while it gets lowered.

it is just crazy.

the slightest error and the whole thing is POOF!.

10 YEARS OF EFFORT AND $3 BILLION DOWN THE DRAIN.

Hmmmm.........JPL.
This is gonna work for sure. I can even take a bet on it.
Nowever they will be using some other tech than the one depicted in the video.

Originally posted by Angelic Resurrection
Hmmmm.........JPL.
This is gonna work for sure. I can even take a bet on it.
Nowever they will be using some other tech than the one depicted in the video.

i hope this thing works.

i really really,really do.


If this skycrane thing fails we should get the knives out for Nasa to allow this sheer recklessness risk taking to be implemented in this mammoth project.

Originally posted by nobodysavedme

Originally posted by Angelic Resurrection
Hmmmm.........JPL.
This is gonna work for sure. I can even take a bet on it.
Nowever they will be using some other tech than the one depicted in the video.

i hope this thing works.

i really really,really do.


If this skycrane thing fails we should get the knives out for Nasa to allow this sheer recklessness risk taking to be implemented in this mammoth project.

The engineers who know about things things (i.e., "rocket scientists") claim this method is one of the least dangerous for a rover of this size (being too heavy to use the airbag systems used by Sojourner and the twin MERs)

I realize that the cables need to unreel and cut on cue, and there is an inherent danger that they won't, but there are also inherent dangers in other "traditional" landing systems that would require legs and ramps:

Landing Challenges that led to the Sky Crane Design

The sheer size of the descent stage would result in a daunting engineering challenge: get a bulky rover safely down to the surface from a perch many feet above the ground atop its lander.

"This rover is 900 kilograms, it is a beast, it is the size of a car," said Steve Sell, an entry, descent and landing engineer at the Jet Propulsion Laboratory. "So you're trying to land something very heavy, so that means you need sizable engines."

More powerful rocket engines could kick up billowing clouds of dusty debris as the lander approached touchdown "so you tend to want to keep the engines farther away from the surface," Sell said.

"That makes you want to have longer legs, and having longer legs means your center of gravity is higher and then it's much easier to tip over," he said. "Or you need to be very wide. It tends to drive you [to a] larger and larger [lander] in order to do that and be stable."

Then there is the little matter of getting the rover down to the surface after landing.

"Let's say you solved all that and were able to land and you now had to drive a one-ton rover off the top of a platform, either down ramps or some other kind of mechanism," Sell said. "If you were oriented in a way that maybe wasn't favorable to your wheels, like you were tilted to your side, you could slide sideways off the ramps. Maybe there are rocks where the bottoms of the ramps would normally touch and you can't deploy the ramp in the first place."

Faced with those and other sobering scenarios, the MSL engineers came up with a novel alternative. Instead of rolling the costly rover off an elevated, possibly tilted lander, why not do away with the landing legs altogether? Why not attach the rover to the bottom of the rocket-powered descent stage and then lower it directly to the surface on the end of a long cable?

Source

So you see -- even a craft with the engines underneath, that requires long legs, high center of gravity, and a long retractable ramp would present its own set of dangers inherent in the system. Engineers feel even more so than the sky-crane.

Originally posted by Soylent Green Is People



So you see -- even a craft with the engines underneath, that requires long legs, high center of gravity, and a long retractable ramp would present its own set of dangers inherent in the system. Engineers feel even more so than the sky-crane.

edit on 8/3/2012 by Soylent Green Is People because: (no reason given)

you put the lander in a BOX with retro rockets on the four corners at the edges 3/4 of the way up so that the center of gravity keeps it stable.

you land very slowly and they can certainly afford to expend the fuel as the crane will HOVER while the lander is being winched down.

that is lander plus crane weight hovering and expending fuel.this fuel could have been used to land the whole "lander in a box" down very very slowly.

once landed one side of the box falls down and acts as a ramp.lander moves out.

end of story.

i really hope it works and i would love to be proven wrong..but if that sky crane thing goes wrong they can't expect any mercy from me.

the Nasa "engineers" have forgotten the KISS principle.

KEEP IT SIMPLE ,STUPID.

reply to post by nobodysavedme

The box will added weight (precious weight that could instead be used for rover instruments) and your box still has its own inherent dangers -- e.g., it may not open correctly, or at all, and there is still the danger that a obstacle may prevent the ramp from deploying, or have a large rock at the bottom of the ramp preventing the rover from going in that direction. As the landing procedure is designed now, the rover can back and has a better chance of getting free if it happens to land amongst boulders.

I'm not saying these are the primary reasons to go with the sky-crane, but I'm just showing that every landing system comes with its own set of challenges. You say "Keep it Simple, Stupid", but the sky-crane isn't overly complex (relatively speaking) either. Both methods require the craft to slow to a hover first, no matter if it plans to land or plans to lower the rover on cables. The cable system could be simple (again relatively speaking), albeit, just like your box, it needs to work.

Look, it's not that I have 100% absolute blind faith that the NASA engineers know what they are doing, but the bottom line is this: If I was planning a Mars Rover, and I was given two choices for picking the designers of the landing system -- (1.) A group of engineers who have successfully landed spacecraft on Mars before, and have put their collective minds together in brainstorming the pros and cons of ALL possible landing systems, or (2.) some unknown guy on the internet...
...who do you think I would choose to put more faith in.

Those engineers have already considered the exact same thing you are saying, and they feel the sky-crane is still better. Give their experience in these matters over yours (I'm assuming you never landed a spacecraft before), I would need to put my faith in the people with the knowledge and experience.

Sure -- This sky-crane system could certainly fail, but so could your box system (plus the box adds weight).

reply to post by nobodysavedme

once landed one side of the box falls down and acts as a ramp.lander moves out.

You seem pretty stuck on this method.

What if the lander, lands right in front of a boulder and the darn door wont open? Whats next, just send up a blow torch on a robotic arm to cut it out?

I personally like the crane method. It is a test to see if we can get more complex with our methods. Sure it may fail, but how many Mars missions fail anyways? I will let you Google the answer to that.

We need to expand our horizons if we are ever going to make it anywhere in space.

Originally posted by Xterrain
youtu.be...

...Now why wasn't a 'sky crane' used to lower Armstrong to the surface of the Moon? If dust is such a problem for this thing, it had to be a problem for the Lunar Module. Yeah yeah, Mars and the Moon aren't the same...duh, but they're both covered in dust, yet no dust cloud was shown in any film on the Moon Landings.

Not to mention the moon has even less atmosphere than the Moon...where's all of this applied physics during any of the moon landings?

Because this is a conspiracy website and we all know that NASA has a different explanation for the common people than their own reasons, it must be something else.

The use of a sky-crane is because they have an other undisclosed militairy mission for the crane. If I am correct informed this crane flies off into the distance away from the rover. Did NASA ever say were or how it will crash..., will it crash into the surface without any usefull last experiment?

I don't know....having an expensive craft just fly off until it drops doesn't sound much like NASA to me.

Originally posted by Soylent Green Is People
reply to post by nobodysavedme

 

The box will added weight (precious weight that could instead be used for rover instruments) and your box still has its own inherent dangers -- e.g., it may not open correctly, or at all, and there is still the danger that a obstacle may prevent the ramp from deploying, or have a large rock at the bottom of the ramp preventing the rover from going in that direction.

The box is just a frame with very thin walls to prevent the so called dust blowing into the rover.the walls,ultra light materials which exist already.


the ramp can unlatch at the top on any side at all.basically all the "walls" can just fall away and even if all 4 walls can't unlatch the rover can drive through them.

the walls simply prevent the much vaunted dust from getting into the rover.they are very thin and light.

the rover also a laser after all able to vaporize rock.

reply to post by nobodysavedme

It sounds as if the sides of your box is on the outside edge of the whole landing assembly. They would need to be to just unfold as a ramp (i.e., they can't be set too far in from the edge, or the edge of the landing platform, or else the platform would get in the way of the ramp).

So, now with the sides out near the edge of the landing platform, those sides can't be vertical, because of the room constraints of the aeroshell (the entire spacecraft assembly needs to be certain dimensions to fit within the limits of the aeroshell).

I assume that means the sides of the craft (at the front and back of the rover, so they could act as ramps) would be angled toward the center, so they could be long enough to reach the ground without creating too much vertical height in the whole craft assemble (although I'm not sure the sides CAN be long enough in your design to act as ramps -- but let's say they can be, for the sake of discussion).

Considering the length of the side/ramp, and the fact that it would need to be angled inward, there would need to be relatively strong motors to swing those sides open to form ramps, considering the torque involved.

There would also need to be a few pyrotechnic devices to unlatch the sides of the box, but there are pyrotechnics involved in cutting the cables used in the sky-crane method, so the pyros in the box method aren't adding any additional inherent danger over the sky-crane.

Basically, I'm just trying to point out that the box method would still need to fit the space constraints of the aeroshell AND still work. Perhaps it could be done, but it could be just as complex (maybe moreso?) than the sky-crane.