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MSL Landing Timeline: What To Expect Tonight

samzenpus posted about a year and a half ago | from the break-it-down dept.

Mars 140

An anonymous reader writes "When the Curiosity rover lands on Mars later tonight, it'll be executing a complex series of maneuvers. JPL will be relying on the Mars Odyssey orbiter to relay telemetry back to Earth in time-delayed real-time, and if all goes well, we'll be getting confirmation on the success (or failure) of each entry, descent, and landing phase, outlined in detail here."

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140 comments

Rings around Uranus! (-1)

Anonymous Coward | about a year and a half ago | (#40889675)

Better wash your asshole!

So WHAT'S THE FUCKING TIME ALREADY !! (-1, Troll)

Anonymous Coward | about a year and a half ago | (#40889705)

Never seen the time !! Does anybody really know what time it is ?? Does anybody really care ?? Know what time ??

Re:So WHAT'S THE FUCKING TIME ALREADY !! (1)

hawguy (1600213) | about a year and a half ago | (#40890107)

Never seen the time !! Does anybody really know what time it is ?? Does anybody really care ?? Know what time ??

If you'd have clicked through to the article, you'd see the whole timeline. Though I'm not sure why you were modded down as a troll, it's a valid question and it seems that many news sources only say "late Sunday night" without giving any times. in any case:

The landing stage separates from the cruise stage at 10:14:34pm PST.

Here's the last few seconds of the timeline (again, see the linked article [ieee.org] for the full timeline):

10:31:08 PM: At about 20 meters above the surface, MSL keeps decelerating down to 0.75 m/s.
10:31:14 PM: Less than 20 meters from the surface, the sky crane shuts off four of its eight engines as the rover separates and begins to descend on cables.
10:31:15 PM: MSL releases its "bogie" wheels, getting ready for touchdown.
10:31:30 PM: TOUCHDOWN! WOOHOO!!! Curiosity knows when she's on the ground when the load on the tether that she used to get from the skycrane to the ground goes slack.
10:31:33 PM: Cables connecting Curiosity to the skycrane are cut, and the skycrane flies off for a crash landing. /quote>

Re:So WHAT'S THE FUCKING TIME ALREADY !! (5, Informative)

hawguy (1600213) | about a year and a half ago | (#40890137)

Just noticed a typo in the article -- it's actually PDT, not PST.

NASA has a convenient countdown timer here:

http://www.nasa.gov/mission_pages/msl/index.html [nasa.gov]

Re:So WHAT'S THE FUCKING TIME ALREADY !! (2)

camperdave (969942) | about a year and a half ago | (#40890597)

Just give it in GMT and let us worry about daylight saving time conversions.

Re:So WHAT'S THE FUCKING TIME ALREADY !! (-1)

Anonymous Coward | about a year and a half ago | (#40890689)

fuck GMT. yeah that's right, FUCK GMT!

Re:So WHAT'S THE FUCKING TIME ALREADY !! (0)

Anonymous Coward | about a year and a half ago | (#40890631)

If so I can't imagine why.

I predict abject failure. (0)

Anonymous Coward | about a year and a half ago | (#40889707)

During entry.

Not for any definition of "real time" that I know. (2, Informative)

mark-t (151149) | about a year and a half ago | (#40889739)

Telemetry will be continuously relayed back to earth, true, but with not much less than about a 15 minute latency, owing to the fact that Mars roughly a quarter of a light-hour from earth right now.

Re:Not for any definition of "real time" that I kn (-1)

Anonymous Coward | about a year and a half ago | (#40889747)

Did you mean this [imgur.com]? If so, you're completely incorrect.

Re:Not for any definition of "real time" that I kn (0, Informative)

Anonymous Coward | about a year and a half ago | (#40889769)

Real time simply means that there are deadlines on the system (in the technical sense).
Here the deadline is simply so relaxed that using that term becomes useless.
The real question we should be asking is what does time-delayed mean?
Is there some other non-temporal delay that I'm not aware of?
Space delayed? why are they even saying delayed? Doesn't the travel time automatically delay the signal, or are they adding extra delay?
Maybe they are using negative time delay to make the signal "real time".

Re:Not for any definition of "real time" that I kn (5, Insightful)

Anonymous Coward | about a year and a half ago | (#40889775)

Telemetry will be continuously relayed back to earth, true, but with not much less than about a 15 minute latency, owing to the fact that Mars roughly a quarter of a light-hour from earth right now.

That IS indeed real time. Relativity tells us nothing can have an effect here in less time. I don't know if you're trolling or just ignorant, but by your definition you can never look at the stars, galaxies or nebulae in the sky in real time either because they're all at varying distances and we're seeing light that originated anything from about 4 to several million years ago. With telescopes you can go back billions.

Re:Not for any definition of "real time" that I kn (-1)

mark-t (151149) | about a year and a half ago | (#40889849)

The single most important criteria for something to qualify as "real time" in data communications is low latency. 14 and a half minutes is not low.

Re:Not for any definition of "real time" that I kn (2, Insightful)

Anonymous Coward | about a year and a half ago | (#40889951)

The single most important criteria for something to qualify as "real time" in data communications is low latency. 14 and a half minutes is not low.

Then by your definition NOTHING in space is real time. You look up into the sky and everything you're seeing is sending it's light to you from the past.

Re:Not for any definition of "real time" that I kn (3, Interesting)

khallow (566160) | about a year and a half ago | (#40890937)

Then by your definition NOTHING in space is real time. You look up into the sky and everything you're seeing is sending it's light to you from the past.

Duh. Real time is a bit subjective, but it basically is a threshold of control over a system. The strict definition is that a system is real time, if it meets strict time constraints imposed on it (I gloss over some important nuance). So in a sense, one can have real time systems with say, years of lag, for really generous time constraints.

For me, I have an informal definition of real time, namely, a control methodology which wouldn't change, if communication lag were instantaneous.

For example, the human body wouldn't move differently even if human nerves were transmitting signals instantaneously. Walking, running, and such still are the best means for moving. You might be able to try other movement forms (such as cartwheeling), but these wouldn't give you an advantage in normal operation over the usual means of movement.

So in this sense, the human body and its normal means of moving about are "real time". Movement of the MSL and other rovers remotely controlled from Earth have less optimal movement schemes (there's a lot of need to evaluate terrain obstacles, for example, resulting in a lot of move-then-stop operation) than if someone were controlling them from nearby on the Martian surface. So these systems are not real time in my sense.

Now suppose instead of the MSL, one were piloting this fine piece of gear [wikipedia.org], one of the largest excavators in the world. Suddenly that 15 minute lag time is not so significant and the machine probably wouldn't operate all that differently, if the operator was sitting in a cockpit directly rather on distant Earth.

Since I mentioned systems with extremely long lag still qualifying as real time, consider this example. One could set up vast streams of gargantuan slow moving space vehicles carrying basic crude, bulk resources (water, organic compounds, metals, etc) between different planetary systems, say moving at the speed of the Voyager spacecraft. It might take 50,000 years to make the trip and adjustments in trajectory would be very minimal and glacial. Would it matter if one had instantaneous communication? Not really. The years of communication lag have no real effect on the system.

Re:Not for any definition of "real time" that I kn (2, Insightful)

Anonymous Coward | about a year and a half ago | (#40889957)

No, that's just your personal set of criteria that doesn't have anything to do with reality.

Real-Time is without artificial delay. Yes, there's 14 minutes actual delay, but it's not artificial, it is literally the fastest possible time.

If 14 minutes prevents it from being real time, then 14 seconds should too, as should 14 milliseconds, or 14 nanoseconds. All of them are arbitrary amounts of time, all of them are large amounts of latency relative to something.

Re:Not for any definition of "real time" that I kn (0)

mark-t (151149) | about a year and a half ago | (#40890099)

Owing to the fact that we will know the lander has already reached the surface (in unknown condition) by the time we get the first signal it has entered the atmosphere, the delay cannot *POSSIBLY* be considered real time because too many events that can or will affect the system will have occurred by then.

Re:Not for any definition of "real time" that I kn (1)

hawguy (1600213) | about a year and a half ago | (#40890371)

Owing to the fact that we will know the lander has already reached the surface (in unknown condition) by the time we get the first signal it has entered the atmosphere, the delay cannot *POSSIBLY* be considered real time because too many events that can or will affect the system will have occurred by then.

But since the information reaches us as quickly as reasonably possible it can still be considered real-time. (I said "reasonably possible", since there's some finite processing time that's incurred when an event is recorded, encoded for transmission to the earth, received, decoded, then broadcast to the world which means that it will take longer to receive the information at home than is physically possible if we all had telescopes that could resolve the landing in "real time").

Otherwise, where would you draw the line?

Does a solar satellite give us "real time" information about the sun even though any data it receives is already 8 minutes old? Do we have "real time" communications with a lunar lander, even though everything it sends has a 1.28 second radio delay? Can we watch events at the London Olympics in "real time" even if codec and satellite delays delay the signal by a second or two? If you watch a sporting event live, are you really seeing it in "real time" since you're not seeing the action 100m away for 833ns.

Re:Not for any definition of "real time" that I kn (4, Insightful)

mark-t (151149) | about a year and a half ago | (#40890613)

You draw the line at any signal latency that is too slow to meaningfully respond to in the context that the signal was originally sent from. There's a reason why interrupt handlers in real-time OS's need to finish their job in as few computing cycles as possible.

Re:Not for any definition of "real time" that I kn (1)

hawguy (1600213) | about a year and a half ago | (#40890723)

You draw the line at any signal latency that is too slow to meaningfully respond to in the context that the signal was originally sent from. There's a reason why interrupt handlers in real-time OS's need to finish their job in as few computing cycles as possible.

So in the event of a fully autonomous landing that wasn't designed for any human input or control, is a 15 minute delay "real time" or not? Once the landing sequence starts, there's no going back or adjusting the sequence until the entire 15 minute landing sequence is over, even if a human was orbiting Mars.

An interrupt handler in a Real-Time OS doesn't need to finish its job in as few computing cycles as possible, it only needs to finish within the guaranteed interrupt latency time, which could be a few microseconds or could be 15 minutes. Real time doesn't mean fast, it means it meets hard deadlines.

Re:Not for any definition of "real time" that I kn (0)

Anonymous Coward | about a year and a half ago | (#40890965)

Stupid discussions like this one arise when perfectly useful expressions are replaced by inferior, more complex expressions merely to make people sound more expert or scientific. In the olden days, they would have said "Live images will be beamed back by the lander". No one would have been in any doubt what that meant and this bullshit discussion would never have needed to take place, in 'real time' or slightly delayed.

Re:Not for any definition of "real time" that I kn (3, Insightful)

Waffle Iron (339739) | about a year and a half ago | (#40890761)

Owing to the fact that we will know the lander has already reached the surface (in unknown condition) by the time we get the first signal it has entered the atmosphere

Relativity says that there is a 14 minute delay in *some* frames of reference. In other frames of reference, the delay is longer. For others (those occupied by the radio signal photons, for example), the landing events and our reception of the signals happen simultaneously.

Getting hung up over what you imagine is the "time delay" between two points in spacetime that are outside of each others' light cones is kind of pointless.

Re:Not for any definition of "real time" that I kn (1)

fisted (2295862) | about a year and a half ago | (#40890115)

plain wrong

Re:Not for any definition of "real time" that I kn (0)

mark-t (151149) | about a year and a half ago | (#40890269)

Try making an os that is defined to take 14 minutes to respond to interrupts and see if you can pass it off as "real time"

Re:Not for any definition of "real time" that I kn (0)

Anonymous Coward | about a year and a half ago | (#40890737)

I don't mean to be arrogant or rude, but this is a common misconception about what a "real time" OS would be.
http://en.wikipedia.org/wiki/Real-time_operating_system
It has nothing to do with getting things done fast, it's more about when getting things done.

Re:Not for any definition of "real time" that I kn (0)

Anonymous Coward | about a year and a half ago | (#40890253)

No, the computing definition of "real time" means guaranteed latency, not necessarily low latency. What the guarantee is depends on the specific system. An industrial controller may require a one second response guarantee while a radar system may require millisecond response.

Re:Not for any definition of "real time" that I kn (0)

NF6X (725054) | about a year and a half ago | (#40889955)

That IS indeed real time. Relativity tells us nothing can have an effect here in less time. I don't know if you're trolling or just ignorant, but by your definition you can never look at the stars, galaxies or nebulae in the sky in real time either because they're all at varying distances and we're seeing light that originated anything from about 4 to several million years ago. With telescopes you can go back billions.

Unless you live near a big city, in which case most of the light you can see in the sky at night (other than moonlight) originated within the last quarter millisecond.

Re:Not for any definition of "real time" that I kn (4, Funny)

Anonymous Coward | about a year and a half ago | (#40889885)

Telemetry will be continuously relayed back to earth, true, but with not much less than about a 15 minute latency, owing to the fact that Mars roughly a quarter of a light-hour from earth right now.

True, but for a blueworlder, the blueworld-received-time is real-time, for any definition of real-time consistent with relativity.

Speaker K'Breel knows the instant the Martian Defense Force succeeds in its mission, or fails, and either way he has enough time to throw a Junior Reporter's gelsac beneath the spot where the Skycrane will crash-land. At the moment of impact/invasion, the most recent transmissions from his spies on the Blue World will show a clock dated 10:14 PDT, but that's irrelevant. As far as the blueworlders are concerned, they find out at 10:31 PDT. Loyal Martian Citizens can start celebrating/covering their gelsacs early, but have to wait another 15 minutes (until their view of the blueworlders' clocks show 10:31) before they can enjoy true schadenfreude at the blueworlders' pain, or have hopefully protected their gelsacs in preparation for the ever-merciful Speaker for the Council's reaction to his view of the blueworlders' whoops of joy.

Re:Not for any definition of "real time" that I kn (0)

Anonymous Coward | about a year and a half ago | (#40889931)

Me thinks you are missing the important fact that telemetry beamed from spacecraft is *always* impacted by the transmission delays inherent to the speed of light. In this case it's just more pronounced.

The telemetry from Curiosity is 'real-time' in the context of when it is received here on Earth.

Re:Not for any definition of "real time" that I kn (0)

Anonymous Coward | about a year and a half ago | (#40889977)

It's NBC real time.

Re:Not for any definition of "real time" that I kn (1)

black6host (469985) | about a year and a half ago | (#40890847)

Telemetry will be continuously relayed back to earth, true, but with not much less than about a 15 minute latency, owing to the fact that Mars roughly a quarter of a light-hour from earth right now.

Given this post, and all the other by you below, I think they should have just told you (and only you, as the rest of us have no problem with this) that the landing was happening about 15 minutes later than it is. I bet you'd be happy then :)

(Meant in good fun!)

Re:Not for any definition of "real time" that I kn (1)

jamesh (87723) | about a year and a half ago | (#40891069)

Telemetry will be continuously relayed back to earth, true, but with not much less than about a 15 minute latency, owing to the fact that Mars roughly a quarter of a light-hour from earth right now.

So you'll be sitting in the crowd watching one direction (or whatever you kids are into these days) complaining that you should be closer to the front because the light from the stage is taking multiple nanoseconds to reach you, which is unacceptable because you paid full price for a live performance.

Did Send Your NameTo Mars happen (1)

Anonymous Coward | about a year and a half ago | (#40889749)

Anyone know if the "Send Your Name To Mars" chip actually made it onto the rover? Would love to be able to tell my wife and kids our names are on Mars.

http://marsparticipate.jpl.nasa.gov/msl/participate/sendyourname/

I showed my son (just turned 4) a couple of the publicity videos made by Nasa including the Shatner narrated landing.and he wanted to know if we could buy the toy of it. I had to explain there was none, but apparently Hotwheels has come out with one (just the rover itself though, not the whole descent package).

http://www.wired.com/geekdad/2012/08/hot-wheels-curiosity/

Re:Did Send Your NameTo Mars happen (0)

Anonymous Coward | about a year and a half ago | (#40890113)

I submitted my name and got a virtual "certificate" with a reference number on it. I saved the reference number because I figured I could look the cert up later on but can't find any links to do that. Does anybody know how I can get my certificate now using my reference number?

crazy (1)

Anonymous Coward | about a year and a half ago | (#40889755)

the amount of engineering, programming and math that went into this... (among other things i'm sure) I hope it goes well

Re:crazy (4, Funny)

skipkent (1510) | about a year and a half ago | (#40889785)

Don't forget the imperial to metric conversions!

Re:crazy (5, Funny)

M. Baranczak (726671) | about a year and a half ago | (#40890083)

Not many people know this, but the Stonehenge scene in "This is Spinal Tap" was based on something that really happened to Black Sabbath. The band wanted a life-sized replica of Stonehenge for their stage show, just like in the movie. They drew up the plans, but at some point (nobody's sure where) 14 feet became 14 meters... So they wound up with this giant thing that cost way more than they planned, and worst of all, it wouldn't even fit on any of the stages they were playing. After this, and a series of similar mishaps, NASA stopped hiring members of Black Sabbath.

Re:crazy (2, Informative)

Anonymous Coward | about a year and a half ago | (#40890557)

Close(ish) to some fact. Read the real story by the singer at the time:

http://www.gillan.com/anecdotage-12.html

Re:crazy (3, Interesting)

M. Baranczak (726671) | about a year and a half ago | (#40890835)

Geezer Butler tells a completely different story. [archive.org]

It had nothing to do with me. In fact, I was the one who thought it was really corny. We had Sharon Osbourne's dad, Don Arden, managing us. He came up with the idea of having the stage set be Stonehenge. He wrote the dimensions down and gave it to our tour manager. He wrote it down in meters but he meant to write it down in feet. The people who made it saw fifteen meters in stead of fifteen feet. It was 45 feet high and it wouldn't fit on any stage anywhere so we just had to leave it the storage area. It cost a fortune to make but there was not a building on earth that you could fit it into.

Re:crazy (0)

Anonymous Coward | about a year and a half ago | (#40890361)

Ya, that is the scary part. On one promotional video, they say something to the effect of "20 METERS from the surface, we have to lower the rover on a tether which is 21 FEET long..."

http://www.space.com/16265-7-minutes-of-terror-curiosity-rover-s-risky-mars-landing-video.html

Maybe this was just a slip of the tongue, or maybe they really mean 20 meters and 21 feet. But why mix units like that?!!?

Re:crazy (2)

camperdave (969942) | about a year and a half ago | (#40890625)

Well, that's a lot better than it being 20 feet from the surface and then lowering it on a tether 21 metres long.

Re:crazy (0)

Anonymous Coward | about a year and a half ago | (#40890821)

At least that would let you get to the ground. 20 meters high with a 21 foot rope leaves you hanging about 44.6 feet in the air!

Re:crazy (1)

hlavac (914630) | about a year and a half ago | (#40889817)

That's what is worrying me, especially the programming part. My prediction is total failure due to a stupid software bug.

Re:crazy (3, Funny)

gmhowell (26755) | about a year and a half ago | (#40890047)

Don't worry, I only used a couple of GOTO statements.

Re:crazy (2, Funny)

Anonymous Coward | about a year and a half ago | (#40890857)

I only used one...

GOTO MARS;

Re:crazy (1)

Anonymous Coward | about a year and a half ago | (#40890153)

It's OK, they included Clippy to guide the lander.

"Hello, I see you're trying to land on a planet, would you like some help with that?"

Re:crazy (-1, Flamebait)

arth1 (260657) | about a year and a half ago | (#40889869)

the amount of engineering, programming and math that went into this... (among other things i'm sure) I hope it goes well

That depends on your definition of "goes well". They have already fumbled once - the mechanism for rotating the observer failed. This, they can hopefully work around, but it already shows that they haven't planned/designed/produced this 100%.

I'd give it even odds on whether this will work or be yet another casualty in the Mars exploration saga.
NASA has already stated that they won't be the leader in space exploration anymore, but I'd like to see them go out with a few successes, not with a whimper.

Re:crazy (0)

Anonymous Coward | about a year and a half ago | (#40889997)

I am feeling kind of pessimistic about this. It just seems like it is way, way too complex. Almost like a bunch of engineers sat around a table and tried to one up each other.
It just doesn't seem like the sort of thing that ends well.

Having said that, you pointing out the mechanism for rotating the observer. Understand this, in projects like this there is NEVER EVER ANYTHING THAT CAN ONLY BE DONE A SINGLE WAY.

Not only that, but it is critical that not only can you do something like rotate the observer several different ways, but those ways are all different ways of doing it. In other words, you want redundant systems that will survive whatever tempest took out the main system.

Re:crazy (2)

flyingsquid (813711) | about a year and a half ago | (#40890595)

Not only that, but it is critical that not only can you do something like rotate the observer several different ways, but those ways are all different ways of doing it. In other words, you want redundant systems that will survive whatever tempest took out the main system.

True, there are certain phases of the mission where you can recover from a malfunction. If there's a software problem en route to Mars, or a hardware malfunction once the rover is on the ground, you can try to find a way to fix or work around the problem. The problem with the landing, obviously, is that you've just got one shot. If the pulleys jam or the cables tangle, if the explosives don't cut the skycrane free, if it selects a bad landing spot or comes in too fast... and it's all happening 15 light-minutes away, so by the time NASA figures out something is wrong, it's already too late to do anything. If something fails during that phase, that's $2.5 billion spent adding another crater to the surface of Mars.

Re:crazy (1)

ColdWetDog (752185) | about a year and a half ago | (#40890607)

They're already hyping the danger part with the little graphic that says "Earth 15, Mars 24".

K'Breel and the council will be pleased!

Re:crazy (3, Informative)

Man On Pink Corner (1089867) | about a year and a half ago | (#40890675)

They have already fumbled once - the mechanism for rotating the observer failed.

That's not a fumble. That's a ten-year-old spacecraft, long past its primary mission, with a temporary problem that they were able to work around.

Re:crazy (4, Informative)

flyingsquid (813711) | about a year and a half ago | (#40890437)

If you haven't already caught it, here's the animation showing how the whole thing is supposed to work: http://www.youtube.com/watch?v=BudlaGh1A0o [youtube.com]

. The whole thing has an amazingly sci-fi feel to it, like it's the opening scene of a sci-fi blockbuster movie. We really do live in amazing times when you think about it.

The skycrane/rover detach from the parachute at around 2:00 and you can watch as the sky crane lowers the rover at 2:48. It does seem a little too elaborate, and my gut feeling watching it is that using such a complicated landing mechanism is just asking for something to go wrong. But then again... well, think about it. Pulleys are pretty simple machines, and we've been using them for thousands of years. There are a lot of machines on this rover that are vastly more complicated than pulleys and cables- the heat shield, the parachute, the nuclear reactor, the onboard computer, the antenna, the camera that finds the landing site, the rocket motors, the software.

I sure as hell hope it all works, though. Unlike the last mission, there's just the one rover, and there's a hell of a lot riding on it. With the cuts to NASA's planetary science program, we won't be headed back to Mars for a long, long time, and it will be a lot harder to get the program started again if Curiosity fails.

Re:crazy (0)

camperdave (969942) | about a year and a half ago | (#40890677)

Well, almost exactly the same system [youtube.com] worked well for Spirit and Opportunity, so it should be fine for Curiosity. Actually, things should work out better for Curiosity, since it isn't going to be dropped like a stone and bounced all over the planet, but placed ever so gently onto the surface.

"Time Delayed Real Time" (3, Interesting)

BBF_BBF (812493) | about a year and a half ago | (#40889767)

Meh... really?...

"Time Delayed Real Time"

More like "Real Time as constrained by the Speed of Light", it's not like NASA is doing what NBC is doing with the olympics... :rolleyes:

You're right. Not like Olympics (1)

Anonymous Coward | about a year and a half ago | (#40889807)

Meh... really?...

"Time Delayed Real Time"

More like "Real Time as constrained by the Speed of Light", it's not like NASA is doing what NBC is doing with the olympics... :rolleyes:

You're right. No one ever threw an object all the way to Mars as part of the Olympics ;-)

Re:"Time Delayed Real Time" (1)

Malf.me (2697131) | about a year and a half ago | (#40889845)

NBC is probably too busy with a closeup shot of a crying young Russian girl after the Fobos-Grunt incident [wikipedia.org] to cover the MSL. With plenty of derisive commentary of course.

Re:"Time Delayed Real Time" (2)

pla (258480) | about a year and a half ago | (#40890395)

it's not like NASA is doing what NBC is doing with the olympics... :rolleyes:

Speaking of which, have you seen the latest shots of the Curiosity crash site? Man that thing went down har... uh... I mean... uh... Look how the markets reacted to another NASA failu... Um, no, wait... Tune in "live" to see the landing in just four more hours! Will Phelps take gold? Will the skycrane smash down right on top of the rover? The world waits in rapt anticipation!

Any live video? (0)

Anonymous Coward | about a year and a half ago | (#40889809)

It would kind of suck if all we were getting were digits and shots of the control room.

I don't think NASA pays too much attention to the PR side of things...probably why budgets are being slashed.

Re:Any live video? (1)

Anonymous Coward | about a year and a half ago | (#40890405)

It would kind of suck if all we were getting were digits and shots of the control room.

I don't think NASA pays too much attention to the PR side of things...probably why budgets are being slashed.

Talk about a troll!

  Google "7 minute of terror" for proof NASA pays attention to PR. Then consider the justification of doubling the cost so that we can have a second craft or adding a boom and camera to take the kind of video you want to see...assuming it's even possible. I have no idea what the schedule will be for the deployment of the mast, and first images but if they could factor it in to a live broadcast I'm sure they will.

This isn't a Hollywood movie or Star Trek. This is real.

When is it landing? (1)

unencode200x (914144) | about a year and a half ago | (#40889829)

I'm seeing conflicting reports... Is it tonight (as in a few hours from now) or tomorrow (27 hours from now)?

Re:When is it landing? (1)

tysonedwards (969693) | about a year and a half ago | (#40889857)

The lander will begin it's descent at 08:23:00 PM Pacific tonight.

Re:When is it landing? (1)

Anonymous Coward | about a year and a half ago | (#40889991)

http://www.nasa.gov/mission_pages/msl/index.html

Re:When is it landing? (1)

Nyeerrmm (940927) | about a year and a half ago | (#40890105)

It is tonight (the night of Sunday Aug. 5 in the US).

However, on the east coast, and in UTC, this is actually early in the morning on Aug 6, so by some definitions you could call it 'tomorrow'.

Hollywood Treatment (4, Informative)

InsertCleverUsername (950130) | about a year and a half ago | (#40889847)

I'm really excited, but I doubt the live broadcast will measure up to the bitchin' action movie NASA made of Curiosity's "Seven Minutes of Terror!"
http://www.youtube.com/watch?v=pzqdoXwLBT8 [youtube.com] Enjoy!

Re:Hollywood Treatment (0)

Anonymous Coward | about a year and a half ago | (#40889877)

I'm really excited, but I doubt the live broadcast will measure up to the bitchin' action movie NASA made of Curiosity's "Seven Minutes of Terror!"
http://www.youtube.com/watch?v=pzqdoXwLBT8 [youtube.com] Enjoy!

That clip left my son (just turned 4) wanting us to buy him the toy ;-)

Why the skycrane? (2, Interesting)

Anonymous Coward | about a year and a half ago | (#40889861)

The Viking landers were about the same size and used classic retro-rockets. Why does the Curiosity use this much more complex arrangement? I couldn't find an easy answer. Is it so the rocket blast doesn't damage the wheels? Is it so the rover doesn't lug around the dead weight of the rockets once it's landed? I really don't get it.

Re:Why the skycrane? (5, Informative)

andsens (1658865) | about a year and a half ago | (#40889911)

Dust. You don't want martian dust stirred up by the rockets covering all of the mechanics once you have landed.

Re:Why the skycrane? (0)

Anonymous Coward | about a year and a half ago | (#40890025)

Pop-off dust covers on the instruments seems simpler than a sky-crane that disengages then flies away.

Re:Why the skycrane? (0)

Anonymous Coward | about a year and a half ago | (#40890067)

How about a detachable cover that is removed after the dust settles.

Re:Why the skycrane? (1)

Anonymous Coward | about a year and a half ago | (#40890571)

Then you make the thing even more top heavy then the already dangerously off balanced design you'd have with retrorockets, and further increase the risk of landing on your side (falling over). You also introduce two more sources of mission failure (1) the ramp you'd need from using a legged lander, and (2) failure of the cover to detach.

Re:Why the skycrane? (1)

Anonymous Coward | about a year and a half ago | (#40889913)

The Viking landers were about the same size and used classic retro-rockets. Why does the Curiosity use this much more complex arrangement? I couldn't find an easy answer. Is it so the rocket blast doesn't damage the wheels? Is it so the rover doesn't lug around the dead weight of the rockets once it's landed? I really don't get it.

The "7 minutes of terror" video Nasa put together quoted dust fouling up the rover as the reason. I don't know why they couldn't let the dust settle, then blow off a thin housing of some description, but there is no question that would add some weight. In any case people spent YEARS coming up with this design so it is unlikely anything someone is going to come up with in a few minutes of pondering has not been thought of already.

Re:Why the skycrane? (2)

trout007 (975317) | about a year and a half ago | (#40890079)

The mass of curiosity is much more than Viking if you include the mass of the sky crane. If you put it all in the surface it would be about 2-3 times more massive.

I think it all came down to mass. You could of had the exact same system with 3 legs on the sky crane and just wait until after landing to lower the rover. But that would add the mass of some very large structure which due to the damn rocket equation would push them beyond what they could launch.

Gelsacs! (0)

Anonymous Coward | about a year and a half ago | (#40889889)

I haven't seen any gelsac related posts for a while though.

I've long thought it would... (2)

Anubis IV (1279820) | about a year and a half ago | (#40889965)

...be interesting to have a "news" program that only aired news reports which were, say, a year old, that way people could look back with hindsight and see how trivial the things were that seemed so big at the time, thus hopefully giving them some perspective on the world as a whole, but I always thought it was just a pipe dream. This whole thing has me thinking that, "In other breaking news from yesterday..." might become a real catch-phrase.

From the other side of the dateline ... (0, Funny)

Anonymous Coward | about a year and a half ago | (#40890411)

Here in NZ, we've already seen it descend. Can't tell you how it came out, owing to a non-disclosure agreement but ...

150 kg dead weight? (1)

jackbird (721605) | about a year and a half ago | (#40890487)

10:28:46 PM: At this point, MSL has decelerated to less than 500 m/s. It fires off six 25kg tungsten weights that it was using to offset its center of gravity straight out the side of the aeroshell to rebalance itself, reducing its angle of attack to close to zero.

Can one of the rocket scientists on here explain why, when every gram to orbit is accounted for, 150kg of dead weight was the only way to do this? Couldn't they have at least put some kind of small stationary experiments, retroreflectors for earth-based lasers (like on the moon), or radio repeaters in the things that would be no big loss if they didnt survive re-entry?

Re:150 kg dead weight? (5, Informative)

chalker (718945) | about a year and a half ago | (#40890583)

It all has to do with shifting the center of mass. From the official NASA press kit: http://mars.jpl.nasa.gov/msl/news/pdfs/MSLLanding.pdf [nasa.gov]

After the turn to entry, the back shell jettisons two solid tungsten weights, called the “cruise balance mass devices.”
Ejecting these devices, which weigh about 165 pounds (75 kilograms) each, shifts the center of mass of
the spacecraft. During the cruise and approach phases, the center of mass is on the axis of the spacecraft’s
stabilizing spin. Offsetting the center of mass for the period during which the spacecraft experiences dynamic
pressure from interaction with the atmosphere gives the Mars Science Laboratory the ability to generate lift,
essentially allowing it to fly through the atmosphere. The ability to generate lift during entry increases this mission’s
capability to land a heavier robot, compared to previous Mars surface missions.
The spacecraft also manipulates that lift, using a technique called “guided entry,” to steer out unpredictable
variations in the density of the Mars atmosphere, improving the precision of landing on target.
During guided entry, small thrusters on the back shell can adjust the angle and direction of lift, enabling the
spacecraft to control how far downrange it is flying. The spacecraft also performs “S” turns, called bank reversals,
to control how far to the left or right of the target it is flying. These maneuvers allow the spacecraft to
correct position errors that may be caused by atmosphere effects, such as wind, or by spacecraft modeling
errors. These guided entry maneuvers are performed autonomously, controlled by the spacecraft’s computer
in response to information that a gyroscope-containing inertial measurement unit provides about deceleration
and direction, indirect indicators of atmospheric density and winds.

After the spacecraft finishes its guided entry maneuvers, a few seconds before the parachute is deployed, the
back shell jettisons another set of tungsten weights to shift the center of mass back to the axis of symmetry.
This set of six weights, the “entry balance mass devices,” each has a mass of about 55 pounds
(25 kilograms). Shedding them re-balances the spacecraft for the parachute portion of the descent.

Re:150 kg dead weight? (1)

jackbird (721605) | about a year and a half ago | (#40890621)

So it's actually 300 kg dead weight, but allows them to actually land a bigger rover? That's really cool.

Any reason not to try to embed little experiments in the weights though?

Mars Homeland Security (2)

Camel Pilot (78781) | about a year and a half ago | (#40890501)

Well great... publicize the time and location and you are just making the formidable Mars Homeland Security's job easy. Loose lips sinks ships.

If all goes well (1)

Arancaytar (966377) | about a year and a half ago | (#40890753)

we'll be getting confirmation on the success (or failure)

An interesting definition of "all going well"...

What? No 3D animation? (1)

Whatsmynickname (557867) | about a year and a half ago | (#40890793)

This is the year 2012, no 3D animation on what the MSL is doing right now? Jeez!

Re:What? No 3D animation? (0)

Anonymous Coward | about a year and a half ago | (#40890819)

eyes.nasa.gov ( JRE required, not Linux friendly)

Re:What? No 3D animation? (1)

Anonymous Coward | about a year and a half ago | (#40890831)

This is the year 2012, no 3D animation on what the MSL is doing right now? Jeez!

A little digging will turn it up:

http://eyes.nasa.gov/

but the server seems swamped

I can respect the geek appeal of the engineering (1)

codepunk (167897) | about a year and a half ago | (#40890853)

I can respect the geek appeal of the engineering. However I compare it to writing a console app in java when a bash,perl or python script would have gotten it done without including 400 jar files.

Some links (3, Informative)

jomama717 (779243) | about a year and a half ago | (#40890891)

Here are some good links that I have cobbled together mostly from previous slashdot articles:

Happy viewing! Fingers crossed!

p.s. watching the simulation while listening to the beautiful blue danube is kind of fun :)

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