APOD: Curiosity Before Mars: Seven Minutes... (2012 Jul 31)

[Jim Leff]

I'm curious as to why they didn't use aerobraking for this mission. Yes, it can take a while, perhaps six months of repeated passes, but it would greatly slow the craft and result in, I assume, a gentler approach to landing.

I'd guess more fuel, more mission time, and a whole new set of potential downsides.

But, most importantly, don't get the misimpression that this is some flakey, haphazard, geez-I-hope-it-works plan. Yes, it's complex and highly unlikely to our eyes, but the engineers are quite confident. We're used to seeing complicated, novel mechanisms as being iffy. But bear in mind that this one's been engineered to an extreme degree. It ain't some kid shooting off bottle rockets!

[neufer]

I'm curious as to why they didn't use aerobraking for this mission. Yes, it can take a while, perhaps six months of repeated passes, but it would greatly slow the craft and result in, I assume, a gentler approach to landing.

MSL has no difficulty using a heat shield in order to drop from the atmospheric interface velocity of 5,800 m/s down to 470 m/s.

And it has no difficulty using a parachute in order to drop from 470 m/s down to a terminal velocity of 100 m/s.

The problem comes from having a parachute terminal velocity of 100 m/s.

(A more reasonable landing velocity of 1 m/s would require a parachute with a diameter of ~1 mile.)

[Vonskippy]

Makes me worried when the Nasa engineers can't sync a simple audio track to the video track on a 5 minute youtube video.

Lets hope they did a better job on the 7 minute landing sequence.

I wonder if Vegas has a betting pool for this landing?

[geckzilla]

Makes me worried when the Nasa engineers can't sync a simple audio track to the video track on a 5 minute youtube video.

Lets hope they did a better job on the 7 minute landing sequence.

I wonder if Vegas has a betting pool for this landing?

NASA engineers probably had nothing to do with editing the video. That's what video editors are for. Two separate jobs.

[Anthony Barreiro]

This is a very exciting video. I'm looking forward to the moment of relief and joy when we get the first signal from Mars Science Laboratory Curiosity transmitting from Gale Crater. Thanks and best wishes for a successful mission to the folks who have worked so hard to get this craft to Mars.

[ta152h0]

and enjoy an ice cold one on the evening of the 5th. And have a 5th ????????

[minkfarms]

OK kiddies, I remember when we couldn't even hit the moon. In my humble opinion, in this very new century, this feat will stand as one of the great technological achievements of space exploration. Its intricacies and payoff should thrill the public and that is so important for future robotic exploration.

[NoelC]

Ambitious and impressive! Best of luck.

Did anyone else see/get this little joke?

As a software engineer I got a good laugh out of it.

-Noel

[NoelC]

Makes me worried when the Nasa engineers can't sync a simple audio track to the video track on a 5 minute youtube video.

Lets hope they did a better job on the 7 minute landing sequence.

I wonder if Vegas has a betting pool for this landing?

There's nothing wrong with the audio/video sync. Chances are they use better computers than yours.

-Noel

[saturno2]

In this mission I worry about the weight of Curiosity Rover.
This robot is very " heavy"

[Beyond]

Ambitious and impressive! Best of luck.

Did anyone else see/get this little joke?

HalfMil.jpg (25.52 KiB) Viewed 2765 times

As a software engineer I got a good laugh out of it.

-Noel

At first, i thought there was something 'fishy' about this. It wouldn't play or anything. Then i noticed that the 'fishyness' is the joke

[geckzilla]

There's nothing wrong with the audio/video sync. Chances are they use better computers than yours.

-Noel

The audio gets out of synch slightly for me at the end. I don't think it's my computer. But I also didn't notice it until Vonskippy pointed it out. It's like a tenth of a second off and gets worse towards the end.

[BMAONE23]

Too bad they didn't include a Video Camera in the Sky Crane for footage of the actual landing

[neufer]

Click to play embedded YouTube video.

There's nothing wrong with the audio/video sync. Chances are they use better computers than yours.

The audio gets out of synch slightly for me at the end. I don't think it's my computer.
It's like a tenth of a second off and gets worse towards the end.

By the time you start hearing the narrator he will either have stopped moving his lips or have been dead for at least 7 minutes.

[ta152h0]

BM
I think they do have a descent camera

[neufer]

I think they do have a descent camera

• On Curiosity, itself, pointing down.

<<MSL Mars Descent Imager (MARDI): During the descent to the Martian surface, MARDI will take color images at 1600×1200 pixels with a 1.3-millisecond exposure time starting at distances of about 3.7 km to near 5 meters from the ground and will take images at a rate of 5 frames per second for about 2 minutes. MARDI has a pixel scale of 1.5 meters at 2 km to 1.5 millimeters at 2 meters and has a 90-degree circular field of view. MARDI has 8 GB of internal buffer memory which is capable of storing over 4,000 raw images. MARDI imaging will allow the mapping of surrounding terrain and the location of landing. JunoCam, built for the Juno spacecraft, is based on MARDI.>>

[Bix Dugan]

Boy, this is complicated. Why not just safely splash down in one of the Canals? Put some spider legs on that probe and walk right out of the water.?

[Baaaab]

What is 500,000 lines of COD3 ?

[Case]

What is 500,000 lines of COD3 ?

Q: Why is it useful to count the number of Lines Of Code (LoC) ?
A: The idea is that LoC should never be used to measure productivity, but more to do test coverage estimation and software deadline estimation.

[neufer]

Click to play embedded YouTube video.

[neufer]

[b][color=#0000FF]Annotated image of Mars by[/color][/b] [url=http://jaicoa-observatory.com/]Efrain Morales[/url]

---

Why not just safely splash down in one of the Canals?

. Maybe they will just do that.

<<Where will the Mars Science Laboratory Curiosity rover land? This annotated image of Mars by Efrain Morales shows where on Mars Curiosity will set down, if all goes well, at about 05:31 UTC on Aug. 6 (10:31 p.m. PDT on Aug. 5, 1:31 a.m. EDT Aug. 6). The landing site is 4.6 degrees south latitude, 137.4 degrees east longitude, near base of Aeolis Mons, also known as Mount Sharp, a layered mountain that rises 4.8 kilometers (3 miles), inside Gale Crater.>>

[johnlbee]

Amazing!
http://mars.jpl.nasa.gov/msl/raw/?s=0

[orin stepanek]

curiousity's photo! http://en.wikipedia.org/wiki/Mars_Science_Laboratory

[neufer]

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Mars Reconnaissance Orbiter HiRISE has done it again!!
Posted By Emily Lakdawalla, 2012/08/06

<<In 2008, Mars Reconnaissance Orbiter snapped
an amazing photo of Phoenix descending
to the surface of Mars under its parachute.

Now it's repeated the feat, with Curiosity.

I think this image pretty much speaks for itself.
Absolutely stunning.>>

---

Mars orbiter plans for a Curiosity close-up
by Eric Hand NASA/JPL/Univ. Arizona, 05 Aug 2012

<<The MRO will slew into position and take a snap of Curiosity’s parachutes 60 seconds before landing, just before the rover is released from the back shell. It could even be possible to discern the heat shield on the ground. “We get one shot,” says Alfred McEwen, principal investigator of HiRISE (High Resolution Imaging Science Experiment) at the University of Arizona in Tucson.

This time, the chance of catching Curiosity on camera is only 60%, says McEwen. With Phoenix, there was about an 80% chance. The difference is because of the relative paths of the spacecraft. For the Phoenix landing, HiRISE’s long and narrow field of view was closely aligned with the path of the lander. For the Curiosity landing, the MRO will be much closer and looking almost directly down at Curiosity. But the paths are nearly perpendicular, which means that HiRISE’s field of view — a narrow north–south track about 6 kilometres wide on the ground — might not contain Curiosity, which will be barreling east along its 20-kilometre-long landing ellipse.

There is a silver lining, however. Not only will the MRO be closer, but Curiosity’s parachute is about twice the size of Phoenix’s. In the Phoenix snap, the parachutes were just 10 pixels across. McEwen says that Curiosity’s parachutes could cover 50 pixels, making for a black-and-white image as detailed as 35 centimetres per pixel. And McEwen estimates that there’s a 20% chance Curiosity will fall along the central swath of HiRISE’s field of view, where there are colour detectors. “If we’re really, really lucky we’ll catch it in our colour strip,” he says.

McEwen expects to get the data back to Earth by 1 a.m. Pacific daylight time on 6 August. His team will spend a frantic few hours trying to spot Curiosity and process the image before delivering it to the Jet Propulsion Laboratory (JPL) in Pasadena, California, by 3 a.m. So forget the fish-eyed, fuzzy thumbnails that Curiosity’s hazcams are supposed to return first. By the time of the 9-a.m. press briefing on Monday morning, the JPL could have a beautiful surprise waiting for the public: a memento (hopefully not mori) of the most complicated landing ever attempted in the Solar System.>>

[BMAONE23]

Here is another MSL site to whet your curiosity for images from Gale Crater
http://mars.jpl.nasa.gov/msl/multimedia/images/