Updates Mars Science Laboratory (Curiosity)

[Urwumpe]

I'll be happy when all this talk of the skycrane is done and done. It's overdone!

I'll be happy when it worked.

 

[Keatah]

I read some .pdf's on how the hypersonic aeromaneuvering stuff is supposed to work. But they didn't explain how it knows when to fire thrusters to stay on course. Anybody got an explanation?

 

[Urwumpe]

I read some .pdf's on how the hypersonic aeromaneuvering stuff is supposed to work. But they didn't explain how it knows when to fire thrusters to stay on course. Anybody got an explanation?

It is all sensed by a IMU, with ejectable ballast weights providing trim. When the first ballast is jettisoned, the CoG is no longer on the centerline, like it was during cruise phase. For parachute deployment, the remaining ballast weights are dropped and the CoG is on the center line again.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090007730_2009006430.pdf

Star Trackers on the Cruise Stage provide the final navigation updates before the cruise stage is separated, from that point on, it is all done by integrating accelerations in 6DOF.

 

[orb]

NASA News Release:
RELEASE : 12-257
Daring NASA Mars Mission Broadcast Lands In Times Square

July 31, 2012

WASHINGTON -- The Toshiba Vision screen in New York City's Times Square will become the largest East Coast location for the public to see live mission coverage of Curiosity, NASA's most advanced planetary rover, as it lands on the Martian surface at 1:31 a.m. EDT August 6.

The Toshiba Vision screen will broadcast NASA TV coverage beginning at 11:30 p.m. EDT August 5 and continuing through 4 a.m. EDT the next day. Programming will originate from Mission Control at NASA's Jet Propulsion Laboratory's (JPL) in Pasadena, Calif. The rover is on a precise course for a landing beside a Martian mountain to begin 2 years of unprecedented scientific detective work.

"In the city that never sleeps, the historic Times Square will be the place for New Yorkers to participate in this historic landing," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate. "When you think of all the big news events in history, you think of Times Square, and I can think of no better venue to celebrate this news-making event on Mars."

Getting Curiosity to the surface of Mars will not be easy. During a critical period lasting only about 7 minutes, the MSL spacecraft carrying Curiosity must slow down from about 13,200 mph (about 5,900 meters per second) to allow the rover to land on the surface at about 1.7 mph (three-fourths of a meter per second). For the landing to succeed, hundreds of events will need to go right, many with split-second timing. All are controlled autonomously by the spacecraft.

Prominently positioned below the world-famous New Year's Eve ball in Times Square, the Toshiba Vision dual LED screens will allow viewers to see the action from Mission Control, including receipt of the first signal from Mars following a successful landing. "We're pleased the Toshiba Vision screens will offer a unique view of this great scientific achievement, the landing of the rover Curiosity on Mars," says Eddie Temistokle, senior manager of corporate communications and corporate social responsibility for Toshiba America Inc.

Visitors to Times Square can hear the audio portion of NASA's coverage along with other listeners around the world by tuning in to the online radio station Third Rock Radio. This is the first time Third Rock Radio will provide live coverage of a NASA event. Third Rock Radio can be streamed from the NASA homepage at and on smart phones and tablets through the Tuneln mobile app.

In the first several weeks after landing, JPL mission controllers will put the rover through a series of checkouts and activities to characterize its performance on Mars while gradually ramping up scientific investigations. Curiosity then will begin investigating whether an area with a wet history inside Mars' Gale Crater ever has offered an environment favorable for microbial life.

{...}



SPACE.com: NASA to Broadcast Mars Rover Landing From NYC's Times Square Sunday Night

Discovery News: Mars Rover Curiosity Makes it to Times Square

Universe Today:

• What Will Curiosity’s “View” Be as it Approaches the Red Planet?
  
  
• Join Universe Today’s Live Webcast of the Curiosity Rover Landing

 

[Spacethingy]

What happens to the probe after dropping the rover? Just a random smash, or something more scientific?

 

[Keatah]

It flies up, up, and away in my beautiful, my beautiful, balloon..
And then crashes some arbitrary distance from the landing site.

---------- Post added at 05:56 PM ---------- Previous post was at 05:50 PM ----------

http://www.youtube.com/watch?NR=1&v=TIxm0Th55Iw

 

[Screamer7]

It flies up, up, and away in my beautiful, my beautiful, balloon..
And then crashes some arbitrary distance from the landing site.

---------- Post added at 05:56 PM ---------- Previous post was at 05:50 PM ----------

http://www.youtube.com/watch?NR=1&v=TIxm0Th55Iw

May the Probe be with him.

 

[SolarLiner]

https://www.facebook.com/photo.php?...36730240.23875.110938085622842&type=1&theater
Entry, Descent and Landing autopilot software uploaded and in functions. Really close to the T0 time !

 

[Screamer7]

From 5.9 m/s to 405 m/s in 4 minutes and 15 seconds. I wonder what the G-load would be on MSL?

 

[MattBaker]

From 5.9 m/s to 405 m/s in 4 minutes and 15 seconds. I wonder what the G-load would be on MSL?

The heaviest G-load should be in the parachute sequence. Just 24 seconds from parachute deployment to heat shield separation, but 380 m/s delta-v.
So on average we end up with nearly 12 m/s^2, somewhere in the area of a braking car. But in the seven minutes of terror video they mentioned 9G at parachute deployment, that's more than Apollo ever achieved...

 

[orb]

NASA: NASA's Curiosity Rover Faces its Moment of Truth

Universe Today:

• Quick and Curious Facts About the Mars Science Laboratory Mission
  
  
• Curious About Curiosity’s Chemistry Mission?

 

[orb]

Discover Magazine - Bad Astronomy: Curious about Curiosity? Here’s info on where to watch!

The Planetary Society Blog: Videos: Where are Curiosity's science instruments and how do they work?

[ame="http://www.youtube.com/watch?v=diygR-TeXoI"]Exploring Curiosity--Part 2: The Other Science Instruments - YouTube[/ame]

SPACE.com:

• Daring Mars Rover Landing Has High Stakes for NASA
  
  
• New NASA Mars Rover is a Red Planet Mini-Truck, Ford Says

Discovery News: Curiosity: The Ultimate Off-World Vehicle

 

[Keatah]

Am I right in reading that the rover's RTG is a re-designed unit with no direct heritage to the ultra-reliable cassini and voyager rtg's?

This redesigned rtg is sensitive to shock and is (supposedly) outputting less power than it should. And they've had to reduce the traverse distances quite a bit, as well as cut the sample analysis to 1/3rd of what was originally planned.

 

[tblaxland]

Follow the flight of MSL into Mars...the attached scenario file puts a DG on the same trajectory as MSL at 2012-Aug-03 00:00:00 UTC. State vectors courtesy of JPL Horizons.

The good news is that it appears to be heading for Gale crater

 

[Urwumpe]

Am I right in reading that the rover's RTG is a re-designed unit with no direct heritage to the ultra-reliable cassini and voyager rtg's?

That is right, but wrong as well. The MMRTG is based on the SNAP 19 design that powered Viking and Pioneer probes. The RTG of Cassini is based on the SNAP 19 as well and the MMRTG uses the same GPHS modules as Cassinis GPHS-RTG.

All RTGs had been highly reliable compared to other sources of electricity.

The difference between this and older generations is, that SiGe thermocouples are no longer in production and had to be replaced in the design by modern semiconductors based on Zirconium and Palladium.

This redesigned rtg is sensitive to shock and is (supposedly) outputting less power than it should. And they've had to reduce the traverse distances quite a bit, as well as cut the sample analysis to 1/3rd of what was originally planned.

No idea since I don't know what kind of baseline you are talking about there. But it is happening pretty often that initial feasibility studies had been more feasible than financially realistic.

 

[cljohnston]

Y'all can follow it in realtime here...

Eyes on the Solar System

I jumped ahead to preview the EDL phase, and they've done a wonderful job on the meshes and animations. (Almost like getting to run Orbiter on my Mac!)

 

[orb]

Some news links from the last day:

NASA:

• NASA Hosts Social Media Events Across Seven Agency Field Centers
  
  
• Newest NASA Mars Mission Connects Past and Future
  
  
• Curiosity's First Daredevil Stunt

RAD charged particle flux observations during ~7 months of cruise included contributions from 5 solar energetic particle events. The inset compares the particle flux observed by RAD to that observed by instruments on the ACE spacecraft. The MSL spacecraft structure (backshell, heatshield, etc.) provided significant shielding from deep space radiation, significantly reducing the particle flux compared to ACE.
Credit: NASA/ACE/RAD​

NASA JPL:

• Newest NASA Mars Mission Connects Past and Future
  
  
• NASA Hosts Social Media Events Across Seven Agency Field Centers

ESA:

• Timeline: ESA spacecraft and station track critical arrival at Mars
  
  
• Mars Express marks the spot for Curiosity landing
  
  
• Watch live Mars Express tracking NASA Mars landing

Click on image to enlarge

Oblique view of Mount Sharp inside Gale Crater, with the original and revised landing ellipses marked.
Credits: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS​

DLR:

• Radiation measurements with 'Curiosity'

Universe Today:

• 4 Days to Mars: Curiosity activates Entry, Descent and Landing Timeline – EDL Infographic
  
  
• Comedian Stephen Colbert Talks with NASA’s John Grunsfeld About Curiosity Rover Landing
  
  
• Reminiscent of Apollo, Australian Facilities Will Receive First Signals of Curiosity Rover Landing
  
  
• 3 Days to Red Planet Touchdown – Watch the Harrowing Video of Car-Sized Curiosity Careening to Crater Floor
  
  
• HiRISE Camera to Attempt Imaging Curiosity’s Descent to Mars
  
  
• Incredible View of Curiosity Rover’s Landing Site

SPACE.com:

• Mars Rover Landing: Q & A with Curiosity's Chief Scientist John Grotzinger
  
  
• TV Comedian Stephen Colbert Hypes NASA's Huge Mars Rover Landing
  
  
• Mars Rover Curiosity Will See Red Planet As Never Before
  
  
• NASA Marking Historic Mars Rover Landing with Flurry of Events
  
  
• Excitement Builds for Mars Rover's Landing Sunday
  
  
• NASA's Huge Mars Rover Landing: How to Watch Live & Get Involved
  
  
• What If the Curiosity Rover Finds Life on Mars?
  
  
• Touching Mars: Huge NASA Rover Carries Strong Arm for Red Planet
  
  
• NASA Mars Rover's Risky Landing Plan: A Step-By-Step Guide
  
  
• NASA: Huge Mars Rover's Sky Crane Landing Was 'Least Crazy' Idea
  
  
• Why NASA's Big Mars Rover Has a Laser to Zap Rocks
  
  
• How NASA's New Mars Rover Will Phone Home
  
  
• Mars Rover Curiosity Tells Her Story on Twitter

Discover Magazine - Bad Astronomy:

• Curiosity’s chem lab on Mars

SpaceRef:

• Curiosity Measured Radation On Its Way to Mars

Florida Today:

• Curiosity on track for early Monday landing on Mars
  
  
• Curiosity rover mission not about Martians

Aviation Week:

• Mars Science Lab Repositioned For Landing

 

[Keatah]

Everything I've read so far is that the skycrane is pretty stupid. It only knows how high it is when it deploys the rover. I read nothing to indicate that it can avoid rocks or rough terrain. What if the rover lands half-way on a boulder and tips over?

 

[Ripley]

I'm pretty sure one of the on-board cameras scans the ground during descent to find the optimal touch-down spot.

 

[C3PO]

Everything I've read so far is that the skycrane is pretty stupid. It only knows how high it is when it deploys the rover. I read nothing to indicate that it can avoid rocks or rough terrain. What if the rover lands half-way on a boulder and tips over?

That's why NASA selected a landing site without large boulders. IIRC MSL can handle landing on a slope of at least 35°. I have some experience with off-road driving, and most people freak out before even reaching 10° sideways tilt.