October 20, 2017

Astro-Event: “Occupy Mars!”

Curiosity at Gale… (Artist concept. Credit: NASA/JPL).

It’s not every day that Earthlings land embassaries on another world. This weekend, NASA will go for an eighth landing on the Red Planet as Curiosity touches down in Gale Crater. We were lucky enough to attend our 3rd #NASATweetup for the launch last November, seeing off the Mars Science Laboratory enroute to Mars. And now the big day is finally here. On the morning of August 6th, 2012 at 1:31 AM EDT/5:31 UTC, MSL will begin its perilous descent through the tenuous Martian atmosphere to the surface of the Red Planet. Suffice to say, that this is the most nail-biting part of any mission; in seven minutes, the rover has to go from 3.5 miles per second to a dead stop through a sequence of braking, parachute deployment, and an innovative sky-hook landing system that’s never been used on Mars. As of this writing, parties worldwide are planned to celebrate the event, and NASA TV will go live Sunday night at 11PM to cover the occasion. Heck, Times Square plans to have coverage!

Of course, there won’t be any live footage of the rover descending to the surface of Mars; signals currently take about 14 minutes traveling at the speed of light to reach Earth, and even these must be downloaded and processed. Perhaps the best we can hope for early Monday morning is an “I’m here” signal from Curiosity sitting in Gale crater. Over the coming days after the landing, expect to see views of the descent via the Mars Reconnaissance Orbiter and its HiRISE camera, a thrilling video from the descent camera mounted on the underside of MSL, and the first panoramas of its new home.

Looking west at dusk this weekend… (Created by the Author in Starry Night).

The good news is YOU can step out and see Mars this weekend, low in the dusk sky. Mars-spotting is easy; it currently forms a triangle with the planet Saturn and the bright star Spica visible about an hour after sunset to the west. Saturn sits at magnitude +0.8 and is 10 Astronomical Units (A.U.s) distant, while Mars is currently at magnitude +1.1 & is 1.6 A.U.s distant while & Spica sits at magnitude +0.96 & is a whopping 263 light years distant. Mars is currently tiny, at only 5.7” arc seconds across and about 90% illumination, a far cry from opposition earlier this year. Conventional wisdom is that Mars generally doesn’t show much surface detail in a backyard telescope below 6” in size, but the northern polar cap and a slight gibbous phase may just be apparent at high magnification with a good sized instrument. The three form an equilateral triangle in early August in the constellation Virgo and are also of nearly equal brightness.

So, how can you tell which is which? Here’s a nifty trick; stars twinkle, planets don’t. This is because stars are extremely far away; their teeny angular diameter is effectively a point source, which can be cleanly distorted by the atmospheric cells overhead. It may not seem like it, but planets such as Saturn and Mars do have a tiny apparent diameter, as revealed by even a small telescope.  And while Saturn has a whitish-yellow hue to it, Mars appears ruddy-to-orange to the naked eye, a good way to tell ‘em apart; do make an effort to see Mars for yourself as this weekend’s drama unfolds!

3x generations of rover tires and a (simulated) RTG! (Photo by Author).

We also had a chance to conduct two interviews this week related to the Mars Curiosity landing. First up was an interview with Rod Pyle, science journalist and author of Destination: Mars.

It was great to talk to Mr. Pyle about science and space writing in general and Mars exploration in particular. Mr. Pyle has been personally involved in TV, journalism, & public relations for decades and it was interesting to hear his take on space exploration.

One thing we found striking from his book was just how engineers got useful images for the press from those early missions. This was actually done via hand-coloring large pasted together strip sheets; “You win hearts and minds with images” Mr. Pyle mentioned in reference to those very early Mariner missions, adding that even today, getting data is like “Doing brain surgery through a million mile+ long soda straw.” Indeed, transmission bandwidth and data rate tend to be the primary limiting factor even today on any deep space missions.

We also discussed what would the consequences be of an MSL success or failure. Perhaps a hugely successful surface science mission by MSL may provide the impetus for an eventual sample return mission. Still, take the example of Viking; Mr. Pyle astutely pointed out that although Vikings I & II were wildly successful, we didn’t return to Mars for another 20+ years. On the down side, a failure of MSL may perhaps mean that we won’t no return to the Red Planet for another decade. Right now, only MAVEN remains on the future launch schedule for departure in 2013.

We also discussed how long MSL will last and how long could it last with its onboard MMRTG. MSL’s primary science mission is slated for 1 Martian year (or 687 Earth days); the power cell may be expected to operate at over 50% output for 6-7 years, but engineers are always great at coaxing out more with less.

We were also fascinated to discuss the ill-fated history of Russia’s Mars exploration program outlined in the book. Why have the Russians been consistently unsuccessful in exploring Mars? The author notes that while the Russians are great at doing dependable & proven things such as going to and from Low Earth Orbit, their command and control is not so adept at longer deep space journeys.

On a lighter note, we also talked of all things in the wacky realm ‘space travel denialism’. The author notes that there’s no Mars landing conspiracies out there to parallel the “Moon landing hoaxers…” other than the Viking “face” of course!

When asked if there’s anything he’d wished Curiosity was equipped with, the author mentioned that he was disappointed that there’s no mike! The unfortunate Mars Polar Lander had one, as did Mars Phoenix, on which the microphone never functioned properly. Alas, we’ll have to wait until a later mission to hear the “sounds of Mars…”

The author also noted that of 40 launches to the Red Planet, 18 were successes and 22 failures, the most recent of which was Phobos-Grunt earlier this year. And although that comes out to an overall ~45% success rate, it should be noted that only one out of seven NASA landings have failed to date (Mars Polar Lander) a much more encouraging sample space!

The breaks down those stats as 40 attempts, if you count the ESA orbiter and lander (Beagle) as one attempt and cull out the oddities (DAWN,etc). Its hard to define overall because of (instances such as) the Express orbiter which succeeded but the Beagle lander failed; likewise, USSR had partial successes, but little useful data was returned, so they were mission failures.

The scorecard of Mars exploration thus stands as;

US Successes: 12 out of 18 attempts.

Soviet/Russian: 19 attempts (including Grunt), 4 partial (Mars 3 landing, Mars 3 orbiter; Mars 5 and 6 returned some data) successes, but zero successful missions overall.

Europe: 2 launches, 1.5 success (Express & Rosetta succeeded, Beagle failed); mission success overall.

Japan: 1 launch, failed.

China:(Included with Grunt)

Finally we asked when might we see the first astronaut on Mars? Should we go? The “around 2035 date” is often cited in the press, though it’s not clear if that journey will be made by astronauts, cosmonauts, or taikonauts… The author stated that space exploration remains “absolutely imperative”, and had these final thoughts on man’s need to explore:

“Americans have been characterized as a restless society. These clichés often spring from smaller truths; in this case, the expansion West and our ascension in the 20th Century. It often feels that, outside of defense and the information sector, some of this restlessness has been replaced by a passive interest in consumption. In my opinion, this is the beginning of a downturn in American innovation and prowess. So in the case of space exploration, I think there is more to it than the substantial long-term economic technological and educational benefits- there is also the less measurable benefit to our society of imagination, inspiration and the excitement generated by accomplishing great things. And the exploration of Mars, the other planets and space in general is a great thing.”

We also got a chance to talk with Raymond Frost from Teledyne DALSA. Mr. Frost is the Process Integration Scientist in charge of project management and process development at Teledyne DALSA’s Semiconductor foundry in Bromont, Quebec. The company manufactured the digital image sensors for the Navigation & Hazard avoidance cameras on Curiosity. The hazard avoidance cameras are stationed on the four corners of the rover, while the navigation camera is positioned on its mast. Teledyne also built duplicate chips for the cameras on Spirit & Opportunity as well as imaging sensors for the Mars Reconnaissance Orbiter and Phoenix lander.

Mast cameras on MSL. (Credit: NASA/JPL).

The custom sensors differ from CCDs that you would get commercially in that the pixel size is much larger and can function in low light conditions. The cameras on Curiosity are 1 megapixel frame transfer devices and have the physical dimensions of 1” x ½”. For comparison, a typical 1 megapixel CMOS chip in an off-the-shelf consumer camera or mobile phone might be only a few millimeters square. The two NavCams and the four HazCams are stereoscopic, meaning that they use two chips per camera. Together, they will serve multipurpose roles in getting the rover where it needs to be. Expect the Rover to produce some stunning imagery early next week after landing, possibly as early as Monday. And like on Spirit and Opportunity, expect MSL’s Nav- & HazCams to produce 3D anaglyphs, so keep those 3D glasses handy!

Calibration target for a separate set of cameras (MAHLI & APXS)… note the 1909 Lincoln penny!

(Credit: NASA/JPL).

“We’re pleased to know that technology designed 12-13 years ago is still working today,” Mr. Frost said in reference to the chips on Opportunity & Spirit. If Curiosity lasts for a decade, Mr. Frost and the folks at Teledyne DALSA are confident that its CCD detectors will function as well. Mr. Frost will be watching the landing live on NASA TV (as will we) Sunday night going into Monday morning.

The mighty 111 megapixel chip! (Credit: Teledyne DALSA).

Teledyne DALSA also built a 111 megapixel chip (10560 x 10560) for a CCD detector in 2006 which was the first chip larger than 100 megapixels. This was constructed for the United States Naval Observatory, and wasn’t surpassed until the advent of PanSTARRS in 2011.

Teledyne DALSA is based out of Waterloo, Ontario and you can follow them on Twitter @TeledyneDALSA.

Rupes Recta sightings: Finally, thanks to all who heeded our call July to hunt for the Lunar X, Rupes Recta and more last month; expect more challenges in the bizarre lunar features department soon. The good news is, this feature is visible twice every 29.5 day lunation somewhere in the world… Ed Kotapish calculated these times for the remainder of 2012;




AUG 10 1409 SET

AUG 25 0454 RISE
SEP 09 0141 SET

SEP 23 1702 RISE
OCT 08 1343 SET

OCT 23 0621 RISE
NOV 07 0227 SET

NOV 21 2042 RISE
DEC 06 1554 SET

DEC 21 1143 RISE


Good hunting!



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