Starship Asterisk*

Great animation. Made it worth having my Flash player installed, as opposed to the Flash player's main mission displaying unwanted ads. One comment on the lander engineering, though:

I would have put the dirt hopper on the edge of the deck, not in the middle. That way when the dirt scoop drops dirt into the hopper, stray dirt won't be as likely to spill on the deck. The dirt in the animation was well behaved, but how will it act in the real (Martian) world?

Towards the end of the animation you can see a beam of green light shooting upwards. I wonder what is it for. Is it a laser? Or just an artistic license?

I did like the solar panel fold-out, that seemed really cool engineering. But wouldn't the energy production be better if the panels were pointed at the sun? The way the animation shows it, the sun is low and the panels would only receive under 50% sunlight.

Judging by the animation, the landing with the thrusters seems tricky, both balance-wise and the timing, as a lot of speed reduction has to be done in a short time, as the parachute doesn't brake that much with only 1% of the atmospheric pressure we have here. Be safe, Phoenix!

I would like to suggest a minor correction to today's APOD. The Phoenix lander will deploy it's braking parachute. If it deploys a breaking parachute the lander will be destroyed.

PlainBill

Yup Bill .. with speelers like that breaker braker good buddy we'd might be better off sending in a 18 wheeler.

Good show, though, Nasa. But I wonder how mad the Martian mothers are going to be when their kids get fried by those landing rockets.
"MMADDE" Martian Mothers Against Damned Deranged Earthlings".

Seriously .. there should have been a more intelligent way of landing that thing than frying what they're looking for. Maybe it will malfunction and another little piece of creation will be saved the ravages of humankind's morbid stupidity and disrespect for life.

Hello All,

Phoenix had a successful landing, communicated at 7:53 EDT. An adjustment in it's orientation via it's thrusters has allowed the solar panels to be repositioned east/west for optimum gain.

P.S.

It landed flat, or should I say on a flat surface- .25 degree of tilt. Remarkable feat (feet?)!

rafa wrote:Towards the end of the animation you can see a beam of green light shooting upwards. I wonder what is it for. Is it a laser? Or just an artistic license?

The green laser is part of the meteorologic sensing package supplied by Canada.

Thrilling!
Congratultions!

Considering the difficulties the Soviets faced in sending back pictures from Venus 30 years ago Phoenix was not much of an accomplishment .. almost like a walk to the corner store. The technology Phoenis is using for sampling soil seems primitive to me .. I would have thought they could have done it using lasers. I guess Nasa's just not as advanced as I am. 8)

Sputnick wrote:Considering the difficulties the Soviets faced in sending back pictures from Venus 30 years ago Phoenix was not much of an accomplishment .. almost like a walk to the corner store.

Mars is an extremely difficult planet to land on- much more so than Venus. The combination of fairly high gravity and very little atmosphere makes it really tricky to slow down. The aerobraking maneuver required on Mars is trickier to execute than aerobraking on either Earth or Venus.

The technology Phoenis is using for sampling soil seems primitive to me .. I would have thought they could have done it using lasers.

Do just exactly what with lasers? They aren't magic probes. The scoop is designed to retrieve material from under the surface (very important, since surface dust is highly altered), and bring it into an instrument capable of performing different sorts of analysis. A laser couldn't get below the surface, and it would be very limited in terms of what it could be used for (actually, the laser couldn't detect anything, it would only be part of some sort of spectral analyzer).

Sputnick wrote:Considering the difficulties the Soviets faced in sending back pictures from Venus 30 years ago Phoenix was not much of an accomplishment .. almost like a walk to the corner store. The technology Phoenis is using for sampling soil seems primitive to me .. I would have thought they could have done it using lasers. I guess Nasa's just not as advanced as I am. 8)

Perhaps. Either that or you don't actually understand the key instruments on this mission:

Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) - Considering that atomic force microscopes didn't even exist until over 20 years after the Soviet Lunakhod rovers, I'd say it's a major stretch to call this primitive.

Thermal Evolved Gas Analyzer (TEGA) - Able to heat samples up to 1000 degrees and deliver the resulting vaporized gases to a mass spectrometer. "The mass spectrometer is sensitive to detection levels down to 10 parts per billion, a level that may detect minute quantities of organic molecules potentially existing in the ice and soil."

Meteorological Station (MET) - Here's your laser. Plus a nice, ultra-lightweight weather station. Also, Mars Science Laboratory, to launch next year will have a laser spectrometer called ChemCam, but it won't be nearly as capable as the MECA and TEGA instruments on Phoenix.

The robotic arm is no cheap toy, either.

And don't forget, NASA, ESA, Japan, and Russia have all messed up Mars missions easier than this. If Phoenix continues to be successful, it will be the first time the international space community has broken the 50% mark for Mars mission success:

http://www.bio.aps.anl.gov/~dgore/fun/P ... ecard.html

My memory may be misled, but I recall Venus as having 600 mph winds, and for sure the atmosphere is so thick it can't be seen through. I can't imagine gravity differences being so different as to mount a challenge. The Soviets' achievement was miraculous, and I can't imagine what secret technology Russia has today, because their publicized technology is impressive enough (torpedo capable of speeds of hundreds of miles an hour .. not that I want anyone to use torpedoes or bombs or bullets.)

I admit my laser knowledge is limited, but they could blast through to subsoil .. and I thought they were developed to the point of being capable of reading wavelengths in smoke. I guess I'm probably wrong about the latter.

What my post really meant was pinpoint landing on Mars should be easy today with what was done 30 years ago on Venus. I really don't care .. life is everywhere, even (it is speculated) in the transition zone of Mercury.

Sputnick wrote:My memory may be misled, but I recall Venus as having 600 mph winds, and for sure the atmosphere is so thick it can't be seen through.

That thick atmosphere is precisely what makes getting to the surface easier. Actually landing required a degree of luck, since the earlier landers didn't really have the smarts to dodge any big rocks. Even now, with smarter landers, luck is still important.

I admit my laser knowledge is limited, but they could blast through to subsoil .. and I thought they were developed to the point of being capable of reading wavelengths in smoke. I guess I'm probably wrong about the latter.

Not entirely. It would certainly be possible to use a laser to heat a specimen and then perform spectral analysis on the resulting light, maybe even the smoke. But that's a very limited analysis, and practically useless if you're looking for complex molecules. Phoenix is capable of a much richer array of testing.

What my post really meant was pinpoint landing on Mars should be easy today with what was done 30 years ago on Venus.

Like I said, Venus and Mars are apples and oranges. If you want to make a comparison, it should be between the Viking landers and the Phoenix. They faced similar problems.

Sputnick wrote: I admit my laser knowledge is limited, but they could blast through to subsoil

Which is why when someone uses a laser pointer in a presentation, it burns through the building. Or not.

Do you have any idea how large and power hungry large lasers like that are? You'll need to send a warehouse sized building and a nuke plant to mars if you want to do anything to the soil. And, of course, you've destroyed what you were looking for in the process.

Thanks Chris,

It's nice to know that I'm not tottally wrong, sometimes.

Sounds like the uncertainty principle on a bizarrely large scale.

That thick atmosphere is precisely what makes getting to the surface easier. Actually landing required a degree of luck, since the earlier landers didn't really have the smarts to dodge any big rocks. Even now, with smarter landers, luck is still important.

There is a reason NASA is not sending probes to Venus, at 90 times the Earth's atmospheric pressure and temperatures reaching 450 degrees C Venus is not a trip to Grandma's house either.

Venera-9 and -10 had to have a camera lenses made from cut diamond and when the probes landed they lasted an incredible 30+ minutes in an environment that would melt Pb. Hat's off the the Rooskies!

Dr. Skeptic wrote:There is a reason NASA is not sending probes to Venus, at 90 times the Earth's atmospheric pressure and temperatures reaching 450 degrees C Venus is not a trip to Grandma's house either.

Absolutely. Getting a probe to survive for any period of time on Venus is a much greater problem than it is on Mars. I was talking about the problems involved in actually landing a probe. Mars is generally more difficult than Venus in that respect.

astrolabe wrote:It landed flat, or should I say on a flat surface- .25 degree of tilt. Remarkable feat (feet?)!

Remarkable indeed. There are two very remarkable images: the descend of Phoenix as seen by another man-made machine: the HIRISE orbiter.

• Dark image
  Light image

The press kit mentiones that its targeted landing site is at 68° north. Since the tilt angle of Mars is comparable of that of planet Earth, Phoenix is around or above the Martian polar circle.

Two monks explored new ground. One walked on hot volcanic rocks and survived with burned feet. The other walked in cool sand. Whose research was more enlightening?

apodman wrote:Two monks explored new ground. One walked on hot volcanic rocks and survived with burned feet. The other walked in cool sand. Whose research was more enlightening?

A completely inappropriate question/implication.

In a resource constrained environment, even pure research/exploration needs to consider potential "bang for the buck". It appears pretty much inarguable that that consideration favors Mars exploration over Venus exploration.

If one considers potential future follow-ons (up to and including habitation possibility) it makes much more sense to concentrate on Mars. That is not to say that Venus should be totally ignored, but extensive surface exploration thereof certainly shouldn't be a high priority at this point.

Sputnick wrote:Considering the difficulties the Soviets faced in sending back pictures from Venus 30 years ago Phoenix was not much of an accomplishment .. almost like a walk to the corner store. The technology Phoenis is using for sampling soil seems primitive to me .. I would have thought they could have done it using lasers. I guess Nasa's just not as advanced as I am. 8)

The U.S. has succeeded in five out of six Mars lander attempts.

The only "successful" Russian Mars lander (out of five or six attempts):
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http://en.wikipedia.org/wiki/Mars_3
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<<Through aerodynamic braking, parachutes, and retrorockets, the lander achieved a soft landing at 45° S, 158° W and began operations. After 14.5 seconds, at 13:52:25, transmission on both data channels stopped for unknown reasons and no further signals were received at Earth from the martian surface. It is not known whether the fault originated with the lander or the communications relay on the orbiter. A partial panoramic image returned showed no detail and a very low illumination of 50 lux. The cause of the failure may have been related to the extremely powerful martian dust storm taking place at the time which may have induced a coronal discharge, damaging the communications system. The dust storm would also explain the poor image lighting.>>
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http://en.wikipedia.org/wiki/Exploration_of_Mars
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<<The high failure rate of missions launched from Earth attempting to explore Mars has become informally known as the Mars Curse. Some suggest, entirely in jest, that there is some supernatural force trying to prevent or punish the exploration of Mars. The Galactic Ghoul is a fictional space monster that consumes Mars probes, a term coined in 1997 by Time Magazine journalist Donald Neff.
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As of the end of 2006, of 37 launches from Earth in an attempt to reach the planet, only 18 succeeded, a success rate of 49%. Eleven of the missions included attempts to land on the surface, but only six transmitted data after landing.
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The U.S. NASA Mars exploration program has had a somewhat better record of success in Mars exploration, achieving success in 12 out of 17 missions launched (a 71% success rate), and succeeding in five out of six (a 83% success rate) of the launches of Mars landers.>>
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First and foremost, I have to give three cheers to JPL and the folks at Tucson for a flawless landing of the Phoenix. Makes me proud of being a native of Arizona.

I have seen two versions of the wideangle photo of the plain where the spacecraft landed showing the landscape to the horizon; the first photo was black/white, the second (APOD May 26, 2008) is in color.

I am curious whether the atmosphere on Mars would appear light pink to human eyes as shown in today's APOD?

AZJames wrote:I am curious whether the atmosphere on Mars would appear light pink to human eyes as shown in today's APOD?

The human eye is a tricky instrument (as are many human senses): The brain compensates for color cast when exposed to such a view long enough. You might see pink, but you wouldn't remember it as being that pink.