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Posted by: nprev Sep 29 2006, 11:01 PM

What if Mariner 4's flyby had occurred right across Tharsis & Coprates Chasma, showing volcanoes & canyons instead of heavily cratered terrain? (I understand that trajectory determinants prevented this from happening, of course, but still...). Do you suppose that Mars exploration would have been thrown into hyperdrive during the heady '60s, perhaps enough to sustain manned efforts beyond Apollo?

Doug, my apologies if this is OT for this section...there seem to be some interesting implications here for the imaginative, though.

Posted by: DonPMitchell Sep 30 2006, 02:53 AM

What if Mars-1 had worked and returned 1440 x 1440 pixel images of Mars in 1962?

I don't think better pictures would have prompted a manned landing attempt though. The Apollo program was already incredibly expensive, and going to Mars would have cost several times more.

Posted by: Myran Sep 30 2006, 09:06 AM

Even worse, if von Brauns vision actually had been realized. Its likely that one attempt to land humans on Mars would have become a catastrophic failure. There's several reasons for that, breakdown of machinery are one, but the most important are the severe medical problems related to long time exposure to weightlessness are that of long-term radiation exposure, neither well known back then but that have been indentified since. Yes identified only, no true counter are found for either.

Some of those have been mentioned here in the http://www.unmannedspaceflight.com/index.php?showtopic=2836 to mention one thread.

So if one attempt have been made, even without a truly catastrophic end, it might have have far reaching consequences with a situation where astronauts reached the orbit of Mars but unable to land, or even worse, actually reach the surface but unable to perform any meaningful exploration.

The result could have been a blow to space exploration as a whole, that I feel secure in saying it is best that it never was attempted. So overall I do think it was for the best to go with this unmanned strategy as we have done in the real world.

Posted by: DonPMitchell Sep 30 2006, 04:17 PM

Well I've been told to shut up whenever I've said this before (not that that means much to me), but I think long-term human habitation of Mars requires some careful strategic thinking that is pretty much absent from current space programs. Instead of making real progress with a series of automatic probes, laboratories and factories, the emphasis has been on expensive high-propaganda-value missions that are basically one-shot deals. Like Apollo, you spend a fortune landing a man somewhere remote, by the fastest means possible, and after the media event is over there is nothing lasting to show for it.

Posted by: centsworth_II Sep 30 2006, 04:24 PM

Nothing lasting in terms of manned flight, but do you not think the science from the returned moonrocks and other experiments was a worthwhile lasting contribution?

Posted by: DonPMitchell Sep 30 2006, 07:27 PM

I'm not sure that's the right question to ask. Were the Moon rocks worth $135 billion? Of course not. We could have gotten Moon rocks like the Soviets did for one percent of that cost. I think the actual and intended benefits of Apollo were:

1. Mobilize Americans to become scientists and engineers

2. Demonstrate the superiority of capitalism over socialism

3. Economically stimulate high-technology industry

4. Boost national morale

I'd love to see that kind of national mobilization happen again, but I don't think repeating the exact same program would have those benefits today. Thomas Friedmann has suggested that American energy independence would be a good program. Who knows?

Posted by: dvandorn Sep 30 2006, 07:31 PM

Here's an attempt to hijack the thread and keep it from devolving in to the argument Doug says *will not* happen here:

If we're talking about "what-if" scenarios, and we can change bigger factors, then I'd say the only thing that would have caused an immediate and rapid program for a manned Mars expedition would have been obvious, large-scale signs of life and/or intelligent occupation of the planet (i.e., large structures, etc.).

The real issue, then, becomes: Did the Mariner 4 optics have the ability to show such things? Had we run an Earth encounter with Mariner 4, would the images and other data sent back have been the least bit helpful in identifying whether or not Earth sustained life, much less intelligent life?

I have a pretty fair idea that they would not... And if not Earth, how Mars?

-the other Doug

--------------------

You (machines) can't stop Smith. I can.
- Neo

Posted by: nprev Sep 30 2006, 08:53 PM

Adroitly hijacked, oDoug!

In answer to your question, probably not...but the craters in the images perpetuated a "Moon-like" perception that really took the air out of the entire impetus at its very beginning. If M4 had flown over Olympus Mons instead, how different would our initial and enduring perceptions have been?

Posted by: Myran Sep 30 2006, 09:10 PM

Im not that certain I agree with you dvandorn.

At the time of the first probes to Mars, hardly anyone in their right mind did believe there were canals made by any contemporary intelligent life on Mars. That except a few science fiction writers, but I dont include Arthur C or Bradbury with 'the Martian chronicles' there - at least I did read the story of the latter as one allegory of what happened to the native american peoples. With that perspective it was also a grand impact personally with my own similar perspective.

But we were supposed to get the subject back on track here!

Lets take the ideas we had about Mars at that time and imagine they had been on the mark!

Many of the public, and some scientists wanted to believe the planet had wide areas of moss or lichens as well as some smaller patches of liquid water on the surface. This was a widespread idea to explain the seasonal variations we now know are caused by atmospheric haze and sandstorms.

So if the ideas of that time would have been correct, such vegetation could have been visible from orbit or flyby missions. In addition Mars would have had a thicker atmosphere with a large part of nitrous oxides which is a greenhouse gas which would have caused a warmer climate.

With all those characteristics taken together, Mars could have been directly habitable!
Not with one breathable atmospehere, far from it, but a higher partial pressure would have simpified many things like any building as well as spacesuits. And with vegetation and nitrous oxides in the atmosphere that might be turned into fertilizers and nitrate compounds so the intrepid pioneers might actually could have been able to grow crops directly in the soil there. And the colonizer would have been a happy individual indeed, all he would have to do was to remove his helmet or breathing mask to take a sniff for a good laugh now and then.

All things taken together would have made Mars valuable land for the superpowers, so if this make-belief land had been true - I would think the space race would have been aimed at Mars instead of the Moon, since Russia and USA would have fought to be the first to claim this new land for their political system and philosophy.

Posted by: OWW Sep 30 2006, 10:22 PM

What if the Mariner pictures had shown a Lowellian Mars instead? Now that would have inspired the Space Program!

This reminds me of a SciFi favorite of mine: the short story 'The Gods of Mars' (by Gardner R. Dozois, Jack M. Dann & Michael Swanwick) in which a bunch of astronauts arrive at Mars while a global dust storm is raging. When the dust finally settles they can't believe what they are seeing... Highly recommended.

Posted by: Decepticon Oct 1 2006, 02:41 AM

Could someone here try to recreate what Mariner 4 would have seen if it did cross areas?

Posted by: Bill Harris Oct 1 2006, 06:37 AM

Back then we thought that we were masters of the universe and could do anything to everything. Look at the environmental disasters we were creating on Earth. And we were wanting to terraform Mars-- can you imagine what would happen if were introduced a large quantity of water and an atmosphere into the Martian environment? The place likely would not be habitable for the next 4 billlion years...

The fantasies of childhood.

--Bill

Posted by: DonPMitchell Oct 1 2006, 07:15 AM

I'll take a stab at that simulation, but this is just scaled to match the Mariner-4 camera, and eyeballing the noise levels in actual Mariner-4 images:

[attachment=7819:attachment] [attachment=7820:attachment]
Mariner-4 (Actual) Valles Marinaris (Simulated)

It's tricker to know what Mars-1 would have seen. The Mars-1 camera was built by the same people who did Zond-3's, but it was in some respects better than the Zond-3 camera. It just weighed too much, because it used 70mm film.

[attachment=7821:attachment]

Here's an actual Mars-4 image. Mars-1 would have sent back an image of this resolution. Their Mars-1 telemetry system for images used orthogonal coding in the signal (in fact, pulse-position modulation).

Posted by: DonPMitchell Oct 1 2006, 07:20 AM

Can you be more explicit about why you think terriforming Mars would not be possible?

Posted by: edstrick Oct 1 2006, 09:17 AM

The Mariner 4 sim looks entirely reasonable. Note that Mariner did see graben radial to Tharsis crossing the large crater in frame 11 as a "lineation" which was noted, but not resolved as an actual graben.

Mariner 6 clearly recognized chaotic terrain, tentatively identified as "thermokarst" as well as the large chaos regions on the east end of Valles Marineris. The chaotic terrain was seen in 2 or 3 narrow angle frames, while eastern Valles Marineris was poorly seen in high-sun wide-angle frames, disappearing into camera-noise toward the noontime limb.

The large depressed areas were also sort-of recognized in UV spectrometer rayleigh-scattering atmosphere depth sensing and IR spectrometer CO2 absorption depth sensing.

Posted by: DonPMitchell Oct 1 2006, 03:51 PM

Mariner-9 was a turning point for American probes, I've always thought. I'd argue it was the point at which the US surpassed the Soviet's in the sophistication of planetary probes. We still couldn't send an 8-ton probe to Mars like they could, but our electronics and camera technology was advanced enough that we could do more with a lot less.

Posted by: nprev Oct 1 2006, 04:16 PM

Couldn't agree more. Mariner 9 clearly established UMSF as the preferred method of planetary exploration by virtue of its results and its durability.

More speculation: What if all the Soviet Mars probes had worked? They were of course desperate for them to do so, both scientifically and for symbolic purposes (the red planet, after all). Do you think that they would have become more aggressive in both manned and UMSF? What would the US have done in response?

Posted by: DonPMitchell Oct 1 2006, 07:44 PM

James Burke wrote that they kept a picture of Venera-1 on the wall at JPL, to remind them that the Russians were ahead. They were well aware that Mariner-2 was a huge stroke of good luck, with a pretty crappy spacecraft.

Sputnik, Luna-3, Vostok-1 were all a bit disturbing to the US. There could have been more impresseve successes --photos from Mars and Venera capsules on Venus in 1962, and a Moon landing with pictures in 1964, etc. But ultimately, I don't think the Soviet system could have stayed ahead.

Landing a man on the Moon was carefully calculated to be the first major thing that America could do before the Russians, with almost no danger of getting scooped. They knew they had to catch up, but they also knew they were up against a burocratically planned socialist economy that couldn't make enough toilet paper for its people, much less land a man on the Moon.

I admire the spunk and cleverness of the Soviet scientists, but they were working in a hopeless system. They couldn't get modern electronic parts, they couldn't get sufficient QA. They flew 6-ton spacecrafts to Venus, filled with vacuum tubes and gears and relays. It's fascinating, but there was never any question of them beating the Americans.

Posted by: edstrick Oct 2 2006, 10:07 AM

Mariner 2 flew with a lot of luck, but it was the real working prototype (based on Ranger) for the Mariner series, starting in mature form with Mariner Mars 64. The near total success of Mariner 2 proved that the essential design was right, and just needed maturing.

There were two real problems on Mariner 2. The Microwave Radiometer was apparently damaged during launch, I think they suspected a thermal shroud was damaged. One of the 2 channels was greatly reduced in sensitivity, and it's response was actually reversed! The other worked reasonably well. This sort of problem was instrument-specific, of course.

The spacecraft overheated badly, and failed not long after the Venus encounter, quite likely due to the overheating. Getting thermal control "right" took time. Modeling was not adequate, and in-space behavior of materials didn't match predictions as they outgassed, changed color, whatever. Mariner 4 actually carried an engineering experiment, besides it's science instruments and the experimental solar light pressure stabilization paddles. It carried a small set of candidate thermal control "plaques" on the sun-facing side of the main body of the spacecraft, with a temperature sensor behind each one to monitor it's temperature changes relative to predicted values as the mission proceeded.

Teeny-tiny "micro-experiments" like that can often be fitted on missions and return significant value for the future. The Magnets on Mars landers are also "micro-experiments", as was Geoff Landis's (I think) dust accumulation experiment of the Sojourner rover.

Posted by: tedstryk Oct 2 2006, 11:10 AM

I have always thought that a problem with the Soviet craft, especially in the early days, was the fact that they were not constantly transmitting, meaning that problems could develop and kill them with much less data to doa post-mortem. That and the need for pressurization.

Posted by: JRehling Oct 2 2006, 02:59 PM

Actually, what if Mariner 4 had only returned one image and it was the "Face"?

That extremely unlikely event would have made it a noncrazy hypothesis that it was an artifact. Then there'd be a long slow hiss of disappointment as more missions flew by.

Posted by: angel1801 Oct 2 2006, 03:30 PM

I believe that first impression of a body (ie planet, moon, etc) is important. If the first impression really wows the people, politicans and the scientific community, they will demand another mission. If not, future missions are very hard to justify, let alone get funded and launch.

Where first impressions were good:

Jupiter
Saturn
Titan
Moon
Neptune
Europa
Io
Miranda
Ariel
Triton

Where first impressions were not good:
Uranus
Mercury
Venus
Mars [1]
Pluto
Rhea
Oberon
Enceladus

[1] Mars is big news and popular largely because of the 1950's (and earlier) Sci-fi connotation


You see, us humans like seeing eye candy, even when it comes to outer space!

Posted by: dvandorn Oct 2 2006, 03:32 PM

Maybe it's just because I started following space exploration back in the 60s, but I have always been mystified by the negative reaction to "engineering experiments" on board any type of space probe.

I know, we can now use computer models to predict the operation of engineering systems. However, such models are only as accurate as the data input into them. It seems to me that, if an engineer feels the need to gather empirical data to support a model, it should be allowed if at all possible.

Engineering experiments might not return a ton of data about the planets, but they can make possible the next generations of spacecraft that *will* return such data. As such, I think they ought to be embraced and not sneered at...

-the other Doug

Posted by: DonPMitchell Oct 2 2006, 05:36 PM

Mariner-2 was a repurposed ranger probe, yes. And the ranger series had a long history of failure. The lunar missions didn't work until Ranger-7 in 1964. Heads rolled over this, and there was a congressional inquiry. Mariner-2 suffered a number of systems failures:

1. Failure of one solar panel very early in the mission.

2. Failure of the temperature control system (a bad design, not a failure to function). By the time of Venus encounter, the spacecraft was over 100 C. I say "over" because the thermometers were off scale by then.

3. The optical navigation sensors used for attitude control were slowly going blind, only a few percent of normal signal by the time it reached Venus.

JPL was "Just Plain Lucky" as they joked at the time.

THe probe passed Venus at a rather great distance, which reduced the value of its magnetometer, but it got close enough to tell that Venus did not have as strong a field as the Earth. Venera-4 provided the first accurate measurement of the field.

The most important experiment of Mariner-2 was the mesurement of microwave limb darkening. Most historians fail to mention that one of the two microwave channels did not actually show limb darkening. And in fact, this measurment was performed from Earth by radio telescopes several months before the Mariner encounter.

OK, I'm beating a dead horse here. Mariner-2 still deserves an important place in history, as the first spacecraft to reach another planet and return data.

Posted by: tedstryk Oct 3 2006, 12:31 AM

Granted, given the horrible luck of the early U.S. lunar program, it is almost a balancing out of things that Mariner-2 made it.

Posted by: dvandorn Oct 3 2006, 02:35 AM

Don, that is great work. Looks exactly like the Mariner 4 image quality. Thanks!

-the other Doug

Posted by: MizarKey Oct 10 2006, 09:19 PM

What happened to Don's Mariner 4 simulation images from post #13? This thread isn't very old but the pics are gone.

Posted by: ugordan Oct 10 2006, 09:32 PM

Maybe he accidentally erased all his attachments again?

Posted by: djellison Oct 10 2006, 09:33 PM

Nothing done by me or the team.

Doug

Posted by: helvick Oct 10 2006, 09:45 PM

Doug,

Don's messages refer to these attachments which appear to be dead links now.

attachmentid=7819
attachmentid=7820
attachmentid=7821

Posted by: djellison Oct 10 2006, 10:03 PM

We've not touched them. If they've gone, then Don has deleted them ( and they can not be restored technically or indeed legally )

Doug