Comments on: Vikings spotted on Mars

By: life on mars « YoYo-Dyne Propulsion Labs: Reno Division

life on mars « YoYo-Dyne Propulsion Labs: Reno Division — Sun, 10 Dec 2006 16:19:44 +0000

[...] “we need better images (maybe from the new probe orbiting Mars now), and spectra would be nice (to be able to see what chemicals are there). Even better would be to land a rover near there to get samples, though gullies down the sides of crater walls would make a perilous journey for any robot. If these aren’t water gullies, we’ll all be disappointed, but that’s science.” [...]

By: Irishman

Irishman — Thu, 07 Dec 2006 18:51:46 +0000

Lab Lemming, no, no Earth-based scopes have that kind of resolution of the moon. Some adaptive optics scopes may be getting into the range of 25m per pixel or so – I’m not entirely sure what the latest is.

But you shouldn’t have to wait much longer for lunar orbiters. NASA has schedule the Lunar Reconnaisance Orbiter to launch by the end of ’08.

By: Lorne Ipsum

Lorne Ipsum — Wed, 06 Dec 2006 22:51:35 +0000

Melusine,

You may yet get your chance. I haven’t counted pixels yet, but it looks like the Viking landers weren’t photographed at the highest available HiRISE resolution. There may be better pictures coming down the pike…

Lorne

By: Melusine

Melusine — Wed, 06 Dec 2006 17:28:56 +0000

Thanks, Mike, that link was useful – and colorful. Yeah, they’re quite far away to trudge over just to look at. Still, I’m curious what shape these dead landers/rovers are in. It would be cool to have a close-up picture.

By: seaducer

seaducer — Wed, 06 Dec 2006 13:33:41 +0000

Thanks for the answers guys. Being a certified diver I kind of figured our Hero would have got a nasty case of dcs, but that makes for bad tv. I guess I should have looked that stuff up myself, but I am feeling lazy lately…Thanks again

By: Lab Lemming

Lab Lemming — Wed, 06 Dec 2006 07:59:31 +0000

Dear BA,
Are there any Earth-based telescopes that can image the moon at this resolution, or will we need to wait for the next lunar orbiter?

By: Peter Barrett

Peter Barrett — Wed, 06 Dec 2006 05:02:27 +0000

I’m looking forward to some piccies of Sojourner and Pathfinder.

By: Geroge

Geroge — Tue, 05 Dec 2006 23:27:01 +0000

I would bet a rover could see HiRES. They could look at each other at the same time. The ISS is around 0 magnitude at times, so the smaller HiRES, though further from the sun, would still be bright enough for Spirit.

By: Jack Hagerty

Jack Hagerty — Tue, 05 Dec 2006 23:00:03 +0000

Oops, the proposed rocket motor is bi-propellant, not monopropellant.

- Jack

By: Jack Hagerty

Jack Hagerty — Tue, 05 Dec 2006 22:56:28 +0000

seaducer says: “Hmm, a few stupid questions I guess. I am guessing that Mars has some sort of atmosphere, or else the parachute wouldnâ€™t work?”

Yes, Mars has a thin atmosphere, but it is thick enough to be useful The surface pressure is about the same as on Earth at 110,000 feet (34.000 meters). It gets lower as you get higher, but because Mars has a lower gravity than Earth (about 1/3g) it thins out less quickly. This means that at some point above the surface (I don’t have the actual altitude in front of me) the atmosphere is actually denser than Earth’s at the same altitude.

But the effectiveness of a parachute is dependent on other factors than density, such as the cross sectional size, drag coefficient and speed. Especially speed. The key function is called “dynamic pressure” (Q) which is defined as 1/2 rho V^2 where “rho” (Greek letter) is the density and “V” is the velocity. Since these things are coming in very fast, there is plenty of “Q”, even with very little “rho”. Of course, once they slow down, their terminal velocity is still very high, hence the need for braking rockets just before touchdown.

There’s even enough air for an airplane to fly, if you’re clever enough. Check out:
http://www.aurora.aero/science/MarsFlyer.html

(sorry if you have to cut-and-paste that, I don’t know how to do the link thing.)

The project uses the same Mars entry hardware as the current two rovers, except that when the parachute detaches rather than inflating airbags and bouncing to a stop, the airplane deploys wings and flies around for several hours collecting data. It uses a restartable monopropellant rocket motor for propulsion. They’ve already flown a balloon-launched sub-scale prototype from 110,000 feet down to the ground (there should be video on that site).

- Jack

By: Viking on Mars? at MrReid.org

Viking on Mars? at MrReid.org — Tue, 05 Dec 2006 22:00:07 +0000

[...] Is there a Viking on Mars? [...]

By: Chip

Chip — Tue, 05 Dec 2006 20:31:24 +0000

I don’t know. But Beagle II is smaller and may be in many pieces. There are may derelicts on the surface of Mars. See this Wiki link for “Mars Curse”:
http://en.wikipedia.org/wiki/Exploration_of_Mars#Mars_Curse

By: PK

PK — Tue, 05 Dec 2006 19:27:27 +0000

Does anybody know if HiRISE is giong to look for beagle II?

By: Mike

Mike — Tue, 05 Dec 2006 18:52:54 +0000

Melusine said

“t would be cool to see how the Viking L 1 & 2 materials have held up over 30 years. I was looking all over the HiRISE site, but couldnâ€™t find what I wanted: a big map of Mars showing where the rovers are in conjunction with the Viking landers spots. How many sols or Earth days would it take to reach them, if possible? Iâ€™m trying to get a sense of distance/time between them all.”

try http://www.google.com/mars – click on ‘spacecraft’. No scale on this view but you’re looking at the whole planet so even though Opportunity is in the same area as Viking 1,on the ground they’re hundreds of miles apart.

By: Irishman

Irishman — Tue, 05 Dec 2006 18:29:17 +0000

seaducer said:
>Hmm, a few stupid questions I guess. I am guessing that Mars has some sort of atmosphere, or else the parachute wouldnâ€™t work? I am also guessing that there is not much wind on Mars or the chute would have blown away?

> Do we know the composition of that atmosphere? Would Arnolds eyes really bug out like that?

Information is not hard to find.

Mars has a very thin atmosphere composed mostly of the tiny amount of remaining carbon dioxide (95.3%) plus nitrogen (2.7%), argon (1.6%) and traces of oxygen (0.15%) and water (0.03%). The average pressure on the surface of Mars is only about 7 millibars (less than 1% of Earth’s), but it varies greatly with altitude from almost 9 millibars in the deepest basins to about 1 millibar at the top of Olympus Mons. But it is thick enough to support very strong winds and vast dust storms that on occasion engulf the entire planet for months. Mars’ thin atmosphere produces a greenhouse effect but it is only enough to raise the surface temperature by 5 degrees (K); much less than what we see on Venus and Earth.

http://www.nineplanets.org/mars.html

By: Gary Ansorge

Gary Ansorge — Tue, 05 Dec 2006 15:35:00 +0000

AH. Arnold, such a drama ,,,king,,,
Eyeballs bugging out? Why? They’re full of fluid, not gas. GAs readily expands in a low pressure environment. In tests here on earth, back in the 1950s , we exposed pilots to extreme pressure drops to see what might happen if they bailed out at very high altitudes. The worst case scenario causes blood blisters and a popped eardrum, not exploding eyeballs. Our skin can retain enough pressure to keep blood liquid even in a hard vacuum, but air trapped in the lungs would try to invade the blood as bubbles, ie, embolisms and of course, would tend to blow out thru the mouth, nose and sometimes ears(the popped ear drum I mentioned). Worst problem is pneumatic embolism, which occurs when the difference between internal pressure and external pressure exceeds 2 lbs/square inch. Thats also what causes bubbles in the blood when divers come up from depth. Embolisms can be caused from rising about 4 feet in water. But note: it’s all about gas expansion, not eyeballs popping or liquids boiling in a vacuum. It just don’t happen that way. We are remarkably durable organisms and if we could be conditioned to breathing pure O2 at a pressure of less than 2 PSI, could even survive exposure to hard vacuum, though our ears might suffer. I guess ear plugs might be in order.

Gary 7
Great pics. Loved the blowups. Looked a bit like my ex was driving,,,

By: Melusine

Melusine — Tue, 05 Dec 2006 15:30:57 +0000

It would be cool to see how the Viking L 1 & 2 materials have held up over 30 years. I was looking all over the HiRISE site, but couldn’t find what I wanted: a big map of Mars showing where the rovers are in conjunction with the Viking landers spots. How many sols or Earth days would it take to reach them, if possible? I’m trying to get a sense of distance/time between them all.

Gosh, I did a book report on Mars in 4th grade – the pictures now are so amazing compared to then.

By: Michelle

Michelle — Tue, 05 Dec 2006 15:04:08 +0000

Pure awesomeness! I like seeing our bots on another planet. Makes you feel like you succeeded at something.

I just wish I had a camera this good.

By: Andy Varga

Andy Varga — Tue, 05 Dec 2006 13:47:40 +0000

I had the same thought about the parachute. It’s my guess this will be used by conspiracy people as “evidence” it was all faked and that the guy who “doctered” these pics didn’t think about the weather LOL.

My second comment iss on the Spirit and it’s tracks. Looks like it has back tracked a bit. Funny to think that they get a rover onto another planet with limited time (even it lasted 10X+ longer than planned) and just kept going in circles. [Insert joke about who’s driving and getting lost here}

By: seaducer

seaducer — Tue, 05 Dec 2006 13:28:37 +0000

Hmm, a few stupid questions I guess. I am guessing that Mars has some sort of atmosphere, or else the parachute wouldn’t work? I am also guessing that there is not much wind on Mars or the chute would have blown away?

Do we know the composition of that atmosphere? Would Arnolds eyes really bug out like that?

Thanks…Drew

By: Zoot

Zoot — Tue, 05 Dec 2006 12:22:26 +0000

“No, not the pillaging kind.”

As I just woke up and haven’t had my coffe yet for a moment there I actually thought it was. They were expert sailors after all.

By: gengar

gengar — Tue, 05 Dec 2006 09:47:45 +0000

The Martians have probably nicked the landing pads and put it up on bricks.

By: Chip

Chip — Tue, 05 Dec 2006 08:59:27 +0000

It would be fascinating to see what the Viking landers really look like up close and how their materials have aged sitting on Mars all these years.

By: Sticks

Sticks — Tue, 05 Dec 2006 08:45:48 +0000

Is there any way the rovers could get to the Viking landers or Sojourner. That would be really cool a picture of one lander by another.

By: csrster

csrster — Tue, 05 Dec 2006 08:15:04 +0000

Har Har. I was on holiday with my mum in Blackpool. The first landing was set for the 4th of July but was delayed for technical reasons, iirc.