Mars Exploration Rover Mission

JPL ^ | 1-3-04 | JPL

[bonesmccoy]

Mission Timeline: Entry, Descent, and Landing

The entry, descent, and landing (EDL) phase begins when the spacecraft reaches the Mars atmospheric entry interface point (3522.2 kilometers or about 2,113 miles from the center of Mars) and ends with the lander on the surface of Mars in a safe state.

The rovers will arrive during the latter half of the northern winter/southern summer on Mars. Rover A will land at approximately 2:00 p.m. local time on Mars (with Earth set an hour after landing), whereas Rover B will land at around 1:15 p.m. local time on Mars (with Earth set as long as two-and-a-half hours after landing). That means that both rovers will land in the Martian afternoon while the Earth is still in view, allowing the Earth to receive the landing signal if the lander is on the base petal.

Entry, descent, and landing for the Mars Exploration Rover mission is an adaptation of the Mars Pathfinder method:

An aeroshell and a parachute decelerate the lander through the Martian atmosphere.

Prior to surface impact, retro-rockets are fired to slow the lander´s speed of descent, and airbags are inflated to cushion the lander at surface impact.

After its initial impact, the lander bounces along the Martian surface until it rolls to a stop.

The airbags are then deflated and retracted, and the lander petals and rover egress aids are deployed.

Once the petals have opened, the rover deploys its solar arrays, and places the system in a safe state. Communications during entry, descent, and landing will occur through a pair of low-gain antennas, one mounted on the backshell and the other on the rover itself. About 36 ten-second radio tones will be transmitted to Earth during descent through the atmosphere, which takes approximately six minutes. These tones are coded to indicate the accomplishment of critical steps in the entry, descent,and landing timeline. [More on these tones in the communications section]

A step-by-step guide to everything that will happen will be provided prior to entry, descent, and landing.

[ChadGore]

omg . .I see it ! Is that Dennis Kusinich ? . . lol

[e_engineer]

I was thinking Beavis or Butthead, but Kusinich is better.

[brityank]

... some rocks were pounded into the surface and have that 'muddy' looking soil smushed up in a ring around them.

Thanks for the great pics and threads with the details and discussion -- I finally got some time to let the thread load through.

Here's a question or two I have about this pic:

I know we're looking for water, but what other liquids could be used in its place? Mars has an average temperature of -60^oC, which I will guesstimate ranges from -100^oC to 0^oC. Methane+ (C+H+) has various freezing and boiling points, providing for a liquid phase under those temperatures. However, I find no real info as to the liquidity under less than nominal 14.7psi other than the boiling point decreases as pressure does, but not in a linear fashion. What about the freezing point? Does it also change as much with pressure?

Those rocks at the bottom right looks like they've been smushed into moist soil, as there seem to be small clumps, that if perfectly dry, would fall.

Be a hell of a note if the Rover drives off and gets stuck in a Methane+ Mud pit!

[bonesmccoy]

Actually, if there were methane, I believe that prior missions would have detected venting of the methane into the CO2 rich atmosphere.

But your point is very interesting because if you recall, the Viking lander experiment that searched for biological processes turned up some strange readings that may have been partly related to a chemical reaction of some kind.

I've never heard an explanation for the Viking lander biological sciences results. If you have, please post.

If it were actually water, you would see more frost and ice during the Martian night.

[brityank]

If it were actually water, you would see more frost and ice during the Martian night.

I doubt that we will find H₂O as a free liquid anywhere on Mars; the Pathfinder vs. Viking Lander 1 Temperatures all fall below 0^oC. The ice cap on the South Pole is CO₂, but does follow a seasonal pattern.

I picked the Methane+ liquids, as there are several that are in a liquid state from 0^oC down below 100^oC, and could possibly be a binder of the fine-grained dust on the plain. With the very low gravity, and the extremely low atmospheric pressure, I wonder just what differences in observation we need account for in our expectations.

As I've said before, I'm so dumb I don't even know what questions to ask -- but it is fun trying to figure some of this out. I am fairly certain we won't find liquid water in the top few feet, unless there is some type of geothermal activity below, but I've seen no info to confirm that.

The only thing I saw on the biological sciences from Viking is the rust being a part of the reaction of Iron, Oxygen, and Water -- all evidence that there is bound water and oxygen that may be recoverable.

[PoorMuttly]

Muttly finds it suspicious that NASA has not mentioned that Flounder on the lower right of the photo.


Muttly want Mars flounder too !!!!

(not that he doesn't already have one...but 2 would be even better. First one stringy)

[shaggy eel]

,,, a stringy flounder? Go for a male one Muttly!

[bonesmccoy]

missed that post of yours... that's huge news.

There has to be organics around on Mars.

The p=chem redox reactions would be operative on the surface... right? Also, the oxidation is clear from all the rust.

So, there's tons of Oxygen tied up in the oxides.

If there's ice water... we really could seriously be thinking about terraforming sooner than the next 1000 years.

[bonesmccoy]

If the traces of water are correct (see post above this one in thread), doesn't it suggest that the planet had far more water than is evident today?

Is it all tied up in the huge Martian poles?

We really need to do radar ranging on the planet to study the depth of the Mars poles.

Do you know if there is any data to suggest that the Mars poles are deeper than expected?

Maybe the planet is in such a deep freeze that the polar caps have all the water from the rest of the planet?

[Paradox]

We really need to do radar ranging on the planet to study the depth of the Mars poles.

Doesn't the Mars Express orbiter have this capability?

[Far Right Field]

missed that post of yours... that's huge news. There has to be organics around on Mars.

I suspect the carbonates are more indicative of life than any other mineral there, but who knows? The inorganic method of carbonate formation requires heat and free water in combination with free carbon, oxygen and the atoms of calcium , manganese or whatever, and lots of time. The organic method just requires the right kind of calcium loving animal, CO2 and water.

The p=chem redox reactions would be operative on the surface... right? Also, the oxidation is clear from all the rust. So, there's tons of Oxygen tied up in the oxides.

Every where you look you see iron oxide. The red of mars is, I believe, the various forms of iron oxide. Tons? Megatons more likely. Just heating the oxide will separate the 2 elements IIRC.That might be doable with solar concentrators.

If there's ice water... we really could seriously be thinking about terraforming sooner than the next 1000 years.

I suspect we will eventually Terraform Mars when we do go to space. It might be like in the Kim Stanley Roberson's series Red, Green, and Blue Mars. Or as simple as a solar mirror melting the ice trapped in the poles to cause a greenhouse effect.

[NormsRevenge]

Spirit Reaches for a Closer Look

This image taken by the front hazard-identification camera on the Mars Exploration Rover Spirit, shows the rover's robotic arm, or instrument deployment device. The arm was deployed from its stowed position beneath the "front porch" of the rover body late Thursday night Pacific time. This is the first use of the arm to deploy the microscopic imager, one of four geological instruments located on the arm. (Jan. 16)

+ Larger image

[tet68]

I guess I'm just spoiled by the coverage on touchdown,
I want more! More than one or two photos per day.
Arggggggggggh!

[bonesmccoy]

there is a page with all the raw images.

They're pulling engineering data right now and prepping for the science work. The pictures take up bandwidth that the science instruments need.

So, I'm sure that they're jockeying for bandwidth for each experiment.

[Museum Twenty]

bump for later.