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.

[bonesmccoy]

i don't get it.

How's that rock so smooth?

Is that erosion from wind?

Or is that erosion from water?

If it's from water, we're in for some gnarly science return!

[bonesmccoy]

Is that a "mark" from the air bag?

Or, is that a shred of torn air bag sitting on the surface?

[Momaw Nadon]

Good question.

I don't know the answer.

[Godebert]

" Is that a "mark" from the air bag? Or, is that a shred of torn air bag sitting on the surface?"

Looks like some sort of fossilized Martian sea critter to me.

[RightWhale]

JPL said they are thinking dried seabed. Could still be water or ice farther down. Look for seaweed. :)

[Momaw Nadon]

[clearvision]

They (NASA,JPL person) said it is "soil" disturbed by airbag retraction. They expressed interest because of the look of the marks.

[HighWheeler]

The Nova program is repeating and updating the mission at 8 pm tonight.

How about initiating your ping list?

[KevinDavis]

I think this thread deserves a re-ping...

Space Ping! This is the space ping list! Let me know if you want on or off this list!

[GeronL]

If it was unearthed... (unMarsed??) by the landing... then it would defintitely interest the scientists

[GeronL]

It might not be a rock.... it might be MUD!! OK, probably not...

[GeronL]

#2754= That does look like mud, and those small rocks look like something from a stream bed.... could something BIG be sitting right next to the lander?? This could become the luckiest lander mission of all time!

[Ernest_at_the_Beach]

Thanks.

Howlin, are you on the ping list of Kevins?

[Howlin]

I sure hope so. Maybe we should publish it on a thead like the do over on the daily threads so we can all have it in case somebody is "absent."

[tet68]

What has been happening?
The NASA feed doesn't seem to be very consistant,
mostly puff pieces etc.
I sure wish they would stay with more live programing on this.

[GeronL]

what do you think it is in #2754??

[Ernest_at_the_Beach]

CSPAN just finished with todays briefing and is showing it again later!

[P.O.E.]

Just pondering why so many small rocks spread relatively uniformly over such a large area.

[GeronL]

former floor of a lake??