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.

[Maringa]

This will never happen in our life times, but I often wondered what it would be like if we had the developed capability of mining or relocating Europa (Jupiter's moon) to an orbit between Earth and Mars, and see what would happen if all of the ice melted to form an ocean. From there introduce, algae that would convert any CO2 to O2 and eventually provide enough water vapor and oxygen formation for a sustainable atmosphere. Another thing would be to mine sections of Europa, transport them to Mars, and let the ice melt, sublimate, etc. enough to increase the atmospheric pressure of Mars, and then figure out a way to produce/convert oxygen out of the abundant iron oxide or electrolysis of the transported ice. Again, never will happen in the next 200-300 years,

Meanwhile on earth, a war on terror continues....

[RightWhale]

This is Columbia Station.

[apillar]

Are they having a noon briefing today, (Wednesday 8th)? I'm desk bound today so If somebody can post a general synopsis or link I would greatly appreciate it...

[apillar]

...oops make that Wednesday the 7th...

[Far Right Field]

There will be a routine daily briefing at 9 AM PST every day, I guess for the foreseeable future. Todays briefing is interesting for several reasons because of the following:

1. The lead geologist says that the geologists in the team want to go to the hills southeast of the lander. Sleepy hollow is no longer a real priority for some in the team. He also said all the instruments were checked out and ready to go, and the geological team was ready to go to work. I detected a distinct tension between the geological lead and the spacecraft lead. He also said that Gusev may have been a lake bed once, but today it is a rock strewn plain. He also added that the surface imprint that looks like mud was not particularly interesting, in fact it was rather boring.

2. The Spacecraft lead is still worried about the airbag retraction, so today they will lift the petal with the problem airbag about 20 degrees and then pull the airbag under the petal, then re-lower the petal.

3. The location in Gusev is now called the Discovery site, for the last year disaster.

4. They have released a new hi res 3D image of the octant they had yesterday as well as the same octant with the blanks filled in.

That is about all I remember from the news conference, some of these other nerds may be able to fill in the missing parts. Like names. I am terrible with names.

[Far Right Field]

Sorry that should be Columbia station, not Discovery.

[Past Master Councilor]

"Sleepy hollow is no longer a real priority for some in the team. . . . I detected a distinct tension between the geological lead and the spacecraft lead."

---

I'm sorry to hear this.
Look near before you look far.

[Far Right Field]

I'm sorry to hear this.
Look near before you look far.

---

I am not unhappy about the tension so much, because the spacecraft lead loses his job after Spirit leaves the ship. That is until Opportunity lands. But I agree that there is a whole lot of looking that has to be done before going to the mountains. Also we are on a tight schedule because at about sol 91 Spirit runs out of sunlight intense enough to keep the batteries charged.

Also, did you note the fractured rock in the lower left front of the first octant? That thing looks like frost fracture to me.

[Past Master Councilor]

in which pic? (the "fractured" rock)

[Far Right Field]

in which pic? (the "fractured" rock)

---

http://www.marstoday.com/viewsr.html?pid=11460

It is down toward the bottom of the image there at

http://images.spaceref.com/news/2004/P2302.med.jpg

It is the split rock to the right of the high black notch in the image.

[bonesmccoy]

Interesting photo... the rock color does remind one of the rock color on Mars.

There is a remarkable load on the NASA servers. To see the press release on the hits from the other night,

Go to http://www.jpl.nasa.gov/releases/2004/9.cfm

[bonesmccoy]

Look what I just found on the JPL website!

[bonesmccoy]

Thanks for summarizing the day's conference.

The Sleepy Hollow area may be a nice area for spacecraft engineers because it's relatively close, flat, unobstructed, and looks inviting.

The geologists have always wanted to do "more science". That's the whole reason Harrison Schmitt was sent as the Lunar Module Pilot on Apollo 17.

The guy who should have gone was probably Shoemaker because he did the most "real science".

Anyways, I'm not surprised to hear of discussion between the Geology crowd and the Engineering team. That discussion went back and forth for 10 years around the Apollo program.

You get the planetary geologists to the surface after a 300 million mile trek. Then, the geologist complains that he should have been landed in another area.

If you're around the program enough, you can make standard complaints for each field of study.

Life sciences complains that they don't have enough samples and not enough payload priority. They point to the physical science team and ask why they get all the priority.

The physical science guy (Geology) complains that they never get to land in the interesting areas (because the engineers always pick flat places to land in and the doctors won't let the program take "unnecessary risk".)

The engineering team is complaining that they don't have enough space, enough lift capability and enough money. Then, they get complaints from the payload guy asking for a different trajectory, orbit, throw, and time of launch.

The booster guys complain that they don't get enough info from NASA or from the payload guys; so the launch will happen on Day N at Time T, but the payload guy is otherwise out of luck.

The payload guy complains that they have to keep shifting their number because the booster guy changed his engine's performance.

The engine guy...

Heh... makes me enjoy being in healthcare...

Oh yeah, have I told you about the complaints between the hospitals and physicians lately?

Well...let's see...there's (oh...heck...dinner time!)

[Ernest_at_the_Beach]

That had to be exciting at both ends of the phone line!

[ForGod'sSake]

Interesting photo...

This photo contains an interesting formation. Time and the elements create some curious sculptures do they not?

FGS

[Vinnie_Vidi_Vici]

Does anyone have a password for the NASA site which has ALL of the images from mars?

here is the url

http://marsrovers.jpl.nasa.gov/gallery/all/spirit.html

[Phil V.]

I've e-mailed them asking why the restricted access. Can you do the same?

[Vinnie_Vidi_Vici]

Sure, I'll do the same. The non-conspiratorial side of me says that they are limiting access to keep the servers from being overwhelmed and letting educators and researchers have fist crack at the photos first. The other side of says that they have better shots of that unexplanable lettuce patch at the lower right of the hi res image that they don't want to share.

[Phil V.]

HARRRR!

I like your other side         ;)

Actually they've located a red-legged frog. They need to keep the evidence from the EPA because an environmental impact report will take longer than the alloted time for the mission . . .

[tet68]

Any thing new happening?
It seems like coverage has slowed to a crawl.