Astronomy Picture of the Day 01-24-04

Explanation: Looking down from orbit on January 14, ESA's Mars Express spacecraft scanned a 1700 by 65 kilometer swath across Valles Marineris - the Grand Canyon of Mars - with its remarkable High Resolution Stereo Camera. This spectacular picture reconstructs part of the scanned region from the stereo colour image data recording the rugged terrain with a resolution of 12 metres per pixel. Joining Mars Global Surveyor and Mars Odyssey, Mars Express has been orbiting the red planet since December 25th, returning scientific data, acting as a communications relay, and even making coordinated atmospheric observations with NASA's Spirit rover on the surface. The Beagle 2 lander was released from Mars Express making a landing attempt also on December 25th, but no signal has been received so far.

There is still a serious problem with the Spirit rover.

SATURDAY, JANUARY 24, 2004
0400 GMT (11:00 p.m. EST Fri.)

While efforts to revive the Spirit rover continue, the sister-craft Opportunity remains on course for its Saturday night/Sunday morning landing on the Red Planet.

Opportunity's touchdown at Meridiani Planum -- a smooth, flat plain near the equator halfway around the planet from Spirit's Gusev Crater landing site -- is scheduled for 12:05 a.m. EST (0505 GMT).

The landing site for Opportunity was selected because scientists believe there is an Oklahoma-sized area of gray hematite, a mineral that usually forms in the presence of water.

"Gray hematite is a mineral indicator of past water. It is not always associated with water, but it often is," said Joy Crisp, project scientist for the Mars Exploration Rover project.

The rover will search for the material to determine if the hematite layer comes from sediments of an ancient ocean, from volcanic deposits altered by hot water, or from other environmental conditions in the planet's distant past.

"Hematite forms in a number of different ways on Earth but most of them involve the action of liquid water," added Steve Squyres, the rovers' principal investigator. "So you can think of the hematite mineral signatures being kind of a beacon that's saying to us, 'hey, water may have been here.' Now we don't know how it formed, it could have been a hydrothermal system, could have been a lake, we're not sure. But it says, mineralogically, water."

Opportunity carries the same set of science tools as Spirit -- multiple cameras, a rock-grinding device and sophisticated instruments to determine the composition of soil and rock samples.

"We want to know if the grains of hematite appear to be rounded and cemented together by the action of liquid water or if they're crystals that grew from a volcanic melt. Is the hematite in layers, which would suggest that it was laid down by water, or in veins in the rock, which would be more characteristic of water having flowed through the rocks," Crisp wonders.

NASA's orbiting Mars Global Surveyor discovered a couple of years ago that Meridiani Planum featured gray hematite, prompting researchers to send a rover to the locale.

"The area where we are going has 10 to 15 percent gray hematite. What are the other materials found with the hematite? Clays and carbonates would indicate there had been water in the area. If the area had been volcanic, you would expect to see other types of minerals like olivine and pyroxene," Crisp says.

"We're very interested to know if this region could have been like Yellowstone, with hot springs, so we'll be looking to see if there are other minerals in the area such as those at Yellowstone."

The battle cry of NASA's Mars exploration program is "follow the water." Proving that Mars once had liquid water would help to determine if the planet could have supported life long ago.

"Knowing just how the hematite on Mars was formed will help us characterize the past environment and determine whether that environment was favorable for life. One big question, of course, is whether life ever started on Mars. This mission probably won't tell us that, but it may well lead to future mission that can answer that question."

We will provide live updates on this page throughout the landing!

0330 GMT (10:30 p.m. EST Fri.)

Despite two commands from engineers on Earth to enter sleep mode to conserve power, Spirit remained awake all day Friday, Mission Control reported late tonight.

"Shortly before (3 p.m. EST), controllers were surprised to receive a relay of data from Spirit via the Mars Odyssey orbiter. Spirit sent 73 megabits at a rate of 128 kilobits per second. The transmission included power subsystem engineering data, no science data, and several frames of 'fill data.' Fill data are sets of intentionally random numbers that do not provide information," NASA officials said.

"Spirit had not communicated successfully through Odyssey since the rover's communications difficulties began on Wednesday."

FRIDAY, JANUARY 23, 2004
2055 GMT (3:55 p.m. EST)

The crippled Spirit rover remains in critical condition on the surface of Mars, engineers said today, the victim of ongoing electronic seizures that have caused its central computer to reboot itself more than 60 times over the past two days.

Engineers successfully coaxed the rover to beam back limited engineering data during two brief communications sessions and they were relieved to discover the spacecraft's power system was providing the necessary life support. But Spirit's state of mind was clearly -- and unusually -- different in both sessions, ruling out any simple explanations for what might have gone wrong.

Read full story.

1945 GMT (2:45 p.m. EST)

Pete Theisinger, manager of the Mars Exploration Rover project, says Spirit is in "critical condition" as it sits at Gusev Crater.

"We do not know to what extent we can restore functionality to the system because we don't know what's broke. We don't know what started this chain of events. I think, personally, that is a sequence of things. And we don't know, therefore, the consequences of that.

"I think it is difficult, at this very preliminary stage, to assume that we did not have some type of hardware event that caused this to start. Therefore, we don't know to what extent we can work around that hardware event and to what extent we can get the software to ignore that hardware event, if that is what we eventually have to do.

"So we have a long way to go here with the patient in 'intensive care.' But we have been able to establish that we can command it, and we have been able to establish that it can give us information, and we have been able to establish that the power system is good and we are thermally OK. Those are all very, very, very important pieces of information and state.

"We are a long, long, long way from being done here. But we do have serious problems and our ability to eventually work around them is unknown.

"I'm trying to tell you do not to expect a big sea change in either knowledge or theory in the next several days because this is a very complex problem and we have very limited visibility."

1930 GMT (2:30 p.m. EST)

During the question-and-answer portion of today's briefing, project manager Pete Theisinger gave this summary:

"The software is in X-band fault mode. We surmise it got there because of some problem with the high-gain antenna pointing, and that is why the second high-gain antenna pass on Wednesday did not work. It gives us a little bit of a tale-tell for what is going on with the processor now.

"But as I pointed out to you, the flight software is not functioning normally. The two times we have gone and communicated with the system, we have gotten different flight software behaviors. Therefore we do not have assurance the next time we go and ask for it we will get either one of those two behaviors or perhaps a third behavior.

"We are trying to look at those responses to determine 'ok, how come it's behaving that way? And how come when we boot up it doesn't get better?' Those are the kinds of questions we are raising at the moment.

"We have quite a bit of information but clearly not as much as you would like."

We will have a complete story wrapping up the news conference as soon as possible.

1905 GMT (2:05 p.m. EST)

While engineers work to understand and fix Spirit's troubles, a team reconstructing the rover's entry, descent and landing has made great progress.

This "path" of Spirit's landing has left "marks" on Mars as seen by the orbiting Mars Global Surveyor and Spirit's Descent Image Motion Estimation System camera. See the image here.

1855 GMT (1:55 p.m. EST)

Here is project manager Pete Theisinger's briefing to reporters from earlier this hour:

"We have been able to command Spirit and we have gotten limited data in return. The flight software is not behaving normally.

"I would like to go into some details of the chronology of events that have happened since I talked to you yesterday.

"When I left here yesterday there was preliminary indication that a request for an acknowledgement sent to the spacecraft at what would have been an emergency or fault command rate was received and acknowledged from the spacecraft -- and that was correct. The spacecraft did see us yesterday.

"We attempted to command the spacecraft to send us telemetry yesterday. We were very late in the day and on top of a UHF command session, and that command did not work for what we believe were those reasons.

"This morning, we sent an early beep to the spacecraft and did not get a response. As we were preparing to send a second, the spacecraft talked to us. We got very fractional frames and then moved very quickly to ask it to speak to us for 30 minutes at 120 bits per second. We got 20 minutes of transmission in that occasion, which was a single frame of engineering data repeated.

"Then we repeated that full sequence of events and we got about 15 minutes of engineering data at 120 bits per second where the frames were updated for 15 minutes and then for the second 15 minutes we had nothing but fill data.

"The spacecraft attempted a short communication window at the end of the day, which ended.

"The spacecraft has been in a processor reset loop of some type, mostly since Wednesday, we believe, where the processor wakes up, loads the flight software, uncovers a condition that would cause it to reset. But the processor doesn't do that immediately. It waits for a period of time -- at the beginning of the day it waits for 15 minutes twice and then for the rest of the day it waits for an hour -- and then it resets and comes back up.

"The indications we have on two occasions is that the thing that causes the reset is not always perceived to be the same. We are confused by that, but that's the facts as we presume them to be right now.

"We know that the sequence which began on Wednesday morning to do some calibration of one of the Mini-TES motors, that sequence did not run to completion. And we know that the spacecraft believes it is now in an X-band fault condition, which can be caused by a large number of things, but one of them could be the inability to move the high-gain antenna.

"If you recall, we did know as of 1 o'clock Mars Time on Wednesday that the spacecraft did not believe itself to be in a fault condition, although it could be having problems. We know that because we tried this beep at 31.25 (bits per second) that day and it worked. That's not a rate we would expect if the spacecraft thought it was a fault condition.

"The team is basically taking the data it had this morning, as collected, and moving forward and analyzing what they know and preparing a plan of action for tomorrow and for the days following. We believe, based upon everything we know right now, that we can sustain the current state of the spacecraft -- from a health standpoint -- for a substantial, perhaps indefinite amount of time. There is no indication that we have an imminent power problem or thermal issue. There's indications that (the spacecraft has) not been going to sleep at night like we expected -- that we have been up for a lot or most of both nights -- and we are looking at what things could cause that to take place.

"An anomaly team has been formed, completely separate from the Opportunity team. They will working a schedule that will look like 0500 Mars Time to about 1500 Mars Time. So they are going to synch up with the Spirit's day. So that means tonight they will be coming in about midnight. The first part of that will be kind of a re-examination of the data, whatever they have been able to collect and analyze in the period of time and kind of a go-forward plan for the day. They will be on consoles for the day and then there will be a post-day, couple-hour meeting of what they know and to work on theories.

"I expect this to go on in this mode for several days of talking to the spacecraft, gathering more data, winnowing out theories, testing those theories against spacecraft observables and continuing that process.

"I think we should expect that we will not be restoring functionality to Spirit for a significant period of time -- I think many days, perhaps a couple of weeks -- even in the best of circumstances, from what we see today.

"Now, we have Opportunity coming in tomorrow night. We have the lander passivation sequence is going to start running tonight. We have made the appropriate personnel and staffing adjustments to make sure we have completely severed the efforts and that we can sustain Opportunity's (entry, descent and landing).

"It is likely, depending upon what happens in the next 48 to 72 hours, that we may not continue the Opportunity impact-to-egress with the same pace and dispatch that we did on Spirit. It depends on if we can get Opportunity to a defined, sustainable state on the ground and we can continue to make progress against Spirit with those assets, we will likely do that and try and continue to make progress on Spirit to get it back to some level of functionality. That's a decision the project will make in consultation with management as we take the temperature of this thing over the next couple of days."

1807 GMT (1:07 p.m. EST)

At the news conference underway right now, project manager Pete Theisinger says that the data received from Spirit this morning indicates that the rover's flight software is "not behaving normally."

An anomaly team has been formed to continue gathering data from the rover and narrow the possible causes of the situation.

Theisinger says the rover should be able to sustain its health for an indefinite amount of time. He also noted that restoring Spirit to normal operations could take a couple of weeks.

1700 GMT (12:00 p.m. EST)

Teams are still analyzing the information received from the Spirit rover this morning, the Jet Propulsion Laboratory says. A news conference with project officials to provide a status report on recovery operations is scheduled for 1 p.m. EST today.

1512 GMT (10:12 a.m. EST)

Mission Control has received actual data from Mars Exploration Rover Spirit after commanding the craft to transmit the information.

"The spacecraft sent limited data in a proper response to a ground command, and we're planning for commanding further communication sessions later today," said project manager Pete Theisinger.

Officials have not yet said what the data indicated or other details.

The data was received in a communication session that began at 8:26 a.m. EST (1326 GMT) and lasted 20 minutes at a data rate of 120 bits per second.

JPL says it sent the command to the rover at 8:02 a.m. EST (1302 GMT) via the Deep Space Network complex in Spain telling Spirit to begin transmitting.

Spirit stopped sending scientific and engineering health data on Wednesday, then missed several scheduled communications sessions. A heart beat "beep" was received yesterday confirming at Spirit could hear Earth and responded with the simple tone. A signal was also detected earlier this morning, prior to the retrieval of data.

1449 GMT (9:49 a.m. EST)

NASA's Deep Space Network communications station near Madrid, Spain, received a signal from the Spirit rover at 7:34 a.m. EST (1234 GMT) today, officials report.

"The transmissions came during a communication window about 90 minutes after Spirit woke up for the morning on Mars. The signal lasted for 10 minutes at a data rate of 10 bits per second," the Jet Propulsion Laboratory announced.

Mission Control plans to issue commands to Spirit seeking additional data from the spacecraft during the subsequent few hours.

A news conference is planned for 1 p.m. EST today

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