Archive for the ‘Spirit’ category

xkcd Spirit

January 29, 2010

xkcd (a comic which you should all be reading if you aren’t already) has a nice comic up today about Spirit. Click the image to see the whole thing.

So we’ll go no more a roving…

January 27, 2010

With yesterday’s news of Spirit’s defeat at the hands of the sulfury sands of Mars, I was reminded of this poem. It is by Lord Byron, but I first encountered it in one of my favorite short stories in this blog’s namesake, Ray Bradbury’s The Martian Chronicles. The story is entitled “And the Moon be Still as Bright”, and the poem is “So we’ll go no more a-roving”:

So, we’ll go no more a-roving
So late into the night,
Though the heart be still as loving,
And the moon be still as bright.

For the sword outwears its sheath,
And the soul wears out the breast,
And the heart must pause to breathe,
And love itself have rest.

Though the night was made for loving,
And the day returns too soon,
Yet we’ll go no more a-roving
By the light of the moon.

Lord Byron (1788-1824)

Spirit is no longer a Rover

January 27, 2010

An animation of Spirit's final attempts to adjust its position in the soft soil of "Troy". Image credit: NASA/JPL-Caltech (click to view if the image is not animating)

In a news conference yesterday, NASA announced that Spirit’s driving days are likely over, but by virtue of remaining stationary, new science possibilities are opened up. Here’s the text from the press release:

After six years of unprecedented exploration of the Red Planet, NASA’s Mars Exploration Rover Spirit no longer will be a fully mobile robot. NASA has designated the once-roving scientific explorer a stationary science platform after efforts during the past several months to free it from a sand trap have been unsuccessful.

The venerable robot’s primary task in the next few weeks will be to position itself to combat the severe Martian winter. If Spirit survives, it will continue conducting significant new science from its final location. The rover’s mission could continue for several months to years.

“Spirit is not dead; it has just entered another phase of its long life,” said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. “We told the world last year that attempts to set the beloved robot free may not be successful. It looks like Spirit’s current location on Mars will be its final resting place.”

Ten months ago, as Spirit was driving south beside the western edge of a low plateau called Home Plate, its wheels broke through a crusty surface and churned into soft sand hidden underneath.

After Spirit became embedded, the rover team crafted plans for trying to get the six-wheeled vehicle free using its five functioning wheels – the sixth wheel quit working in 2006, limiting Spirit’s mobility. The planning included experiments with a test rover in a sandbox at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., plus analysis, modeling and reviews. In November, another wheel quit working, making a difficult situation even worse.

Recent drives have yielded the best results since Spirit became embedded. However, the coming winter mandates a change in strategy. It is mid-autumn at the solar-powered robot’s home on Mars. Winter will begin in May. Solar energy is declining and expected to become insufficient to power further driving by mid-February. The rover team plans to use those remaining potential drives for improving the rover’s tilt. Spirit currently tilts slightly toward the south. The winter sun stays in the northern sky, so decreasing the southward tilt would boost the amount of sunshine on the rover’s solar panels.

“We need to lift the rear of the rover, or the left side of the rover, or both,” said Ashley Stroupe, a rover driver at JPL. “Lifting the rear wheels out of their ruts by driving backward and slightly uphill will help. If necessary, we can try to lower the front right of the rover by attempting to drop the right-front wheel into a rut or dig it into a hole.”

At its current angle, Spirit probably would not have enough power to keep communicating with Earth through the Martian winter. Even a few degrees of improvement in tilt might make enough difference to enable communication every few days.

“Getting through the winter will all come down to temperature and how cold the rover electronics will get,” said John Callas, project manager at JPL for Spirit and its twin rover, Opportunity. “Every bit of energy produced by Spirit’s solar arrays will go into keeping the rover’s critical electronics warm, either by having the electronics on or by turning on essential heaters.”

Even in a stationary state, Spirit continues scientific research.

“There’s a class of science we can do only with a stationary vehicle that we had put off during the years of driving,” said Steve Squyres, a researcher at Cornell University and principal investigator for Spirit and Opportunity. “Degraded mobility does not mean the mission ends abruptly. Instead, it lets us transition to stationary science.”

One stationary experiment Spirit has begun studies tiny wobbles in the rotation of Mars to gain insight about the planet’s core. This requires months of radio-tracking the motion of a point on the surface of Mars to calculate long-term motion with an accuracy of a few inches.

“If the final scientific feather in Spirit’s cap is determining whether the core of Mars is liquid or solid, that would be wonderful — it’s so different from the other knowledge we’ve gained from Spirit,” said Squyres.

Tools on Spirit’s robotic arm can study variations in the composition of nearby soil, which has been affected by water. Stationary science also includes watching how wind moves soil particles and monitoring the Martian atmosphere.

Spirit and Opportunity landed on Mars in January 2004. They have been exploring for six years, far surpassing their original 90-day mission. Opportunity currently is driving toward a large crater called Endeavor and continues to make scientific discoveries. It has driven approximately 12 miles and returned more than 133,000 images.

Time is Running out for Spirit Rover

January 14, 2010

JPL just released this update on Spirit’s status and it doesn’t look good:

The list of remaining maneuvers being considered for extricating Spirit is becoming shorter. Results are being analyzed Wednesday, Jan. 13, from a drive on Sol 2143 (Jan. 12, 2010) using intentionally very slow rotation of the wheels. Earlier drives in the past two weeks using wheel wiggles and slow wheel rotation produced only negligible progress toward extricating Spirit.

The right-front wheel has not rotated usefully since Sol 2117 (Dec. 16, 2009). With the right-rear wheel also inoperable since Sol 2099 (Nov. 28, 2009), Spirit now drives with only four wheels.

Pending results of the latest drive, the rover team is developing plans for their final few attempts, such as driving backwards and using Spirit’s robotic arm to sculpt the ground directly in front of the left-front wheel, the only working wheel the arm can reach. Such activities may take several sols to implement, but time is getting short as winter approaches and the team needs to focus on Spirit’s winter survival.

The amount of energy that Spirit has each day is declining as autumn days shorten on southern Mars. If NASA does determine that the rover will not be able to get away from its current location, some maneuvers to improve the tilt toward the winter sun might be attempted.

I’m on downlink duty for Pancam this week, and I can say that watching each day tick by with, often, just fractions of a millimeter of progress is painful. The team is generally upbeat in the meetings, but there’s a sense of urgency and all eyes are on the calendar as we inch closer to dark days on Mars. Spirit has survived previous Martian winters, but that was with the rover tilted toward the sun to maximize the power available. Right now, Spirit’s tilt is not so good, and I don’t know if we’ll be able to fix it in time.

For more thoughts on the current predicament, head over to the Planetary Society blog.

Be a Martian!

November 17, 2009

Fact #1: As a Mars scientist, I am incredibly spoiled. There are so many missions to Mars right now sending back so much data, that even if they all went silent tomorrow, it would be decades before we managed to look at all the data and figure out what it’s telling us.

Fact #2: There are lots of people out there (I’m looking at you, loyal readers!) who would love to be able to actively participate in exploring Mars. I mean, have you seen the stuff that the folks at UnmannedSpaceflight have managed to put together? They do more with the data from Mars than a lot of scientists!

So, given those two facts, you can see why I think the new “Be a Martian” collaboration between NASA and Microsoft is a great idea. Check out this excerpt from the press release:

Drawing on observations from NASA’s Mars missions, the “Be a Martian” Web site will enable the public to participate as citizen scientists to improve Martian maps, take part in research tasks, and assist Mars science teams studying data about the Red Planet.

“We’re at a point in history where everyone can be an explorer,” said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. “With so much data coming back from Mars missions that are accessible by all, exploring Mars has become a shared human endeavor. People worldwide can expand the specialized efforts of a few hundred Mars mission team members and make authentic contributions of their own.”

How cool is that? It’s a really brilliant idea, and I hope it goes well. A similar project was pioneered by galactic astronomers who had way too many pictures of galaxies to deal with, so they opened up the database to the public in the form of GalaxyZoo. It was a tremendous success, with thousands of people helping to classify millions of galaxies.

I just created my account and played around a bit, and it looks like a very user-friendly introduction to Mars science. You can contribute in two main ways: aligning images to contribute to a global map, and also counting craters. Both of these tasks can sort of be done by computers, but humans will always be better.

There’s more to the Be a Martian site than just work though, there are also lots of goodies like videos and Mars wallpapers, and great information about Mars. There is even a “movie theater” where you can watch the first few episodes of a series of videos called “The Martians”, that focus on people from all over the country who are involved with Mars, ranging from members of the rover teams to enthusiastic amateurs to actors putting on a play about Mars! There are more episodes on the way, and I encourage you to keep watching… you might see someone you recognize. ;)

Bottom line, it looks like a great site, and a great way to get involved in Mars exploration and learn about everyone’s favorite Red Planet and the people who are fascinated by it. What are you waiting for? Head on over and sign up! I’ll see you on Mars!

 

Crescent Earth, Water on the Moon, and Free Spirit!

November 15, 2009

Just a quick post to update you on the latest space news and remind you to keep voting for my article about how MSL is like James Bond.

First of all, the Rosetta spacecraft, on its way to a rendezvous with a comet in 2014, swung by Earth the other day, and took some beautiful pictures:

osiris_color_2009-11-12T12.28UTC_rot_north

Crescent earth as seen by the Rosetta probe.

Second, NASA held a press conference on friday announcing that the LCROSS mission to “bomb the moon” was successful and that they found evidence for hundreds of kilograms of water in the impact plume. This means that the south pole of the moon just got a lot more appealing, both because of the potential as a resource and because the water trapped in permanently shadowed craters could be billions of years old, preserving the history of the solar system much like the ice cores of Antarctica do for the Earth’s past. Check out the Planetary Society article on the discovery for more information.

Third, the rover drivers are finally preparing to extract Spirit from the sand trap where she has spent most of the summer! Once again, the Planetary Society blog has a good summary of the recent NASA press conference.

That’s all for now. I’m off to frantically write bad sci-fi so I can keep up with NaNoWriMo!

 

Ups And Downs for Spirit Rover

May 12, 2009
This picture shows the light-toned, disturbed soil where Spirit is currently stuck. The wheels spin, but just sink deeper in the soft sand.

This picture shows the light-toned, disturbed soil where Spirit is currently stuck. The wheels spin, but just sink deeper in the soft sand.

Recently, Spirit has had some very good news and some very bad news. The good news is that we just had a huge cleaning event, with high winds blowing the solar panels clean so that we are getting power levels that we haven’t seen in years!

The bad news is that this occurred as Spirit got stuck in deep, soft sand. Last week we were commanding drives of tens of meters and getting tens of millimeters of progress. Not a good situation. The extra power boost helps, but Spirit still needs to get out of the soft soil before winter sets in. We had an all-hands meeting yesterday to discuss the plan for the next few weeks. We will be doing tons of imaging and measurements on the soil surrounding the rover to figure out what its mechanical properties are, and the mock-up rover at JPL will be put into the testbed, stuck in similar piles of soil and the engineers on the team will figure out the best way to extract ourselves.

For more info, check out this NASA press release:

May 11, 2009

Mars Exploration Rover Mission Status Report

PASADENA, Calif. — The five wheels that still rotate on NASA’s Mars Exploration Rover Spirit have been slipping severely in soft soil during recent attempts to drive, sinking the wheels about halfway into the ground.

The rover team of engineers and scientists has suspended driving Spirit temporarily while studying the ground around the rover and planning simulation tests of driving options with a test rover at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

“Spirit is in a very difficult situation,” JPL’s John Callas, project manager for Spirit and its twin rover, Opportunity, said Monday. “We are proceeding methodically and cautiously. It may be weeks before we try moving Spirit again. Meanwhile, we are using Spirit’s scientific instruments to learn more about the physical properties of the soil that is giving us trouble.”

Both Spirit and Opportunity have operated more than five years longer than their originally planned missions of three months on Mars and have driven much farther than designed. The rover team has so far developed ways to cope with various symptoms of aging on both rovers.

Spirit has been driving counterclockwise from north to south around a low plateau called “Home Plate” for two months. The rover progressed 122 meters (400 feet) on that route before reaching its current position.

In the past week, the digging-in of Spirit’s wheels has raised concerns that the rover’s belly pan could now be low enough to contact rocks underneath the chassis, which would make getting out of the situation more difficult. The right-front wheel on Spirit stopped working three years ago. Driving with just five powered wheels while dragging or pushing an immobile wheel adds to the challenge of the situation.

Favorably, three times in the past month, wind has removed some of the dust accumulated on Spirit’s solar panels. This increases the rover’s capability for generating electricity.

“The improved power situation buys us time,” Callas said. “We will use that time to plan the next steps carefully. We know that dust storms could return at any time, although the skies are currently clear.”

Behavioral problems that Spirit exhibited in early April — episodes of amnesia, computer resets and failure to wake for communications sessions — have not recurred in the past three weeks, though investigations have yet to diagnose the root causes.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Science Mission Directorate, Washington.

Watching out for Dust Storms

April 15, 2009

NASA just sent out this press release discussing the various ways that we watch out for dust storms that might be dangerous to the rovers. I have actually used data from the Mars Color Imager (MARCI) that they mention in the release, but I used it for the exact opposite task! I wrote programs that search through the images taken by that camera (there are a lot of them, it gets global coverage every day!) over a certain timeframe and choose the least dusty ones. This is useful for removing the effect of the atmosphere and tracking changes on the surface: for example, if I run my program before and after the huge dust storm in 2007, you can see the wind streaks in Gusev crater changing.

Anyway, here’s the NASA press release. You may also be interested in Emily’s post about recent dust activity on Mars.

PASADENA, Calif. — Heading into a period of the Martian year prone to major dust storms, the
team operating NASA’s twin Mars rovers is taking advantage of eye-in-the-sky weather reports.

On April 21, Mars will be at the closest point to the sun in the planet’s 23-month, elliptical orbit.
One month later, the planet’s equinox will mark the start of summer in Mars’ southern
hemisphere. This atmospheric-warming combination makes the coming weeks the most likely
time of the Martian year for dust storms severe enough to minimize activities of the rovers.

“Since the rovers are solar powered, the dust in the atmosphere is extremely important to us,” said
Bill Nelson of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., chief of the engineering team
for Spirit and Opportunity.

Unexplained computer reboots by Spirit in the past week are not related to dust’s effects on the
rover’s power supply, but the dust-storm season remains a concern. Spirit received commands
Tuesday to transmit more engineering data in coming days to aid in diagnosis of the reboots.

After months of relatively clear air, increased haze in March reduced Spirit’s daily energy supply
by about 20 percent and Opportunity’s by about 30 percent. Widespread haze resulted from a
regional storm that made skies far south of the rovers very dusty. Conditions at the rovers’ sites
remained much milder than the worst they have endured. In July 2007, nearly one Martian year
ago, airborne dust blocked more than 99 percent of the direct sunlight at each rover’s site.

The rovers point cameras toward the sun to check the clarity of the atmosphere virtually every
day. These measurements let the planning team estimate how much energy the rovers will have
available on the following day. Observations of changes in the Martian atmosphere by NASA’s
Mars Reconnaissance Orbiter, which reached Mars in 2006, and NASA’s Mars Odyssey, which
reached Mars in 2001, are available to supplement the rover’s own skywatch.

The Mars Color Imager camera on Mars Reconnaissance Orbiter sees the entire planet every day
at resolution comparable to weather satellites around Earth.

“We can identify where dust is rising into the atmosphere and where it is moving from day to
day,” said Michael Malin of Malin Space Science Systems, San Diego, principal investigator for
Mars Color Imager. “Our historical baseline of observing Martian weather, including data from
the Mars Global Surveyor mission from 1998 to 2007, helps us know what to expect. Weather on
Mars is more repetitive from year to year than weather on Earth. Global dust events do not occur
every Mars year, but if they do occur, they are at this time of year.”

Two other instruments — the Thermal Emission Imaging System on Mars Odyssey and the Mars
Climate Sounder on Mars Reconnaissance Orbiter — monitor changes in airborne dust or dust-
related temperatures in Mars’ upper atmosphere. Orbiters also aid surface missions with radio
relays, imaging to aid drive plans, and studies of possible future landing sites.

When orbital observations indicate a dust-raising storm is approaching a rover, the rover team can
take steps to conserve energy. For example, the team can reduce the length of time the rover will
be active or can shorten or delete some communication events.

In recent weeks, frequent weather reports from Bruce Cantor of Malin’s Mars Color Imager team
let the rover team know that the March increase in haziness was not the front edge of a bad
storm. “Bruce’s weather reports have let us be more aggressive about using the rovers,” said Mark
Lemmon, a rover-team atmospheric scientist at Texas A&M University, College Station. “There
have been fewer false alarms. Earlier in the mission, we backed off a lot on operations whenever
we saw a small increase in dust. Now, we have enough information to know whether there’s
really a significant dust storm headed our way.”

At other times, the weather reports prompt quick precautionary actions. On Saturday, Nov. 8,
2008, the rover team received word from Cantor of a dust storm nearing Spirit. The team deleted
a communication session that Sunday and sent a minimal-activity set of commands that Monday.
Without those responses, Spirit would likely have depleted its batteries to a dangerous level.

Winds that can lift dust into the air can also blow dust off the rovers’ solar panels. The five-year-
old rover missions, originally planned to last for three months, would have ended long ago if
beneficial winds didn’t occasionally remove some of the dust that accumulates on the panels. A
cleaning event in early April aided Opportunity’s power output, and Spirit got two minor
cleanings in February, but the last major cleaning for Spirit was nearly a full Martian year ago.

Nelson said, “We’re all hoping we’ll get another good cleaning.”

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars
Exploration Rovers, Mars Odyssey and Mars Reconnaissance Orbiter for NASA’s Science
Mission Directorate, Washington. More information about the rovers is at
http://www.nasa.gov/rovers .  Dust reports from the Thermal Emission Imaging System,
operated by Arizona State University, Tempe, are at http://themis.asu.edu/dustmaps/ . Weather
reports from the Mars Color Imager team are at
http://www.msss.com/msss_images/latest_weather.html .

Rover Huggers

April 11, 2009

Stuart Atkinson just posted a very nice short story over at his blog Cumbrian Sky that you should all go and read. Here’s a teaser:

“Hurry up!” Catriona said loudly into her helmet mike. She didn’t bother to turn round towards her brother as she spoke. She didn’t need to; apart from herself and her mother, whose hand she was clutching tightly, he was the only other person for miles around.


Walking – ‘trudging’ was probably a more accurate term, as he begrudged every step he took – a short distance behind his mother and sister, Leo’s only reply was an angst-ridden heavy sigh. For pity’s sake, shut up Cat! he thought, glaring at the two figures, one tall and slim, one shorter and a lot stubbier, moving across the rock-strewn crown of Homeplate a hundred feet or so up ahead of him. While his mother’s stride was careful and steady, controlled… adult… Cat was bouncing along, as usual, giddy with excitement at the prospect of seeing another piece of ancient martian history. In her white EVA suit with its pink bands he thought his sister looked like a piece of candy bouncing across the ground, each footfall kicking up a small cloud of red and orange dust….


Spirit Hit by Dust Storm

November 11, 2008

pia10128-640

Just when things were looking up for Spirit and we had begun driving, over the weekend we got news from the MARCI team that there was a dust storm headed toward Gusev crater. Sure enough, Spirit is being hit hard and power levels are at an all-time low. Here’s the NASA press release.

But after five years the rover team knows what it’s doing. There was an emergency set of commands sent up to Spirit to cancel everything and minimize its power use. This included turning off the heater on the Mini-TES instrument. In case all of that doesn’t work, the rover will slip into a “low power fault”, meaning it will shut down everything but its clock, and wait for a predetermined amount of time before periodically waking up and calling home. Its scheduled calls home would happen at known times, and the team will be listening for those calls just in case.

As troubling as it is that Spirit is being hit by this storm, I still can’t help but find it amazing that we are at the point where we can watch storms like this form and have time to change our plans accordingly. We just forecasted weather on Mars!