THEN TO MARS

HERE WE COME MARTIANS!

MAY 15, 2008

How NASA's Phoenix Will Land on Mars

By Jeremy Hsu
Staff Writer
posted: 14 May 2008
07:58 am ET

NASA's Phoenix Mars Lander aims to not flame out when it descends to the arctic surface of the red planet in less than two weeks.

The new Martian probe will try to avoid the fate of its crashed predecessor, NASA's Mars Polar Lander, when deploying a parachute and braking rockets to slow its plunge and make a successful three-point landing.

"This is not a trip to grandma's house," said Ed Weiler, associate administrator of NASA's Science Mission Directorate at the agency's headquarters in Washington, D.C. "Putting a spacecraft safely on Mars is hard and risky."

Phoenix managers refer to the probe's descent as "seven minutes of terror" that will define the future of the spacecraft's $420-million mission. The robotic arm-equipped spacecraft is due to land near the Martian north pole on May 25 to study nearby water ice and determine if the region was once habitable for primitive life.

"Hopefully the outcome will be different from the Mars Polar Lander outcome," said Rob Grover, NASA engineer at the Jet Propulsion Laboratory in Pasadena, Calif.

Mars Polar Lander (MPL) entered the Martian atmosphere near the planet's south pole in 1999, but a software glitch caused a premature shutdown of the spacecraft's engines. It crashed while falling at 50 mph (80 kph) instead of making a soft landing. NASA has worked since then to ensure Phoenix doesn't suffer the same fate.

"The number one cause was the faulty indicator on touchdown sensor," Grover told SPACE.com, adding that the sensor falsely told the MPL that it had already landed.

Engineers have since corrected the software issue and made the overall system more robust to avoid future errors.

"We feel like we have adequately tested this vehicle," Phoenix project manager Barry Goldstein said in a Tuesday mission briefing, but added that there is always room for the unexpected. "We fire 26 pyrotechnic events in the last 14 minutes of this vehicle, and every one of those has to go off as planned...We're very hopeful for success on the 25th."

Phoenix User's Guide for Mars Arrival

The exact fate of the lost MPL remains somewhat uncertain because that probe had no way of communicating with Earth once it entered the Martian atmosphere. That won't be the case for Phoenix, which has a small crowd of three Mars orbiters to watch and relay information from the spacecraft throughout landing.

For Goldstein, it is the three-second communications gap between Phoenix's departure from its cruise stage and the first signals to its relay network that gives him the shivers. If Phoenix fails to land successfully, any signals just before landing will prove vital in learning its fate, he said.

"Getting that communications down is the important thing," Goldstein said. "That will be the three seconds that I'm really biting my nails over."

A wraparound antenna sits on Phoenix's back-shell, capable of transmitting an ultra-high frequency signal to Earth via NASA's Mars Reconnaissance Orbiter (MRO) or Mars Odyssey spacecraft Europe's Mars Express orbiter is also on call in case of an emergency, mission managers said.

"This is the first time for any Mars landing having orbital relay communications for both landing and being on the surface," Grover said.

Phoenix will descend and land much the same way that MPL was meant to, plunging into the Martian atmosphere at about 13,000 mph (21,000 kph). That's similar to respective 2004 descents of NASA's Spirit and Opportunity rovers, though Phoenix's arrival would mark first powered landing on Mars since NASA's Viking missions of the 1970s

The probe combines new technology with proven methods for landing, including an Apollo-era Earth entry software algorithm to guide the spacecraft's early descent into the Martian atmosphere.

A Viking-era parachute is designed to open once Phoenix falls within 7.8 miles (12.6 km) above Mars, creating drag to slow the spacecraft as it screams through the atmosphere at supersonic speed. The probe's landing radar should begin giving altitude and velocity of descent as Phoenix nears the surface, so that the onboard computer can make any necessary landing adjustments.

"By the time you get the parachute opening, there can be significant errors in positioning on order of kilometers," Grover said. "So that's where radar is critical, because it turns on and gets fresh knowledge of altitude."

Vertical Martian lander

Two minutes after the parachute deployment, Phoenix will have descended to approximately 0.6 miles (1 km) above the surface. The lander should then jettison its backshell and freefall for half a second before lighting up its engines.

Nine of the twelve engines will pulse furiously 10 times per second — an effect Grover likened to "coming down on a jackhammer." The three non-pulsing engines should fire steadily to help ensure added stability.

"Just before touchdown, we actually pirouette the vehicle," Goldstein said, adding that the move will aid Phoenix's vital solar arrays. "We actually turn it so we maximize solar exposure."

Navigators at JPL can upload fresh orders to Phoenix's guidance computer up to three hours before landing, in case course adjustments are required. However, Grover and other NASA engineers will only be able to stand by and trust in their spacecraft technology once the Mars lander begins its descent.

"We've done all that's humanly possible," Grover said.

NOVEMBER 21, 2007

Astronauts Ready to Tackle Space Station Construction
By Tariq Malik
Staff Writer
posted: 19 November 2007
4:04 p.m. ET

A team of astronauts on Earth and in orbit are poised for a December spaceflight to haul a new European laboratory at the International Space Station (ISS).

The seven astronauts of NASA's shuttle Atlantis are training to launch toward the ISS with the European Space Agency's (ESA) Columbus laboratory as the station's Expedition 16 crew gears up for two planned spacewalks this week to ready the outpost for the new addition.

"We're really excited about this mission," shuttle commander Stephen Frick told reporters Monday on Atlantis's Pad 39A launch site at NASA's Kennedy Space Center in Cape Canaveral, Fla.

Frick and his STS-122 crew are due to launch spaceward on Dec. 6 on an 11-day mission to deliver Columbus to the ISS. They will climb into the 100-ton Atlantis orbiter on Tuesday for a dress rehearsal of their launch day activities.

"So far, we're looking right on schedule for Dec. 6," Frick said. "The real challenge is on the station side. They've just had a ton of work to get done since [the last flight]."

Commanded by NASA astronaut Peggy Whitson, the space station's three-person Expedition 16 crew is currently in the midst of a packed month of spacewalks, robotics and module outfitting to ensure the orbital laboratory's new Harmony connecting module is ready for Atlantis's arrival next month. The station crew moved Harmony to the front of the outpost's U.S. Destiny module last week.

Whitson and flight engineer Dan Tani are now set to stage a pair of spacewalks, on Tuesday and Saturday, respectively, to fold the Harmony node into the station's power and cooling systems. The spacewalks must go smoothly to allow December's shuttle mission to launch, NASA has said.

"These [spacewalks], I expect, will be tough," Tani told Chicago's WBBM Radio in a Monday interview broadcast on NASA TV. "Plus, we know that we are in the critical path to getting the node fully activated."

Tani and Whitson equipped Harmony with a shuttle docking port last week before moving it to the front of Destiny using the station's Canadarm2 robotic arm. The new connecting node will serve as the hub for the ESA's Columbus module and Japan's Kibo laboratory.

"We're looking forward to the work ahead," Whitson said. "We know it's going to be challenging, but we're prepared."

NASA will broadcast the Expedition 16 crew's second spacewalk outside the ISS live on NASA TV on Nov. 20 beginning at 4:30 a.m. EST (0930 GMT). Click here for SPACE.com's ISS mission updates and NASA TV feed.

November 24, 2007

Spacewalkers Wire up Space Station's New Room
By Dave Mosher and
Tariq Malik
posted: 24 November 2007
1:43 p.m. ET

Two spacewalking astronauts wired up the International Space Station's (ISS) newest room Saturday, capping a month-long marathon of work to prepare for the December arrival of a new European laboratory.

Expedition 16 commander Peggy Whitson and flight engineer Dan Tani spent more than seven hours routing ammonia cooling lines and cables for power and data systems between the station and its hub-like Harmony connecting module. The orbital work cleared the way for NASA's planned Dec. 6 launch of its STS-122 mission aboard Atlantis to deliver the European Space Agency's (ESA) Columbus laboratory to the ISS.

"Wow it's almost a full moon," said Whitson, Expedition 16 commander and lead spacewalker as she ventured outside of the station's Quest airlock at 4:50 a.m. EST (0950 GMT).

"Yeah, I've been watching the past couple nights and it's very close," said Tani of the waxing lunar spectacle.

The seven-hour, four-minute spacewalk marked the third in 15 days for the station's Expedition 16 astronauts and served as the finish line for a work marathon that began with a Nov. 9 excursion just after NASA's shuttle Discovery left the ISS.

Discovery's STS-120 crew delivered Harmony to the ISS, but it was up to Whitson, Tani and crewmate Yuri Malenchenko to move the node to its current perch at the front of the station's Destiny lab. There, Harmony will serve as the hub for Columbus and a Japanese laboratory slated to launch next year.

"What we've accomplished in the last 15 days is the equivalent of a very ambitious shuttle assembly mission," said ISS flight director Derek Hassmann after the spacewalk, adding that the three Expedition 16 crew achieved on their own what a team of up to 10 ISS and shuttle astronauts would normally tackle. "Quite honestly, I am just very pleasantly surprised that everything went as well as it did."

Solar wing joint inspection

While much of Saturday's spacewalk chores mirrored those performed by Whitson and Tani in a Tuesday excursion, mission managers did add a new task to their orbital to-do list: the inspection of massive gear that turns the station's starboard solar wings like a paddlewheel to face the sun.

Tani found metallic grit in the gear, known as the starboard Solar Alpha Rotary Joint (SARJ), during a late October spacewalk inspection after engineers on Earth detected odd vibrations and slight power spikes from the 10-foot (3-meter) wide structure. During Saturday's inspection, Tani uncovered a different section of the joint and found similar contamination.

"I see the same damage I saw on the other panel," Tani said. "In fact, I would say there are more shavings here. Again, it looks exactly like ... there's this obvious magnetic attraction."

Station flight controllers have moved the starboard gear only sparingly to avoid further damage, but its counterpart on the station's port side continues to perform flawlessly and showed no signs of contamination during a previous spacewalk inspection.

Tani and Whitson said it appeared that one of the starboard gear's two bearing race rings appeared to be pitted or damaged.

"It sure looks like metal-to-metal damage," Tani said.

The starboard SARJ gear will likely have to be repaired before the major component of Japan's three-segment Kibo laboratory can be installed at the ISS next year, but mission managers said any attempt to fix the joint can wait until after December's planned shuttle flight. Depending on the nature of repair required, the effort could take up to four extra spacewalks, but understanding the full extent of contamination is vital before any attempt is staged, NASA has said.

"I consider that to be, as it turns out, one of the key accomplishments of today's spacewalk," Hassmann said of the Expedition 16 crew's SARJ inspection. "Basically, the damage is significant and it is widespread."

Fluid tray shuffle

Whitson and Tani spent the bulk of their Saturday spacewalk routing a 300-pound (136-kilogram), 18.5-foot (5.6-meter) tray of ammonia cooling system lines between Harmony and the ISS. The work installed the second half of cooling, power and data cables to completely fold Harmony into the space station's systems.

"This is harder than last time," Tani said as he gripped the bulky tray, comparing it to his wrangling with an identical component on Tuesday's spacewalk. Whitson also removed a series of launch restraints on the Harmony and finished hooking up the station's power transfer that allows visiting shuttles to feed off the ISS power grid. The astronauts began their spacewalk more than one hour early and managed a few extra tasks, including the installation of an exterior flood light and setting up tools for spacewalks planned during December's shuttle flight. Saturday's spacewalk marked the 99th dedicated to space station construction and the fourth career excursion for both Whitson and Tani. By the end of the activity, Whitson racked up 25 hours and 40 minutes of spacewalking time while Tani ended with 25 hours and five minutes.

DECEMBER 1, 2007

Space Station's European Lab Set for December Launch
By Tariq Malik
Staff Writer
posted: 16 November 2007
9:53 p.m. ET

WASHINGTON - Seven astronauts and a European laboratory are on track to rocket toward the International Space Station (ISS) next month aboard NASA's shuttle Atlantis.

Commanded by veteran spaceflyer Stephen Frick, Atlantis's STS-122 crew are eager to haul the European Space Agency's (ESA) Columbus laboratory toward the ISS on Dec. 6.

"It will be a very busy mission with also some spacewalks to do space station maintenance tasks and who knows what else," Frick told reporters Friday during a series of mission briefings at NASA's Johnson Space Center in Houston. "Space station assembly missions, these days, are very dynamic."

Frick and his crewmates plan to perform at least three spacewalks during their 11-day mission to attach Columbus to the station's new Harmony node. The station's Expedition 16 crew, commanded by NASA astronaut Peggy Whitson, will perform two spacewalks of their own next week to ensure Harmony and the ISS are ready for December shuttle flight.

"As long as we don't run into any major snags with these [spacewalks], the schedule will support a Dec. 6 launch," said Kenny Todd, NASA's ISS integration and operations manager, of the planned Nov. 20 and Nov. 24 excursions.

Delivered by NASA shuttle astronauts last month, the Harmony node is designed to serve as the anchor for Japan's three-segment Kibo module and the ESA's 1.4 billion Euro (US$2 billion) Columbus lab, which will mark Europe's first permanently crewed science facility to reach space.

"I'm very proud that we will bring up Columbus, the biggest contribution of ESA to the International Space Station," said Atlantis mission specialist Hans Schlegel, an ESA astronaut from Germany.

Atlantis mission specialist Leopold Eyharts, an ESA astronaut from France, will christen Columbus and stay aboard the space station as a new member of the Expedition 16 crew. He will replace U.S. astronaut Dan Tani, who will return to Earth with the STS-122 crew.

Space station joint inspection

NASA is also drawing up plans for a late addition to the mission's third spacewalk that would call for STS-122 mission specialist Rex Walheim to inspect a balky solar wing joint on the station's starboard side. Mission managers may even extend the flight two full days and add a fourth spacewalk to perform a more in-depth inspection, NASA said Friday.

Spacewalkers discovered metal grit inside the massive gear, known as the starboard Solar Alpha Rotary Joint (SARJ), during NASA's STS-120 shuttle mission last month. After examining samples of grit that were returned to Earth, engineers found them to be part of the gear's race ring that rotates the station's starboard solar wings like a paddlewheel to continuously face the sun.

"I think we're still in more of the investigation stage, and that we can do using our regular skills for regular tasks," Walheim told reporters today. "We'll just have to be careful about it."

Atlantis and its STS-122 crew have a slim, week-long window to launch toward the ISS next month. The mission will be NASA's fourth shuttle flight of the year, the largest number since the 2003 Columbia accident.

"We've been really fortunate that things have been working so well for us," said NASA shuttle program manager Wayne Hale, stressing that safety and not schedule pressure will always be paramount. "This is a story of continuing to pay attention to details and not stopping to pat ourselves on the back."

Hale added that NASA shuttle managers will decide sometime this spring whether to proceed with plans to pull the Atlantis shuttle out of service in 2008, or keep flying the spacecraft until the planned 2010 retirement of the entire three-orbiter fleet.

NASA plans to replace its space shuttles with the capsule-based Orion Crew Exploration Vehicle and its Ares I rockets as early as 2013.

Space Shuttle Atlantis Set for Dec. 6 Launch
By Tariq Malik
Staff Writer
posted: 30 November 2007
7:18 p.m. ET

NASA's shuttle Atlantis and its seven-astronaut crew are on track for a planned Dec. 6 launch to the International Space Station (ISS), mission managers said late Friday.

Commanded by veteran shuttle flyer Stephen Frick, Atlantis and its seven-astronaut crew will launch Thursday at 4:31 p.m. EST (2131 GMT) to deliver the European-built Columbus laboratory to the ISS.

"Atlantis is on the pad ready to go, with no major issues or concerns regarding that vehicle," said NASA shuttle program manager Wayne Hale during a briefing at the agency's Kennedy Space Center in Cape Canaveral, Fla.

Atlantis' STS-122 mission will mark NASA's fourth shuttle flight of 2007, the most in a single year since the agency resumed orbiter flights after the 2003 Columbia tragedy, and comes after a packed month of construction work by the station's Expedition 16 astronauts. The three-person crew performed three spacewalks in 15 days and some tricky robotic arm work to ready the station and its new Harmony connecting module for the European Space Agency's Columbus lab.

"In my mind, it's been an unprecedented year for us," said Mike Suffredini, NASA's space shuttle program manager. "I will say, we always knew this particular moment was going to be a challenging moment for us."

Delivered by NASA's shuttle Discovery last month, the Harmony module is designed to serve as the anchor for Europe's Columbus module and Japan's massive, three-segment Kibo laboratory, which will launch in stages next year to further expand the $100 billion space station.

Frick and his STS-122 crewmates will perform at least three spacewalks during their planned 11-day mission to install Columbus, replace ISS hardware and swap out one member of the station's Expedition 16 crew.

If Atlantis' power supplies hold out, NASA may extend the mission by two extra days and add a fourth spacewalk to take another look at a balky rotational joint designed to turn the station's starboard solar wings like a paddlewheel to track the sun. Previous limited inspections by spacewalkers found the joint to be contaminated with metallic grit, and engineers require additional data before they can decide on a repair plan.

"With some power downs, we can get a couple of extra days," Suffredini said. "During a [fourth spacewalk] we'd do some thorough inspections of the solar array joint."

But if Atlantis' power supplies can't support the extra spacewalk or its astronaut crew grows too fatigued, the inspection could be shifted to later in the Expedition 16 mission, he added.

NASA plans to launch some spare parts for the joint aboard Atlantis and another shuttle set to launch in February to prepare for what could be a lengthy repair requiring multiple spacewalks, mission managers said.

Engineers also suspect that indications of a possible air leak in seals between the station's Harmony and U.S. Destiny lab are the result of instrumentation error. A series of tests this week, some of which are still ongoing, have yet to turn up any sign of an actual leak.

"The data suggests this leak does not exist," Suffredini said.

SPACE.com Video Interplayer: NASA's STS-122: Columbus Sets Sail for ISS

Becoming the Future

This image taken by the panoramic camera on the Mars

SCI-TECH CLICK HERE FOR BRITISH MARS ROVER TESTING

Mars vehicle model tested

Exploration Rover Opportunity shows the view of Victoria Crater from Duck Bay. Opportunity reached Victoria Crater on Sol 951 (September 27, 2006) after traversing 9.28 kilometers (5.77 miles) since her landing site at Eagle Crater. Victoria Crater is roughly 800 meters (one-half mile) wide -- about five times wider than Endurance Crater, and 40 times as wide as Eagle crater. The south face of the 6 meter (20 foot) tall layered Cape Verde promontory can be seen in the left side of the inner crater wall, about 50 meters (about 165 feet) away from the rover at the time of the imaging. The north face of the 15 meter (50 foot) tall stack of layered rocks called Cabo Frio can be seen on the right side of the inner crater wall.

This mosaic was taken on Sols 952 and 953 (September 28 and 29, 2006). There are 30 separate pointings through 6 different filters at each pointing. This mosaic was generated from Pancam's 753 nm, 535 nm, and 482 nm filters. Four versions are available at full resolution: this approximate true color rendering, a false color stretch to enhance subtle color differences in the scene, a stereo anaglyph, which appears three dimensional when viewed through red-blue glasses, and a black and white version presented as a cylindrical projection with geometric seam correction.

Image Credit: NASA/JPL-Caltech

NASA's Mars-Bound Phoenix Adjusts Course Successfully

08.10.07

NASA's Phoenix Mars Lander today accomplished the first and largest of six course corrections planned during the spacecraft's flight from Earth to Mars.

Phoenix left Earth Aug. 4, bound for a challenging touchdown on May 25, 2008, at a site farther north than any previous Mars landing. It will robotically dig to underground ice and run laboratory tests assessing whether the site could ever have been hospitable to microbial life.

Image right: Artist concept of Phoenix in space. Image credit: NASA/JPL.

Phoenix today is traveling at about 33,180 meters per second (74,200 miles per hour) in relation to the sun. The first trajectory-correction maneuver was calculated to tweak the velocity by about 18.5 meters per second (41 miles per hour). The spacecraft fired its four mid-size thrusters for three minutes and 17 seconds to adjust its trajectory.

"All the subsystems are functioning as expected with few deviations from predicted performance," said Joe Guinn, Phoenix mission system manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Key activities in the next few weeks will include checkouts of science instruments, radar and the communication system that will be used during and after the landing.

The second trajectory-correction maneuver is planned for mid-October. "These first two together take out the bias intentionally put in at launch," said JPL's Brian Portock, Phoenix navigation team chief. Without the correction maneuvers, the spacecraft's course after launch day would miss Mars by about 950,000 kilometers (590,000 miles), an intentional offset to prevent the third stage of the launch vehicle from hitting Mars. The launch vehicle is not subject to the rigorous cleanliness requirements that the spacecraft must meet as a protection against letting Earth organisms get a foothold on Mars.

The burn began at 11:30 a.m. Pacific Daylight Time. Each of the four trajectory-correction thrusters provides about 15.6 newtons (3.5 pounds) of force. Smaller, attitude-control thrusters pivoted the spacecraft to the desired orientation a few minutes before the main burn and returned it afterward to the right orientation for catching solar energy while communicating with Earth. Their thrust capacity is about 4.4 newtons (1 pound) apiece. The twelve largest thrusters on Phoenix, delivering about 293 newtons (66 pounds) apiece, will operate only during the final minute before landing on Mars.

The Phoenix mission is led by Peter Smith of the University of Arizona, Tucson, with project management at JPL and development partnership at Lockheed Martin, Denver. International contributions are provided by the Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus, Denmark; the Max Planck Institute, Germany; and the Finnish Meteorological Institute. JPL is a division of the California Institute of Technology in Pasadena.

Additional information on Phoenix is available online at: http://www.nasa.gov/phoenix and at http://phoenix.lpl.arizona.edu . Additional information on NASA's Mars program is available online at: http://www.nasa.gov/mars .

Media contacts: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.

Sara Hammond 520-626-1974
University of Arizona, Tucson
shammond@lpl.arizona.edu

Gary Napier 303-971-4012
Lockheed Martin Space Systems, Denver
gary.p.napier@lmco.com

2007-088

NASA Marks 30th Anniversary of Mars Viking Mission
07.14.06 -- Thirty years after the first successful landing on Mars by NASA's Viking spacecraft, the ambitious mission continues to evoke pride and enthusiasm for future space exploration.

+ Full story
Viking Mission Information:
+ Videos and information from "Mars: Past, Present and Future," a conference held June 22 at Langley Research Center.
+ For media: audio clips
+ Viking Fact Sheet
+ Viking 1 Orbiter | + Viking 1 Lander
+ Viking 2 Orbiter | + Viking 2 Lander
+ Archived mission site

NOVEMBER 1, 2007

NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007. The view combines a stereo pair and appears three-dimensional when seen through blue-red glasses.

After several months near the base of the plateau called "Home Plate" in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is "Tsiolkovski Ridge," about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is "Grissom Hill," about 8 kilometers or 5 miles away. At right, the highest point of the horizon is "Husband Hill," to the north and about 800 meters or half a mile away.

Image credit: NASA/JPL-Caltech/Cornell University

The geologic history of ancient Mars—and the kinds of environments that existed back then—are revealed through layered sedimentary rocks. Such rocks are created when weathering breaks down older rock, and wind and water transport the rock fragments to a location where they are deposited and subsequently lithified—turned back into rock—by cementation and compaction.

During its 9 year mission at Mars, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) discovered many complex relationships within martian sedimentary rocks. One of the most complicated locations it found occurs along the southern margin of Melas Chasma, one of the large troughs of the Valles Marineris system.

These images show a portion of a topographic depression eroded into layered rocks. Erosion has revealed layers of different ages—the oldest are at the bottom of the depression. Within this depression are two sets of alluvial—that is, water-lain—sedimentary rock units that retain their original shape, indicating how the sediments were deposited long before the material became rock. In these cases, the processes created fans of debris with finger-like protrusions at the ends and sides of the fans. Also preserved are the channels through which water and sediment flowed. In Figures (A) and (B), the pictures are identical except that in (A) the fans have been colored to indicate their location. Long after these fans were formed, they were buried and subsequently uncovered by more recent erosion.

Figures (A) and (B) are map-projected mosaics of MOC images R12-00541 and R17-01687. They were taken in 2003 and 2004, respectively, during the second MGS mission extension, the third Mars year that MGS was in its nearly-circular, nearly-polar mapping orbit. Figure (C) shows the context of the images in Figures (A) and (B) in the area outlined by a white box. Figure (C) is a sub-frame of Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) image P05_002828_1711_XI_08S076W_070304, acquired last month on 4 March 2007. Sunlight illuminates all of these scenes from the left. The area of interest is located near 9.9°S, 76.6°W.

Citation and Credit
The image(s) and caption are value-added products. MSSS personnel processed the images and wrote the caption information. While the image(s) are in the Public Domain, NASA/JPL/MSSS requests that you credit the source of the image(s). Re-use of the caption text without credit is plagiarism. Please give the proper credit for use of the image(s) and/or caption.

Image Credit:
NASA/JPL/Malin Space Science Systems
—or—
NASA/JPL/MSSS

To cite the image(s) and caption information in a paper or report:
Malin, M. C., and K. S. Edgett (2007), Fossil Fans in Melas Chasma, Malin Space Science Systems Captioned Image Release, MSSS-2, http://www.msss.com/msss_images/2007/04/13/.

Malin Space Science Systems (MSSS) built and operates the Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) and Context Camera (CTX). MSSS also built and operated the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). In addition, MSSS built the Mars Odyssey (ODY) Thermal Emission Imaging Spectrometer (THEMIS) Visible (VIS) camera subsystem, which shares optics with the thermal infrared instrument and is operated at Arizona State University (ASU). MSSS built the Mars Descent Imager (MARDI) for the Phoenix Mars Scout lander and in 2007 is designing and building camera systems for the Mars Science Laboratory (MSL) rover mission, the Lunar Reconnaissance Orbiter (LRO), and the Juno mission to Jupiter.

News Releases

audio Podcast: Is an Asteroid Heading Toward Mars?

video Video: Animation - Possible paths of asteroid (3Mb - Quicktime)

+ Larger image
This artist rendering uses an arrow to show the predicted path of the asteroid on Jan. 30, 2008, and the orange swath indicates the area it is expected to pass through. Mars may or may not be in its path. Image credit: NASA/JPL
+ High resolution JPG (496Mb)

+ Larger image
The current position of asteroid 2007 WD5, with its orbit shown in blue. The asteroid's orbit stretches from just outside the Earth's orbit at its closest point to the Sun, to the outer reaches of the asteroid belt at its farthest.

+ Larger image
Animation showing the possible paths of asteroid 2007 WD5. On January 30, 2008, the asteroid may pass through any point seen in the dotted area.
+ See animation (3Mb - Quicktime)
Related Links:
+ Near Earth Object program

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Astronomers Rule Out Possibility of Asteroid Impact on Mars
January 11, 2008

Updated Jan 9, 2008 – As expected, scientists at JPL's Near-Earth Object Office have further refined the trajectory estimate for asteroid 2007 WD5 and ruled out any possibility of a Mars impact on Jan. 30. The latest trajectory plot of the asteroid was made possible by adding to previously obtained data some new data from a round of observations acquired by three observatories on the evenings of Jan. 5 through 8. Based on this latest analysis, the odds for the asteroid impacting Mars on Jan. 30 are 0.0 percent. The latest observations come from the German-Spanish Astronomical Center, Calar Alto, Spain; the Multi-Mirror Telescope, Mt. Hopkins, Ariz.; and the University of Hawaii telescope, Mauna Kea, Hawaii.

For more information, visit the Near-Earth Object site at http://neo.jpl.nasa.gov/ .

Updated Jan 2, 2008 – With new observations taken Dec. 29, Dec. 31 and Jan. 2 by the Magdalena Ridge Observatory in New Mexico, scientists at NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif., have updated their trajectory estimates for the asteroid. Based on this latest analysis, the odds for the asteroid impacting Mars on Jan. 30 are now about 1-in-28, or 3.6 percent. New Mexico Tech operates the Magdalena Ridge Observatory.

Updated Dec. 28, 2007 -- Astronomers have identified asteroid 2007 WD 5 in archival imagery. With these new observations, scientists at NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif have refined their trajectory estimates for the asteroid. Based on this latest analysis, the odds for the asteroid impacting Mars on Jan. 30 are now 1-in-25 -- or about 4 percent.

WASHINGTON - Astronomers funded by NASA are monitoring the trajectory of an asteroid estimated to be 50 meters (164 feet) wide that is expected to cross Mars' orbital path early next year. Observations provided by the astronomers and analyzed by NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif., indicate the object may pass within 30,000 miles of Mars at about 6 a.m. EST (3 a.m. PST) on Jan. 30, 2008.

"Right now asteroid 2007 WD5 is about half-way between Earth and Mars and closing the distance at a speed of about 27,900 miles per hour," said Don Yeomans, manager of the Near Earth Object Office at JPL. "Over the next five weeks, we hope to gather more information from observatories so we can further refine the asteroid's trajectory."

NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called "Spaceguard," plots the orbits of these objects to determine if any could be potentially hazardous to our planet.

Asteroid 2007 WD5 was first discovered on Nov. 20, 2007, by the NASA-funded Catalina Sky Survey and put on a "watch list" because its orbit passes near Earth. Further observations from both the NASA-funded Spacewatch at Kitt Peak, Ariz., and the Magdalena Ridge Observatory in New Mexico gave scientists enough data to determine that the asteroid was not a danger to Earth, but could potentially impact Mars. This makes it a member of an interesting class of small objects that are both near Earth objects and "Mars crossers."

Because of current uncertainties about the asteroid's exact orbit, there is a 1-in-75 chance of 2007 WD5 impacting Mars. If this unlikely event were to occur, it would be somewhere within a broad swath across the planet north of where the Opportunity rover is located.

"We estimate such impacts occur on Mars every thousand years or so," said Steve Chesley, a scientist at JPL. "If 2007 WD5 were to thump Mars on Jan. 30, we calculate it would hit at about 30,000 miles per hour and might create a crater more than half-a-mile wide." The Mars Rover Opportunity is exploring a crater approximately this size right now.

Such a collision could release about three megatons of energy. Scientists believe an event of comparable magnitude occurred here on Earth in 1908 in Tunguska, Siberia, but no crater was created. The object was disintegrated by Earth's thicker atmosphere before it hit the ground, although the air blast devastated a large area of unpopulated forest.

NASA and its partners will continue to track asteroid 2007 WD5 and will provide an update in January when further information is available. For more information on the Near Earth Object program, visit: http://neo.jpl.nasa.gov/.

An audio interview/podcast regarding 2007 WD5 is available at: http://www.jpl.nasa.gov/multimedia/podcast/mars-asteroid-20071221/

A videofile related to this story is available on NASA TV and the Web. For information and schedules, visit: http://www.nasa.gov/ntv.

Media Contact: DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

Grey Hautaluoma 202-358-0668
NASA Headquarters,Washington
grey.hautaluoma-1@nasa.gov

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Mars Express Probes Red Planet's Unusual Deposits

11.01.07

The radar system on the European Space Agency's Mars Express orbiter has uncovered new details about some of the most mysterious deposits on Mars: the Medusae Fossae Formation. It has provided the first direct measurement of the depth and electrical properties of these materials, providing new clues about their origin.

The Medusae Fossae Formation consists of enigmatic deposits. Found near the Martian equator along a divide between highlands and lowlands, they may represent some of the youngest deposits on the surface of the planet. This is implied because there is a marked lack of impact craters dotting these deposits.

Image right: This image combining a topographic map viewed obliquely (color portion of image) with a radargram of the subsurface (monochrome portion) shows features of mysterious Martian deposits named the Medusae Fossae Formation. Image credit: NASA/JPL-Caltech/ESA/Italian Space Agency/Univ. of Rome/Smithsonian
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NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages NASA's roles in the Mars Express mission. Mars Express has been collecting data on the Medusae Fossae Formation deposits using its Mars Advanced Radar for Subsurface and Ionospheric Sounding (Marsis). Between March 2006 and April 2007, Mars Express flew over the Medusae Fossae Formation deposits many times, taking radar soundings as it went.

"This is the first direct measurement of the depth of these deposits," said Thomas Watters of the Smithsonian Institution, Washington, D.C., lead author of a new report on the findings in the journal Science. "We didn't know whether they were just a thin veneer or much thicker." The radar observations found the Medusae Fossae Formation to be massive deposits more than 2.5 kilometers (1.4 miles) thick in places. The instrument reveals the depth based on the time it takes for the radar beam to pass through the layers and bounce off the plains material underneath.

The Medusae Fossae deposits intrigue scientists because they are associated with regions that absorb certain wavelengths of Earth-based radar. This had led to them being called "stealth" regions, because they give no radar echo. However, the radar instrument on Mars Express uses longer wavelengths than Earth-based radar experiments. At these wavelengths, the radar waves mostly pass through the deposits, creating subsurface echoes when the radar signal reflects off the plains material beneath.

A variety of scenarios has been proposed for the origin and composition of these deposits. Firstly, they could be volcanic ash deposits from now-buried vents or nearby volcanoes. Secondly, they could be deposits of wind-blown materials eroded from Martian rocks. Thirdly, they could be ice-rich deposits, somewhat similar to the layered ice deposits at the poles of the planet, but formed when the spin axis of Mars tilts over, making the equatorial region colder.

Deciding among these scenarios is not easy, even with the new data. The Marsis data reveal the electrical properties of the layers. These suggest that the layers could be poorly packed, fluffy, dusty material. However it is difficult to understand how porous material from wind-blown dust can be more than two kilometers (more than a mile) thick and yet not be compacted under the weight of the overlying material.

On the other hand, although the electrical properties are consistent with water-ice layers, there is no other strong evidence for the presence of ice today in the equatorial regions of Mars. "If there is water ice at the equator of Mars, it must be buried at least several meters below the surface," said co-author Jeffrey Plaut of JPL. This is because the water vapor pressure on Mars is so low that any ice near the surface would quickly evaporate.

So, the mystery of Mars's Medusae Fossae Formation continues. "It is still early in the game. We may get cleverer with our analysis and interpretation, or we may only know when we go there with a drill and see for ourselves," Plaut said.

Giovanni Picardi at the University of Rome "La Sapienza," Italy, principal investigator of the radar experiment, said "Not only is Marsis providing excellent scientific results, but the team is also working on the processing techniques that will allow for more accurate evaluation of the characteristics of the subsurface layers and their constituent material. Hence, the possible extension of the mission will be very important to increase the number of observations over the regions of interest and improve the accuracy of the evaluations."

The Mars Advanced Radar for Subsurface and Ionospheric Sounding was funded by NASA and the Italian Space Agency and developed by the University of Rome in partnership with JPL. Italy provided the instrument's digital processing system and integrated the parts. The University of Iowa, Iowa City, built the transmitter for the instrument, JPL built the receiver, and Astro Aerospace, Carpinteria, Calif., built the antenna. JPL is a division of the California Institute of Technology in Pasadena.

For additional information about Mars Express, see http://www.esa.int/marsexpress . For additional information about NASA's Mars exploration, see http://www.nasa.gov/mars .

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

ESA Media Relations Office 33-1-53-69-7155
European Space Agency, Paris

2007-126

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NASA's Mars Exploration Rover Opportunity rover spent about 300 sols (Martian days) during 2006 and 2007 traversing the rim of Victoria Crater. Besides looking for a good place to enter the crater, the rover obtained images of rock outcrops exposed at several cliffs along the way.

The cliff in this image from Opportunity's panoramic camera (Pancam) is informally named Cape St. Vincent. It is a promontory approximately 12 meters (39 feet) tall on the northern rim of Victoria crater, near the farthest point along the rover's traverse around the rim. Layers seen in Cape St. Vincent have proven to be among the best examples of meter scale cross-bedding observed on Mars to date. Cross-bedding is a geologic term for rock layers which are inclined relative to the horizontal and which are indicative of ancient sand dune deposits. In order to get a better look at these outcrops, Pancam "super-resolution" imaging techniques were utilized. Super-resolution is a type of imaging mode which acquires many pictures of the same target to reconstruct a digital image at a higher resolution than is native to the camera. These super-resolution images have allowed scientists to discern that the rocks at Victoria Crater once represented a large dune field, not unlike the Sahara desert on Earth, and that this dune field migrated with an ancient wind flowing from the north to the south across the region. Other rover chemical and mineral measurements have shown that many of the ancient sand dunes studied in Meridiani Planum were modified by surface and subsurface liquid water long ago.

This is a Mars Exploration Rover Opportunity Panoramic Camera image acquired on sol 1167 (May 7, 2007), and was constructed from a mathematical combination of 16 different blue filter (480 nm) images.

Spirit's West Valley Panorama (Approximate True Color)

01.02.08

Spirit's West Valley Panorama

NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

After several months near the base of the plateau called "Home Plate" in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is "Tsiolkovski Ridge," about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is "Grissom Hill," about 8 kilometers or 5 miles away. At right, the highest point of the horizon is "Husband Hill," to the north and about 800 meters or half a mile away.

This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers to produce an approximately true-color panorama.

Image credit: NASA/JPL-Caltech/Cornell University

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This Month in Exploration - December

12.03.07

Visit "This Month in Exploration" every month to find out how aviation and space exploration have changed throughout the years, improving life for humans on Earth and in space. While reflecting on the events that led to NASA's formation and its rich history of accomplishments, "This Month in Exploration" will also reveal where the agency is leading us -- to the moon, Mars and beyond.

The Cygnet I rests on Bras d'Or Lake before flying. Credit: American Kitefliers Association
100 Years Ago

December 6, 1907: Thomas Selfridge flew the Cygnet I, a kite-like aircraft, for about seven minutes before it descended and eventually crashed into Bras d'Or Lake in Cape Breton, Nova Scotia. The Cygnet was developed by the Aerial Experiment Association, whose membership included Selfridge, Alexander Graham Bell, Mabel Hubbard Bell, Frederick Baldwin, John McCurdy and Glenn Curtiss.

75 Years Ago

December 15, 1932: The International Shrine of Aviators was dedicated at the Mission Inn in California. The inn’s owner, Frank Miller, commissioned the construction of the shrine. The Famous Fliers’ Wall bears 150 copper wings to honor famous aviators. Honored members of this wall include Orville Wright, Chuck Yeager, John Glenn and Amelia Earhart.

The Famous Flier's Wall at the International Shrine of Aviators. Credit: missioninnmuseum.com
50 Years Ago

December 17, 1957: The U.S. Air Force completed the first successful test launch of the Atlas intermediate range ballistic missile, which flew 500 miles downrange from Cape Canaveral. This launch occurred on the 54th anniversary of the Wright brothers' first flight.

35 Years Ago

December 7, 1972: NASA launched Apollo 17 via a Saturn V rocket to begin the last lunar landing mission of the Apollo program. After landing the lunar module in the Taurus-Littrow region of the moon, astronauts Eugene Cernan and Harrison Schmitt set up experiments, took pictures and gathered samples of the lunar soil. The lunar rover experienced its first fender bender on this mission.

Overview

Apollo: Expandng Our Knowledge of the Solar System

On May 25, 1961, President John F. Kennedy announced the goal of sending astronauts to the moon before the end of the decade. Coming just three weeks after Mercury astronaut Alan Shepard became the first American in space, Kennedy's bold challenge set the nation on a journey unlike any before in human history.

Image left: The massive Saturn V lifts off July 16, 1969, powering Apollo 11 into orbit. Click for high resolution image.

Eight years of hard work by thousands of Americans came to fruition on July 20, 1969, when Apollo 11 commander Neil Armstrong stepped out of the lunar module and took "one small step" in the Sea of Tranquility, calling it "a giant leap for mankind."

Innovation and even improvisation were necessary along the way. In December 1968, rather than letting lunar module delays slow the program, NASA changed plans to keep the momentum going. Apollo 8 would go all the way to the moon and orbit without a lunar module; it was the first manned flight of the massive Saturn V rocket.

Six of the missions -- Apollos 11, 12, 14, 15, 16 and 17 -- went on to land on the moon, studying soil mechanics, meteoroids, seismic, heat flow, lunar ranging, magnetic fields and solar wind. Apollos 7 and 9 tested spacecraft in Earth orbit; Apollo 10 orbited the moon as the dress rehearsal for the first landing. An oxygen tank explosion forced Apollo 13 to scrub its landing, but the "can-do" problem solving of the crew and mission control turned the mission into a "successful failure."

The program also drew inspiration from Apollo 1 astronauts Gus Grissom, Ed White and Roger Chaffee, who lost their lives in a fire during a launch pad test in 1967.

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30 Years Ago

December 8, 1977: The U.S. Navy launched the Naval Ocean Surveillance System 2. While in orbit, this spacecraft deployed multiple satellites to perform ocean surveillance.

Astronaut Eugene Cernan on the lunar surface in the Taurus-Littrow valley. Credit: NASA
25 Years Ago

December 16, 1982: The Soviet Union’s third Iskra, which means “spark” in Russian, entered the atmosphere and burned up after only four weeks in orbit. Iskra-3 was a 62-pound amateur radio satellite powered by a solar cell that was launched into space by the Salyut-7 space station.

15 Years Ago

December 2, 1992: NASA launched Space Shuttle Discovery to begin STS-53. Discovery carried five crew members and eleven unclassified experiments. The mission lasted 7 days and 7 hours.

10 Years Ago

December 24, 1997: EarlyBird-1 was launched aboard a Start-1 rocket from Svobodny, Russia. EarthWatch, Inc. developed this Earth-imaging satellite for commercial use. Four days after launch, the company lost communication with the satellite. They later replaced EarlyBird with the QuickBird satellites.

Five Years Ago

December 14, 2002: The National Space Development Agency of Japan (NASDA) launched the Advanced Earth Observing Satellite-II, a remote-sensing spacecraft used to track global climate changes, from Tanegashima Space Flight Center. NASDA is now a part of the Japan Aerospace Exploration Agency.

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Present Day

December 18, 2007: Mars will be a mere 56 million miles away from Earth. It will not be this close again until 2016.

December 24, 2007: Mars will be in opposition, which means that Mars and the sun will be on directly opposite sides of Earth. The red planet will remain in the sky throughout the night and set once the sun begins to rise from the east. Its position will allow great views through an amateur telescope.
Emily Owens (Analex Corporation)

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FEBRUARY 16, 2008

Early Mars 'too salty' for life

By Helen Briggs
BBC science reporter, Boston

Mars rover (Nasa)
Experts said the findings 'tightened the noose' on hopes of life on Mars
The Red Planet was too salty to sustain life for much of its history, according to the latest evidence gathered by one of the US rovers on Mars' surface.

High concentration of minerals in water on early Mars would have made it inhospitable to even the toughest microbes, a leading Nasa expert says.

Clues preserved in rocks that were once awash with water suggest the environment was both acidic and briny.

The observations were made by the US space agency's Opportunity rover.

It has spent months examining rocks on an ancient Martian plain.

'Ghost of a chance'

Dr Andrew Knoll, a member of the rover science team, and a biologist at Harvard University, Cambridge, US, said the finding "tightens the noose on the possibility of life".

Speaking at the annual meeting of the American Association for the Advancement of Science (AAAS) in Boston, he said conditions on Mars in the past four billion years would have been very challenging for life.

Artists impression of a Mars rover (Omega/HRSC/Esa)
The quest for life on Mars will go on with the next generation rover
"It was really salty - in fact, it was salty enough that only a handful of known terrestrial organisms would have a ghost of a chance of surviving there when conditions were at their best," he explained.

The US Mars rovers - Opportunity and its twin, Spirit - have now spent more than 1,400 days on the Martian surface.

As their work comes to an end, Nasa has its hopes set on the Phoenix lander, which is due to reach Mars on 25 May.

The Phoenix mission will land near the planet's north pole, and aim to dig under the frozen surface in search of signs of microbial life, past or present.

The next-generation rover, the Mars Science Laboratory (MSL), is set to leave Earth in 2009, and land in 2010.

Twice as long and three times as heavy as Spirit and Opportunity, it will collect Martian soil and rock samples, and analyse them for organic compounds.

Click on the years below to follow the race to Mars...



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Introduction

The first close-up pictures of another world are taken in the 1960s, when a space craft flies past Mars, depicting a barren wilderness.

The United States and Russia spend billions over the next 25 years trying to land a space probe on Mars. Only three are successful - Nasa's Viking landers in 1976 and its Mars Pathfinder in 1997.

A new search for water and life on Mars begins in 2003, with Europe's first solo mission to Mars and the launch of Nasa's Mars Exploration Rovers.

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