Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 

NASA's Mars Polar Lander Close To Touchdown

On Saturday [New Zealand Time] the Mars Polar Lander descent camera will capture Martian surface as never seen before. And for the first time internet users will be able to listen to the sounds of the red planet.

The Mars Polar Lander was launched on January 3, 1999 and will land on December 3, 1999 [USA Date time].

Image Courtesy of NASA

The lander is presently cruising to Mars and is in good health. Currently, the flight team is continuing science checkouts of instruments on the spacecraft and is busily preparing for surface operations. On November 30, the spacecraft fired its thrusters for 12.6 seconds to fine-tune its path for arrival at the Martian south pole on December 3.

For just under two minutes a camera directed toward the south polar region of Mars will capture and store a series of about 20 images unique in the annals of planetary exploration: the surface of a planet (other than the moon) as seen from altitudes ranging from about 4 miles to only about 30 feet.

NASA has also installed microphones on the polar lander and expects to hear sounds from wind, tornadoes, and meteors hitting the planet's upper atmostphere. The sounds will be broadcast live via realaudio links from the NASA website.

The camera, known as the Mars Descent Imager, or MARDI, will be positioned between the legs of the Mars Polar Lander, with the exhaust of the hydrazine engines in view. It will begin clicking its shutter after the lander vehicle's heat shield has been jettisoned -- about 6.5 kilometers (about 4 miles) above the surface -- and while the craft is still swinging on its parachute harness. The last few images -- perhaps eight -- will be captured after the parachute has been jettisoned at about the 1 kilometer (.62 mile) altitude and as the craft makes a controlled descent, slowed by retro rockets, to the frigid northern edge of the Martian south pole's layered terrain.

"MARDI's images will make all of us much more comfortable in making interpretations of the lander's pictures because they will give us a context," says Peter Thomas, a senior researcher with Cornell University's astronomy department. "For the first time we will have a complete scale of pictures of Mars, from less than a millimeter all the way up to orbiter pictures." The camera has a 70-degree field of view, and the estimated difference in resolution between the first and the last black-and-white images will be a factor of about 800.

Thomas is one of three Cornell researchers on the MARDI team, led by Michael Malin, president of Malin Space Science Systems, San Diego. Also participating in the development of the imaging system, and present at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., to interpret the images after they are received from the Mars Polar Lander, are Cornell astronomy professors Joseph Veverka, who also is chair of the Cornell astronomy department, and Steven Squyres. Also on the team are M.A. Caplinger of Malin Space Science and M.H. Carr of the U.S. Geological Survey in Flagstaff, Ariz. MARDI was developed under a $3.5 million JPL contract.

At present, the highest-resolution images of the Martian surface, taken from orbit, are made up of pixels (or picture elements) each covering 1 1/2 yards of terrain. That is about to change dramatically to images with each pixel covering a fraction of an inch of the surface.

The descent camera pictures will be used to interpret ground features and will aid in the mission's main purpose, studying the layers of ice and dust covering the polar region. These images will be captured with a "nesting" technique, meaning that each successive image will be nested within the previous picture. As the spacecraft loses altitude, each successive image will cover a smaller area within the previous larger image. The camera has no ability to aim, but simply points where the spacecraft points. "The first image will be several kilometers on one side, but the camera has a fairly wide angle so that even with the spacecraft swinging on a parachute, the images should remain nested within one another," says Thomas.

The nesting technique, he notes, will enable researchers to find a ground feature, such as a boulder, in the image taken closest to the ground, then work back to the largest picture. The spacecraft's electronic memory retains each image, plus details of when the image was taken, which direction the spacecraft was pointing at the time and its altitude. In this way, says Thomas, "you can take pictures and reconstruct them from that geometry."

The number of images returned to JPL will be limited by the storage capacity of the spacecraft's memory. For this reason, the on-board computer has been programmed both to reject some images taken by the camera and to write over others. The computer will be instructing the camera to capture images in different image formats (in terms of pixels) based both on altitude and the number of images already taken. If the computer determines that the altitude has not changed sufficiently, it will not save the image.

"If the memory's storage is full and the camera is still taking images, the computer is programmed to throw out some lower-resolution pictures," says Thomas. "We want to maintain nesting and protect the higher resolution images as we get really close to the surface. Those images closer to the surface are of platinum value."

The "overwhelming purpose" of the descent camera's images, says Thomas, is to tie what will be seen with the lander's camera on the surface of Mars with images taken a few feet from the surface. "We've seen the whole of Mars in 100-meter resolution, but only 1 percent of the surface in three-meter resolution. These images will be filling the gap."

© Scoop Media

 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines


Cyclone Gita: Metservice Forecasts Gita To Impact New Zealand - Be Prepared

Cyclone Gita is expected to approach New Zealand from the northwest. There remains some uncertainty with regards to the speed and track of Gita, but the passage of this system across New Zealand on Tuesday and Wednesday is likely to bring a period of highly impactful severe weather.

People should be aware of the potential for coastal inundation, especially where high waves,low atmospheric pressure and strong onshore winds come together ... More>>

 

'Hit And Run' Raid: NZDF Had Reports Of Civilian Casualties

The NZDF received intelligence updates within one or two days of the August 2010 SAS raid in Afghanistan that reported civilian casualties, including the death of a child, new OIA documents reveal... it appears they did not bother to investigate nor made any effort to help the victims. More>>

ALSO:

Christchurch Public Meeting: Complete U-Turn By Labour And NZ First On TPP

The TPP might have been re-branded as the CPTPP but it's still the same bad deal says Professor Jane Kelsey, New Zealand's expert on international economic regulation. More>>

ALSO:

Commerce, Etc: Thicker Bright Line For Real Estate

Revenue Minister Stuart Nash has confirmed the bright-line test on residential property sales will be extended from two years to five years in legislation currently making its way through Parliament.More>>

ALSO:

Prison Inspections: Reports on Manawatu and Paremoremo Released

The Office of the Inspectorate today released reports into Manawatu Prison and Auckland Prison (Paremoremo), the first two resulting from a programme of inspections of New Zealand prisons. More>>

Whistle Blowers: Government To Review Law On Protection

Work has begun on a review of the Protected Disclosures Act 2000, Minister of State Services Chris Hipkins said today. More>>

ALSO:

Gordon Campbell: On National’s Leadership Contest

National needs a new leader able to: (a) compete with, undermine and defeat a currently popular and politically adept Prime Minister; (b) define whether National now sees itself as being a traditional conservative party or a modern neo-liberal one; (c) devise a strategy that addresses National’s chronic lack of a viable coalition partner More>>

ALSO:

Christchurch: PM Launches 100% Electric Car Share Offering

The Southern Hemisphere’s biggest deployment of pure battery electric cars and largest pure EV car sharing model was officially launched in Christchurch today by Prime Minister Jacinda Ardern. More>>

ALSO:

 
 
 
 
 

LATEST HEADLINES

  • PARLIAMENT
  • POLITICS
  • REGIONAL
 
 

Featured InfoPages