Mars Gets Broadband Connection - New orbiter will provide high data rates

[Wilms]

Mars Gets Broadband Connection

New orbiter will provide future missions with high data rates

By: Barry E. DiGregorio

When NASA's Mars Reconnaissance Orbiter reaches the Red Planet next month, it will immediately seek out areas where water once flowed, try to identify habitats where ancient life might have thrived, and start mapping the entire planet in unprecedented detail. But the orbiter's arrival at Mars will also set the stage for a new epoch in spacecraft telecommunications. Its onboard Electra UHF relay transceiver will serve as an engineering test bed for new communications and navigation technology that will be required for all future orbiters, landers, and rovers, to provide the faster data rates required for transfer of information from rovers and landers on the Martian surface to orbiters circling above.

The early Mars landers, like the 1976 Viking and the 1997 Mars Pathfinder, sent data directly back to Earth using X-Band antennas that could manage no more than 1 to 10 kilobits per second of data. But when Spirit and Opportunity landed on Mars in January 2004 to explore its surface, they carried cameras that could produce dramatic panoramic pictures representing 500 megabytes of data. Accordingly, rather than transfer data straight back to Earth, their X-Band system first transferred data to the Mars Global Surveyor and Mars Odyssey orbiters, which were equipped with UHF transceivers that could support transfer rates of up to 128 kb/s.

In the new system to be tried out with the Mars Reconnaissance Orbiter, once the orbiter receives data from a lander or rover it will transmit the information back to a series of large radio telescopes located on Earth, the Deep Space Network. The orbiter's 3-meter-long high-gain antenna and 100-watt transmitter will be able to send data at up to a maximum of about 6 megabits per second at the minimum Earth-to-Mars distance of 55.7 million kilometers and roughly 0.6 Mb/s at the maximum distance of 401.3 million kilometers. The Mars Reconnaissance Orbiter has 160 gigabits of solid-state memory and a processor able to operate at up to 46 million instructions per second, to store and manipulate data obtained from craft on the surface of Mars.

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Thus, it "offers a highly capable, flexible, and evolvable framework for relay communications in support of Mars exploration," says Chad Edwards, the Mars chief telecommunication engineer at JPL. New error-correction codes can be implemented at any time during a mission, and protocols can be modified in response to unforeseen developments.

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http://www.spectrum.ieee.org/feb06/2810




Spacecraft Parts: Telecommunications

Telecommunications System

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With its large-dish antenna, powerful amplifier, and fast computer, Mars Reconnaissance Orbiter can transmit data to earth at rates as high as 6 megabits per second, a rate ten times higher than previous Mars orbiters. This rate is quite high considering that Mars Reconnaissance Orbiter will achieve it while 100 million kilometers (62 million miles) from Earth. Over its two-year primary science mission, the spacecraft is predicted to transmit more than 34 Terabits--that's 34 million million bits. To put it another way, that's more than all the data transmitted by all previous JPL spacecraft put together!

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http://marsprogram.jpl.nasa.gov/mro/mission/sc_telecomm.html

[Salviati]

1. Yeah, but I bet the ping sucks....

That's really cool though, more data = more better

[Dogmudgeon]

2. Even better, they get the first 6 months FREE!

And a free modem.

And a free subscription to Rhapsody.

How can you beat that deal?

--p!

[Spinzonner]

3. Yeah, but wait until their ISP

(Interplanetary Service Provider) raises their rates.

[Wilms]

4. Then it's back to the low-gain antenna. n/t

[Orsino]

5. ...that will immediately be saturated by downloads...

...from hotgreenbabes.com

[Wilms]

6. Now in (a rather elliptical) orbit.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=102&topic_id=2158966&mesg_id=2158966

[Barking Spider]

7. Fed up with WIFI connection fee at Martian Starbucks.

[Dead_Parrot]

8. It's all very well geting high speed to the orbiter...

But where will they find the USB lead to reach the surface?