Engineers Begin Shutting Down Phoenix Lander Instruments
Written by Nancy Atkinson
It appears the end is nigh for the Phoenix Mars Lander. Today, engineers have begun to shut down some of the lander's instruments and heaters. But this is in hopes of extending the mission by saving power as available sunlight begins to wane with the approach of Martian autumn. But at the same time, the spacecraft requires more power to run heaters in order to survive as the temperatures decline. “If we did nothing, it wouldn’t be long before the power needed to operate the spacecraft would exceed the amount of power it generates on a daily basis,” said Phoenix Project Manager Barry Goldstein of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “By turning off some heaters and instruments, we can extend the life of the lander by several weeks and still conduct some science.”
Today, commands were sent to disable the first heater, one that warms the robotic arm, the robotic arm camera and the TEGA instrument – the Thermal and Evolved Gas Analyzer. Likely, this means no more digging and no more "baking and sniffing" of soil samples. Engineers say by shutting down this heater, they'll save 250 watt-hours of power.
Before power was shut down to the arm and the camera, Phoenix took one last image of the "Holy Cow" ice patch underneath the lander.
Over the next several weeks, four survival heaters will be shut down, one at a time, in an effort to conserve power. The heaters serve the purpose of keeping the electronics within tested survivable limits. As each heater is disabled, some of the instruments are also expected to cease operations. The energy saved is intended to power the lander’s main camera and meteorological instruments until the very end of the mission.
Engineers are also preparing for solar conjunction, when the sun is directly between Earth and Mars. Between Nov. 28 and Dec. 13, Mars and the sun will be within two degrees of each other as seen from Earth, blocking radio transmission between the spacecraft and Earth. During that time, no commands will be sent to Phoenix, but daily downlinks from Phoenix will continue through NASA’s Odyssey and Mars Reconnaissance orbiters. At this time, controllers can’t predict whether the fourth heater would be disabled before or after conjunction.
In the final step, Phoenix engineers may turn off a fourth heater — one of two survival heaters that warm the spacecraft and its batteries. This would leave one remaining survival heater to run out on its own.
“At that point, Phoenix will be at the mercy of Mars,” said Chris Lewicki of JPL, lead mission manger.
The Phoenix team has parked the robotic arm on a representative patch of Martian soil. No additional soil samples will be gathered. The thermal and electrical-conductivity probe (TECP), located on the wrist of the arm, has been inserted into the soil and will continue to measure soil temperature and conductivity, along with atmospheric humidity near the surface. The probe does not need a heater to operate and should continue to send back data for weeks.
Throughout the mission, the lander’s robotic arm successfully dug and scraped Martian soil and delivered it to the onboard laboratories. “We turn off this workhorse with the knowledge that it has far exceeded expectations and conducted every operation asked of it,” said Ray Arvidson, the robotic arm's co-investigator, and a professor at Washington University, St. Louis.
Source: JPL
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October 28th, 2008 at 7:11 pm
I know it's wishful thinking, but if only the Phoenix would rise from the ice in the spring and start functioning again.
October 28th, 2008 at 9:04 pm
I wonder if they'll even try that?
October 28th, 2008 at 11:13 pm
before phoenix is completely disabled a message should be sent from earth to mars saying"good bye george bush welcome barack obama
October 28th, 2008 at 11:24 pm
1) This is why Mars *has* to be colonized by humans — so they can build a museum for all the faithful, hardworking hardware we've sent to Mars over the years, where future generations can see real pieces of their history. 2) Giovani — Before you get too excited about Obama, consider that New Horizons and several other space missions took off or were continued, whereas under the Clinton and Carter administrations, nothing of much importance was done in space except for followups. The Democrats have become hostile to space-related activities and the funding thereof. Lyndon Johnson, like Eisenhower and Kennedy before him and Nixon after him, helped us get to the Moon, and, furthermore, generated a US budget *surplus*. The Democrats weren't always hostile to space-related endeavors, but they sure are that way now, whereas the Republicans manifestly aren't hostile to such projects, and are willing to fund them. *Now* who do you want to win this election?
October 28th, 2008 at 11:30 pm
space exploration and means of escaping earths gravity was started by truman and continued by kenedy both democrats
October 29th, 2008 at 3:14 am
Political reality is that Obama will win. He will have to do the "tax and spend" that his opponents decry to get people working.
Instead of arguing about the coming election, I'd suggest boosting space exploration, spending on that instead of near east wars.
Send letters to Congress.
October 29th, 2008 at 10:25 am
It is a really sad time… But three cheers to phoenix who gave so much science in such a short period of time..
Good Bye!!
You are very fondly remembered….
October 29th, 2008 at 11:22 am
No Mars Microphone I guess?
October 29th, 2008 at 12:54 pm
well there was the recording of the landers entry into the atmosphere…
October 29th, 2008 at 3:47 pm
I just wish the cameras could keep snapping into the Martian winter. It would be great to see the landscape changing with ice/snow build up… I think that would be something the public could get excited about.
October 29th, 2008 at 7:37 pm
ARGH!?!!? I am Voting for CTHULU! He will see to the Lesser EVIL of BOTH CANDIDATES!
But seriously, please, there are enough issues with politics muddling science. Let's make an effort not to exacerbate the problem.
What Phoenix needs is a nice thick blanket of snow to insulate it over the coming months.
October 29th, 2008 at 8:11 pm
Even with the Marsian summer temp.
it means the end for Phoenix period! absolutly
no recovery possible! Once the heaters are off
the electronics will not survive!
No matter who is President of the US of A!
Put your digital camera (not in a bag) in the freezer today and take it out in the Marsian spring and see if it works? Or your computer will do in stead of camera. Set your freezer
at below -300F. Happy haloween