IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
Power Levels
briv1016
post Sep 5 2008, 07:12 PM
Post #1


Member
***

Group: Members
Posts: 238
Joined: 18-December 07
From: New York
Member No.: 3982



This has been discussed within other threads before but considering how important it is becoming, I think it deserves its own thread.

Since we are now on sol 100 with fall fast approaching, I was wondering if anyone has been keeping track of the power levels for Phoenix. Any idea when they might have to add recharging sols into the sol-to-sol planning? How low might the power levels be on Sept 30 and will that affect further mission extensions?
Go to the top of the page
 
+Quote Post
01101001
post Sep 5 2008, 08:39 PM
Post #2


Member
***

Group: Members
Posts: 101
Joined: 29-January 06
Member No.: 667



I don't know where the power readings are reported.

Apropos the general situation: Space.com: 90 Days on Mars: Phoenix Lander Sends Martian Postcard (August 28)

QUOTE
The amount of power generated by Phoenix's two solar arrays is also on the decline, with the probe currently generating about 2,500 watt-hours each day - or about 1,000 watt-hours less than when it landed - because of waning sunlight. The absolute minimum needed for Phoenix to perform the most basic operations is about 1,000 watt-hours, mission managers said.

"We're predicting that's the end of mission," Goldstein said, adding that current projections put that power benchmark in November.

Go to the top of the page
 
+Quote Post
CosmicRocker
post Sep 7 2008, 05:47 AM
Post #3


Senior Member
****

Group: Members
Posts: 2223
Joined: 1-December 04
From: Marble Falls, Texas, USA
Member No.: 116



I suspect this has already been explained on this forum, but I can't recall it. Is there any possibility that this amazing device might be revived when the sun returns to these northern regions of Mars' next year, or is "lights out" the end of the road for Phoenix? unsure.gif


--------------------
...Tom
Go to the top of the page
 
+Quote Post
briv1016
post Sep 7 2008, 07:25 AM
Post #4


Member
***

Group: Members
Posts: 238
Joined: 18-December 07
From: New York
Member No.: 3982



QUOTE (CosmicRocker @ Sep 7 2008, 01:47 AM) *
I suspect this has already been explained on this forum, but I can't recall it. Is there any possibility that this amazing device might be revived when the sun returns to these northern regions of Mars' next year, or is "lights out" the end of the road for Phoenix? unsure.gif



Isn't this entire region covered by solid CO2 ("dry ice") in the winter. I think that would spell the end for any electronic device.
Go to the top of the page
 
+Quote Post
Guest_Zvezdichko_*
post Sep 7 2008, 07:56 AM
Post #5





Guests






QUOTE
The absolute minimum needed for Phoenix to perform the most basic operations is about 1,000 watt-hours, mission managers said.


Isn't that very much compared to MERs?
Go to the top of the page
 
+Quote Post
djellison
post Sep 7 2008, 10:07 AM
Post #6


Administrator
****

Group: Chairman
Posts: 13778
Joined: 8-February 04
Member No.: 1



QUOTE (Zvezdichko @ Sep 7 2008, 08:56 AM) *
Isn't that very much compared to MERs?


It's also older electroncis compared to MER, and far more challenging conditions ( requiring more heating etc )


And, for what I think is probably the 10th time on this forum. Yes - there is a 'lazurus' code onboard incase it wakes up in the spring, but no one realistically expects it to survive.

Doug
Go to the top of the page
 
+Quote Post
Guest_Zvezdichko_*
post Sep 7 2008, 10:22 AM
Post #7





Guests






Sorry. I forgot that many of its parts are actually old (Mars 2001 Surveyor lander, etc)...

I also don't expect it to survive. Even the NEAR spacecraft didn't.
Go to the top of the page
 
+Quote Post
djellison
post Sep 7 2008, 10:34 AM
Post #8


Administrator
****

Group: Chairman
Posts: 13778
Joined: 8-February 04
Member No.: 1



I'd also add that the compact, well insulated WEB of the rovers probably performs a far better job of insulating itself than the Phoenix design.

Doug
Go to the top of the page
 
+Quote Post
Guest_Zvezdichko_*
post Sep 7 2008, 10:52 AM
Post #9





Guests






It's probably right, but for a mission of this type - when the most basic instruments have single-use ovens and beakers, all task will be accomplished until the sun fully sets.

I'll be very interested to see the MET and LIDAR functioning up to this time, though .
Go to the top of the page
 
+Quote Post
Deimos
post Sep 7 2008, 01:20 PM
Post #10


Martian Photographer
***

Group: Members
Posts: 272
Joined: 3-March 05
Member No.: 183



QUOTE (djellison @ Sep 7 2008, 10:34 AM) *
I'd also add that the compact, well insulated WEB of the rovers probably performs a far better job of insulating itself than the Phoenix design.

Not my specialty, but I imagine so. The PHX EBs were originally spec'd for an equatorial mission, and they have no RHUs. They're beefed up enough that energy dissipation into the EBs occasionally affected operations due to the need to avoid being too hot (as with the MERs). But of course the PHX payload could dump more energy into the boxes than the MERs could. Spirit demonstrates another difference--the rovers can sleep 23.9 h /sol if needed. PHX requires periodic, brief housekeeping wakeups like Mars Polar Lander would have needed. The way PHX works is suited to one of the goals, getting diurnal coverage of the atmospheric state.

So on the face it is shocking to see that PHX survival energy is comparable to the best days of Spirit's life ... but that is just the difference between the missions. The PHX panels were designed for PHX (OK, M'01, but for the way the lander uses energy) -- lots of area, no worries about mobility. But the MER's of course would need much more energy per day with no RHU and a peak temperature of -30 or so, even ignoring the other considerations.
Go to the top of the page
 
+Quote Post

Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 30th September 2014 - 03:54 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.