Author Topic: NASA - Mars 2020 Rover  (Read 65374 times)

Offline Blackstar

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Re: NASA - Mars 2020 Rover
« Reply #240 on: 12/17/2018 12:51 pm »
Maybe you need to re-phrase your question for clarity.

Offline Star One

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NASA - Mars 2020 Rover
« Reply #241 on: 12/20/2018 08:03 pm »
DPA Will Be First Microphone Company to Broadcast from Mars (Seriously)

Quote
DPA’s d:dicate 4006 Omnidirectional Microphone will capture the audio while the MMA-A Digital Audio Interface will be used to record and send audio to a computer through its USB connection. Both mics will be paired with MMP-G Modular Active Cables, which act as ultra-transparent preamplifiers. The Mars 2020 spacecraft is currently being assembled at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California and the DPA products will be installed onto the vehicle in early 2019.
« Last Edit: 12/20/2018 08:05 pm by Star One »

Offline joseph.a.navin

Re: NASA - Mars 2020 Rover
« Reply #242 on: 12/30/2018 03:43 pm »
I heard from a lecture in 2016 that Curiosity only has like five or so years left due to the power source degrading. What is the expected lifespan of the Mars2020 rover?

Offline Blackstar

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Re: NASA - Mars 2020 Rover
« Reply #243 on: 12/30/2018 05:34 pm »
Presumably it's going to be very similar to the lifetime for Curiosity. The Pu-238 in the MMRTGs can be blended for specific heat output, meaning that they can make an RTG run hotter and longer if necessary for the mission. However, considering the way that the rovers work, with the RTGs powering batteries during nighttime, and considering that the rovers are very similar, it seems unlikely that they could change the MMRTG's power output without requiring changes to the rover, which of course costs more money.

Offline vjkane

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Re: NASA - Mars 2020 Rover
« Reply #244 on: 12/30/2018 09:22 pm »
Presumably it's going to be very similar to the lifetime for Curiosity. The Pu-238 in the MMRTGs can be blended for specific heat output, meaning that they can make an RTG run hotter and longer if necessary for the mission. However, considering the way that the rovers work, with the RTGs powering batteries during nighttime, and considering that the rovers are very similar, it seems unlikely that they could change the MMRTG's power output without requiring changes to the rover, which of course costs more money.
That's long enough that 2021 should see four operating rovers on Mars: Curiosity, Mars 2020, ExoMars, and the Chinese mission.  I was hoping for five... depends I guess on whether its just a problem of too much dust on Oppy's cells or a temperature-related permanent fault.

Also, Curiosity's (and eventually Mars 2020's) declines will be slow.  It will take longer and longer to charge the batteries, and hence operations and travel will stretch out.  If you look at the discussions of Curiosity extended missions, they talk about what can be done before this slow down starts to seriously affect operations.  Eventually, we'll get a stationary lander for some period of time.

Offline ccdengr

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Re: NASA - Mars 2020 Rover
« Reply #245 on: 12/30/2018 11:18 pm »
I heard from a lecture in 2016 that Curiosity only has like five or so years left due to the power source degrading.
The MMRTG has a minimum design lifetime of 17 years after fueling (where I think that's defined as output power down to 50% of initial).  I'm not sure exactly when MSL's RTG was fueled (before or after the launch slip) but if it was in 2008 then the design life is reached in 2025.  But as Van says, it can keep going for quite a while after that with reduced operational tempo, assuming nothing else fails.

The power loss curve is not linear, and much of the advantage of the MMRTG is in waste heat used for thermal control rather than electrical generation.  See Figure 2 in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001769.pdf

Offline vjkane

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Re: NASA - Mars 2020 Rover
« Reply #246 on: 12/30/2018 11:28 pm »
The power loss curve is not linear, and much of the advantage of the MMRTG is in waste heat used for thermal control rather than electrical generation.  See Figure 2 in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001769.pdf
The "waste" heat decay is much slower than the electrical power decay.  The former is driven by Pu-238 decay, which has a half life in the 90ish years if memory serves me correctly.  The latter is driven primarily by degredation of the thermocouples.

Offline zubenelgenubi

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Re: NASA - Mars 2020 Rover
« Reply #247 on: 12/31/2018 09:16 pm »
The power loss curve is not linear, and much of the advantage of the MMRTG is in waste heat used for thermal control rather than electrical generation.  See Figure 2 in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001769.pdf
The former is driven by Pu-238 decay, which has a half life in the 90ish years if memory serves me correctly.
It does!  Half-life = 87.7 y
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Offline Star One

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Re: NASA - Mars 2020 Rover
« Reply #248 on: 01/07/2019 03:48 pm »
How NASA’s Rover Team Reimagined Mars 2020

 

Online catdlr

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Re: NASA - Mars 2020 Rover
« Reply #249 on: 02/15/2019 12:15 am »
Mars 2020 Rover Build Update


NASA Jet Propulsion Laboratory
Published on Feb 14, 2019

Tour the Spacecraft Assembly Facility at NASA's Jet Propulsion Laboratory and see the Mars 2020 mission under construction. Project System Engineer Jennifer Trosper explains the hardware being built and tested, including the rover, descent stage, cruise stage, back shell and heat shield. This NASA mission is preparing to launch to the Red Planet in 2020 and land in 2012. For more about Mars 2020, visit https://mars.nasa.gov/m2020

https://www.youtube.com/watch?v=TPXU_uQThGo?t=001

Tony De La Rosa

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