One of my favorite wheeled EVs ever...

[SpaceEVDriver]

Just came across this video clip while searching for something else and figured I'd share.

This is the Mars Science Laboratory (also known as MSL or Curiosity) engineering model. The two biggest differences between it and the one currently operating on Mars (since 2012) is that this one is on Earth and it has a big power harness connected to it instead of using radioisotope thermal generators to charge its batteries. They do use batteries from time-to-time when they need to test something specific, but usually it's on a tether.

They bring this out when they need to figure out an issue with the rover on Mars. It might be wheel slippage, it might be something wrong with one of the instruments or instrument arms, etc. They'll build a replica of the ground environment to simulate what the rover is encountering on Mars and use the engineering model to help figure things out.

This is about the size of a Mini Cooper.

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[SpaceEVDriver]

Also, we commanded an orbiting spacecraft to turn and slew with a high-resolution scanning camera, and capture this photo of MSL while it and its landing crane were descending through the Martian atmosphere on its parachute.

 

[Logal727]

Also, we commanded an orbiting spacecraft to turn and slew with a high-resolution scanning camera, and capture this photo of MSL while it and its landing crane were descending through the Martian atmosphere on its parachute.

Now your username makes sense! How cool!

 

[Gimme_my_MME]

The two biggest differences between it and the one currently operating on Mars (since 2012) is that this one is on Earth

 

[Mach1E]

How is the range when it’s cold?

Does it qualify for the full $7500 credit?

 

[phil]

One of my favorite wheeled EVs ever...

Several of the most popular EVs have wheels.

 

[SpaceEVDriver]

How is the range when it’s cold?

Does it qualify for the full $7500 credit?

About 150 meters if driven at top speed of 5 cm/second (0.09 mph). But there aren't any semis to worry about, and this is a sight-seeing trip, so we usually go slower and make a lot of stops.

The measured ground surface temperatures have ranged from quite nice (22 ⁰C/ 71 ⁰F) to quite awful (-100 ⁰C / -212 ⁰F). The engineers like to keep the lithium-ion battery above -40 ⁰C and below 40 ⁰C, so there are a number of thermal controls to manage that. There's no heat pump, so when the battery or electronics box needs to be warmed up, resistive heaters are turned on and the heat is circulated via a fluid pump. And it circulates the fluid in reverse if it needs to cool the battery and electronics box.

The RTG generates a little over 100 Watts, down from about 110 watts at the time of assembly in about 2010.

The batteries and all of the components were built in the US, so presumably it might have qualified for a tax credit, but I don't know what those were in 2010/2011 when this vehicle was produced.

 

[SpaceEVDriver]

The battery chemistry on MSL is Nickle-Cobalt-Oxygen (NCO) cathode with meso-carbon microbeads anodes (MCMB-LiNixCo1-xO2), using a low-temperature carbon electrolyte. So this isn't the same chemistry as the Mustang battery (NCM and LFP).

Here's a plot of the lifetime testing behavior of several of the engineering test cells (so not measured on Mars, measured in a Mars-like lab on Earth) at various Depth-of-Dicharge cycles, using a C/5 discharge rate.

 

[Jimrpa]

Just came across this video clip while searching for something else and figured I'd share.

This is the Mars Science Laboratory (also known as MSL or Curiosity) engineering model. The two biggest differences between it and the one currently operating on Mars (since 2012) is that this one is on Earth and it has a big power harness connected to it instead of using radioisotope thermal generators to charge its batteries. They do use batteries from time-to-time when they need to test something specific, but usually it's on a tether.

They bring this out when they need to figure out an issue with the rover on Mars. It might be wheel slippage, it might be something wrong with one of the instruments or instrument arms, etc. They'll build a replica of the ground environment to simulate what the rover is encountering on Mars and use the engineering model to help figure things out.

This is about the size of a Mini Cooper.

How long will the RTG last?

 

[Jimrpa]

About 150 meters if driven at top speed of 5 cm/second (0.09 mph). But there aren't any semis to worry about, and this is a sight-seeing trip, so we usually go slower and make a lot of stops.

The measured ground surface temperatures have ranged from quite nice (22 ⁰C/ 71 ⁰F) to quite awful (-100 ⁰C / -212 ⁰F). The engineers like to keep the lithium-ion battery above -40 ⁰C and below 40 ⁰C, so there are a number of thermal controls to manage that. There's no heat pump, so when the battery or electronics box needs to be warmed up, resistive heaters are turned on and the heat is circulated via a fluid pump. And it circulates the fluid in reverse if it needs to cool the battery and electronics box.

The RTG generates a little over 100 Watts, down from about 110 watts at the time of assembly in about 2010.

The batteries and all of the components were built in the US, so presumably it might have qualified for a tax credit, but I don't know what those were in 2010/2011 when this vehicle was produced.

It has a top speed of 180 m/hr? Also, how can it have a “range” when it has an RTG? Couldn’t you just send a command to just drive until the RTG decays to the point where it isn’t producing sufficient power?

 

[SpaceEVDriver]

It has a top speed of 180 m/hr?

I'm not sure what the "m" here means. If you mean meters, then yes. 180 meters/hour, but it very, very rarely gets up to the top speed.

Also, how can it have a “range” when it has an RTG? Couldn’t you just send a command to just drive until the RTG decays to the point where it isn’t producing sufficient power?

During peak demand, and while driving, the motors, thermal control, electronics, instruments etc., together pull more than the 100 Watts generated by the RTG. While the RTG is charging the batteries all the time, the battery output is more than the input during operations or driving, so we have to park and let the battery recharge from the RTG. This is usually at night unless it's especially cold.

The RTG end-of-life due to generating too little power to keep the rover alive is about 17 years and 72 watts. However, the engineers and scientists are going to do some clever things and will likely be able to extend that a bit more.

 

[JohnFoxeSheets]

Couldn’t you just send a command to just drive until the RTG decays to the point where it isn’t producing sufficient power?

I hate those non-stop road trips. You should always make a bunch of stops and look around...

 

[JohnFoxeSheets]

This stuff is sooooo cool. I started my career doing test systems for spacecraft and it is really amazing to be part of something really big, impactful, and literally out of this world.

 

[SpaceEVDriver]

This stuff is sooooo cool. I started my career doing test systems for spacecraft and it is really amazing to be part of something really big, impactful, and literally out of this world.

I'm constantly amazed that I get to do this stuff! I grew up in poverty on an off-grid ranch in the middle of nowhere and had no idea that these kinds of opportunities existed until much later in life.

 

[JohnFoxeSheets]

I'm constantly amazed that I get to do this stuff! I grew up in poverty on an off-grid ranch in the middle of nowhere and had no idea that these kinds of opportunities existed until much later in life.

Wow, what a wonderful life story! I grew up on a sugar plantation in Hawaii and while it certainly wasn’t poverty, I never imagined that I’d end up building stuff for spacecrafts. Life has its amazing twists and turns…

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