Perseverance

Gazoo

Dumb Dumb
To quote a famous song, "In fact, it's cold as hell...."
Wonder how they're handling the extreme cold charge scenario? Heaters would use a lot of energy. Nuke?
Yes. It produces about 110 watts.

 

FilterGuy

What, me worry?

Tech Specs (https://mars.nasa.gov/technology/helicopter/)​


Mass1.8 kilograms
Weight4 pounds on Earth; 1.5 pounds on Mars
WidthTotal length of rotors: ~4 feet (~1.2 meters) tip to tip
PowerSolar panel charges Lithium-ion batteries, providing enough energy for one 90-second flight per Martian day (~350 Watts of average power during flight)
Blade spanJust under 4 feet (1.2 meters)
Flight rangeUp to 980 feet (300 meters)
Flight altitudeUp to 15 feet (5 meters)
Flight environmentThin atmosphere, less than 1% as dense as Earth's


How did you learn they were using off the shelf batteries?
I am still looking for the article that said it uses off-the-shelf batteries. I'll post it if I find it again.

Wonder how they're handling the extreme cold charge scenario? Heaters would use a lot of energy. Nuke?
From the articles I have read, they are using heaters. It also sounds like they are charging it very slowly. My guess is that the craft is completely shut down at night with only heaters keeping it above some pre-determined minimum temperature to avoid damage. I am also guessing they are expecting some warming from sunlight during the day...... but that is speculation on my part. One good thing is that the thin air is not a good thermal conductor, so whatever heat they generate will tend to stay in the craft.

From the discription of the steps they are taking over the next several weeks, they are not sure if it will survive the cold Martian night let alone fly. I keep reading statements like "if it survives the cold Martian night...."
 

curiouscarbon

Solar Addict
i read that the downward facing lidar for distance to ground measurement is from sparkfun, a hobby electronics place. quite inspiring to see COTS design philosophy be tested in situ on mars.

have bought some of sensors from that place for projects over the years, and it’s really crazy and awe inspiring to to think that some of the off the shelf consumer parts could fly on another planet

gee whiz!

the moxie experiment is really appealing to me


generating oxygen in situ experiment for potential of breathing and fuel use
 

Rider

Photon Sorcerer
Right? I had it streaming when it happened, but I was in the kitchen and never got to see it (I was makin stuffed peppers).
You didn't miss anything, the "live stream" was computer generated. This is the first video of the real thing.
 

Rider

Photon Sorcerer
11 minutes, 22 seconds or thereabouts. But that's just the first packet receipt. I'm sure a whole video takes a lot of time.

Data Rates/Returns​


The data rate direct-to-Earth varies from about 500 bits per second to 32,000 bits per second (roughly half as fast as a standard home modem). The data rate to the Mars Reconnaissance Orbiter is selected automatically and continuously during communications and can be as high as 2 million bits per second. The data rate to the Odyssey orbiter is a selectable 128,000 or 256,000 bits per second (4-8 times faster than a home modem).


An orbiter passes over the rover and is in the vicinity of the sky to communicate with the rover for about eight minutes at a time, per sol. In that time, between 100 and 250 megabits of data can be transmitted to an orbiter. That same 250 megabits would take up to 20 hours to transmit direct to Earth! The rover can only transmit direct-to-Earth for a few hours a day due to power limitations or conflicts with other planned activities, even though Earth may be in view much longer.
 
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snoobler

Solar Honey Badger
Moderator
MRO peak bandwidth at Mars/Earth closest is 3-4Mbit, and Percy is limited to 2Mbit when it can communicate with MRO overhead.

This event and the ability to replay it in high quality vid was most awesome.
 

DerpsyDoodler

Solar Enthusiast
11 minutes, 22 seconds or thereabouts. But that's just the first packet receipt. I'm sure a whole video takes a lot of time.

Lol...that’s worse than 56k dialup...and the low end is worse than 2400 baud. It’s funny to think about how high tech this mission is and yet they only have this tiny sliver of bandwidth to work with. I understand limitations of communications from hundreds of thousands of miles away. It’s still funny to think about...or perhaps I’ve just got a really good buzz. Regardless, they put that sliver to good use. That’s some damn sexy engineering.
 

FilterGuy

What, me worry?
Lol...that’s worse than 56k dialup...and the low end is worse than 2400 baud. It’s funny to think about how high tech this mission is and yet they only have this tiny sliver of bandwidth to work with. I understand limitations of communications from hundreds of thousands of miles away. It’s still funny to think about...or perhaps I’ve just got a really good buzz. Regardless, they put that sliver to good use. That’s some damn sexy engineering.
Think about it. A ping is 22.5 minutes!!! Not exactly gaming speed. :)
 

svetz

Works in theory! Practice? That's something else
Staff member
Moderator
rats... got spoofed... it (ingenuity flying on mars) hasn't happened yet
 
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