71–80 of 150 posts
Earlier quoted context omitted.
Helium's lifting capability is proportional to the density of the atmosphere, which is very low on Mars.
Is it viable to use vacuum instead of helium?
Didn't this use mostly off the shelf parts? If so, I wonder how this will impact costs on future missions. If they can do more with consumer hardware, they can save budget to apply toward more science.
Earlier quoted context omitted.
Interesting note about this: the speed of sound on Mars is only ~70% of that on Earth, due to less atmospheric density. Might change your Mach numbers!
It's not due to less density, but rather a different gas composition (CO2 vs. N2+O2).
The speed of sound in an ideal (calorically perfect) gas is given by
a = sqrt( gamma * R * T )
Earth:
R = R_atm = 287 J / (kg * K)
gamma = 1.44
T = 293 K (taking room temperature as an average temperature)
Mars:
R = R_CO2 = 188 J / (kg * K)
gamma = 1.37
T = 210 K (from a quick google, about -60 deg C)
a_mars = 232 m/s
a_earth = 347 m/s
Didn't this use mostly off the shelf parts? If so, I wonder how this will impact costs on future missions. If they can do more with consumer hardware, they can save budget to apply toward more science.
"off the shelf" in aerospace means that you can buy it from an aerospace manufacturer, and don't have to build it in house. There's considerably more engineering behind these products than the equivalent consumer electronics
edit: from another comment: https://news.ycombinator.com/item?id=39081718
It looks like it's just a couple of (important) components that can handle the quirks of not being radiation-hardened, but it's still significant.
On Jupiter Broadcasting there was a lot of interviews on how this was a Linux powered device and could be the first of many new Linux devices on Mars by JPL. If I remembered correctly they used a space hardened Power cpu with an ancient version of Yocto since the newer versions of it did not have working drivers. When the rover had an issue they actually used the helicoptor's userspace command line GNU utilities to d…
Wow, such a great testament to The Unix Philosophy of building small, modular, focused tools that can be combined together to do all sorts of interesting and more complex tasks. I'm sure no one imagined using these utilities from a helicopter to retrieve rover logs to aid in diagnostics, but here we are. What a cool story.
Earlier quoted context omitted.
The original Elon Musk biography describes how a legacy aerospace engineer joined spacex and was tasked with a part: > He got a quote back for $120,000. “Elon laughed,” Davis said. “He said, 'That part is no more complicated than a garage door opener. Your budget is five thousand dollars. Go make it work.’”
This is a terrifying anecdote.
On Jupiter Broadcasting there was a lot of interviews on how this was a Linux powered device and could be the first of many new Linux devices on Mars by JPL. If I remembered correctly they used a space hardened Power cpu with an ancient version of Yocto since the newer versions of it did not have working drivers. When the rover had an issue they actually used the helicoptor's userspace command line GNU utilities to d…
> When the rover had an issue they actually used the helicoptor's userspace command line GNU utilities to debug and get logs from the rover to send to Earth. Wow, such a great testament to The Unix Philosophy of building small, modular, focused tools that can be combined together to do all sorts of interesting and more complex tasks. I'm sure no one imagined using these utilities from a helicopter to retrieve rover l…
We will use more helicopters instead of rovers for new missions ? Or larger crafts would be much harder or riskier to use ? Or maybe have a helicopter that can move the rover with the equipment to different locations.
In the shorter term, I see the helicopter as making the rover more capable, by finding routes and destinations of interest. And the rover makes the helicopter more capable by providing a recharging station. So they're both at their best when working as a system. Maybe a rover can support multiple choppers.
Does it? I thought the helicopter was just solar powered.
Didn't this use mostly off the shelf parts? If so, I wonder how this will impact costs on future missions. If they can do more with consumer hardware, they can save budget to apply toward more science.
Earlier quoted context omitted.
> When the rover had an issue they actually used the helicoptor's userspace command line GNU utilities to debug and get logs from the rover to send to Earth. Wow, such a great testament to The Unix Philosophy of building small, modular, focused tools that can be combined together to do all sorts of interesting and more complex tasks. I'm sure no one imagined using these utilities from a helicopter to retrieve rover l…
now if we just teach those tools to kids instead of turning them into spreadsheet office robots, that would be great.