Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Mars Helicopter Is Online and Getting Ready to Fly

universetoday.com

Post reply on HN
Print view View original

191–200 of 265 posts

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#191

Post by jeremyjh »

tus89 wrote: post #123
julienchastang wrote: post #93

Fun fact: This is not the first time a space program has flown on another planet. The Soviets launched weather balloons on Venus during the Venera missions [1] [1] https://en.wikipedia.org/wiki/Vega_program#Balloon

If we understand "flight" as being the use of a wing to generate lift in an atmosphere, then I think we can safely say this is the first time we have flown on another planet. I assume this little helicopter actually has rotary wings rather than fans.

The term used in the article was “powered flight”. This distinction is relevant in the history of aviation on earth as well, and usually that term is used.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#192

Post by adrianpike »

cosmonaughty wrote: post #186
dragonwriter wrote: post #184

Earlier quoted context omitted.

> If those helicopter blades spin 40x faster than a real chopper at sea level air pressure on earth, the turbulence alone would disintegrate the flywheel and blades and destroy the whole thing. So how did they test it? The obvious method would be a large vacuum chamber, evacuated enough to simulate martian atmospheric pressure. Google it and, yes, that's exactly it. https://en.m.wikipedia.org/wiki/Ingenuity_(helicopt…

The link I posted points to a YouTube video of a vacuum chamber reduced to "Martian" pressure. It should have been obvious that my question was rhetorical, and that I provided the answer. Watch the YouTube video and compare it to the AVR cartoons that NASA is giving for millions of dollars per day.

Googling NASA + AVR led me down a rabbit hole towards Atmel microcontrollers, what do you mean by AVR in this context?

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#193

Post by jbuch »

jzer0cool wrote: post #160

Neat! Didn't know a drone/helicopter was part of the mars mission payload. Is this autonomous or remote controlled?

They give it high-level commands like "run this flight pattern at 11am", but there's no human controlling a joystick.

It takes radio waves 3-20 minutes (depending on orbit position) to travel from earth to mars (and vice versa), so direct control would be impossible.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#194

Post by GimbalLock »

birktj wrote: post #84
marcinzm wrote: post #37

Earlier quoted context omitted.

As the name RAD750 indicates, that processor is designed to be radiation hardened which matters for longer missions. I doubt the Snapdragon 801 will survive as long or have as few errors but it also doesn't matter since Ingenuity isn't aimed for long term usage.

What I imagine for long lived and high-cost missions is using some sort of co-processor setup with a radiation hardened processor and a faster and more modern processor. These rovers run a lot of computer vision algorithms and I believe more powerful hardware would be quite useful. They may already do something like this, however my understanding is that there is a lot of skepticism in integrating these less fault-to…

You’re not far off. The Snapdragon is monitored by some more radiation tolerant hardware (FPGA if I recall correctly).

Great talk about it from the FSW Workshop in 2019.

https://m.youtube.com/watch?v=mQu9m4MG5Gc

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#195

Post by trailbits »

dal wrote: post #105
alpaca128 wrote: post #100

Earlier quoted context omitted.

> ...arguably the first _powered_ flights were done by the sky cranes of Opportunity and Perseverance Not the Apollo 11 lunar module? In contrast to the sky cranes it actually lifted off again.

The moon is not a planet.

It's a fun exercise to work out the Gravitational Force between the Moon and the Earth and between the Moon and our Sun. It will surprise many that the Sun exerts more force on the Moon than the Earth does. So the Earth inflicts a strong perturbation on the motion of the Moon but it's not the dominant gravitational force on the Moon.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#196

Post by mdorazio »

grecy wrote: post #170
dogma1138 wrote: post #31

Earlier quoted context omitted.

Both, but the main limit of a parachute is that our probes don’t go into orbit first but rather crash on Mars. So you enter the atmosphere at higher than orbital speeds. From orbit a parachute might be doable despite the relatively thin atmosphere. Stationary probes can use retro rockets to land because you don’t care about their stationary mass that much. For rovers it’s more tricky so you have to either use airbags…

Thanks for the extremely interesting info > our probes don’t go into orbit first but rather crash on Mars. I'm wondering why they don't go into orbit, and what extra complexities that introduces? In the future are we anticipating Starship to go into orbit, or will it also directly "crash" ?

Going into orbit first would require a significant amount of extra fuel to decelerate and circularize. Heading straight into the atmosphere means more mass can go into the rovers instead of into fuel. It's a trade-off.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#197

Post by KMag »

syoc wrote: post #125
emkoemko wrote: post #108

Earlier quoted context omitted.

and yet they are fine with using a snapdragon arm processor on the helicopter?

> Ingenuity runs Linux (for the first time on Mars) and uses the open-source F' software framework on a 2.26 GHz quad-core Snapdragon 801 processor. Radiation hardened processors aren’t fast enough for the real-time vision requirements of the experiment—but as an unprotected COTS processor, it will fail periodically due to radiation-induced bit flips, possibly as much as every few minutes. NASA’s solution is to use a…

I would be interested in seeing what they did to get Linux booting and their userspace daemon running in ~300ms or less. Depending on their non-volatile storage read rate, using an uncompressed kernel might not actually save boot time. I'm guessing they aren't running traditional init or systemd.

I've been told LinuxBIOS is able to get you a text console login prompt faster than hdd platters can spin up, but it takes Ubuntu tens of seconds on my SSD laptop to get me a login prompt.

I'm surprised they don't have an FPGA MEMS autopilot with a simple degree 2 or 3 polynomial model of the flight dynamics , with the CPU and Linux only being involved in making adjustments to the autopilot. Or, maybe that's what they're doing, and by "falling out of the sky" what they really mean is the autopilot drifting.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#198

Post by lmm »

dogma1138 wrote: post #31
ilamont wrote: post #18

One of the most significant obstacles for landing on Mars will continue to present problems for our heroic helicopter now that it is safely on the surface. The atmospheric pressure on the surface of Mars is only about 1% that of Earth. Does this also limit the use of parachutes on Mars, or require bigger canopies? I know that Perseverance had a parachute for part of the descent, but not the final landing sequence. II…

Both, but the main limit of a parachute is that our probes don’t go into orbit first but rather crash on Mars. So you enter the atmosphere at higher than orbital speeds. From orbit a parachute might be doable despite the relatively thin atmosphere. Stationary probes can use retro rockets to land because you don’t care about their stationary mass that much. For rovers it’s more tricky so you have to either use airbags…

> Both, but the main limit of a parachute is that our probes don’t go into orbit first but rather crash on Mars. So you enter the atmosphere at higher than orbital speeds. From orbit a parachute might be doable despite the relatively thin atmosphere.

> So you enter the atmosphere at higher than orbital speeds. From orbit a parachute might be doable despite the relatively thin atmosphere.

Nonsense. We send orbiters to Mars all the time, often on the same missions as landers. We could absolutely brake to orbit first (which is almost free via aerobraking) before dropping landers, but it wouldn't make any difference to being able to use parachutes, the velocity difference is insignificant.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#199

Post by cosmonaughty »

adrianpike wrote: post #192
cosmonaughty wrote: post #186

Earlier quoted context omitted.

The link I posted points to a YouTube video of a vacuum chamber reduced to "Martian" pressure. It should have been obvious that my question was rhetorical, and that I provided the answer. Watch the YouTube video and compare it to the AVR cartoons that NASA is giving for millions of dollars per day.

Googling NASA + AVR led me down a rabbit hole towards Atmel microcontrollers, what do you mean by AVR in this context?

AVR = Augmented Virtual Reality. It's like CGI on steroids, crack, and speed at the same time.

People still have the naivete to trust things because they are on a screen. Preconceived notions cause one to mentally miss or gloss over the great artistry and manipulation in AVR cartoons.

The vid is worth the few minutes. It is a half decent scientific experiment that shows how rocket propulsion really works, and it shows an extra factor left out of the Newton's law argument: Ejective oxidation cannot occur without atmospheric containment pressure. Countless experiments have proven this. Buyer beware what they show you on a screen.

Re: The Mars Helicopter Is Online and Getting Ready to Fly

#200

Post by macintux »

tachyonbeam wrote: post #117
taf2 wrote: post #111

Earlier quoted context omitted.

For sure the soviets did some neat science work but I think a motorized helicopters flying on Mars is pretty darn cool too compared to a ballon floating in a dense atmosphere it even feels like an advancement

They're both cool because they're both technological firsts. The weather balloon on Venus was in 1985, a whole 35 years ago! https://www.nytimes.com/1985/06/12/us/soviet-drops-weather-b...

Absolutely. The Soviets did some incredibly impressive work with Venus.
Post reply on HN