"The helicopter uses counter-rotating coaxial rotors about 1.1 m in diameter. Its payload will be a high resolution downward-looking camera for navigation, landing, and science surveying of the terrain, and a communication system to relay data to the 2020 Mars rover. The inconsistent Mars magnetic field precludes the use of a compass for navigation, so it would require a solar tracker camera integrated to JPL's visual inertial navigation system. Some additional inputs might include gyros, visual odometry, tilt sensors, altimeter, and hazard detectors. It would use solar panels to recharge its batteries."
Not to be little it but, in short, a drone.
I presume the rocket scientists are jealous ;)
I mean, drones are just a new name for hobby aircraft. People typically associate drones with quad-copters, but people were flying tiny helicopters next to their small replica remote aircraft for decades.
I realize the FAA has official designations for what is a drone (and a lot of older hobby aircrafts may now technically be drones), but it's a word that's really come about because the field is now more accessible/affordable.
With the minor notation that hobby aircraft are permitted in some national parks, while drones are prohibited in all. The Parks Service operates a number of model aircraft airports in some national parks.
(I'm not moaning about the perceived inequity with the "drones;" just pointing out a curiosity. I've hated drones ever since they started ruining my ability to peacefully enjoy nature.)
>it's a word that's really come about because the field is now more accessible/affordable
I think it's a word that comes about because the marketers know that douchebags will respond to pretending that they're part of some secret military high-tech spy ops program, and not flying a Chinese plastic quadcopter.
"Model aircraft" is for nerds. "Drone" is for monster truck owners and wannabes.
There are a multitude of ways to pilot quadcopters, combining the 4 different transmitter modes (Mode 1, Mode 2, Mode 3, Mode 4) with the different control modes (Acro, Rate, Horizon, etc). The lack of standardization can be maddening for beginners - it's like learning Git, Github, and DVCS, while learning to code.
It's a UAV if you want to get back into the subject matter we're discussing though. I do wonder how well it'll do in the Martian atmosphere, especially if it gets caught charging in a sandstorm.
PS: Unmanned Rockets are Drones that shoot fire.
When i think "quadcopter", I think of something smaller than what NASA has proposed.
First of all, they would need an absurdly large directional antenna to even receive GPS satellites. GPS signals are already below the noise floor on Earth's surface, and we use mathematical trickery to extract them from the background. Secondly, even that would only be possible when Earth's over the horizon at the location of the probe. Thirdly, the whole span of GPS satellites as viewed from Mars would be a small fraction of arc second, i.e. basically all coming from the one place. Lastly, there's extra light lag that you have to compensate for, that depends on relative position and orientation of Earth and Mars.
No, GPS is not suited for use in space, especially not far away from Earth. However, I read once that some Earth orbit missions did in fact look / make use of the GPS signals, as in (low) Earth orbit, they're actually easier to receive than on the ground.
While Earth is in the Martian sky, and if the signal were strong enough, a viewer could average receiving signals from over half of the constellation rather than only half a dozen. Furthermore the time signals would originate from many of the satellites moving less orthogonally to the viewer and instead moving toward and away from the viewer.
Compared to measuring the sun relative to a changing horizon, it seems plausible that an extremely precise direction and altitude relative to Earth could give even more precise location on Mars.
Not contradicting you, but just to be clear: GPS satellites are not in geostationary orbits above the equator, or even in geosynchronous orbits. Rather, they are in medium-Earth orbits and their time-averaged density over the Earth is only a little lower over the poles as the equator. At some parts of the month, there are as many visible at the poles as at the equator. See Fig. 4 here:
The GPS Wikipedia page also has a reasonable illustration of their orbits.
(And I corrected my comment to refer to figure 4, not 2.)
Not just timing, also space - Earth is a fraction of an arc second on Martian sky, pretty much a very small dot. All your signals would be coming from that small dot, i.e. practically on top of one another.
The difference in position between the satellites is at best 40,000 km (MEO orbits and satellites in opposite positions around Earth would give you the largest baseline), the difference from Mars to Earth is > 50M kilometers. So when viewed from Mars this would be like trying to triangulate your position in the United States based on signal sources spaced a very short distance apart somewhere in Moscow.
(sorry for the strained analogy)
Another problem with the approach is that of the two possible solutions that are the result from computing your location from GPS satellites one of the solutions is deep inside the Earth, which for both radio related reasons and reasons of practicality can be safely ignored. From a location in space very far away that trick no longer works so you will end up having to pick one of several answers.
Of course you could stick a GPS like transmitter into every Mars orbiter we launch from now on so that at some point there will be enough coverage locally to allow navigation, but that's a pretty expensive trick, besides that you'd also need a bunch of base stations in order to properly compute the orbits of the satellites to the required precision so that you can tell the satellites where they are.
So could we deploy, say, the first three satellites that use a modified version of GPS at first that allows you to get a very slow, inaccurate fix, but a fix nonetheless?
On Earth, similar systems were used for the TRANSIT satellites, and the Cospas-SARSat program. The latter is really cool, as it used weather satellites in low earth orbit to find a person in distress, using a cheap transmitter that's placed on a plane, boat, or very famously, Richard Branson's watch.
The way it works is that the device transmits a very stable frequency. (Perhaps modulated by the identity of the person in trouble part of the time.) As the satellite passes by, it relays the signal to the ground in a way that preserves the doppler shift. When you know the position of the satellite and the doppler shift, you can know the closest point and the distance from it.
After a few passes of your one satellite (or multiple satellites, if you have them), you can get a location that's good enough to start search and rescue.
Of course, time has passed since this was designed in the 70s and early 80s, and now GPS has fallen in price to the point where it's everywhere. So now, the devices send GPS coordinates with the identity info.
Mars is fifty million kilometers away. A GPS reliever on Mars looking for Earth satellites wouldn't be able to hear anything.
However, that does bring up an interesting idea. Maybe rovers could navigate using the position of the stars? It doesn't require you to launch 4+ GPS satellites into martian orbit.
TL;DR you need to see the stars and you need to know what time it is
Consider it like running. How far can you run in 1 second. That's the Moon. How far can you run in 21 minutes. That's Mars. It's 1260 times the distance.
I recall with previous landers, how solar charging performance would degrade, then pick up after what was surmised to have been a wind storm event.
I always thought that for exploring another planet, you shouldn't really use something with wheels or wings.
Something different like small "jumping robots" would make a lot more sense in a place where you have literally the ability to do 0-hardware maintenance.
Instead of a single expensive flying robot, why not send a fleet of these little small jumping-robots instead, to more quickly and cheaply explore the area: https://www.youtube.com/watch?v=6b4ZZQkcNEo
Also, I believe most of the activity of these devices is planned out well in advance, so you could even add human review to some of that process. It could take a short flight for a few high-rez pictures, land right near (or exactly) where it took off from, send the pics back to earth for review to pick it's next landing spot.
I once spotted some 'jumping dust' around a leaky faucet and it turned out that it was 100's of these little creatures. They can jump 100's of times their own height!
It's likely we'll see some nightmare uses for such technology in our lifetimes.
Make bounce landing work on another planet.
Make powered landing on another planet routine.
Make remove vehicle operations on another planet routine.
Make soft landing with a rocket sky crane routine.
The helicopter being proposed is "the size of a softball", though, and not the main focus of the mission. The high altitude weather balloons have been much bigger and would probably need a dedicated mission.
I would guess that sending a test helicopter along with another rover would be to do a feasibility test for larger flight-based probes in the future. Test it now with a small helicopter, and you use 10-20 pounds of payload in order to do better wind and atmospheric studies. On the other hand, if you send a probe that uses flight as its primary mode of transportation, and some unknown unknown causes it to fail, you've scrapped the entire mission.
However I agree with you, they will be testing it extensively in as close to Martian conditions as they can achieve.
A video has them flying that thing inside a pressure chamber without payload, so at least in this configuration it has enough power to overcome Earth's gravity. Probably wouldn't lift off on Earth with the payload, though.
So unless they want to reach an otherwise impossible to climb location, I don't see the use for it.
I'm not buying your blanket statement. Atmosphere is not the only limitation - optics are heavy.
It depends on the optics. Modern optics for the visual range are incredibly light.
Also, since you assume optics are heavy, why do you think putting them on a drone is a good idea? You can haul a metric ton of optics in space for years (if not decades) but that drone can probably carry a handful of kg of equipment, and not that many cameras.
It's from Red Planet (2000):
From the series Mars (2006) - https://www.imdb.com/title/tt4939064/.
I thought just keeping rovers warm enough to operate was quite energy consuming.
I hope that they have a software to take measures if the air pressure or the light levels change suddenly.
Couldn't the differences in temperature between shadowed and sunny areas create turbulences?
This sort of "somebody should have thought about that (and fix it), so don't say it", is probably the safe way for people working in a big company that needs to fit in a hierarchy and please their boss. We aren't in this context and have a bigger margin to freely explore any idea and talk about it. To wonder about the dust storms is a valid question.
I expect the real problems would come in scaling it up; I doubt a typical helicopter rotor/head assembly would hold together under the high head speeds needed on Mars (or you could maybe use very long blades, which comes with its own problems).
I'm sure NASA has mapped out some waypoints, but there's no way to really control the actual flight remotely without a human in orbit.
The cost of failure is so high that these ideas have to be flushed out and tested for years. There is literally no way to fix these robots once (or even if) they make it to their destinations.
Not unless we figure out how to turn off gravity or invent teleportation.
In this particular case, there are also a lot of acronyms that have entered such common usage (like radar) that capitalizing them would seem odd. And too many capped acronyms, Studly Caps, hyphenations etc. hurt readability after a while.
(Personally, I find it irritating and more annoying to read, both in prose and in code.)
In other news, Hepatitis C is making a big comeback here in Denver. It's the sort of disease we used to laugh about being a "third world" problem back in the day. We don't use the term "third world" anymore, but we are becoming one nonetheless.
I can't stop thinking about what archaeologists will think about us in a thousand years, they will struggle so much to even come up with plausible theories, much less agree on them.
No, it's just your imagination that's limited. This is a good idea to test on Mars. Want crazier stuff? Google Venus blimps, or go and find papers about flying supersonic aircraft on Mars.
> I can't stop thinking about what archaeologists will think about us in a thousand years, they will struggle so much to even come up with plausible theories, much less agree on them.
I guess you're implying we should be spending that money on Hepatitis C, to which I'll answer "no, we shouldn't", as money spent on space is pretty useful there on the margin, so you should look for sources of money elsewhere, where there's just too much of it. And if anything, archaeologists will think we've been dumb to put such absurd amounts of wealth to stupid zero sum games and entertainment, instead medical research, space exploration, and basic sciences. But that's just my guess :).