It seems to be rotating via reaction wheels (via this[0]). I haven't yet figured out how it translates, though.
EDIT: if you have gravity available, the video on that site illustrates a clever way to use those reaction wheels to move around by tumbling.
EDIT2: "for maneuvering around in space there are twelve electric micro-fans or μFans"[1]. The SE thread has a screenshot of a video which shows the placement of those fans.
The use of fans is disappointing; that means it can't go outside. My first thought when seeing it is that it'd be great for doing external inspections, and could even have its own private little airlock to get in and out.
Maybe they could make a version with ionic thrusters, that stays outside all of the time. It could have a 'nest' where it parks and refuels when not in use.
Ion thrusters have tiny acceleration, which is why they're best on deep space missions (slow and steady wins the race). I wouldn't think they'd be practical for this type of thing, which you'd want to go one or a few kilometers per hour over distances of tens of meters.
I'm sure there are very strict rules about having anything flammable or explosive on board ISS, which pretty much means you can't have a drone that can move under its on propulsion both inside and outside the station.
NASA's Manned Maneuvering Units used compressed nitrogen. But I'm not sure there'd be a huge benefit to having indoor/outdoor capabilities in a single drone. You'd have to cycle the airlock every time it went in or out, and it would be bulkier and less efficient in either mode than a dedicated unit.
Easier to start inside, where you can pick it up if it runs out of batteries or glitches out. Less chance of poking a hole in something critical, as well.
Or maybe not whole rails, but just fixtures the drone could grab onto. You could supply the drone with power and control signals through the fixtures, and the drone could kinda travel everywhere by just grabbing onto a nearby fixture, then releasing the previous one. Wouldn't that be great? /s
From a related video: the reaction wheels spin up while keeping total angular momentum at zero, then apply a rapid (magnetic) brake to transfer the momentum to the body (from the wheels). I'm assuming if you do that precisely enough (and in three dimensions), you can generate linear movement.
I'm not positive, but I'm pretty sure wherever you put the wheels, you aren't going to get the drone to rotate about any point other than its center of mass.
Makes sense, when thinking of it like a force - any where you push at the exterior (or interior) that's not directly at the center, would cause rotation around the center. I gather internal forces would add up/cancel out and never end up in a vector that pushes on the center of mass.
The system in the (cool) video is in contact with a table.
The table exerts a "normal" force on the cube, allowing a change in vertical momentum. If the system in question is the cube alone, this is an external force.
This method could be used if the drone were cubic and near a wall of the space-station, by kicking off of the wall. That could get it moving, but until it hit the opposite wall, there's nothing it could do to stop.
how does conservation of linear momentum apply?
edit: this question was asked when the parent comment claimed that this machine could "generate linear momentum" from the wheels.
Imagine holding up a bicycle in the air from the midpoint. Now spin both wheels in opposite directions. No movement. Now apply one brake. Now you have movement. Now do that in three dimensions with precision and you have this thing.
Conservation of momentum applies when there are "no external forces", which wouldn't be the case here when you apply the brake.
EDIT: Yeah, my apologies. I didn't mean to write "momentum".
The brake is an internal force though (the force and its reaction both act on the bicycle). The whole unit's only external forces are from the fans so that's all it can use to translate. That and bumping into things.
Come to think of it - in air you're constantly bumping into things - air molecules. I think it could technically be possible to steer in zero-g within an atmosphere by pure rotation (e.g. consider that a fast-spinning object is kind of a (crappy) fan).
Can it face you with one of its fans and run it at the same high speed as the opposite fan, to keep you cool, and take photos of you with your hair blowing in the wind?
well, momentum is defined as the product of mass and velocity. movement implies velocity, and we are not talking about massless things here, so yes, movement implies momentum.
They also don't say, but they link to this article: http://www.kenkai.jaxa.jp/eng/research/electrical/triaxial.h... which has a lot more technical detail. Unfortunately I don't have time to dig deeper, but hopefully it will help you search a bit better.
Precision and speed, reaction wheels can go from start, rotate you one degree and then stop all motion. With fans your going to end up constantly correcting because you never hit zero rotation.
While non zero, the spherical shape and minimal ISS airflow generally makes this a non issue. You can use those reaction wheels to calibrate very precise adjustments over time, you can also just bump into something to get rid of excess rotation.
Note, space telescopes effectively use both approaches.
It may also minimize the impact all of that moving air has on everything else in the station. Without gravity, fans blowing your things around could get annoying.
I was looking for the same thing. It has got a motor inside and uses some kind of momentum to rotate. Another motor makes it go forward, but at a snail's pace.
It's great to see automation save on expensive human labor for taking picture. Now the trick is to automate a lot of the human labor up there. No need waste tons of money for what amounts to glorified lab assistants.
Love the robot, but I'm uncomfortable at what I see as an implication in the article that now the astronauts should stop taking pictures and do more productive things instead.
I'm pretty sure there's values to that activity beyond having photographic registrations to show afterwards. (I'm also not convinced the little ball of cuteness is anywhere close to matching their choice of scenes yet)
They'll should still have plenty of time for taking photos. Astronauts usually work a regular 8-ish hour work day up in the ISS and have weekends etc...
2 of those working hours each day are blocked out for exercise, too, so this should be a real boon.
They work 8 hours a day including exercise? That seems bizarre to me. I know we don't want them burning out, etc., but if we're sending astronauts up there at great expense I'd think we'd want to ask them to put in a little more than 8 hour days.
16 hours a day plus weekends seems like a ridiculous amount of free time given that there's no commuting, family time (other than calls), yard work, social engagements, etc.
> In the 19th century, when organized labor first compelled factory owners to limit workdays to 10 (and then eight) hours, management was surprised to discover that output actually increased – and that expensive mistakes and accidents decreased. This is an experiment that Harvard Business School’s Leslie Perlow and Jessica Porter repeated over a century later with knowledge workers. It still held true. Predictable, required time off (like nights and weekends) actually made teams of consultants more productive.
The mistakes/accidents bit is especially compelling when talking about a $100 billion spacecraft.
Startup culture would do well to learn from this lesson.
Bear in mind that in space exercise is mandatory, because the lack of it considerably reduces the time a given person can spend there, which in turn would require more frequent launches, which are expensive.
Also - they're the best of the best. They sort of earned the privilege of not doing overtime.
I think you might be grossly underestimating the psychological impact of spending 6 months inside a place the size of an apartment with no day or night cycle, a constant feeling of weightlessness, and no ability to go outside or feel things like wind or rain.
They're stuck inside there anyways. If it were me, I suspect I'd prefer to stay occupied. I'm not saying we should work them to the bone, but 16 hours a day plus weekends just seems like a lot of time to fill when there's limited options anyways.
BTW, I'm being down-voted above for expressing surprise at the claim the crew only works 8 hours daily including 2 hours exercise. But the example crew day shown in the following link suggests (by my reading) that it's more like 11 hours (7:30-7:30 with an hour of lunch):
I don't think they actually work just eight hours a day. There's a lot of maintenance work to do and it's not like there are many things to do on your free time. Although now that there's the full six-person crew, the schedules are probably less tight.
I guess it also depends on what constitutes "work". The station is their home as well as workplace, after all. And when your home is an aluminum can in a vacuum, there's quite a bit of housework to do. Also, these are six-month missions, unlike week-or-two-long Shuttle flights which naturally had a tighter schedule.
I suspect part of the use of a picture-taking drone is that NASA people on the ground can have the drone go take a picture of something right now, rather than having to interrupt an astronaut or wait until they're not busy with something more important.
Most of the ISS is probably connected to sensors and remotely accessible, but there are probably still a lot of cases where they actually need someone to look at something.
Wait they finally came out with the drone? I remember this was being teased when the ISS first launched. This is awesome! NASA / JAXA should make a plush toy or regular drone that could be used on the ground for fundraising.
NASA is working on a similar (but more capable and larger) robot right now, with plans to open-source all the code. I'm curious what the internals of JAXA's robot look like. That thing is pretty small.
If you put a fabric covering on any flexible structure and then flex it, the fabric has a tendency to gather at the joints. I'm surprised he has not elastic straps on his ankles as well as I'b bet without the usual forces in play I would think his pants would ride up his calves towards his knees as well.
There is an entire community of people however who collect "evidence" that the ISS is a hoax! This would be exactly the kind of "proof" they'd love!
