NASA has three smartphones orbiting the earth as mini-satellites(npr.org)
npr.org
NASA has three smartphones orbiting the earth as mini-satellites
http://www.npr.org/2013/04/26/178846158/can-you-hear-me-now-cellphone-satellites-phone-home
17 comments
What sort of analysis was used to figure out the power and protection requirements you needed to make these viable?
Are these within reach of an individual to build, if not to launch?
If I build one, how do I launch it?
Why do the signals need to be crowdsourced over Ham?
What are your personal favorite/most cool applications for lots of cheap satellites?
Are these within reach of an individual to build, if not to launch?
If I build one, how do I launch it?
Why do the signals need to be crowdsourced over Ham?
What are your personal favorite/most cool applications for lots of cheap satellites?
* Mostly trial and error, surprisingly -- the idea was to keep everything in low power mode as much as possible, and see if solar panels would let us keep charge. Turns out that they can; one of the sats has panels. Another just has batteries and will die down.
* Yes, definitely. One of the sats was even hand soldered.
* You talk to NASA, the cost to launch one commercially would be around $20K. We mostly piggybacked on a rocket that was being tested.
* Because there was no budget for following these things on the ground, honestly :) Plus it gets people involved.
* We were talking about having these things detect circular cloud formations to indicate a possibly forming hurricane, and having a "real" weather sat take a better look on its next pass.
* Yes, definitely. One of the sats was even hand soldered.
* You talk to NASA, the cost to launch one commercially would be around $20K. We mostly piggybacked on a rocket that was being tested.
* Because there was no budget for following these things on the ground, honestly :) Plus it gets people involved.
* We were talking about having these things detect circular cloud formations to indicate a possibly forming hurricane, and having a "real" weather sat take a better look on its next pass.
If I paid the $20k commercial price, would I be guaranteed a slot on a rocket? And do paying CubeSat customers bump off those that were given free tickets? Is anyone else offering reliable, commercial CubeSat launches for that price (or less)?
Sadly no.
The phonesats waited in a box for more than a year in order to find room.
The phonesats waited in a box for more than a year in order to find room.
What were the biggest challenges you faced while adapting a smartphone for use in space? At any time, were there any technical hurdles you felt could prohibit the entire project?
* You're not allowed to use electrolytic caps in space... seems trivial, but it really forces you to change designs for things.
* Technical hurdles not really, but there was a lot of bureaucracy involved.
* Technical hurdles not really, but there was a lot of bureaucracy involved.
Interesting how the press just calls these things "smartphones" but if they were iPhones, we'd see endless articles about Steve Jobs' vision, iPhone in the headline, etc.
There's something shameful about how little attention the excellent Android project gets. Those are Nexus One phones, a phone from Jan 2010. I feel Android being open and mallable for NASA is pretty noteworthy, but the press just sells this as a "smartphone" instead of really discussing the technical platform that makes stuff like this possible so quickly and so cheaply.
There's something shameful about how little attention the excellent Android project gets. Those are Nexus One phones, a phone from Jan 2010. I feel Android being open and mallable for NASA is pretty noteworthy, but the press just sells this as a "smartphone" instead of really discussing the technical platform that makes stuff like this possible so quickly and so cheaply.
This is like being upset that someone referred to a Bentley as a car, which you consider a conspiracy based on people liking Ferraris more.
Alternate theory: the media calls it a smartphone because it's, well, a smartphone.
Alternate theory: the media calls it a smartphone because it's, well, a smartphone.
The problem is unlike iPhone using Android by it's self in a headline is often ambiguous. Saying Android Smartphone is accurate but while iPhone is shorter than Smartphone it takes far more space to say Android Smartphone thus the useage discrepancy. Which is one of the main issues with choosing that trademark.
Reminds me of the old "IBM/Compatible" vs "PC."
I think part of it is that for NPR, "smartphone" resonates with a larger audience, while Ars Technica or Slashdot might be more specific with "Android phone" or even "Nexus One".
Also, its a Linux phone as well, standing on the shoulders of all of the years of work poured into making an awesome kernel to build operating systems like Android off of. And the rocket used to launch the satellites. And microsatellite launch programs (like cubesat).
At the end of the day sometimes to get people interested in an article, you just need to find a simple human way to connect to their life--or in this case, their pocket.
Also, its a Linux phone as well, standing on the shoulders of all of the years of work poured into making an awesome kernel to build operating systems like Android off of. And the rocket used to launch the satellites. And microsatellite launch programs (like cubesat).
At the end of the day sometimes to get people interested in an article, you just need to find a simple human way to connect to their life--or in this case, their pocket.
The launch was kinda neat too:
http://www.youtube.com/watch?v=V3L7crGudVU
Finless rocket? How does it steer/stabilize? Do the engines have fine control over which side their fire perhaps?
I guess fins are useless outside of atmosphere anyway.
http://www.youtube.com/watch?v=V3L7crGudVU
Finless rocket? How does it steer/stabilize? Do the engines have fine control over which side their fire perhaps?
I guess fins are useless outside of atmosphere anyway.
I don't know that I'd describe the launch as "neat". I'm searching for the right word to describe it... I guess maybe.... "nominal".
Anyway, almost all modern rockets don't use fins. They steer using thrust vectoring and attitude control thrusters.
Anyway, almost all modern rockets don't use fins. They steer using thrust vectoring and attitude control thrusters.
Anyway, almost all modern rockets don't use fins.
...they don't start working until you're fast enough (quite high above the ramp, which is a sensitive area where you really need it) and they stop working once you leave the atmosphere (which is all too soon for an orbital carrier). Why bother with them?
...they don't start working until you're fast enough (quite high above the ramp, which is a sensitive area where you really need it) and they stop working once you leave the atmosphere (which is all too soon for an orbital carrier). Why bother with them?
This has been being done for a long time. Saturn V's were thrust vectored too. For any large scale rocked, the fins are far to large to move like on smaller missiles.
This works well to cut down on mass and drag and is especially useful for silo/sub launched missiles where fins don't fit well in the launch tube.
This works well to cut down on mass and drag and is especially useful for silo/sub launched missiles where fins don't fit well in the launch tube.
Before someone corrects you with a photograph, the ascent stage had fins in addition to the vectoring on the F-1s. However, my understanding, though I might be wrong, is that those were intended for stabilizing the vehicle instead of acting as control surfaces.
You need to play more Kerbal Space Program http://kerbalspaceprogram.com/
When was the last time you saw a rocket with fins?
Probably steered through thrust vectoring. Liquid fuel rocket engines are often built to gimbal, typically 1...2 degrees to each side. http://en.wikipedia.org/wiki/Rocket_engine#Thrust_vectoring
Another possible method of steering is to build four or more reaction jets around the rocket; could be fed with a monopropellant or exhaust from the main engine or its turbopump.
Another possible method of steering is to build four or more reaction jets around the rocket; could be fed with a monopropellant or exhaust from the main engine or its turbopump.
If you can deal with slight decreases in thrust, you can also do thrust vectoring with injecting water or other suitable liquid into the nozzle in proper places. Could be mechanically simpler than gimbals in some cases.
Thrust vectoring owns the sky! Now you've got me thinking of cellphones turning on a dime, Macross Zero style.
I assume the engines are gimbal mounted and can direct their thrust.
One of my friends is on the team that built this: thrust vectoring.
What a lame twist of ageism NPR added to that story. Stay tuned for part two, where the kids teach Crockrell how to tweet and check his email.
One of the largest CubeSat (the form factor of these satellites) conferences is actually happening right now. It can be live streamed or replayed here:
http://mediasite01.ceng.calpoly.edu/Mediasite/Catalog/pages/...
You can find out more about who else is building this type of hardware here: http://cubesat.org/index.php/collaborate/suppliers
You can find out more about who else is building this type of hardware here: http://cubesat.org/index.php/collaborate/suppliers
Imagine someday where many people own their own personal satellite.
Not sure what it would be useful for on a personal level, but I bet they will come up with something.
I also wonder if they could send 1000 to orbit the moon or another planet in a network to do surveys.
Not sure what it would be useful for on a personal level, but I bet they will come up with something.
I also wonder if they could send 1000 to orbit the moon or another planet in a network to do surveys.
> Imagine someday where many people own their own personal satellite.
Nice thought, but (unless the satellite is in geostationary orbit, very expensive) it won't work. Imagine having your own personal satellite that is only accessible for perhaps two short periods in 24 hours (for a mid-northern latitude location).
Better to have a subscription to a system with dozens of shared satellites in random orbits, available 24-7.
Nice thought, but (unless the satellite is in geostationary orbit, very expensive) it won't work. Imagine having your own personal satellite that is only accessible for perhaps two short periods in 24 hours (for a mid-northern latitude location).
Better to have a subscription to a system with dozens of shared satellites in random orbits, available 24-7.
Having your own mapping/sensor satellite would be interesting. You'd need a polar orbit to get really complete coverage, but more likely most of what you'd be interested in is in the lower latitudes and some orbit that is inclined from the equator some amount is all you'd need.
[edit] Here's a catalog of satellite orbits courtesy of NASA: http://earthobservatory.nasa.gov/Features/OrbitsCatalog/
[edit] Here's a catalog of satellite orbits courtesy of NASA: http://earthobservatory.nasa.gov/Features/OrbitsCatalog/
Thanks! I was actually (and perhaps naively) thinking only of a radio relay satellite, not one with optical sensors. Your description is much more interesting.
Once this happens -- once cheap optical survey satellites come into existence (and they will) -- governments are going to go completely nuts. Right now, governments can put pressure on the few survey satellite operators to blur out certain sensitive locations (as in a recent story posted here). But once cheap satellites come into existence, that option will evaporate.
Once this happens -- once cheap optical survey satellites come into existence (and they will) -- governments are going to go completely nuts. Right now, governments can put pressure on the few survey satellite operators to blur out certain sensitive locations (as in a recent story posted here). But once cheap satellites come into existence, that option will evaporate.
Probably before that happens with satellites, it will happen with solar powered high altitude remote control planes, and mounted cameras. Consumer level not military spy drone level.
There's already a driver for this technology - flying the plane while wearing a head mounted display - a currently expensive niche hobby.
There's already a driver for this technology - flying the plane while wearing a head mounted display - a currently expensive niche hobby.
Depends on what you're using it for. If I'm just joining part of a crowd-sourced asteroid detection group (which would require some hardware other than what they put up), I don't need access to it 24/7, if I can batch up some photos I can collect them in batches, etc. I wouldn't use one of these for internet access or something, I've got much better options for that already.
My original post imagined only a radio relay satellite. You're talking about something that's much more interesting, a satellite with sensors and a way to relay its data to the surface. I'm sure this will happen eventually, and I agree it's a pretty exciting prospect.
In your scenario, a small number of overflights each 24 hours would be more than enough time to download the stored data.
In your scenario, a small number of overflights each 24 hours would be more than enough time to download the stored data.
The reason launching microsats is affordable is because they are piggybacking on someone else's rocket. The delta cost to launch a microsat on a rocket someone already paid full freight for is essentially zero.
There aren't any rockets going to the moon, much less another planet, that they can piggyback on... so, yes, they could send 1000 to orbit the moon, but you would have to pay full freight on the rocket. Ouch.
There aren't any rockets going to the moon, much less another planet, that they can piggyback on... so, yes, they could send 1000 to orbit the moon, but you would have to pay full freight on the rocket. Ouch.
HOWEVER, upper-stages to move satellites to GTO are ejected out of earth orbit (for safety reasons - you don't want it to add to the space junk problem). These ejected stages are taken through an Earth-Moon Lagrange point, before being navigated on a low-energy path to a heliocentric orbit. There's no reason a microsat can't hitch a ride on an upper stage, and then wait until the ejected stage reaches the L-point before deploying itself, at which point it's downhill to anywhere in cislunar space.
People are currently working on doing this: http://www.lunarcubes.com/
People are currently working on doing this: http://www.lunarcubes.com/
Even if you were launching only microsats (without any other payload), I'm not sure the cost per satelite would be that high? Wikipedia (http://en.wikipedia.org/wiki/Comparison_of_orbital_launch_sy...) says the cheapest option right now is $2200/kg for LEO, so about $200 for a 100g phone. I guess going to the moon is about 10x more, but that's still not unreasonable...
You don't buy payload space by the kilogram. You buy it by the rocket, with the smallest launches costing millions of USD each. That per-kilogram figure is just the number that comes out when you divide the launch cost by the maximum theoretical payload capacity.
Of course. The proposal is to buy a rocket to send a large number of small satelites somewhere, and split the cost among the satelite owners.
SpaceX's Grasshopper project is likely to make the price come down a lot RSN.
These are in such low orbit that they're still protected by the Van Allen belts. They'd get obliterated by radiation if they were much higher or around the moon, etc.
It also isn't the first phone in space. The UK sent on up earlier this year.
It also isn't the first phone in space. The UK sent on up earlier this year.
I bet somewhere in the Pentagon they have wasted the money to developed a radiation hardened smartphone chip for them to fantasize surviving nuclear fallout.
If so, then NASA could use it for space?
This is an interesting read http://en.wikipedia.org/wiki/Radiation_hardening#Radiation-h...
Maybe they can just shield conventional chips with depleted boron.
If so, then NASA could use it for space?
This is an interesting read http://en.wikipedia.org/wiki/Radiation_hardening#Radiation-h...
Maybe they can just shield conventional chips with depleted boron.
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I think Vernor Vinge has something like that in one of his end-of-civilization post-singularity novels, let's see... Marooned in Realtime, yes. (Great read, too.)
Sounds like a fun place to keep an off-site backup, if there's ever a way to get enough bandwidth without disrupting other systems.
The picture on that article is really misleading--it looks like you're seeing the curvature of the earth, and are therefore high up in space, but it's probably just the effect of a fish-eye lens, as evidenced by the curved upper surface and the distorted box.
couple thoughts.
1. isnt this small enough to look like space debris, and maybe dangerous?
2. "The mobile phones are designed to be thrown around the room and for people to drop them in water. They're really robust bits of technology," -- i'm not sure how this physical durability has any bearing on its performance in near absolute-zero temps and in the radiation of space without being using radiation hardened silicon...not to mention that it would never be subjected to any of the things described.
1. isnt this small enough to look like space debris, and maybe dangerous?
2. "The mobile phones are designed to be thrown around the room and for people to drop them in water. They're really robust bits of technology," -- i'm not sure how this physical durability has any bearing on its performance in near absolute-zero temps and in the radiation of space without being using radiation hardened silicon...not to mention that it would never be subjected to any of the things described.
"isnt this small enough to look like space debris, and maybe dangerous?"
The fact that they said this burns up when it runs out of "juice" implies that it is in very low Earth orbit, where the atmosphere still exists and imparts drag. These will reenter the atmosphere on a moderately predictable time scale and burn up. Space junk is only a problem at higher orbits which can be stable for very long periods of time without propellant.
As for 2... they put on up and it worked. What's the point of theorizing about how it might not work, when they've already done it? It might stand up to a good solar blast, but that's hardly a surprise, and if it's disposably cheap, who cares?
The fact that they said this burns up when it runs out of "juice" implies that it is in very low Earth orbit, where the atmosphere still exists and imparts drag. These will reenter the atmosphere on a moderately predictable time scale and burn up. Space junk is only a problem at higher orbits which can be stable for very long periods of time without propellant.
As for 2... they put on up and it worked. What's the point of theorizing about how it might not work, when they've already done it? It might stand up to a good solar blast, but that's hardly a surprise, and if it's disposably cheap, who cares?
"It might stand up to a good solar blast, but that's hardly a surprise, and if it's disposably cheap, who cares?"
the phone itself might be cheap, but putting it up there is most certainly not (yet)...which is why most things that are designed to go into orbit are expensive :(
would you care to spend 150k+ to put a $300 cell phone into space for 2 weeks?
the phone itself might be cheap, but putting it up there is most certainly not (yet)...which is why most things that are designed to go into orbit are expensive :(
would you care to spend 150k+ to put a $300 cell phone into space for 2 weeks?
Cubesats are always secondary payloads, usually jettisoned after the first main stage burn. Their mass is insignificant compared to the main payload, so they usually ride for free.
http://en.wikipedia.org/wiki/CubeSat
http://en.wikipedia.org/wiki/CubeSat
So I can't speak for all conditions, but cubesats do not usually ride for free. The prices I've seen are usually in the 50k / unit range. So if you've got a 1U cubesat, expect to spend at least 50k on launch.
Part of the reason for this is that there are integration costs for attaching a cubesat deployer to an existing launch vehicle, as well as liability risks, control and thrust timing modifications etc.
If the data it could collect in those 2 weeks was worth $200k, hell yes. Sign me up for 2 launches/month.
heh, i was gonna add the clause *unless you're the NSA or have some deep pockets
i think as long as launches are limited, the asking price will be kept artificially high anyways to render the cost of the actual satellite minimal compared to the launch expenses, regardless if it's $300 or $300,000 going up.
i think as long as launches are limited, the asking price will be kept artificially high anyways to render the cost of the actual satellite minimal compared to the launch expenses, regardless if it's $300 or $300,000 going up.
> near absolute-zero temps
Although space is cold, due to the vacuum the biggest issue is getting heat away from the devices. That's why the main part of EVA suits is liquid cooling.
> radiation of space without being using radiation hardened silicon
They are only in low earth orbit, so the magnetic field of the earth would provide pretty good protection.
Although space is cold, due to the vacuum the biggest issue is getting heat away from the devices. That's why the main part of EVA suits is liquid cooling.
> radiation of space without being using radiation hardened silicon
They are only in low earth orbit, so the magnetic field of the earth would provide pretty good protection.
Phonesats have low enough mass that magnetorquers can provide all the attitude control, too.
Well, the fact that it's working means that it's working. Your questions may be valid, but either they've been answered by the scientists or they're non-issues.
1. Space debris certainly doesn't have to be small to be dangerous. Objects about 1cm in cross section can be tracked from the ground, and these are in a known orbit, so are probably okay.
2. I heard somewhere that the batteries needed to be replaced but not much else did, don't have a reliable source for that though
2. I heard somewhere that the batteries needed to be replaced but not much else did, don't have a reliable source for that though
The only part that's really being used in the CPU, memory, and sensors. New batteries are installed and new radios and antennas are used bypassing all the on-phone radio equipment. This really is nothing more than a way to hype up a not so useful project. There are dozen of short to medium life cubesats that are launched every year with off the shelf components.
You have a point about the phone being kind of a red herring. Here's a link to the larger CubeSat program:
http://www.nasa.gov/directorates/heo/home/CubeSats_initiativ...
There is significant interest in these small units (10cm on a side, but combinable up to 6 units) on the part of universities. Here's a list of the upcoming launches:
http://www.jpl.nasa.gov/news/news.php?release=2013-073
I think that within NASA CubeSats are regarded with limited interest. The conventional route for a new satellite measurement from the lab to space is via airborne, or in some cases balloon-borne, experiments. That's how, say, new radar, lidar, hyperspectral imaging, etc., technologies are proven. Lab bench, field experiments, airplane, space.
http://www.nasa.gov/directorates/heo/home/CubeSats_initiativ...
There is significant interest in these small units (10cm on a side, but combinable up to 6 units) on the part of universities. Here's a list of the upcoming launches:
http://www.jpl.nasa.gov/news/news.php?release=2013-073
I think that within NASA CubeSats are regarded with limited interest. The conventional route for a new satellite measurement from the lab to space is via airborne, or in some cases balloon-borne, experiments. That's how, say, new radar, lidar, hyperspectral imaging, etc., technologies are proven. Lab bench, field experiments, airplane, space.
The CubeSat program is awesome for universities. There are also lots of launch opportunities from the Chinese, Indians, and Russians. Just yesterday there were a couple university sponsored CubeSats that where launched on a Chinese rocket.
http://amsat-uk.org/2013/04/26/ham-radio-cubesats-successful...
http://amsat-uk.org/2013/04/26/ham-radio-cubesats-successful...
I neglected the international angle. Thanks for that.
The camera is also being used (OK that's technically a sensor...)
regarding 2:
The robustness to physical shock isn't particularly relevant once deployed, but during launch the hardware is subjected to huge vibration and g forces. If the hardware is not well assembled, parts will come off. This poses a risk to the cubesat as well as the launch vehicle.
Also, radiation hardening is statistically a long-term concern for missions. Most large satellites are designed for a minimum 5 year mission, some for 20-25 year missions (many geostationary birds). On those timescales, radiation is a significant issue. These satellites are in a low earth orbit and will be burned up in the atmosphere within a year - probably less. The chances of a single event upset are really small, and there are 3 phonesats. It takes a long time for radiation to degrade the silicon in a chip, much longer than the lifespan of these particular satellites.
Not sure if this is off topic, but shouldn't it be simple to make a high altitude balloon out of a material that doesn't explode so easily when it gets to the lower pressures in low earth orbit?
Or even some kind of contraption that slowly releases gas from the balloon as it detects lower pressure in the atmosphere to help it maintain altitude and prevent the balloon from rupturing?
Or even some kind of contraption that slowly releases gas from the balloon as it detects lower pressure in the atmosphere to help it maintain altitude and prevent the balloon from rupturing?
> Not sure if this is off topic, but shouldn't it be simple to make a high altitude balloon out of a material that doesn't explode so easily when it gets to the lower pressures in low earth orbit?
The very early comms sat experiments in the 50s were just aluminised passive balloons that reflected radio signals bounced off them while in orbit. [1]. However they were there because they were put there by a rocket. I'm not sure if your question is implying that you could float your way up to LEO altitude. I suspect you couldn't with anything that could be engineered.
> Or even some kind of contraption that slowly releases gas from the balloon as it detects lower pressure in the atmosphere to help it maintain altitude and prevent the balloon from rupturing?
This is done already in two ways. One passively does what you describe - a zero pressure balloon - by having a hole in the bottom so helium leaks out as it rises. Eventually enough leaks out that the net lift is zero and it just floats.
The other is a super-pressure balloon [2] which does what you described in your first paragraph - it's strong enough to not explode until the pressure (and so density) of the helium inside increases relative to the outside atmosphere until the lift becomes zero. But we're still a long way from an altitude that could sustain orbit. These operate at relatively low altitudes like 45km/150kft. The drag and heating there would be enormous at orbital velocities!
[1] http://en.wikipedia.org/wiki/Project_Echo [2] http://en.wikipedia.org/wiki/Superpressure_balloon
The very early comms sat experiments in the 50s were just aluminised passive balloons that reflected radio signals bounced off them while in orbit. [1]. However they were there because they were put there by a rocket. I'm not sure if your question is implying that you could float your way up to LEO altitude. I suspect you couldn't with anything that could be engineered.
> Or even some kind of contraption that slowly releases gas from the balloon as it detects lower pressure in the atmosphere to help it maintain altitude and prevent the balloon from rupturing?
This is done already in two ways. One passively does what you describe - a zero pressure balloon - by having a hole in the bottom so helium leaks out as it rises. Eventually enough leaks out that the net lift is zero and it just floats.
The other is a super-pressure balloon [2] which does what you described in your first paragraph - it's strong enough to not explode until the pressure (and so density) of the helium inside increases relative to the outside atmosphere until the lift becomes zero. But we're still a long way from an altitude that could sustain orbit. These operate at relatively low altitudes like 45km/150kft. The drag and heating there would be enormous at orbital velocities!
[1] http://en.wikipedia.org/wiki/Project_Echo [2] http://en.wikipedia.org/wiki/Superpressure_balloon
> I'm not sure if your question is implying that you could float your way up to LEO altitude. I suspect you couldn't with anything that could be engineered.
Even if you could make it, I doubt it would work for very long.
Such a balloon would presumably be quite massive and probably impossible to maneuver. As such it would be a nice target for things that were actually in orbit (moving quite fast relative to it). It would probably become swiss cheese in the matter of days/weeks. (probably not a problem for the balloon itself I suppose, but I can't imagine anything you would be hanging from it would be happy with that.)
Even if you could make it, I doubt it would work for very long.
Such a balloon would presumably be quite massive and probably impossible to maneuver. As such it would be a nice target for things that were actually in orbit (moving quite fast relative to it). It would probably become swiss cheese in the matter of days/weeks. (probably not a problem for the balloon itself I suppose, but I can't imagine anything you would be hanging from it would be happy with that.)
> but shouldn't it be simple to make a high altitude balloon out of a material that doesn't explode so easily when it gets to the lower pressures in low earth orbit?
No, because balloons don't orbit, they follow the wind patterns at a lower altitude than the lowest satellite orbits. And they're relatively short-lived at altitude -- from seconds to days.
> Or even some kind of contraption that slowly releases gas from the balloon as it detects lower pressure in the atmosphere to help it maintain altitude and prevent the balloon from rupturing?
No, not "releases gas" -- that would lose the gas irreversibly. Instead, consider a scheme that used solar power to drive a pump to put some of the gas under pressure as needed, and releases it later as needed to maintain altitude. Sort of how a submarine maintains its buoyancy by filling tanks with either water or gas, depending on the need, and that does this by putting the gas under pressure to change buoyancy (and avoid losing the gas).
But balloons don't have very long lifetimes at the moment. This might change in the future.
No, because balloons don't orbit, they follow the wind patterns at a lower altitude than the lowest satellite orbits. And they're relatively short-lived at altitude -- from seconds to days.
> Or even some kind of contraption that slowly releases gas from the balloon as it detects lower pressure in the atmosphere to help it maintain altitude and prevent the balloon from rupturing?
No, not "releases gas" -- that would lose the gas irreversibly. Instead, consider a scheme that used solar power to drive a pump to put some of the gas under pressure as needed, and releases it later as needed to maintain altitude. Sort of how a submarine maintains its buoyancy by filling tanks with either water or gas, depending on the need, and that does this by putting the gas under pressure to change buoyancy (and avoid losing the gas).
But balloons don't have very long lifetimes at the moment. This might change in the future.
Can you actually get something into ORBIT via balloon?
That doesn't sound plausible but I could be wrong.
That doesn't sound plausible but I could be wrong.
With just a balloon, no.
To get something into a stable orbit you have to get it high enough to avoid significant atmospheric drag. In practice this requires an altitude of at least 200km [1] - although even at this altitude an orbit will decay fairly rapidly. The IIS orbits at 400km and most remote-sensing satellites are at 500km+.
Contrast this with Helium balloons, which usually top-out at an altitude of 35-50km with the record being 53km [2].
To stay in low-earth orbit you also need an orbital velocity of 7.8km/s. A balloon launched at the equator has about 0.5km/s horizontal component of velocity due to the earth's rotation and will not gain any as it lifts.
What you could do is use a balloon to carry a rocket up to its height ceiling before igniting [3]. This saves on fuel, but there are safety issues caused by the non-steerability of the balloon.
[1] http://en.wikipedia.org/wiki/Low_Earth_orbit
[2] http://en.wikipedia.org/wiki/Flight_altitude_record#Unmanned...
[3] http://en.wikipedia.org/wiki/Non-rocket_spacelaunch#Balloon
To get something into a stable orbit you have to get it high enough to avoid significant atmospheric drag. In practice this requires an altitude of at least 200km [1] - although even at this altitude an orbit will decay fairly rapidly. The IIS orbits at 400km and most remote-sensing satellites are at 500km+.
Contrast this with Helium balloons, which usually top-out at an altitude of 35-50km with the record being 53km [2].
To stay in low-earth orbit you also need an orbital velocity of 7.8km/s. A balloon launched at the equator has about 0.5km/s horizontal component of velocity due to the earth's rotation and will not gain any as it lifts.
What you could do is use a balloon to carry a rocket up to its height ceiling before igniting [3]. This saves on fuel, but there are safety issues caused by the non-steerability of the balloon.
[1] http://en.wikipedia.org/wiki/Low_Earth_orbit
[2] http://en.wikipedia.org/wiki/Flight_altitude_record#Unmanned...
[3] http://en.wikipedia.org/wiki/Non-rocket_spacelaunch#Balloon
One advantage of launching a rocket from high altitude is that the optimal rocket nozzle shape and size changes substantially depending on the ambient air pressure. For example, the Space Shuttle Main Engine is about 25% more efficient in vacuum than at sea level.
In hindsight, I really could have worded my original question better. It didn't even occur to me that the way I worded the question implied maintaining its position, my bad.
I was just curious if you could get the balloon to maintain an altitude within low earth orbit, without concern for where the balloon actually drifts.
I was imagining a way to get the balloon to behave as a buoy at sea (not anchored), floating above the thicker atmosphere the same way a rubber balloon or raft would drift at sea.
I was just curious if you could get the balloon to maintain an altitude within low earth orbit, without concern for where the balloon actually drifts.
I was imagining a way to get the balloon to behave as a buoy at sea (not anchored), floating above the thicker atmosphere the same way a rubber balloon or raft would drift at sea.
There was a plan to get something into orbit by lifting in a balloon, then putting in a vehicle that was a cross between a wing and a balloon where as it accelerates, it generates lift, pushing it up so that drag becomes less, etc, eventually launching cheaply. But I haven't heard of the company in a while.
http://en.wikipedia.org/wiki/Orbital_airship looks like what I'm thinking of.
http://en.wikipedia.org/wiki/Orbital_airship looks like what I'm thinking of.
No — balloons only increase your altitude. They can't give you orbital velocity.
Remember: orbit isn't just altitude, it's sideways motion too. In any case, there isn't enough atmosphere to get any buoyancy at that height.
Just a note for Amateur Radio operators, they are seeking help in hearing the packets!
The U.S. government apparently places commercial restrictions on the kind technology that makes this kind of wonderful technology (and possibly scientific) innovation possible for the everyman. For example, a rocket enthusiast once told me that any GPS chip sold on the commercial market can't function past Mach 1. Sad to think that even with basically quotidian materials now putting space in reach of the common man, during my lifetime it will still be an alien thing and the business of billionaires.
It's 1000 knots and 60,000 ft, and this is only to meet U.S. ITAR export requirements. There's nothing inherent about the civilian GPS signal itself that prevents you from computing a fix beyond those limits.
For example, you could buy one of these: https://www.sparkfun.com/products/10981
and then design a baseband yourself. I'm currently aware of at least three people that are working on this or have already done it. You'll need to actually take the time to learn how GPS works, and it'll probably take you about a year, but it's definitely possible.
For example, you could buy one of these: https://www.sparkfun.com/products/10981
and then design a baseband yourself. I'm currently aware of at least three people that are working on this or have already done it. You'll need to actually take the time to learn how GPS works, and it'll probably take you about a year, but it's definitely possible.
It's called COCOM limit (historical reasons), and you can have it turned off at the factory if you can talk them into it / have a valid reason to. Oddly enough "we want to send up a small satellite, and we are calling from a NASA facility" was not a good enough reason. Surprisingly GPS will work decentish in LEO, if you can get past that. The GPS satellites are in semisynchronous orbit.
Noisebridge has been doing this since 2010: https://www.noisebridge.net/wiki/Spacebridge.
These are satellites in orbit, not suborbital balloon payloads.
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How long until the paparazzi get their own satellite?
Quite unlikely. For paparazzi style imaging, satellites are very unsatisfactory.
1) Clouds. Major bummer.
2) Intermittent time on target - most the time when something interesting is happening, the satellite will be over some other place in the world. Geostationary satellites solve the "hover overhead" problem, but then see #1, #3, #4, #5.
3) Atmospheric distortion. Resolution is inherently limited unless you use adaptive optics.
4) The lens required to get decent resolution isn't going to fit on a microsat. See also #3.
5) Blurry pictures of the tops of celebrities' heads ain't gonna sell well.
1) Clouds. Major bummer.
2) Intermittent time on target - most the time when something interesting is happening, the satellite will be over some other place in the world. Geostationary satellites solve the "hover overhead" problem, but then see #1, #3, #4, #5.
3) Atmospheric distortion. Resolution is inherently limited unless you use adaptive optics.
4) The lens required to get decent resolution isn't going to fit on a microsat. See also #3.
5) Blurry pictures of the tops of celebrities' heads ain't gonna sell well.
I was thinking piratebay.
Balloons/UAVs are more reliable when it comes to communications. Getting a suitable satellite into orbit that allows for reliable communication is way too expensive.
There was talk of doing a Pirate Bay dirigible at one point.
There was talk of doing a Pirate Bay dirigible at one point.
Sooo, a lot more dangerous space trash in the future?
Cubesats are in general some of the safest / least junky spacecraft in orbit.
There are several factors that influence how much space debris a spacecraft will generate:
1. Surface area vs. density - If a spacecraft is large and has lots of floppy solar panels and things hanging off of it, it's much more likely to be involved in a collision, and if it is involved in a collision, it's more likely that it will generate secondary debris dangerous to other spacecraft.
2. Orbital lifetime - If a spacecraft is in orbit for longer, it's more likely to be involved in a collision.
Cubesats are usually very dense, with few or no deployable components. Cubesats are also typically deployed in a low orbit that has a short lifespan - less than 2 years or so.
There are of course exceptions to both of these rules, but the phonesats are not.
There are several factors that influence how much space debris a spacecraft will generate:
1. Surface area vs. density - If a spacecraft is large and has lots of floppy solar panels and things hanging off of it, it's much more likely to be involved in a collision, and if it is involved in a collision, it's more likely that it will generate secondary debris dangerous to other spacecraft.
2. Orbital lifetime - If a spacecraft is in orbit for longer, it's more likely to be involved in a collision.
Cubesats are usually very dense, with few or no deployable components. Cubesats are also typically deployed in a low orbit that has a short lifespan - less than 2 years or so.
There are of course exceptions to both of these rules, but the phonesats are not.
Very dense = high ballistic coefficient = longer orbital lifetime
Though I generally agree that CubeSats are relatively safe / low junkyness.
In fact, most (US only maybe?) CubeSats have to demonstrate an orbital lifetime of less than 25 years to get a frequency allocated. (The FCC regulating space debris via frequency allocation is an interesting debate for another thread.)
Though I generally agree that CubeSats are relatively safe / low junkyness.
In fact, most (US only maybe?) CubeSats have to demonstrate an orbital lifetime of less than 25 years to get a frequency allocated. (The FCC regulating space debris via frequency allocation is an interesting debate for another thread.)
These were supposed to launch about a year ago, but the rocket kept being delayed.
The phones are Nexus Ones (and a Nexus S, which I didn't work on so I cannot comment) with a custom kernel to enable their serial port.