Video Planet Labs Has Launched Over 100 Imaging Satellites with Many More to Come (Video) 15
Slashdot: So what you might see on Google satellite imagery is that old?
Sean: Exactly. Google is an aggregator of many different satellite sources. They recently actually acquired a satellite imagery start up Skybox. So they do have their own satellite now to do these things, but before that their Google Maps was built using landsat data and other data that's available through the U.S. government and through other entities. What we're doing is actually going to be supplying our own spacecraft in orbit and then we will be using the data from our constellation to build a global mosaic much like Google Earth. The difference in our mosaic is that instead of being updated on 10 months and 10 years we're going to have a daily cadence and what that will allow us to do is change detection on human time scales. So we can actually see deforestation and other events as they happen. And then another application for our data is in disaster response. We actually had a little bit of a success with that recently with the earthquake in Nepal. We were able to, the day after the earthquake in Nepal, turn over our entire imagery set from Nepal, that was the most recent base map of Nepal that existed prior to the quake which allowed disaster responders and the Nepalese government to have more context about where to send resources after the earthquake.
Slashdot: Now to do that you’ve built some interesting hardware. Let's talk about the hardware table next to you.
Sean: Sure. So this is a one-to-one model of our Dove spacecraft, it's actually the entire size of it, it is 10 centimeters by 10 centimeters by 30 centimeters. And then actually we have a little bit of extra space that we get because of the spring that deploys them. So if you look over at the
Slashdot: That cylinder underneath that’s the extra room you’re talking about?
Sean: Yeah, this is the kind of the free space we get.
Slashdot: Explain where that fits?
Sean: If you look at our deployer here, it's actually just a spring and what we can do is actually use the space that's available to us inside of the spring when it's under compression and that gives us a little bit of extra space for our satellite. So we're within that form factor but we also work with our partners to develop our deployment mechanisms to have access to that extra space.
Slashdot: Now this is a three unit cube set, can you like to talk about what's inside, what are the guts?
Sean: Sure. So inside our Dove, we use only commercial off-the-shelf products. So NASA and other space companies, they have to test a product for up to 10 years before they're willing to send them into space. We're willing to get parts off DigiKey and send them up the next day. Our record is sending something to orbit in nine days. We sent 2 Doves up in the nine days following the Antares explosion. We’re able to kind of rally and get all the left over parts and get some extra pieces from DigiKey to put together two functional satellites, send them through full qualification testing and then out the door and they launched, shipped out of our lab nine days later and then we're on the very next launch up to the International Space Station.
Slashdot: And when you say rally, it's because some of your own satellites were the ones that were destroyed.
Sean: Yeah, we lost 26 on Antares. Yeah.
Slashdot: That's quite a bit, but you've launched a lot more than that already as well.
Sean: Yeah, correct. So we've launched 113 or so, so far. I actually don't know the exact number off the top of my head but that's also one of things we're trying to do too. We don’t watch every single satellite as if it is this billion dollar asset because of the size. So whereas NASA will have on the order of 200 operators per spacecraft, we have about four people in our Mission Control Center and it’s fully autonomous. So the spacecraft in orbit is fully autonomous, it knows when it should be imaging, it knows when it should be downloading data, the ground stations are fully autonomous. They schedule passes and communicate with the satellite. And we have a large optimizer code that takes into account everything from cloud forecasting to power state dissemination on the spacecraft to create a heat map on the planet of when we should be taking images and what their value is to us at that time.
Slashdot: Now let me ask, in launching that many microsatellites you gained probably a lot of knowledge about things that are efficiencies, you’re not on the scale of NASA launching a shuttle, but at the same time, what have you learned that it’s good advice for people who are doing their one-off academic project, microsatellites?
Sean: Oh, sure. Planet Labs actually has developed quite a few different technologies that we're looking forward to actually sharing with the community. So, there have been microsatellites that were lost that could've been helped by technology that we've created on the spacecrafts. So, we are actually eager to help the community and we’re pretty excited to be releasing some things in the near future to help the small satellite community. And we kind of released some information about that at a conference last year and hopefully, in the near future, we’ll have more in public domain.
Slashdot: Okay. Now, one thing about the spacecraft you’ve got right here, the model rather, is you have a big red button here. What happens when you press this button?
Sean: When you press this big red button, we go from our
Slashdot: It's got to be somethingexciting.
Sean: ourstone satellite mode into our operational satellite mode. So, this is basically what happens when we’re in orbit, we deploy out of the space station, and you can actually see here, our Doves coming out of the ISS. And the satellites when they're released have to maintain a low drag, stay for as long as they can and once we're out of station, we’ll command from Earth that the solar panels deploy and then we’ll have – open our satellite into its normal operating condition.
Slashdot: Now yours obviously contain cameras, can you talk a little bit about what the imaging capabilities are?
Sean: Sure. So, the optics are limited by our physical form factor size. So, we're right at the diffraction limit of a 10-centimeter optic, so we have a three to five meter ground pixel, which is a nice thing for us because it allows us to complete our objective of counting every tree on the planet, but it also allows us to get away from the privacy concerns of – we don’t see cars, we don’t see people, but instead we just see anything larger than about three meters.
Slashdot: Now, besides the camera, you obviously have to have communication gear on there to beam down to Earth. Can you talk about that a little bit?
Sean: Sure. Planet Labs developed our own radio systems internally. We have a bi-directional UHF transceiver which is how we send and receive telemetry from the satellite. We have a high speed expand element which is part of the shared spectrum for Earth imaging satellites and then we have an S-band uplink which we use just for packet access. So we basically send some large amounts of data to our S-band link down and then we have a slower link up to sort of say packet receive.
Slashdot: Now, you have the solar panel, it deploys here, are there also things aboard that require battery power as well?
Sean: Yeah. So, the spacecraft orbits every 90 minutes. And for about 50 minutes of that, we’re in sunlight and then for 40 minutes of that, we’re in eclipse of the Earth and actually it’s even a little bit more beneficial than that, we see more sunlight. But on board, we have a battery pack that will allow us to maintain power throughout. But really the idea behind Planet is that we’re capturing images – we're capturing imagery always, while the satellite is in sunlight and then when we go into the shadow of the Earth that's when we downlink our data. So, one of our highest powered states is when we’re sending down imagery from space and so we have to have enough battery backup on board to allow us downlink the data in eclipse.
Slashdot: When these fail, what sort of components seem to fail first?
Sean: So, there's nothing on our satellite that isn't single string, so we see – basically, we have redundancy in our constellation instead of within our satellites. So, failures onboard the spacecraft are kind of what you would see in most commercial electronics. But really in our orbits, we are fairly well thermally coupled to the Earth. So, actually within the spacecraft, we see 0C to 40C, which is pretty nice on electronics, but we’re in vacuum, so you have to take into account things like, you can’t use electrolytics and other things of that nature. But as far as failure modes, we see latch events but we also have lots of systems on board the spacecraft which will shut down subsystems under short circuit events.
Slashdot: Now from the ground station, if need be, could you upgrade firmware, something like that, or is it not worth it?
Sean: Absolutely, yeah. So our spacecraft is released – early released off and we take that agile approach. So we iterate over the spacecraft bus every three months as far as electronics and then the software is constantly upgraded, so we will send a spacecraft into orbit with the code in subsystems maybe not 10% written, because we don't need to actually have that for another three months but the release deadline for getting the spacecraft to the pad is so far before it will deploy in orbit that we have lots of time to actually write that software, so...
Slashdot: It still takes some confidence?
Sean: It does, it does. So what you have to do is have confidence in your bootloader, that's really what you may call it. So the bootloader is always 100% done and the challenge is getting your payload finished, which is on the software team, too.
Slashdot: What is the underlying OS?
Sean: I’m sorry.
Slashdot: What is the underlying OS?
Sean: We actually have multiple processors onboard. We're running our own version of Linux on our CPU which is constantly upgraded. We use a modular design for a CPU so we can actually upgrade our processor very quickly. So we are flying an Atom moving to the latest generation with that as well. And then we also have other ARM cores, and then we also have a lot of massively parallel systems onboard. So we have subsystems that we run basically on large FPGAs.
Slashdot: If people want to get involved and want to follow your progress or want to get into the world of microsatellites, what would be your first piece of advice?
Sean: PlanetLabs is hiring. We're always looking for great people to come and join our team. I think we have something like 30 job recs open right now on our website, planet.com. And then we're also eager to work with students. We have internships that are open year round for students to come and work with us of any level of education and to get more involved in the small satellite community. There is tons of conferences that happen every year, Small Sat would be one that I'd recommend people go to. Yeah, the new space movement is happening and there is tons of companies out there that are eager to hire people to work on these things. Especially there seems to be a problem with people in embedded software knowing that the satellite world exists, you can work on code that goes to space, it’s kind of exciting and there are – it just doesn't seem to be people applying for these jobs, so let's get on Slashdot.
If you know some fantastic embedded programmers that want to work on tiny little space robots to help life on earth -- or electrical engineers, we’re looking for more electrical engineers all the time too.
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Their smaller size means they experience higher drag relative to their mass, they will fall out of orbit much more quickly than a full sized satellite in a similar orbit would. Since they are earth observing, and with very limited optics I would venture a guess that they are in a very low orbit and will come down relatively quickly.
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For a given density, the satellite's cross sectional area (and drag) are proportional to the square of the linear size but the mass is proportional to the cube of the linear size so drag has a smaller effect on larger satellites.
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COTS and no internal redundancy (Score:3)
So, reading this the one thing that I get above all else is their plan is to accept a very high failure rate and make up for it with more units sent to space. I wonder if this approaching being economically viable is a good thing or not for space exploration. Are more companies that have high acceptable losses going to lead to a general prevalence in the industry. Which might mean that, like secure software, hardware capable of getting men to Mars might be considered "unachievable".
Re: COTS and no internal redundancy (Score:1)
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hardware capable of getting men to Mars might be considered "unachievable".
They said nothing about a Mars mission. They do Earth imaging.
Get your goals straight. "Space" is not one monolithic goal, but myriad goals, each with their own design-optimization parameters.
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I understand that this company has no desire to go to Mars. But clearly, they've looked at the costs of launching things into orbit, and the cost of perfecting things, and it's better to overlaunch for redundancy than have redundant systems onboard. If launches are cheap enough then they can just try to launch supplies to the IIS and have it blow up on the launch pad three times.
Although space is not monolithic, people hired for a Mars shot are going to be hired from the "space" industry/education. If we
flash video - I thought those were forboden now (Score:1)
I thought we weren't supposed to use flash any more. CVE's [nist.gov] & mozilla & facebook [arstechnica.com]
I don't want to have unprotected vids.