Are we moving to the Chrome only world?
Works in Safari.
Planet: Imaging the entire Earth every day
11–20 of 144 posts
Re: Planet: Imaging the entire Earth every day
#12Are we moving to the Chrome only world?
Using a UA switcher and FF, I can't seem to find anything broken. I think the author of this page is just a bit zealous for chrome. It also seems to work without UA switcher, but still states it won't work. ¯\_(ツ)_/¯
Perhaps the modern equivalent of “best viewed in Netscape”?
Re: Planet: Imaging the entire Earth every day
#13So many questions:
1. How did they get 150 satellites into low orbit?
2. Is it becoming a hazard to have all the satellites and space junk possibly making it difficult to launch anything down the road?
3. Aside from tracking the objects, has anyone made any calculations as to when these things will become a hazard?
Re: Planet: Imaging the entire Earth every day
#14So many questions: 1. How did they get 150 satellites into low orbit? 2. Is it becoming a hazard to have all the satellites and space junk possibly making it difficult to launch anything down the road? 3. Aside from tracking the objects, has anyone made any calculations as to when these things will become a hazard?
They are launched in groups. Lots of them are really small.
Re: Planet: Imaging the entire Earth every day
#15So many questions: 1. How did they get 150 satellites into low orbit? 2. Is it becoming a hazard to have all the satellites and space junk possibly making it difficult to launch anything down the road? 3. Aside from tracking the objects, has anyone made any calculations as to when these things will become a hazard?
1. They launched by piggybacking on rockets that were launching larger satellites. For instance, they launched 88 on this record-setting PSLV launch: https://www.nasaspaceflight.com/2017/02/indias-pslv-record-1...
2. People generally have a poor understanding of how vast space is. Congestion in specific low-Earth orbits is definitely a concern, but the devil is in the details. For instance, launching to Sun-Synchronous orbit (SSO) [1] above ~600 km is considered to pose significant risk to on-orbit assets, because of how many satellites are in SSO and the kinetic energy their carry, however to really assess the risk, you need to do a lot of detailed population studies (I've done some of this stuff). In a nutshell, launching more satellites can be generally considered to increase risk of on-orbit collision and fragmentation, but quantifying it requires a lot of maths and physics.
3. Yes! There's is extensive and on-going research on this topic. Most people know the Kessler Syndrome [2], but honestly space debris research goes a lot further than that. This review by J.-C. Liou is a great starting point: https://commons.erau.edu/cgi/viewcontent.cgi?article=1233&co...
Re: Planet: Imaging the entire Earth every day
#16So many questions: 1. How did they get 150 satellites into low orbit? 2. Is it becoming a hazard to have all the satellites and space junk possibly making it difficult to launch anything down the road? 3. Aside from tracking the objects, has anyone made any calculations as to when these things will become a hazard?
1. Many of these satellites are cubesats. They hitch rides as secondary payloads on launches, and in batches. In Planet's case, they've launched many batches, some as large as 20-48 satellites.
2. Not really. Kessler syndrome is the general name for this phenomenon, but it's not a huge concern in LEO. In LEO, there is enough atmospheric drag to naturally deorbit spacecraft. For US based companies, regulations mandate that they have a deorbit plan within 25 years. For most cubesats, their orbits are low enough that they'll naturally deorbit within 5-7 years.
3. Most people generally think that any hazard in LEO will not be caused by launching more objects, but by having objects collide (or having some weaponry intentionally explode objects) causing debris that is spread more widely and too small to track. Currently JSpOC in the US tracks most objects the size of a baseball or larger in LEO and coordinates with various commercial and private entities to put into place plans for collision avoidance where possible.
Re: Planet: Imaging the entire Earth every day
#17Can’t see anything on the globe, just a circle.
On mobile it says to use desktop to see all the of the pictures which I can confirm there's way more.
Edit: checking the source code it only shows "20% of the photos" on mobile
The visual below shows the locations of 20% of the photosRe: Planet: Imaging the entire Earth every day
#18> Parts of the landmass can also be missing due to complete cloud cover that day. See the Amazon, Central Africa, or Northern Australia for example.
Aka great places to start a terrorist or drug organization!
The invasion of Iraq got delayed by a few days due to cloud coverage. It would definitely impede surveillance to have clouds often blocking satellites.
Re: Planet: Imaging the entire Earth every day
#19I worked for RapidEye during the launch in 2008. Exciting times!
If I remember correctly, their planned lifetime for imaging was 7 years, so it's quite amazing that they're still active 11 years later.