well, the kessler syndrome [1] is a real phenomenon and has real consequences. More satellites == more debris == high probability of collisions which can create a positive feedback loop.
It requires real management and processes ahead of time, not after the fact.
I'm interested and considering getting an amateur radio license.
It's not clear yet, but I wanted to get a single portable device that allows for reception of all the most important frequencies, which I think includes shortwave, HF, VHF, NOAA weather and the amateur radio bands.
There are a few "hardware" Wideband radio receivers out there, depending on budget. Have a look at the site links below - the site does not claim to be a definitive list, and is focused around the pictures of the equipment.
The "big three". Some of the more modern bits of kit cover "DC to Daylight" frequencies.
Not sure what other people do, but I always publish at a journal then put my manuscript on arxiv, or whatever field equivalent, and then on my personal website.
First -- Thanks! But second, how do you have the right to that ? Doesn't the institution you work for or the paper's co-authors restrict distribution so to maximize the royalties and recoup research costs ?
Research institutions don’t get royalties from papers. If they license or commercialize discoveries, they will get royalties. Papers are not a source of income for them and are typically a cost center as they pay for subscriptions to the journals full of papers written by scientists they employ.
To add to the other replies, most journals allow you to post a preprint to arxiv or your personal site as long as you don’t use their final layout, typesetting, and branding
Submit manuscripts as e-mail attachment to the Editorial Office at ajmds@scihub.org, A manuscript number will be mailed to the corresponding author same day or within 72 hours
There are closed form equations that can be used for the angular position of the sun, which will be more than accurate for this purpose.
Then it's mostly some simple trig to determine areas that have a line of sight to the sun.
I have this on my to-do list because in my bedroom on a full moon the light will come through one specific window onto our pillows. i wanted to automate either curtains or something to predict when it'll happen.
Maybe eventually I'll get around to something like this
I think what they are referring to is "angular momentum dumps". The reaction wheels have a fixed maximum amount of angular momentum. This is a function of the speed of the wheels themselves since the mass/moment of inertia is fixed.
Over time external forces continue to add momentum to the system (from drag/solar radiation pressure). In order to maintain a desired pointing direction this means the wheels must increase in velocity to "absorb" this momentum.
Eventually you need to "dump" the momentum using another external force, such as thrusters, or in this case the same solar radiation pressure.
Goal is to orient spacecraft such that external forces can be used to spin down the various reaction wheels, thereby "dumping" momentum out of the wheels.
This is pretty common on all spacecraft, but gets complicated/innovative when you have to do it in an emergency or if you don't have a full set of reaction wheels.
Just adding it because I think it's a cool use of the word.
When reaction wheels are operating at maximum speed and can no longer exchange momentum with the spacecraft in both directions, they are considered 'saturated'.
'Saturated' is used in control systems engineering for any value (sensor input, drive output etc.) that has reached maximum or minimum value and can't be further increased/decreased. It's the same sense of the word as used in the HSV colour space in computer graphics.
I bought it from an upperclassman for 25 cents.
Still on my shelf and I used it to design my own astrodynamics course to teach during grad school.