Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
The International Telecommunication Union defines “deep space” to start at a distance of 2 million km (approximately 0.01 AU) from the Earth’s surface. NASA’s Deep Space Network has variously used criteria of 16,000 to 32,000 km from Earth. [wikipedia.org]
The moon is only 382,500 km away. This is the wrong technology for talking to the moon.
I guess we’ve found the pedant in the room. It’s “deep space” because its coverage extends to deep space. It doesn’t mean that everything that it talks to has to be that far away.
They’re not very high in Florida.
Anything beyond geostationary orbit height is deep space. The word deep is relative, for example the deep end of a swimming pool might only be 6 ft.
“the deep end of a swimming pool might only be 6 ft.”
Great. Now we are going to be measuring ‘deep space’ in Olympic swimming pools.
Great. Now we are going to be measuring ‘deep space’ in Olympic swimming pools.
Great. Now we are going to be measuring ‘deep space’ in Olympic swimming pools.
OSPs are a bad unit for volume because there is no standard depth. The specified depth is at least two meters, but there is no maximum.
The length is also unspecified. 50 meters is the distance to the touch panel, not the distance between the ends of the pool.
How many Rhode Islands is that?
Currently, the DSN is used for basically every mission above geostationary orbit. This includes the moon and e.g. the Lagrange points.
NASA is trying to address this by building Lunar Exploration Ground Sites [nasa.gov] (LEGS) to take over most communication with lunar missions.
So, do you refuse to drive on the interstate unless you expect to cross at least one state border during your trip?
…that this is something long past review, maintenance, and serious investment.
It’s not – ahem – “rocket science” to see that the data-management necessity for space missions is something that’s only going to grow*.
But let me also observe that the US as a country is the wealthiest society that has EVER EXISTED IN HUMAN HISTORY…but we still want so much stuff, we have to borrow 20-25% of our budget every year against the future conviction that we’ll be wealthier then than we are today.
I don’t have a solut
Antennas don’t have to be as durable in microgravity. Mount them on the Lunar Gateway which NASA is already planning. Have it be a hub that stores incoming transmissions and transmits them down to Earth as bandwith is available.
The 8K video example is ridiculous. This is interplanetary space, some tradeoffs are required
When you’re already spending umpty million dollars to get something into space, you might as well use the best camera you can get rather than an old instamatic.
This is a discussion about bandwith over solar-system scale distance. Get off your iphone and try learning something
So you would rather NOT figure out how to improve the bandwidth?
Surely whether or not one could have 8K would be a function of *bandwidth*, not a function of propagation delay.
“I bet Vint doesn’t even understand how or why data is phase modulated when transmitted to and from space.”
I wouldn’t put a great deal of money behind that bet if I were you.
Our planet’s climate is dynamic. Our Star’s Solar cycle and Earth’s axial tilt have a huge part to play in our climate.
Our planet’s climate is dynamic. Our Star’s Solar cycle and Earth’s axial tilt have a huge part to play in our climate.
Our star’s solar cycle results in a periodic brightness change of ~1 Watt per square meter (yes, we measure it); this variation would affect global average temperature by no more than 0.1 degrees C. But the solar cycle has an 11 year periodicity, so it would show up as a sine wave in temperature graphs, not a continuous rise. The cycles of Earth’s axial tilt, on the other hand, have periodicity of 26,000 years; far too slow to account for than the currently observed warming.
So: no, these factors don’t explain the observed warming.
The climate would warm up even if Man didn’t exist on Earth.
The climate would warm up even if Man didn’t exist on Earth.
The Earth does indeed have natural factors resulting in climate changes as well as human factors– most notably the 100,000 year cycle of glacial advance and retreat, driven by Milankovitch variations. But the currently-measured human-induced changes are much faster that the natural changes.
And all of this is well known, and extensively studied.
“Our star’s solar cycle results in a periodic brightness change of ~1 Watt per square meter (yes, we measure it); this variation would affect global average temperature by no more than 0.1 degrees C”
You missed the detail that our atmosphere is a chaotic system, which by definition can be influenced by the smallest of change over time.
A dripping faucet is chaotic. How long it takes for a drip to fill a bucket is not. Averaging a noisy system reduces noise. See, for example, https://chaosbook.org/chapters… [chaosbook.org]
Weather is chaotic. Climate isn’t.
And you missed the part that we measure all this.
Next priority, though, would be to add new locations, roughly spaced in between the existing locations. Likely candidates would be: 1) attached to the ESA’s launch facility in French Guyana,
Next priority, though, would be to add new locations, roughly spaced in between the existing locations. Likely candidates would be: 1) attached to the ESA’s launch facility in French Guyana,
Nope. Your want receivers in deserts, not rain forests! Rain kills the reception. (And preferably, high altitude deserts: at the shortest wavelengths, even humidity drops the signal.)
2) somewhere in India,
2) somewhere in India,
Not a bad idea, if you’re thinking the desert areas of Rajasthan, or other parts of the northwest.
and 3) Hawaii, maybe,
and 3) Hawaii, maybe,
Good idea. But space on the mountaintops is limited, and there’s a lot of pushback against even the new large telescopes; doubt you’d ever get permission to put up a hundred meter radio dish. (Might try the Haleakal High Altitude
If you want desert, either Afghanistan or Pakistan would probably be your best bet in that part of the world.
If you want desert, either Afghanistan or Pakistan would probably be your best bet in that part of the world.
You’re seriously suggesting that the US build critical (and expensive) space infrastructure in Afghanistan or Pakistan?
For one on one of the Hawaiian islands. consider HaleakalÄ, on Maui. Yes, it’s still considered active, but there’s not been an eruption in over 500 years.
For one on one of the Hawaiian islands. consider HaleakalÄ, on Maui. Yes, it’s still considered active, but there’s not been an eruption in over 500 years.
Yes, I suggested that as a reasonable choice.
ESA has its own DSN, with 30 meter dishes in Spain, Australia and Argentina. NASA and ESA can and do use each other’s groundstations if necessary.
The Voyager signals can be received by linking several 34-m dishes in an array. The 70 m antennas are required to send commands to the Voyagers; this is due to a combination of antenna gain and transmitter power (the 70 m dishes have 100 kW transmitters, while the 34 m dishes have 20 kW transmitters).
NASA is refurbishing 34 m antennas to all have the same receiver/transmitter capabilities, to improve redundancy, the Voyagers may remain an exception.
Scrap SLS and switch to Starship saving billions.
Scrap SLS and switch to Starship saving billions.
Might want to wait until Starship flies at least once. Successfully.
Cute new toy: cue the media.
Repair an old toy? No sale
This is why highways and bridges fall into disrepair, etc etc.
In THIS case there’s a good argument that the new projects demanding service from the network should be charged explicitly for using it, given that getting extra funding for most of the projects that do now – with the probable exception of Voyager – is a lost cause.
They just need to create a network of all those dishes that people have mounted on their houses.
If something is a problem government agencies “sound the alarm” and “paint a dire picture” which is just an emotional BS part of a plan to beg for more money.
Watch for this behavior.
A private company evaluates priorities and allocates budgets based on priorities.
The DSN is important but NASA does a lot of unmandated BS work that isn’t as important.
Not being able to give anything up is how toddlers behave.
And bureaucrats.
This has nothing to do with ‘unmandated BS work’.
The DSN supports missions in space, which are NASA’s mandate. The problem is that when deep space missions are approved, insufficient budget is made available to expand the DSN to support the new mission. Worse, while the number of deep space missions has risen, DSN funding has declined, so the existing resources are being spread over more and more missions. Artemis is a case in point. NASA’s working on new ground stations specifically for nearby missions for
LEGS aren’t going anywhere.
I would think having a decent network on Earth first would be a good idea. E.T. doesn’t need access to video card drivers. I do.
This summary, at least, completely ignores all the work by NASA (and partners like MIT Lincoln Lab) in the area of space laser communications over the last decade-plus. In fact, a lasercom terminal capable of 260Mbps from the moon has already been delivered for the Orion capsule. (JWST’s Ka-band downlink is “up to” 28Mbps, by comparison.) An unmanned lunar orbiter a decade ago was doing 40-622MBps down via lasercom.
Yes, optical communication absolutely has its tradeoffs, but NASA has seen it as a way for
There may be more comments in this discussion. Without JavaScript enabled, you might want to turn on Classic Discussion System in your preferences instead.
Microsoft To Unbundle Teams From Office, Seeks To Avert EU Antitrust Fine
Paramount DMCAs ‘Star Trek’ Fan Project
The easiest way to figure the cost of living is to take your income and add ten percent.