2000 bps for 16 months
is something like 9.7GB. Let's hope they release it as a two-DVD boxed set :-)
PLUTO FLYBY: Here's your IT angle, all you stargazing pedants
NASA's Pluto-skimming podule, New Horizons, is now within a million miles of its freezeworld target - but we won't get the data 'til later. While the spacecraft and the dwarf planet are a mere skip from each other in galactic terms, the flyby is far from settled for NASA's IT staff, who used a well-deserved coffee break to …
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Monday 13th July 2015 16:08 GMT Ken Hagan
Re: "...approximately 2,000 bits per second..."
"Where are the relay stations doing long elliptical orbits past Saturn?"
Unless they have dishes that are about half the (linear) size of the receiving dish on Earth, they wouldn't help. (Actually, that's the break-even point. To *help*, they'd need to be even bigger.) Also bear in mind that anything on a long elliptical orbit spends most of its time in a totally unhelpful location. You'd need *lots* of *big* dishes. Similar considerations apply to any interplanetary internet you care to imagine.
It seems to me that what we actually need is a better power source, so that the original signal can be several orders of magnitude larger. Or maybe some very carefully steered laser link, so that the limited power is directed more efficiently in the right direction.
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Monday 13th July 2015 17:31 GMT Duncan Macdonald
Re: "...approximately 2,000 bits per second..."
A laser link would not be effective - there is too much background radiation at optical wavelengths and the maximum size for an optical telescope is far smaller than the maximum size for a radio telescope so less energy would be collected by the receiver on Earth. Unfortunately the only way at present to improve the data rate is to increase the power received on Earth which means more electrical power for the transmitter and/or a larger transmitting antenna and/or larger receiving antennas.
Unfortunately the power is constrained for a number of reasons (not least the desire to limit the radiation release if the launch vehicle explodes!!).
The transmitting antenna size is constrained by the dimensions of the launch vehicle.
If enough money was available then it would be possible to construct additional receiving antennas - replacing each individual receiving antenna with 4 identical antennas linked together would allow for a doubling of the transmission rate
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Monday 13th July 2015 18:41 GMT Anonymous Coward
So there's just no practical way to increase the data rate much?
Guess we'll just have to move Pluto closer for the next mission.
(space is just so damn big and empty that, per Hofstadter's Law, it boggles me to contemplate even when I think I've pre-boggled myself. Unless wormholes and ansibles come to save us I fear humanity will live and die out here in the solar system, just possibly managing to exchange very slow postcards with alien penpals)
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Monday 13th July 2015 21:06 GMT Anonymous Coward
Re: So there's just no practical way to increase the data rate much?
Just pack a small monolith!!!
A hundred million miles beyond Mars, in the cold loneliness where no man had yet traveled, Deep Space Monitor 79 drifted slowly among the tangled orbits of the asteroids. For three years it had fulfilled its mission flawlessly – a tribute to the American scientists who had designed it, the British engineers who had built it, the Russian technicians who had launched it. A delicate spider's-web of antennas sampled the passing waves of radio noise – the ceaseless crackle and hiss of what Pascal, in a far simpler age, had naively called the "silence of infinite space." Radiation detectors noted and analyzed incoming cosmic rays from the galaxy and points beyond; neutron and X-ray telescopes kept watch on strange stars that no human eye would ever see; magnetometers observed the gusts and hurricanes of the solar winds, as the Sun breathed million-mile-an-hour blasts of tenuous plasma into the faces of its circling children. All these things, and many others, were patiently noted by Deep Space Monitor 79, and recorded in its crystalline memory.
One of its antennas, by now unconsidered miracles of electronics, was always aimed at a point never far from the Sun. Every few months its distant target could have been seen, had there been any eye here to watch, as a bright star with a close, fainter companion; but most of the time it was lost in the solar glaze.
To that far-off planet Earth, every twenty-four hours, the monitor would send the information it had patiently garnered, packed neatly into one five-minute pulse. About a quarter of an hour late, traveling at the speed of light, that pulse would reach its destination. The machines whose duty it was would be waiting for it; they would amplify and record the signal, and add it to the thousands of miles of magnetic tape now stored in the vaults of the World Space Centers at Washington, Moscow, and Canberra.
Since the first satellites had orbited, almost fifty years earlier, trillions and quadrillions of pulses of information had been pouring down from space, to be stored against the day when they might contribute to the advance of knowledge. Only a minute fraction of all this raw material would ever be processed; but there was no way of telling what observation some scientist might wish to consult, ten, or fifty, or a hundred years from now. So everything had to be kept on file, stacked in endless air-conditioned galleries, triplicated at the three centers against the possibility of accidental loss. It was part of the real treasure of mankind, more valuable than all the gold locked uselessly away in bank vaults.
And now Deep Space Monitor 19 had noted something strange – a faint yet unmistakable disturbance rippling across the Solar System, and quite unlike any natural phenomenon it had ever observed in the past. Automatically, it recorded the direction, the time, the intensity; in a few hours it would pass the information to Earth.
As, also, would Orbiter M 15, circling Mars twice a day; and High Inclination Probe 21, climbing slowly above the plane of the ecliptic; and even Artificial Comet 5, heading out into the cold wastes beyond Pluto, along an orbit whose far point it would not reach for a thousand years. All noted the peculiar burst of energy that had disturbed their instruments; all, in due course, reported back automatically to the memory stores on distant Earth.
The computers might never have perceived the connection between four peculiar sets of signals from space-probes on independent orbits millions of miles apart. But as soon as he glanced at his morning report, the Radiation Forecaster at Goddard knew that something strange had passed through the Solar System during the last twenty-four hours.
He had only part of its track, but when the computer projected it on the Planet Situation Board, it was as clear and unmistakable as a vapor trail across a cloudless sky, or a single line of footprints over a field of virgin snow.
Some immaterial pattern of energy, throwing off a spray of radiation like the wake of a racing speedboat, had leaped from the face of the Moon, and was heading out toward the stars.
(One may notice that Arthur C. Clarke didn't exactly get the idea and utility of "hard money". He might have, had he lived till 2015.)
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Tuesday 14th July 2015 19:43 GMT Anonymous Coward
Re: So there's just no practical way to increase the data rate much?
Pluto just passed its closest to Earth for the next couple centuries a while back (remember when Neptune was briefly the further planet?) By the time it is closer than it is today, we might be able to take a vacation there. Well, probably not, but it would be nice to have the option!
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Monday 13th July 2015 17:53 GMT John Smith 19
So far we've come, so far still to go.
16 km/sec --> fastest object to leave Earth.
That's roughly 0.000053 c
Getting to the next star system at that speed is going to take a long time. :(
Looks like the only serious chance is with the fission fragment rocket.
On an IT note. Look at how much practice and planning is done before the event.
Should be SOP for all major 1 shot events (system cut overs of various kinds mostly).
But is it?
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Tuesday 14th July 2015 11:55 GMT Aqua Marina
Getting to the next star system at that speed is going to take a long time. :(
One question I've often wondered. At our current technology level, what speeds would be be able to achieve if the motivation and cash was there? I don't mean concept or drawing board technologies, but rather what we can build right now practically.
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Tuesday 14th July 2015 12:11 GMT ilmari
Re: Getting to the next star system at that speed is going to take a long time. :(
Well, they did test the "throw nukes out the back and ride the shockwave" idea, but with conventional explosives. If the world's nuclear weapons arsenal was appropriated for a spaceship, it could send a toddler to Alpha Centauri before the toddler's retirement age.
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Wednesday 15th July 2015 06:18 GMT John Smith 19
Re: Getting to the next star system at that speed is going to take a long time. :(
"Well, they did test the "throw nukes out the back and ride the shockwave" idea, but with conventional explosives. If the world's nuclear weapons arsenal was appropriated for a spaceship, it could send a toddler to Alpha Centauri before the toddler's retirement age."
Orion uses much smaller propulsion packages (in the kiloton range) than most nuclear weapons.
You could built a lot of them them from the worlds nuclear arsenals.
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Wednesday 15th July 2015 06:18 GMT John Smith 19
Re: Getting to the next star system at that speed is going to take a long time. :(
"One question I've often wondered. At our current technology level, what speeds would be be able to achieve if the motivation and cash was there? I"
With no new technology you're basically looking at hooking a nuclear reactor to a cluster of ion thrusters, possibly boosted by a booster stage that takes beamed microwave power from solar cells in LEO while inside the solar system. Biggest space nuke however was Russian at about 5Kw.
Once outside this you're looking at solar sails going in close to the sun behind an asteroid then accelerating hard.
The best I've seen with known physics IE not fusion, is the fission fragment rocket. That's a pulsed nuclear reactor whose fuel is made in layers < 10 micrometres thick. At that level fission fragments made when a U235 atom fissions can leave the surface of the fuel and using a magnetic field be pointed out the back.
The fragments are moving at between 3 and 5% of the speed of light versus something like the 0.001% of the speed of light of ion thruster streams.
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Tuesday 14th July 2015 08:18 GMT phuzz
Re: Dish mish
The Deep Space Network has complexes in the US, Australia and Spain.
There's a really cool page here that shows you what all of the different dishes are talking to right now. For example right now at 0816UTC one dish in Spain is listening to Rosetta, while another is communicating with Mars Odyssey. Most of the US and Aussie dishes are listening to New Horizons.
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