<<What does New Horizons say when it calls home? Nothing, without the help of software that transforms zeros and ones from New Horizons' computers into images, instrument readings, or useful information on the spacecraft's status. Those datasets are then transmitted to Earth by the telecommunications (radio) system aboard New Horizons. But if our Pluto-bound spacecraft could talk, it would sound something like the 'tune' members of the New Horizons communications team created from actual ranging signals that New Horizons traded with NASA Deep Space Network (DSN) receiving stations earlier this year.>>
Re: Where New Horizons is
Posted: Wed Oct 23, 2013 9:43 pm
by orin stepanek
neufer wrote:
Click to play embedded YouTube video.
Published on Oct 22, 2013
<<What does New Horizons say when it calls home? Nothing, without the help of software that transforms zeros and ones from New Horizons' computers into images, instrument readings, or useful information on the spacecraft's status. Those datasets are then transmitted to Earth by the telecommunications (radio) system aboard New Horizons. But if our Pluto-bound spacecraft could talk, it would sound something like the 'tune' members of the New Horizons communications team created from actual ranging signals that New Horizons traded with NASA Deep Space Network (DSN) receiving stations earlier this year.>>
Wow ; cool! Turn your sound lower before playing! I liked it very much Art!
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 5:12 pm
by orin stepanek
Only 5 AU for encounter with Pluto! Did I say only? Let's see that is only 93 million miles (rounded up) times 5 = 465 million miles to go!
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 6:45 pm
by neufer
orin stepanek wrote:
Only 5 AU for encounter with Pluto! Did I say only? Let's see that is only 93 million miles (rounded up) times 5 = 465 million miles to go!
New Horizons's cameras are an order of magnitude smaller than Hubble so it needs to be less than 4 AU to get better pictures of Pluto.
The Dawn space craft's cameras are an order of magnitude smaller still so Dawn needs to be at least 99% of the distance to Ceres to do better in taking arrival photos (and unlike New Horizons, Dawn will be putting on the breaks heading towards it destination).
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 7:04 pm
by Beyond
Dawn has vacuum brakes, right
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 9:00 pm
by neufer
Beyond wrote:
Dawn has vacuum brakes, right
Right.
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 9:10 pm
by BMAONE23
Certainly better than Air Brakes
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 9:54 pm
by Beyond
Only when there is no air, or the roads are slick. (snow/ice/ETC) For dry roads and big loads, you can't beat air-brakes.
Re: Where New Horizons is
Posted: Thu Oct 24, 2013 10:34 pm
by neufer
Beyond wrote:
Only when there is no air, or the roads are slick. (snow/ice/ETC)
For dry roads and big loads, you can't beat air-brakes.
Exit 9. I like that.
Lets hope it doesn't turn out to be like Planet 9 from outer space
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 12:57 pm
by rstevenson
From the New Horizons page I see that it is taking about 9 years for the probe to travel 32 AUs to Pluto. Proxima Centauri, the nearest star to Sol, is about 269,000 AUs from here. So if we could send a probe there at about the same average velocity as New Horizons has achieved it would arrive in the vicinity of Proxima Centauri in about 75,650 years.
We really need to develop faster probes!
Rob
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 1:01 pm
by makc
Yep, I made this calculator once to show how pathetic our space technology is. Btw, that calculator has Prox. Centauri at only 15000 au... 15,000 ± 700 AU according to http://en.wikipedia.org/wiki/Proxima_Centauri waaaait, that's not the distance to Sun. Need to update my calculator!!!
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 3:04 pm
by rstevenson
One light-year is about 63,240 AUs, and Proxima Centauri is about 4.2 ly from here, or about 265,600 AUs by this calculation. I picked the 269,000 figure off the web somewhere, so I should have checked it. Using 265,600 AUs instead, I get about 74,700 years to get there if our interstellar probe is moving about as fast as New Horizons. Not that we know how to do even that -- yet.
Rob
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 3:13 pm
by makc
updated calculator says that we could get to P.C. in 10 years at only 0.39c (did I say "only" ) corresponding Earth time would be 4.2/0.39 = 10.77 years, quite manageable time spans for both the crew and their relatives.
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 4:16 pm
by neufer
makc wrote:
updated calculator says that we could get to P.C. in 10 years at only 0.39c (did I say "only" ) corresponding Earth time would be 4.2/0.39 = 10.77 years, quite manageable time spans for both the crew and their relatives.
If humans are to go (and/or reason rocket accelerations to be assumed)
then the first ~11,000 AU will have to be achieved at about 1g acceleration
But this ~10 months acceleration phase will only tack on an additional ~5 months to the journey.
rstevenson wrote:One light-year is about 63,240 AUs, and Proxima Centauri is about 4.2 ly from here, or about 265,600 AUs by this calculation. I picked the 269,000 figure off the web somewhere, so I should have checked it. Using 265,600 AUs instead, I get about 74,700 years to get there if our interstellar probe is moving about as fast as New Horizons. Not that we know how to do even that -- yet.
Rob
Rob, you had me worried there for a moment 75,650 seemed an untenable timespan to make the trip worthy, 74,700 is much more practical
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 4:22 pm
by BMAONE23
neufer wrote:
makc wrote:
updated calculator says that we could get to P.C. in 10 years at only 0.39c (did I say "only" ) corresponding Earth time would be 4.2/0.39 = 10.77 years, quite manageable time spans for both the crew and their relatives.
If humans are to go (and/or reason rocket accelerations to be assumed)
then the first ~11,000 AU will have to be achieved at about 1g acceleration
But this ~10 months acceleration phase will only tack on an additional ~5 months to the journey.
If such a technology could be created, we would do better with a constant 1g acceleration for 1/2 the trip then a 1g deceleration for the other half. No more ravages of time in zero g
rstevenson wrote:
One light-year is about 63,240 AUs, and Proxima Centauri is about 4.2 ly from here, or about 265,600 AUs by this calculation. Using 265,600 AUs, I get about 74,700 years to get there if our interstellar probe is moving about as fast as New Horizons. Not that we know how to do even that -- yet.
After multiple gravity assists the 5,600 kg Cassini spacecraft finally left the Earth/Moon system just ~3 km/s shy of Solar System escape velocity. Presumably a Saturn V could place a 47,000 kg spacecraft into a similar (near solar system escape velocity) trajectory. Such a 47,000 kg spacecraft could (given an effective Xenon ion exhaust velocity (Ve) of 29 km/s) launch a ~800 kg interstellar probe that escapes the solar system at a velocity of 120 to 150 km/s = a relative velocity vis-a-vis α Centauri of 140 to 170 km/s. Such a probe could reach α Centauri (or Barnard's star) in from 7700 to 9400 years near to their closest approaches.
Re: Where New Horizons is
Posted: Sat Oct 26, 2013 5:22 pm
by neufer
BMAONE23 wrote:
neufer wrote:
makc wrote:
updated calculator says that we could get to P.C. in 10 years at only 0.39c (did I say "only" ) corresponding Earth time would be 4.2/0.39 = 10.77 years, quite manageable time spans for both the crew and their relatives.
If humans are to go (and/or reason rocket accelerations to be assumed)
then the first ~11,000 AU will have to be achieved at about 1g acceleration
But this ~10 months acceleration phase will only tack on an additional ~5 months to the journey.
If such a technology could be created, we would do better with a constant 1g acceleration for 1/2 the trip
then a 1g deceleration for the other half. No more ravages of time in zero g
If you were just to accelerate for the whole trip (instead of only the first 11,000 AU) for a simply flyby
it would reduce makc's transit time by a factor of 3 but it would require about 24 times the amount of fuel.
And to actually do what you suggest would not only take twice as long as the simply flyby
but would require about 135 times the fuel for a simply flyby
(and ~3,250 times that for makc's ~10 year flyby).
) corresponding Earth time would be 4.2/0.39 = 10.77 years, quite manageable time spans for both the crew and their relatives.
