Deap Space Navigation

Still happens with KaKu band DBS satellite TV - fortunately, it's
during the day when most worthwhile viewers (e.g., those who pay their
bill on time) are at work and so don't call the overworked, underpaid,
under-intelligent CSRs to complain.

--
Herb Schaltegger

Unless the CSR's are watching TV at their desks. Or the supervisors with too
much time on their hands. Or the field techs that have too much time on
their hands. Then the pages start coming out.

Jason Ciastko
Head End Technician
A mega cable company

Jason A. Ciastko wrote:
Still happens with KaKu band DBS satellite TV - fortunately, it's
during the day when most worthwhile viewers (e.g., those who pay their
bill on time) are at work and so don't call the overworked, underpaid,
under-intelligent CSRs to complain.




Unless the CSR's are watching TV at their desks. Or the supervisors with too
much time on their hands. Or the field techs that have too much time on
their hands. Then the pages start coming out.


Head End Technician

On the phone with such a customer: "Hold on sir, give me a moment, and
I'll shut the Sun down so it doesn't interfere with the satellite. Give
it about 15 minutes, and you should be back up and running..."

"robert casey" wrote in message
ink.net...
On the phone with such a customer: "Hold on sir, give me a moment, and
I'll shut the Sun down so it doesn't interfere with the satellite. Give
it about 15 minutes, and you should be back up and running..."

Which inspires the follow-up question: Has there ever been a solar eclipse
at the time (and place)
of seasonal Sattelite/Solar "white-out" (or whatever it is called)?

Steve

Steve Vernon wrote:

"robert casey" wrote in message
ink.net...

On the phone with such a customer: "Hold on sir, give me a moment, and
I'll shut the Sun down so it doesn't interfere with the satellite. Give
it about 15 minutes, and you should be back up and running..."


Which inspires the follow-up question: Has there ever been a solar eclipse
at the time (and place)
of seasonal Sattelite/Solar "white-out" (or whatever it is called)?


ROTFLMAO! :-)

" Unless the CSR's are watching TV at their desks. Or the supervisors with
too
much time on their hands. Or the field techs that have too much time on
their hands. Then the pages start coming out.

Head End Technician

On the phone with such a customer: "Hold on sir, give me a moment, and
I'll shut the Sun down so it doesn't interfere with the satellite. Give
it about 15 minutes, and you should be back up and running..."

I also forgot to mention a Technical Operations Manager tell the local
politico's the reason for sun fade was the sun went between the satellite
and the Earth. Myself and the other technicians that were brought in for
"technical knowledge" shifter in our seats. Luckily the politicos didn't
catch it...

Jason Ciastko

robert casey wrote:


Which inspires the follow-up question: Has there ever been a solar
eclipse at the time (and place)
of seasonal Sattelite/Solar "white-out" (or whatever it is called)?


ROTFLMAO! :-)


I don't know.... could that occur? Eclipses can occur over the majority
of the Earth's surface, and could you have the thing occur with the GEO
satellite near the position of the eclipse in the sky? A lot of the
radio interference could come from the solar corona, and that's visible
during the eclipse.

Pat

"robert casey" wrote in message
ink.net...
Steve Vernon wrote:

"robert casey" wrote in message
ink.net...

On the phone with such a customer: "Hold on sir, give me a moment, and
I'll shut the Sun down so it doesn't interfere with the satellite. Give
it about 15 minutes, and you should be back up and running..."


Which inspires the follow-up question: Has there ever been a solar
eclipse at the time (and place)
of seasonal Sattelite/Solar "white-out" (or whatever it is called)?

The singing you heard yesterday-the stuff somewhat reminiscent of Vogon
poetry- was me, enjoying the benefits of the WildBlue yonder with my
satellite internet service.

It's only a measely 512K (ok, it's only gotten up to 511K) down and 128K
(well, closer to 85K) up, but I'll live with it. After all, I was averaging
about 29K with my dialup.

(Henry Spencer) writes:

It would also be very helpful to have a second southern-hemisphere
DSN site, perhaps in South America. Having only one can become a
severe bottleneck when busy parts of the solar system are in the
southern sky.

Well, there are the old Canarvon and Honeysuckle sites.

--
Paul Repacholi 1 Crescent Rd.,
+61 (08) 9257-1001 Kalamunda.
West Australia 6076
comp.os.vms,- The Older, Grumpier Slashdot
Raw, Cooked or Well-done, it's all half baked.
EPIC, The Architecture of the future, always has been, always will be.

A while back, I wrote:
It would also be very helpful to have a second southern-hemisphere DSN
site, perhaps in South America. Having only one can become a severe
bottleneck when busy parts of the solar system are in the southern sky.

As it turns out, some papers I'm reading now have a concrete example of
this. The combination of the launch timing and the exact trajectory
chosen for Mars Odyssey put its Earth-Mars cruise period mostly fairly
deep in the southern sky. Only the Canberra DSN station had contact with
it for the first month or two. Then Goldstone started to be able to see
it, and only still later could Madrid talk to it.

This turned out to be particularly awkward for navigation, a hot issue
just then with the memory of Mars Climate Orbiter still fresh (and Odyssey
using the same spacecraft-bus design!). The MCO course error had been
roughly perpendicular to the line of sight, so ordinary DSN tracking
(which measures range and velocity along the line of sight) didn't see it.
For Odyssey, JPL badly wanted to be able to use VLBI, which measures
position "on the sky", perpendicular to the line of sight, and thus would
detect such errors. (This hadn't been done for MCO because it's harder,
and MCO navigation was perceived as being a routine job not calling for
unusual measures.) Trouble is, VLBI requires simultaneous observations
by a *pair* of DSN stations; in fact, preferably two pairs, because VLBI
is not sensitive to errors perpendicular to the baseline between the two
stations, so you want two different baselines at an angle to each other.

Only about halfway through cruise did the contact windows for Canberra and
Goldstone start to overlap enough to permit simultaneous observations on
that baseline. And even at Mars arrival, the overlap between Goldstone
and Madrid was short enough, and Madrid communications conditions poor
enough (because Odyssey was so low in Madrid's sky), that VLBI just didn't
work well on that baseline. (They did do Goldstone-Madrid VLBI runs, but
the data was so noisy that just leaving it out of the navigation solutions
entirely made little difference to the results.)
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Sat, 16 Dec 2006, Henry Spencer wrote:

A while back, I wrote:
It would also be very helpful to have a second southern-hemisphere DSN
site, perhaps in South America. Having only one can become a severe
bottleneck when busy parts of the solar system are in the southern sky.

As it turns out, some papers I'm reading now have a concrete example of
this. The combination of the launch timing and the exact trajectory
chosen for Mars Odyssey put its Earth-Mars cruise period mostly fairly
deep in the southern sky. Only the Canberra DSN station had contact with
it for the first month or two.

[discussion of VLBI-based navigation snipped]

I wonder whether someone could build a deep-space tracking station in Chile
or Argentina and *sell* tracking services to the governments who need it? I
don't suppose it would pay, unless one could achieve big savings in hardware
or infrastructure compared to government-operated stations.

You could supplement your income with military or commercial satellite
tracking, communications, radio astronomy, etc.

This might be a dumb idea. Even if it looked potentially profitable, it
would be hard to finance without firm committments from government
customers.

--
Bill Higgins | "The victors write the histories,
Fermilab | and also the DNA sequences."
| --Barry Gehm