Dec 4th News Conference Options

[djellison]

http://www.nasa.gov/home/hqnews/2008/dec/H...MSL_Update.html

From the wording of this announcement, MSL is clearly still on, which is a good thing. We'll have to wait and see.

Doug

[dvandorn]

I just went looking for a rate table of DSN fees, and found the following item in a .pdf file ( http://deepspace.jpl.nasa.gov/advmiss/docs...MEX_AO_2007.pdf ) that describes, among other things, the services and rates for the DSN. There was no actual rate chart; there was a formula for calculating what is called the Aperture Fee:

AF = RB [AW (0.9 + FC / 10)]
where:
AF = weighted Aperture Fee per hour of use.
RB = contact dependent hourly rate, adjusted annually ($1057/hr. for FY08).
AW = aperture weighting:
= 0.80 for 34-meter High-Speed Beam Waveguide (HSB) stations.
= 1.00 for all other 34-meter stations (i.e., 34 BWG and 34 HEF).
= 4.00 for 70-meter stations.
FC = number of station contacts, (contacts per calendar week).

The weighting factor seems to be a multiplier based on a function of aperture size (34m vs. 70m) and number of weekly contacts. An accompanying chart shows the weighting factor for a 70m dish used 28 times per week (i.e., 4 times per day), for example, is 15. The same dish used 14 times a week (twice a day) has a weighting multiplier of a little more than 9. The same numbers of weekly contacts using a 34m dish give you weighting mutiplier of 9 for 28 contacts and 2.5 for 14 contacts.

So, a probe that requires four comm passes a day using a 70m dish looks like it would cost something on the order of $15,865 per hour. That's 28 times $15,865 per week, times 52 per year. That would be $444,220 per month, and $23,990,440 per year. That's based on a reading of the chart, not by plugging numbers into the above formula.

A twice-a-day contact through a 70m dish, again based on the chart, would cost $9,500 or so per comm pass, times 14 passes per week ($133,000), for an annual cost of $6,916,000.

And that all assumes that you're only paying for a single hour of DSN time per pass. In actuality, with calibration times, you're likely going to have pay for a minimum of two hours' worth per pass, possibly more (*). So you might have to double those numbers.

However you slice it up between the various data sources coming through on a MODY or MRO comm pass, total DSN costs add up to millions of dollars a year. So I still think one of the biggest chunks (if not the biggest) of mission operations, extended or otherwise, is DSN time.

-the other Doug

* -- the assumption that each comm pass lasts *at least* an hour is built into the rate structure, I think. At least it says in there: "A station contact may be any length but is defined as the lesser of the spacecraft’s view period, the scheduled pass duration plus calibration times, or 8 hours. For a standard pass, a 45-minute set-up and a 15-minute tear-down time must be added to each scheduled pass to obtain the station contact time (other calibration times apply to Beacon Monitoring and Delta-DOR passes). Note that scheduled pass-lengths should be integer multiples of 1-hour." So even if your comm pass only lasts 12 minutes, it doesn't look like you get the benefit of a pro-rate... dvd