[amsat-bb] Dnepr Upper Stage Apogee

[Paul Stoetzer]

Obviously "beggars can't be choosers" and we are lucky that we have
been able to get several new satellites launched that are providing
and will provide amateur communications, regardless of the orbits.
However, look at the most popular satellites in use now: FO-29 and
AO-7. Both can provide intercontinental communication and up to 22
minute long passes. FO-29 is also popular because of the advantages of
Mode J, especially for portable operations. AO-7 is nearing it's 40th
birthday and can be quite quirky, especially during it's eclipse
cycles, which are getting longer and longer each year as it's orbit
precesses. FO-29 is 18 years old and, though I haven't checked this
out, will probably enter eclipse cycles of it's own in the next year
or so. When the eclipses get too long, the control stations are likely
going to have to turn the transponder off to save the batteries,
meaning we are probably going to lose use of FO-29 for several months;
and, it's always possible that it will fail completely.

As a matter of attracting hams to the amateur satellite service and
keeping them interested, the possibility of intercontinental
communication is important and hopefully launches to take satellites
up higher than 1,000 km can be found in the future, whether it's an
elliptical orbit like FO-29 or this Dnepr's upper stage, the common
high LEO circular orbits above 1,200 km (as these are not cubesat
launches, I'm guessing the costs are prohibitive), or to MEO/HEO (and
we know the difficulties there).

73,

Paul, N8HM

On Sat, Jul 5, 2014 at 9:47 AM, M5AKA <m5aka at yahoo.co.uk> wrote:
>> However, the question of meeting orbital debris mitigation requirements remains
>
> There are, however, no legally binding requirements regarding debris mitigation.
>
>
> In the case of amateur transponder satellites they can be assumed to have an operation lifetime of 40+ years (think OSCAR-7), as I recall debris mitigation suggests re-entry within 25 years of the end of mission. For amateur transponder satellites this might imply 65 years in orbit.
>
>
> But we can see plenty of examples of satellites currently being launched that will still be in orbit thousands of years from now. Certain missions require that satellites are placed in (or achieve through on-board propulsion) near circular orbits in the 1200-2500 km range - it is accepted that such missions could be up there for many tens of thousands of years.
>
> The amateur service could certainly justify transponder satellites in in near circular orbits at that altitude because that is what is required to fulfill the communications mission.
>
> In the case of the Dnepr Upper Stage it looks like it does have a satellite attached to it although that was unintentional - BRITE-Montreal failed to deploy.
>
>
> 73 Trevor M5AKA
>
>
>
>
>
> On Saturday, 5 July 2014, 13:43, Andrew Glasbrenner <glasbrenner at mindspring.com> wrote:
>
>
>
> You are not the only one to notice! All I can say at this point is that it is being investigated. However, the question of meeting orbital debris mitigation requirements remains.
>
> 73, Drew KO4MA
>
> Sent from my iPhone
>
>> On Jul 5, 2014, at 8:28 AM, Paul Stoetzer <n8hm at arrl.net> wrote:
>>
>> Good morning,
>>
>> I noticed that after the last Dnepr launch, it's upper stage was raised to an apogee of 1454 km, putting it in a 1454 km x 609 km orbit with a 97.9 degree inclination, in order to avoid collision with any of the 37 satellites it released.
>>
>> Would it be possible for a future amateur satellite to be deployed AFTER the Dnepr completes it's final burn to take advantage of that high apogee? This would provide service similar to FO-29 with opportunities for intercontinental communications every few months.
>>
>> 73,
>>
>> Paul, N8HM
>> _______________________________________________
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