[amsat-bb] AMSAT-OSCAR 85 TLEs

[Nico Janssen]

All,

The TLEs for the GRACE Cubesats in the Cal Poly list have been updated.
http://mstl.atl.calpoly.edu/~ops/keps/kepler.txt

Based on these new TLEs it is now certain that AO-85 is object 90747,
GRACE-47 in the Cal Poly list. In the official JSpOC Catalog AO-85 is
object 40967, 2015-058D.

73,
Nico PA0DLO


On 2015-10-11 09:26, Nico Janssen wrote:
> All,
>
> Initially the TLEs for the GRACE Cubesats were published only via:
> http://mstl.atl.calpoly.edu/~ops/grace_tle/GRACE_OPM_TLE.txt
>
> Meanwhile more recent TLEs can be found in this list:
> http://mstl.atl.calpoly.edu/~ops/keps/kepler.txt
>
> Using these TLE sets I find that AO-85 is closest to object 90747,
> GRACE_47. Actually AO-85 is now about 10 s early compared to the
> TLEs of object 90747.
>
> I assume Cal Poly will keep these GRACE elements up-to-date in the
> coming days, like they do with the ULTRASat TLEs.
>
> 73,
> Nico PA0DLO
>
>
> On 2015-10-10 22:38, Jerry Buxton wrote:
>> Nico,
>>
>> The first keps we got were based on the OPMs at the time of P-POD
>> deployment per the telemetry.
>> We will likely not receive any others until NORAD starts tracking them,
>> perhaps in a few days.  Still, those will not be available to the
>> general public (from what I understand), they will be posted in our
>> AMSAT keps when we get them.
>>
>> Thank you for the information on the frequency drift!
>>
>> Jerry Buxton, NØJY
>>
>> On 10/10/2015 15:31, Nico Janssen wrote:
>>> All,
>>>
>>> Hours after the launch of AO-85 (ex FOX-1A) the first TLEs for 8 of
>>> the 13 launched Cubesates were published under GRACE 1 through 8.
>>> I have not seen any updates since launch day.
>>>
>>> Today around 18:00 UTC AO-85 was 29 s early compared to the TLE set for
>>> GRACE 8, which is currently leading the group. AO-85 is 41 s early
>>> compared to the TLE set for GRACE 2, that most people will be using 
>>> now.
>>>
>>> So either the early TLEs were not very accurate yet, or the TLEs for
>>> AO-85 were not yet determined and therefore not available in the
>>> initially measured batch. Let's hope we get updated TLEs for all 13
>>> Cubesats soon.
>>>
>>> BTW, there appears to be a small temperature drift on the downlink
>>> signal frequency of AO-85 that may be noticable when using automatic
>>> doppler correction.
>>>
>>> 73,
>>> Nico PA0DLO
>>>
>>>
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>> _______________________________________________
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>