Re: ISS orbit adjustment planned for Apr 19

From: Bob Christy via Seesat-l <seesat-l_at_satobs.org>
Date: Sat, 18 Apr 2020 18:07:07 +0100
Apologies... I did like everyone else, I made an assumption and read the NASA data in the wrong order.

This event is going to REDUCE the height of the ISS orbit by 2 km.

Jonathan McDowell tells me that it will use the Zvezda thrusters - nearly 20 yrs after they went into space.

Bob Christy

> On 18 Apr 2020, at 17:42, Bob Christy via Seesat-l <seesat-l_at_satobs.org> wrote:
> 
> This isn't a regular adjustment using Progress engines. They usually involve firing thrusters for around 4 minutes, provide Δv of about 0.5 m/s and raise ISS orbit by around 1 km.
> 
> The planned firing for this adjustment is about one minute, the Δv will be about 1.0 m/s and it will add 2 km to the orbit.
> 
> I suspect possible use of Cygnus NG-13 thrusters.
> 
> Bob Christy
> 
>> On 17 Apr 2020, at 16:19, Jonathan McDowell via Seesat-l <seesat-l_at_satobs.org> wrote:
>> 
>> Collision avoidance is never planned (or known to be needed) that far (it's
>> been in the schedule for several days already) in advance I think.
>> This is just a regular boost.
>> 
>>> On Fri, 17 Apr 2020 at 06:21, Kevin Fetter via Seesat-l <seesat-l_at_satobs.org>
>>> wrote:
>>> 
>>> On Apr 19, a planned change is the ISS orbit is scheduled to be done. At
>>> first, I thought it would be a orbit boost, but then I thought maybe it
>>> will be done for collision avoidance. as maybe something was to pass to
>>> close to the station without the change in orbit.
>>> 
>>> Anything predicted to buzz the station soon.
>>> 
>>> Kevin
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Received on Sat Apr 18 2020 - 12:07:46 UTC

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