OT: high-accuracy atomic clock to be attached outside of the International Space Station

[David J Taylor]

...an agreement that paves the way for the launch of a high-accuracy
atomic clock to be attached to the outside of the European Columbus
laboratory onboard the International Space Station (ISS).

See more:
http://www.esa.int/esaCP/SEMRDI9K73G_index_0.html

David

[unruh]

On 2009-12-15, David J Taylor <david-...@blueyonder.delete-this-bit.and-this-part.co.uk.invalid> wrote:
> ...an agreement that paves the way for the launch of a high-accuracy
> atomic clock to be attached to the outside of the European Columbus
> laboratory onboard the International Space Station (ISS).

They have high accuracy atomic clocks orbiting up there already (GPS,
Galileo,...) What is significant about this?

[Jan Ceuleers]

unruh wrote:
> They have high accuracy atomic clocks orbiting up there already (GPS,
> Galileo,...) What is significant about this?

Firstly, the linked press release talks about certain physics experiments which can presumably only be carried out in orbit and which require highly accurate clocks.

Secondly though, is the ISS able to receive GPS signals in order to remove the need for its own high-accuracy clock? Assuming that the accuracy that results would still be good enough? I'm asking because I wouldn't expect GPS/Galileo/GLONASS to have been designed with in-orbit receivers in mind.

Jan

[John Hasler]

Jan Ceuleers writes:
> Secondly though, is the ISS able to receive GPS signals in order to
> remove the need for its own high-accuracy clock?

This appears to be a research-grade clock with epecially good long-term
stability.

> Assuming that the accuracy that results would still be good enough?

I don't think GPS time would be adequate for the planned research.

> I'm asking because I wouldn't expect GPS/Galileo/GLONASS to have been
> designed with in-orbit receivers in mind.

GPS was.
--
John Hasler
jha...@newsguy.com
Dancing Horse Hill
Elmwood, WI USA

[Rick WIdmer]

On 12/15/2009 2:02 PM, John Hasler wrote:
> Jan Ceuleers writes:
>> Secondly though, is the ISS able to receive GPS signals in order to
>> remove the need for its own high-accuracy clock?
>
> This appears to be a research-grade clock with epecially good long-term
> stability.
>
>> Assuming that the accuracy that results would still be good enough?
>
> I don't think GPS time would be adequate for the planned research.

This page has some info on the science. Look in the lower right.

http://www.spaceflight.esa.int/users/downloads/factsheets/fs031_10_aces.pdf

One of them is "Absolute synchronization of ground clocks" to within 100ps.

Rick