How does a rocket navigate in space?

[james]

Once a rocket or is in space (e.g. on its way to mars), how does it know
where it is in relation to its pre-programmed route? There is no GPS in
space.

[Derek Lyons]

"james" <nos...@nospam.com> wrote:

A wide variety of ways. It can use an onboard inertial guidance
system, it can use a sun-and-star tracker, it can be tracked from
Earth...

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

[Jeff Findley]

"Derek Lyons" <fair...@gmail.com> wrote in message
news:4af3ad26...@news.supernews.com...

> "james" <nos...@nospam.com> wrote:
>
>>Once a rocket or is in space (e.g. on its way to mars), how does it know
>>where it is in relation to its pre-programmed route? There is no GPS in
>>space.
>
> A wide variety of ways. It can use an onboard inertial guidance
> system, it can use a sun-and-star tracker, it can be tracked from
> Earth...

And for many spacecraft the answer is a combination of methods. Relying on
one method is often subject to errors peculiar to the method.

Jeff
--
"Take heart amid the deepening gloom
that your dog is finally getting enough cheese" - Deteriorata - National
Lampoon

.

[Jochem Huhmann]

fair...@gmail.com (Derek Lyons) writes:

> "james" <nos...@nospam.com> wrote:
>
>>Once a rocket or is in space (e.g. on its way to mars), how does it know
>>where it is in relation to its pre-programmed route? There is no GPS in
>>space.
>
> A wide variety of ways. It can use an onboard inertial guidance
> system, it can use a sun-and-star tracker, it can be tracked from
> Earth...

Basically everything navigation on earth used prior to GPS coming on
line. Well, except a magnetic compass maybe.

Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

[Van Chocstraw]

The old fashioned way, the stars.