NASA orbit simulation software

Hey..

Does anyone knows what programs does NASA use to simulate and predict
the orbit of a spacecraft? and for simulate the reentry phase of the
shutle and from now on orion?

João Gomes wrote:
Hey..

Does anyone knows what programs does NASA use to simulate and predict
the orbit of a spacecraft? and for simulate the reentry phase of the
shutle and from now on orion?


There's no one answer to the first question; every NASA center has its
own trajectory analysis software. NASA does use POST quite a bit but it
is not the only program used.

Regarding the second question, NASA/JSC uses the Descent Design System
(DDS) and Spacecraft Trajectory and Mission Planning Simulator (STAMPS)
to simulate space shuttle entries.

On May 16, 1:19 pm, "Jorge R. Frank" wrote:
João Gomes wrote:
Hey..

Does anyone knows what programs does NASA use to simulate and predict
the orbit of a spacecraft? and for simulate the reentry phase of the
shutle and from now on orion?

There's no one answer to the first question; every NASA center has its
own trajectory analysis software. NASA does use POST quite a bit but it
is not the only program used.

Regarding the second question, NASA/JSC uses the Descent Design System
(DDS) and Spacecraft Trajectory and Mission Planning Simulator (STAMPS)
to simulate space shuttle entries.

And STAMPS can be used with different vehicles?

Is there any change to purchase or to have that software for a project
my university is developing?

João Gomes wrote:
On May 16, 1:19 pm, "Jorge R. Frank" wrote:
João Gomes wrote:
Hey..
Does anyone knows what programs does NASA use to simulate and predict
the orbit of a spacecraft? and for simulate the reentry phase of the
shutle and from now on orion?
There's no one answer to the first question; every NASA center has its
own trajectory analysis software. NASA does use POST quite a bit but i
t
is not the only program used.

Regarding the second question, NASA/JSC uses the Descent Design System
(DDS) and Spacecraft Trajectory and Mission Planning Simulator (STAMPS
)
to simulate space shuttle entries.

And STAMPS can be used with different vehicles?

No. It is shuttle-specific.

Is there any change to purchase or to have that software for a project
my university is developing?

No. STAMPS contains a HAL-to-C translation of the shuttle's onboard
flight software, which is restricted by ITAR.

Jorge R. Frank wrote:

There's no one answer to the first question; every NASA center has its
own trajectory analysis software. NASA does use POST quite a bit but
it is not the only program used.

Boy, _that_ could never lead to a problem, could it? :-D
You read that, and the Mars Polar Orbiter showing up a bit low in its
approach to the planet's atmosphere isn't that big of a surprise, is it?
Talk about potential misunderstandings cropping up as several separate
computer programs try to figure out what something is supposed to do in
detail, and all the space centers try to compare the math from _their_
individual computer program simulations.
One computer program has got to be the most accurate in figuring this
all out, and all NASA centers should use that one, so at least they
could all be on the same page at the same time.
You read something like you just wrote, and frankly you couldn't even
make that sh*t up in a Monty Python sketch.

Pat

* i

Pat Flannery wrote:
:
:One computer program has got to be the most accurate in figuring this
:all out, ...
:

Not necessarily, Pat. There are lots and lots of different factors
involved and different simulations may be better in different areas,
so that sometimes one simulation works better and sometimes another
does.

So there may be no 'best' one and cherry picking from each one to make
a 'best' one is not a simple task.

--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

On May 17, 9:07 am, Fred J. McCall wrote:
Pat Flannery wrote:

:
:One computer program has got to be the most accurate in figuring this
:all out, ...
:

Not necessarily, Pat. There are lots and lots of different factors
involved and different simulations may be better in different areas,
so that sometimes one simulation works better and sometimes another
does.

So there may be no 'best' one and cherry picking from each one to make
a 'best' one is not a simple task.

Pat I think Fred's right, in my limited experience with sims.
One would need 100,000's of different variables in one overall
program.

Just as a simplistic overview...
1) Rocket pre-launch soft/ware.
2) Rocket flight s/w, earth relative navigation.
3) Orbital s/w, earth relative with solar lunar tidals.
4) If you want to extract a LM, that's a specialized
s/w sub-routine.
5) Translunar injection, to lunar orbit, is celestrial
navigation.
6) Softlanding on the moon, is lunar relative, with
thruster control s/w.

Most of those routines need to pass data to other
routines, so they end up being sub-routines, so
in that sense it could be considered as one big s/w
program.
A problem when writing s/w is remembering what
the variables stand for, for example, Pitch. Yaw,
Roll, depend on the applicable spacecraft, so
once (1) and (2) are done, we don't need those
variables in (3), nor do we need those routines.
S/w systems design and management needs to be
compartmentalized into Block Diagrams, then in
each Block is a Block Diagram and so forth.
Regards
Ken

Fred J. McCall wrote::
Not necessarily, Pat. There are lots and lots of different factors
involved and different simulations may be better in different areas,
so that sometimes one simulation works better and sometimes another
does.

So there may be no 'best' one and cherry picking from each one to make
a 'best' one is not a simple task.



Well, one obvious way to check would to have each of the programs
predict exactly where a satellite will end up given its input data
before it is launched, then compare that to what actually happens after
it is launched.
Do that for several launches, and you should be able to figure out which
program gives the best data.
If they are each predicting some aspect of its orbit better than the
others...then it's time to write a new program that incorporates the
best aspects of each of the competing programs and standardize on it.

Pat

"Pat Flannery" wrote in message
lephone...


Fred J. McCall wrote::
Not necessarily, Pat. There are lots and lots of different factors
involved and different simulations may be better in different areas,
so that sometimes one simulation works better and sometimes another
does.

So there may be no 'best' one and cherry picking from each one to make
a 'best' one is not a simple task.



Well, one obvious way to check would to have each of the programs predict
exactly where a satellite will end up given its input data before it is
launched, then compare that to what actually happens after it is launched.

That assumes they're all used for the same thing. Something used for Earth
orbit simulation is probably very different from one used to for launching
to a Lagrange point.

Heck, I could see a sim used for a LEO sat would need to be different than a
sim for a GEO sat.



Do that for several launches, and you should be able to figure out which
program gives the best data.
If they are each predicting some aspect of its orbit better than the
others...then it's time to write a new program that incorporates the best
aspects of each of the competing programs and standardize on it.

But to what real advantage. Now if you change the app to improve one area,
you need ot confirm it in all areas.

Sometimes having separate programs IS the best approach.


Pat




--
Greg Moore
Ask me about lily, an RPI based CMC.

Pat Flannery wrote:
:
:Fred J. McCall wrote::
: Not necessarily, Pat. There are lots and lots of different factors
: involved and different simulations may be better in different areas,
: so that sometimes one simulation works better and sometimes another
: does.
:
: So there may be no 'best' one and cherry picking from each one to make
: a 'best' one is not a simple task.
:
:
:Well, one obvious way to check would to have each of the programs
redict exactly where a satellite will end up given its input data
:before it is launched, then compare that to what actually happens after
:it is launched.
o that for several launches, and you should be able to figure out which
rogram gives the best data.
:If they are each predicting some aspect of its orbit better than the
thers...then it's time to write a new program that incorporates the
:best aspects of each of the competing programs and standardize on it.
:

You're not paying attention, Pat. "... and cherry picking from each
one to make a 'best' one is not a simple task."

--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw