Flight Day 1 redezvous with Space Station altitude targeting ( Orbital mechanics folks...

Targeting the station's altitude increase would give a Flight Day 1
Rendezvous opportunity for an on-time on-day launch. Maybe they shouldn't
waste the Space Station's Rendezvous Targeting Capabilities on the Space
Shuttle, because NASA likes to have a few days On-Orbit before rendezvous.
Soyuz could launch, rendezvous and dock before bedtime. An added bonus
would be an extra couple of days at the Space Station.

I would think Private Astronauts (Space Tourists) would much rather get
out of the cramped ascent/entry vehicle as soon as possible. I mean
really, even if you don't get space sick, do you really want to watch,
smell, and hear the fellow who does, vomiting for a day or two?

--
Craig Fink
Courtesy E-Mail Welcome @
--


On Sat, 02 Dec 2006 07:19:43-0500, John Doe wrote:

Isn't the position of the space station more or less random (in practical
terms) along the orbital path at the time the plane crosses over KSC ?
(aka: launch time for Shuttle)

Does increasing the station's altitude (and incresing the time needed for a
full orbit) really make such a big change to the relative position of ISS
to KSC at the time the orbital plane passes over KSC ?

FD1 requires a highly maneuverable target that sets up the very tight phase
angle
window for launch, and they rarely repeat more than once every four to six
days,
except for very unique altitudes. Tourist convenience is a very poor driver
for such an operational burden.




"Craig Fink" wrote in message
news
Targeting the station's altitude increase would give a Flight Day 1
Rendezvous opportunity for an on-time on-day launch. Maybe they shouldn't
waste the Space Station's Rendezvous Targeting Capabilities on the Space
Shuttle, because NASA likes to have a few days On-Orbit before rendezvous.
Soyuz could launch, rendezvous and dock before bedtime. An added bonus
would be an extra couple of days at the Space Station.

I would think Private Astronauts (Space Tourists) would much rather get
out of the cramped ascent/entry vehicle as soon as possible. I mean
really, even if you don't get space sick, do you really want to watch,
smell, and hear the fellow who does, vomiting for a day or two?

--
Craig Fink
Courtesy E-Mail Welcome @
--


On Sat, 02 Dec 2006 07:19:43-0500, John Doe wrote:

Isn't the position of the space station more or less random (in practical
terms) along the orbital path at the time the plane crosses over KSC ?
(aka: launch time for Shuttle)

Does increasing the station's altitude (and incresing the time needed for
a
full orbit) really make such a big change to the relative position of ISS
to KSC at the time the orbital plane passes over KSC ?

There are other ways to do it rather than a highly maneuverable target.
Time compensates for this, so a much less maneuverable ISS could fly
through a plane/phase window some time in the future. Since it's going to
be doing maneuvers anyway to raise it's orbit, just modify the timing.

ISS hitting a plane/phase window has two constraints, or dependent
variables. Therefore, with two appropriate independent variables it should
be able to hit the window at some future date. The date/time of the
maneuver and altitude of the maneuver should do it, or possibly two dates
and altitude maneuvers.

Oh, you want a bunch of days with rendezvous opportunities. Add another
dependent variable, that makes three. So, the two maneuver reboost would
work. Independent variables: Time of burn 1, altitude of burn 1, Time of
burn 2. Dependant variables: Altitude of burn 2 (really could be
considered as altitude at the rendezvous date + delta altitude due to
drag), future rendezvous orbital plane and phase.

Of course, the altitude of the rendezvous would have to be a fixed altitude
where the Orbital phase remains constant from day to day. In other words
the Revolutions per day would have to be an integer.

http://www.heavens-above.com/orbitdi...ST&satid=25544

Currently, ISS is at 15.7853 revolutions per day. So they would have had
to raise it's altitude some time in the past to an intermediate
altitude, then raised it again to get to an even 16 revolutions per day,
with the right plane and phase.

Ahhh, but regression of the plane would still be a problem for multiple
days. Another dependant variable, without a good independant one. Sorry,
you only get one day. Or two? What is the regression rate of ISS at an
integer revolutions per day altitude?

Orbital Science's Pegasus could easily fix the rendezvous plane problem.
http://www.orbital.com/SpaceLaunch/Pegasus/index.html
Or, a winged ascent vehicles from a fixed launch site with a resonable
amount of crossrange. Also, it may not be as much of a problem for the
Russians who launch due east.

It's just a optimization or constraints problem with three independent and
three dependent variables.

NASA wouldn't be interested in this anyway. I think they like having the
three day rendezvous, the Orbiter is pretty roomy and NASA doesn't sell
tickets. But, the Russian might. A couple of extra days at the Space
Station, fewer days in a cramped capsule, overall it would be a much more
pleasant trip for Private Astronauts (Space Tourist). The Russians already
do a same day deorbit/entry.

16 revs per 24 hour day, 2/3, hummm? A phased locked orbit?

--
Craig Fink
Courtesy E-Mail Welcome @
--

On Sat, 02 Dec 2006 16:44:45+0000, Jim Oberg wrote:

FD1 requires a highly maneuverable target that sets up the very tight phase
angle
window for launch, and they rarely repeat more than once every four to six
days,
except for very unique altitudes. Tourist convenience is a very poor driver
for such an operational burden.




"Craig Fink" wrote in message
news
Targeting the station's altitude increase would give a Flight Day 1
Rendezvous opportunity for an on-time on-day launch. Maybe they shouldn't
waste the Space Station's Rendezvous Targeting Capabilities on the Space
Shuttle, because NASA likes to have a few days On-Orbit before rendezvous.
Soyuz could launch, rendezvous and dock before bedtime. An added bonus
would be an extra couple of days at the Space Station.

I would think Private Astronauts (Space Tourists) would much rather get
out of the cramped ascent/entry vehicle as soon as possible. I mean
really, even if you don't get space sick, do you really want to watch,
smell, and hear the fellow who does, vomiting for a day or two?

--
Craig Fink
Courtesy E-Mail Welcome @
--


On Sat, 02 Dec 2006 07:19:43-0500, John Doe wrote:

Isn't the position of the space station more or less random (in practical
terms) along the orbital path at the time the plane crosses over KSC ?
(aka: launch time for Shuttle)

Does increasing the station's altitude (and incresing the time needed for
a
full orbit) really make such a big change to the relative position of ISS
to KSC at the time the orbital plane passes over KSC ?

On Dec 2, 8:44 am, "Jim Oberg" wrote:
FD1 requires a highly maneuverable target that sets up the very tight phase
angle window for launch, and they rarely repeat more than once every four to six
days, except for very unique altitudes. Tourist convenience is a very poor driver
for such an operational burden.
SAS also argues for giving the crew a couple days of relatively low
workload time before docking. The Russians did first day rendezvous +
docking on some of their early flights, but have since settled on FD
2/3 just like NASA, despite the fact that there is very little to do on
Soyuz if everything is working correctly. There is some argument that
the small space is more comfortable for those suffering SAS. (although
Ansari reported somewhat the opposite.)

On 2 Dec 2006 15:16:47 -0800, in a place far, far away, "hop"
made the phosphor on my monitor glow in such
a way as to indicate that:

On Dec 2, 8:44 am, "Jim Oberg" wrote:
FD1 requires a highly maneuverable target that sets up the very tight phase
angle window for launch, and they rarely repeat more than once every four to six
days, except for very unique altitudes. Tourist convenience is a very poor driver
for such an operational burden.
SAS also argues for giving the crew a couple days of relatively low
workload time before docking. The Russians did first day rendezvous +
docking on some of their early flights, but have since settled on FD
2/3 just like NASA, despite the fact that there is very little to do on
Soyuz if everything is working correctly. There is some argument that
the small space is more comfortable for those suffering SAS. (although
Ansari reported somewhat the opposite.)

I'm sure it depends on the individual (and how susceptible they are to
claustrophobia). I doubt if I could ride a Soyuz at all, myself. For
that matter, I'd have trouble crossing the bridge to the Shuttle (or
in the past, to Apollo) due to acrophobia, though I have no problem
with flying per se.

h (Rand Simberg) wrote in
:

On 2 Dec 2006 15:16:47 -0800, in a place far, far away, "hop"
made the phosphor on my monitor glow in such
a way as to indicate that:

On Dec 2, 8:44 am, "Jim Oberg" wrote:
FD1 requires a highly maneuverable target that sets up the very
tight phase angle window for launch, and they rarely repeat more
than once every four to six days, except for very unique altitudes.
Tourist convenience is a very poor driver for such an operational
burden.
SAS also argues for giving the crew a couple days of relatively low
workload time before docking. The Russians did first day rendezvous +
docking on some of their early flights, but have since settled on FD
2/3 just like NASA, despite the fact that there is very little to do
on Soyuz if everything is working correctly. There is some argument
that the small space is more comfortable for those suffering SAS.
(although Ansari reported somewhat the opposite.)

I'm sure it depends on the individual (and how susceptible they are to
claustrophobia). I doubt if I could ride a Soyuz at all, myself. For
that matter, I'd have trouble crossing the bridge to the Shuttle (or
in the past, to Apollo) due to acrophobia, though I have no problem
with flying per se.

I think some of that depends on footing. The last time I went to KSC, I
walked on the 235' level at the FSS at 39B and walked the catwalk to the
White Room at the 195' level with no effects of acrophobia, despite being
out in the elements and a fairly substantial wind. But when I went into the
VAB and walked on a service platform in High Bay 1, I suddenly got very
anxious and wanted to go nowhere near the guardrails, even though the
platform was at a lower height than the White Room and the walls of the VAB
protected us from the wind. The difference was the footing and the
appearance of protection: the FSS had very solid footing and stout,
permanent steel guardrails. The platform in the VAB was intended to slide
in to surround a shuttle stack and had fairly wobbly footing, and its
guardrails were the chain type.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

In article .com,
hop wrote:
SAS also argues for giving the crew a couple days of relatively low
workload time before docking. The Russians did first day rendezvous +
docking on some of their early flights, but have since settled on FD
2/3 just like NASA...

And for the same reason: it gives time to adjust orbit phasing, allowing
reasonably wide and frequent launch windows. Spacesickness, post-launch
setup activities, etc. are ultimately secondary issues; the orbital
mechanics dominate the problem. (Can you fly docking maneuvers while
spacesick? Well, it may not be much fun, but Apollo did it routinely.)

It's possible to rendezvous not just on the first day, but on the first
*orbit* -- it was done by Gemini -- but unless you use air launch (or just
possibly water launch) to vary the launch location, or have a lot of spare
fuel to play orbital games, or are located on the equator and launching
into an equatorial orbit, it's impractical. And first-day isn't a whole
lot better. Everything has to be just right, which means very infrequent
launch windows, and the windows are also very short, because there's no
slack in the schedule once you lift off.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Dec 2, 9:05 pm, (Henry Spencer) wrote:
And for the same reason: it gives time to adjust orbit phasing, allowing
reasonably wide and frequent launch windows. Spacesickness, post-launch
setup activities, etc. are ultimately secondary issues; the orbital
mechanics dominate the problem. (Can you fly docking maneuvers while
spacesick? Well, it may not be much fun, but Apollo did it routinely.)

Agreed. I was in responding to Craigs suggestion that first day
rendezvous would be more tourist friendly.

In any case, I suspect it will be a long time before tourist comfort is
a driving factor in the market. There are plenty of people in the world
who pay lots of money to do uncomfortable things.

"Henry" == Henry Spencer writes:

Henry It's possible to rendezvous not just on the first day, but on
Henry the first *orbit* -- it was done by Gemini -- but unless you
Henry use air launch (or just possibly water launch) to vary the
Henry launch location, or have a lot of spare fuel to play orbital
Henry games, or are located on the equator and launching into an
Henry equatorial orbit, it's impractical. And first-day isn't a
Henry whole lot better. Everything has to be just right, which means
Henry very infrequent launch windows, and the windows are also very
Henry short, because there's no slack in the schedule once you lift
Henry off.

How much extra fuel would you need to carry to achieve an earlier
rendezvous, but without seriously impacting the launch window size?
Or would the orbital mechanics of going to a higher/slower orbit and
then dropping back down to match cost too much in terms of payload
performance?

Since fuel is cheap, why not spend it to cut down on the time, which
isn't cheap in some sense.

John

On Thu, 1 Feb 2007 15:26:41 -0600, John Stoffel wrote
(in article ):

Since fuel is cheap, why not spend it to cut down on the time, which
isn't cheap in some sense.

Because while fuel itself is cheap, "fuel in orbit" is simply mass until it
gets to orbit, and mass to orbit is NOT cheap.

--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash