SS1 -- one down, one to go!

Numerous news sites (Yahoo, BBC, Google, Reauters) reporting a
successful flight despite control problems, which might be some PIO
(cue Mary).

Engine was cutoff early, so the extra capacity wasn't tested. Not
sure whether a bigger kick at ignition was part of flight.

/dps

On Wed, 29 Sep 2004 16:19:07 -0500, (dave
schneider) wrote:

Numerous news sites (Yahoo, BBC, Google, Reauters) reporting a
successful flight despite control problems, which might be some PIO
(cue Mary).

....Didn't anyone explain to Mike that the victory rolls are supposed
to come at the *end* of the mission?

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

OM wrote:

...Didn't anyone explain to Mike that the victory rolls are supposed
to come at the *end* of the mission?


Before they start building a operational passenger version of that
thing, they had better have a serious reconsideration of its flight
control system; it's had two major excursions from its flight plan on
two successive flights.
Either that, or it might be time to change pilots.

Pat

In article , says...


OM wrote:

...Didn't anyone explain to Mike that the victory rolls are supposed
to come at the *end* of the mission?


Before they start building a operational passenger version of that
thing, they had better have a serious reconsideration of its flight
control system; it's had two major excursions from its flight plan on
two successive flights.
Either that, or it might be time to change pilots.

According to Rutan & co., it's a known problem with SS1 and has
been addressed in the design of the next spacecraft.

But apparently hard to fix once a craft is flyable.

Diane

In article MPG.1bc5afd11e72a232989827@news-server,
Diane Wilson wrote:

According to Rutan & co., it's a known problem with SS1 and has
been addressed in the design of the next spacecraft.

I saw that; he said specifically that the craft was fairly unstable in
roll, which makes sense given the combination of inherently light-weight
construction (which results in a low moment of inertia) and large
control surfaces. I wonder if the flight control system is sufficiently
complex to allow for appropriately modulated control inputs, especially
at the initiation of the roll. I mean, after all, how likely is this
craft to need to roll at very high rates, especially during boost?

But apparently hard to fix once a craft is flyable.

I don't think Rutan's comments really meant that, at least not
literally. The fix - for SS1 at least - could be a simple as rate
limiters for the roll controls, combined with a few more operational
constraints on the weather conditions and trajectories allowed for
launches. On the other hand, it would be very hard to test these
interim fixes fully without substantially delaying their efforts to win
the Prize, either by delaying the planned second flight too long, or by
bumping a new set of two flights out a couple of months and allowing
Armadillo or whomever a shot to get back in the game.

I do believe him, however, when he says that the "next spaceship"
(whether that would be one planned for Virgin Galactic(*) or another
putative SS2-type test craft) has been designed to address this issue.

(*) Self-congratulatory-pat-on-back observation: when Scaled first
unveiled SS1 and Paul Allen's role was still not publicly known, I
suggested the backer might be Richard Branson - it appears I missed the
mark, but not by much! :-p

--
Herb Schaltegger, B.S., J.D.
"Never underestimate the power of human stupidity."
~ Robert A. Heinlein
http://www.angryherb.net

Herb Schaltegger wrote in message ...
In article MPG.1bc5afd11e72a232989827@news-server,
Diane Wilson wrote:

According to Rutan & co., it's a known problem with SS1 and has
been addressed in the design of the next spacecraft.

I saw that; he said specifically that the craft was fairly unstable in
roll, which makes sense given the combination of inherently light-weight
construction (which results in a low moment of inertia) and large
control surfaces. I wonder if the flight control system is sufficiently
complex to allow for appropriately modulated control inputs, especially
at the initiation of the roll. I mean, after all, how likely is this
craft to need to roll at very high rates, especially during boost?

See
http://www.scaled.com/projects/tierone/data_sheets/PDF/Posterboard%20-%20SpaceShipOne.pdf

and

http://www.scaled.com/projects/tierone/data_sheets/PDF/Posterboard%20-%20Flight%20Navigation%20Unit.pdf

While you're at it, you might as well get the other posterboards at
http://www.scaled.com/projects/tierone/info.htm

/dps

In article ,
(dave schneider) wrote:

See
http://www.scaled.com/projects/tiero...ard%20-%20Spac
eShipOne.pdf

and

http://www.scaled.com/projects/tiero...ard%20-%20Flig
ht%20Navigation%20Unit.pdf

While you're at it, you might as well get the other posterboards at
http://www.scaled.com/projects/tierone/info.htm

What makes you think I haven't? There's nothing in the
publicly-released information concerning the details of the
flight-control system, at least at the level of engineering detail
required to addressed the question I raised.

--
Herb Schaltegger, B.S., J.D.
"Never underestimate the power of human stupidity."
~ Robert A. Heinlein
http://www.angryherb.net

OM om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote:
On Wed, 29 Sep 2004 16:19:07 -0500, (dave
schneider) wrote:

Numerous news sites (Yahoo, BBC, Google, Reauters) reporting a
successful flight despite control problems, which might be some PIO
(cue Mary).

...Didn't anyone explain to Mike that the victory rolls are supposed
to come at the *end* of the mission?

OM

I probably should have made the subj line "one up, one to go!"

http://www.scaled.com/projects/tierone/video.htm has a clip from yesterday.

/dps

On Thu, 30 Sep 2004 03:07:35 -0500, Pat Flannery
wrote:

Before they start building a operational passenger version of that
thing, they had better have a serious reconsideration of its flight
control system; it's had two major excursions from its flight plan on
two successive flights.

....Or at least market each flight along the lines of a roller coaster
ride :-P

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

Herb Schaltegger wrote:
(dave schneider) wrote:
See
http://www.scaled.com/projects/tiero...ard%20-%20Spac
eShipOne.pdf

[...]
What makes you think I haven't? There's nothing in the
publicly-released information concerning the details of the
flight-control system, at least at the level of engineering detail
required to addressed the question I raised.

Well, the posterboard implies that the stick-and-rudder is
mechanically linked, although hydralic is possible. The only servos
shown are for the horizontal stabilzers and lower rudders "for trim
and supersonic flight control".

One can make educated guesses at the level of complexity of the flight
control system based on the available information. It looks like the
HS-LR section is the only part that could "modulate" the pilot's
input, but I suppose someone somewhere has done a hydraulic valve that
might serve. Probably Pat Flannery has already translated the
engineering documents from the original 1940s German ;-)

/dps