Setback for Rutan

In article ,
Robert Briggs writes:
Alan Minyard wrote:

At apogee there would be almost no control authority (lack of sufficient air
molecules). Do they have a thruster system for control at that altitude??

If there is *any* remotely usable control authority then the thing ain't
in space for any reasonable value of "space".

A couple or three points:
Control Authority doesn't have to mean aerodunamic controls - SS1
has a cold-gas RCS system for attitude control a very low EAS.

There is no such thing a "a reasonable value of 'space'".
It's not like there's a definite dividing line between Atmosphere
adn Vacuum - the density of the atmosphere thrails off as height
increases, but it doesn't entirely go away. Aerodynamic drag, and
the variations in that that occur was the Earth's atmosphere expands
and contracts due to Solar Radiation, are a significant factor in
the lifetime of an orbiting satellite. (Remember Skylab). That
Orbital Decay that you hear so much of is mostly caused by
atmospheric drag.

(By the same token, I'd like to punch Eugene Sanger, or his
translators, in the nose for starting that whole like of crap about
"skipping" off the Earth's atmosphere with a lifting spacecraft. It
doesn't and can't happen that way. The only way to change your vector
with such a craft while re-entering is to fly up, rather than bounce
up - you've got to be flying fast enough, in thick enough air, to
allow a normal pull-up. (As a reference, note that Columbia had
almost reached an EAS that would have allowed a pull-up, but hadn't
yet))

The definition of where "space" starts is completely arbitrary. The
USAF specifies it as 50 miles MSL. The FAI specifies it as 100 km.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

On Wed, 23 Jun 2004 13:35:44 -0400, (Peter Stickney) wrote:

In article ,
Alan Minyard writes:
On Wed, 23 Jun 2004 07:38:39 -0600, "Jeff Crowell" wrote:

Peter Kemp wrote:
According to BBC reports quoting Rutan there were severe control
problems that forced the pilot (ok, ok, astronaut) to resort to backup
controls just after boost (uncommanded roll) and again near Apogee
(nothing specific mentioned).

From where I sit, let's call him a a pilot... he WAS driving, after all,
not just watching the pretty lights.

Melville and Rutan were on Leno last night, pilot said the problem
was with the trim system near/at apogee, not control system, though
ISTR someone mentioning right after the flight that they had had
some roll instability during the flight, and right after launch it looked
in the video as if the plane (spacecraft?) was rolling back and forth
about 40-50 degrees each way from vertical.


Jeff

At apogee there would be almost no control authority (lack of sufficient air
molecules). Do they have a thruster system for control at that altitude??

Yes - there's a cold-gas RSC system. See my response to Jim Yanik's
post on this thread.

Thanks for the info :-)

Al Minyard

From: Buzzer
Date: 6/23/2004 1:50 AM Central Daylight Time
Message-id:

On Tue, 22 Jun 2004 22:58:19 -0400, Peter Kemp
wrote:

Looks like the flight did not go to plan.

According to BBC reports quoting Rutan there were severe control
problems that forced the pilot (ok, ok, astronaut) to resort to backup
controls just after boost (uncommanded roll) and again near Apogee
(nothing specific mentioned).

He says they're not flying again until they know what the hell
happened, and the next flight will not now be the first for the
X-Prize, but another test flight.

Can't say I blame him, and Starchaser (the next closest IIRC) are 18
months away, so time isn't that critical.

Peter Kemp

And besides they have to try and find all those stupid M&Ms he let
loose in the cockpit.


A miraculous even occurred as a result of the flight. All the M&Msâ„¢ were
converted to Ws.

Dan, U. S. Air Force, retired

From: "Steven P. McNicoll"
Date: 6/23/2004 5:49 AM Central Daylight Time
Message-id: .net


"miso" wrote in message
. com...

Note that they will have to make 2 more trips for the prize if they
miss the 2 week window. Still better to delay then risk life, limb,
and the hardware.


They have to make at least two more trips for the prize regardless of
anything else, as they have yet to make a single qualifying flight.

How did this one not qualify?

Dan, U.S. Air Force, retired

On 23 Jun 2004 21:54:57 GMT, (B2431) wrote:

From: "Steven P. McNicoll"
Date: 6/23/2004 5:49 AM Central Daylight Time
Message-id: .net


"miso" wrote in message
.com...

Note that they will have to make 2 more trips for the prize if they
miss the 2 week window. Still better to delay then risk life, limb,
and the hardware.


They have to make at least two more trips for the prize regardless of
anything else, as they have yet to make a single qualifying flight.

How did this one not qualify?

Not high enough and did not carry 3 humans (although I think 2 of the
"passengers" can be weighted dummies.

Peter Kemp

On Wed, 23 Jun 2004 06:50:21 GMT, Buzzer wrote:

On Tue, 22 Jun 2004 22:58:19 -0400, Peter Kemp
wrote:

Looks like the flight did not go to plan.

According to BBC reports quoting Rutan there were severe control
problems that forced the pilot (ok, ok, astronaut) to resort to backup
controls just after boost (uncommanded roll) and again near Apogee
(nothing specific mentioned).

He says they're not flying again until they know what the hell
happened, and the next flight will not now be the first for the
X-Prize, but another test flight.

Can't say I blame him, and Starchaser (the next closest IIRC) are 18
months away, so time isn't that critical.

Peter Kemp

And besides they have to try and find all those stupid M&Ms he let
loose in the cockpit.

I had to laugh at that. If it were NASA they'd ground the Shuttle for
two years and spend a billion dollars on a new
"M&Ms-don't-become-airborne" system.

In article ,
Peter Kemp writes:
On 23 Jun 2004 21:54:57 GMT, (B2431) wrote:

From: "Steven P. McNicoll"
Date: 6/23/2004 5:49 AM Central Daylight Time
Message-id: .net


"miso" wrote in message
e.com...

Note that they will have to make 2 more trips for the prize if they
miss the 2 week window. Still better to delay then risk life, limb,
and the hardware.


They have to make at least two more trips for the prize regardless of
anything else, as they have yet to make a single qualifying flight.

How did this one not qualify?

Not high enough and did not carry 3 humans (although I think 2 of the
"passengers" can be weighted dummies.

The flight was high enough - IIRC, the apogee was 100.125 km, so they had
1/8 of a km in the bag. (Not enough really, you wnat to have more in
the case of an instrumentation hiccup)

In order to qualigy as an X-Prize flight, it has to be carrying
ballast equivalent to two passengers (And no, you don't get to pick
the passengers, it's a specified weight), and the flight has to have
been pre-announced by 30 days, with another flight following within 14
days.
This flight wasn't intended to be an X-Prize flight, but a test
flight. Burt Rutan's been running an orderly and reaosonable test
program, taking each stage in bite-sized increments, and resolving
problems as he goes. (His normal approach) There hasn't yet been the
30 day pre-boarding call.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

"B2431" wrote in message
...

How did this one not qualify?


The X Prize flights require three people aboard or a pilot and ballast
equivalent to two people. Melvill flew solo and carried no ballast.

"Peter Kemp" wrote in message
...

Not high enough and did not carry 3 humans (although I think 2 of the
"passengers" can be weighted dummies.


It was high enough but did not carry the two passengers/ballast.

On Thu, 24 Jun 2004 02:14:44 GMT, "Steven P. McNicoll"
wrote:


"Peter Kemp" wrote in message
.. .

Not high enough and did not carry 3 humans (although I think 2 of the
"passengers" can be weighted dummies.


It was high enough but did not carry the two passengers/ballast.

Sorry for some reason I had 120km in mind - checking I am wrong
(again!)

Peter Kemp