Danish rocket flies

In article
tatelephone,
says...

On 6/8/2011 3:40 PM, Rick Jones wrote:
In sci.space.policy Pat wrote:
If I'd been doing it, realizing the flight profile was going to be the
same on each passenger flight, it would just be a big solid, like a
glorified JATO bottle.

You've just suggested using a solid to launch humans. Don't we now
have to burn you at the stake?

It's not that large, and we've been using solid fuel engines in the form
of JATO bottles on aircraft for over fifty years.
We used to have small Fairchild regional airliners land at our airport
that carried a JATO bottle in the tailcone in case it lost power in one
of its engines right after takeoff.
Way overbuild the engine casing and it should be as safe as a JATO bottle.

You could take that approach, but the performance would be lousy.
Overbuilding an liquid fueled rocket engine for reliability will result
in much higher performance than doing the same for a solid.

After they fixed the SRBs on the Shuttle due to the Challenger accident,
I'd actually trust them with my life more than the SSMEs, which are very
complex devices.

I wouldn't. You still can't shut down the RSRM's on the shuttle. That
and the SSME's have been tweaked a lot over the years. Today's SSME's
are far more reliable than the originals.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

In article , says...

Pat Flannery writes:

On 6/9/2011 1:44 AM, Jochem Huhmann wrote:
But an amateur rocket with an amateur solid and a passenger strapped on
top of it with no way to shut down the engine and no way to get away?
Bad idea.

There are a lot of proven solid rocket types on the international market
already that one could pick and chose from to use in a unmodified form;
may I suggest a SRAM motor?

I was under the impression that amateur rocketry is about building
rockets, not buying them?

You're correct. Amateur rocketry is all about proving that a few people
working in their spare time can build and fly rockets. Buying an off
the shelf engine like this would be "cheating".

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

On 6/9/2011 1:44 AM, Jochem Huhmann wrote:
But an amateur rocket with an amateur solid and a passenger strapped on
top of it with no way to shut down the engine and no way to get away?
Bad idea.

There are a lot of proven solid rocket types on the international market
already that one could pick and chose from to use in a unmodified form;
may I suggest a SRAM motor?

Pat

In sci.space.history Jeff Findley wrote:
You're correct. Amateur rocketry is all about proving that a few
people working in their spare time can build and fly rockets.
Buying an off the shelf engine like this would be "cheating".

So all the folks at LDRS pour their own motors?

rick jones
--
The glass is neither half-empty nor half-full. The glass has a leak.
The real question is "Can it be patched?"
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

In article XJWdnR6DEsqci2
hdakotatelephone,
says...

On 6/9/2011 2:21 AM, Jochem Huhmann wrote:

There are a lot of proven solid rocket types on the international market
already that one could pick and chose from to use in a unmodified form;
may I suggest a SRAM motor?

I was under the impression that amateur rocketry is about building
rockets, not buying them?

Since they are intending to carry paying passengers on it, this
certainly qualifies as professional rocketry. ;-)

Only if they're paying passengers. If the passenger is one of the
members of "the team" and they're not paying a separate fee for the
ride, it's an amateur launch.

I see this as similar to the experimental (kit/garage) aircraft
industry. If I build an experimental aircraft in my garage from a kit
and register it as such, I'm barred from using it for commercial
purposes. I can, however, fly it myself since I am assuming all of the
responsibility and liability of flying the thing.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011

On 6/9/2011 2:21 AM, Jochem Huhmann wrote:

There are a lot of proven solid rocket types on the international market
already that one could pick and chose from to use in a unmodified form;
may I suggest a SRAM motor?

I was under the impression that amateur rocketry is about building
rockets, not buying them?

Since they are intending to carry paying passengers on it, this
certainly qualifies as professional rocketry. ;-)

Pat

On 6/10/2011 7:20 AM, Jeff Findley wrote:

Since they are intending to carry paying passengers on it, this
certainly qualifies as professional rocketry. ;-)

Only if they're paying passengers. If the passenger is one of the
members of "the team" and they're not paying a separate fee for the
ride, it's an amateur launch.

I see this as similar to the experimental (kit/garage) aircraft
industry. If I build an experimental aircraft in my garage from a kit
and register it as such, I'm barred from using it for commercial
purposes. I can, however, fly it myself since I am assuming all of the
responsibility and liability of flying the thing.

The government basically said they were going to cut this concept some
slack (though I'm sure the passengers who fly on it are going to sign a
pretty comprehensive form saying Virgin Galactic isn't legally
responsible if something goes fatally wrong during a flight, and you
probably want to talk to your insurance company before getting into the
Enterprise, as that may void any policies you have, like climbing Mount
Everest would), but if they have a fatal accident with it on a flight
they are going to come down on it like a rock with regulations, and that
will be the end of suborbital passenger flights.
This seems like a reasonable idea, but it sure puts a lot on Virgin
Galactic's shoulders regarding safety, as one major screw-up, and not
only they, but the whole prospective industry, are dead in the U.S.

Pat

On 6/10/2011 7:52 AM, Niels Jørgen Kruse wrote:
Pat wrote:

On 6/9/2011 2:21 AM, Jochem Huhmann wrote:

There are a lot of proven solid rocket types on the international market
already that one could pick and chose from to use in a unmodified form;
may I suggest a SRAM motor?

I was under the impression that amateur rocketry is about building
rockets, not buying them?

Since they are intending to carry paying passengers on it, this
certainly qualifies as professional rocketry. ;-)

They don't intend to carry paying passengers.

Whoops, we are referring to the Danish rocket instead of SpaceShipTwo.
Considering that the Danish team has at least two improved versions
they've designed (including this unfortunate scale diagram comparing
them in size to a V-2 with swastikas on it, which none of the real ones
had*
http://fb.peterl.org/wp-content/uplo...cd626de0e6.jpg

Outside of this of course:
http://www.lileks.com/institute/stag...963/index.html
....it looks like they've given some thought to sending paying passengers
up an a future version of it.

* I knew a guy from Copenhagen; he told me what happened to all the
citizens of that city that were guilty of collaboration with the Nazis
at the end of the war...it involved a lot of nooses and the city's lamp
posts.
"They told us we were Norse Aryans just like them...we were NOT just
like THEM, we were MORAL CHRISTIANS!".

Pat

Pat Flannery wrote:

Whoops, we are referring to the Danish rocket instead of SpaceShipTwo.
Considering that the Danish team has at least two improved versions
they've designed (including this unfortunate scale diagram comparing
them in size to a V-2 with swastikas on it, which none of the real ones
had*
http://fb.peterl.org/wp-content/uplo...84e1ff6f4cd626
de0e6.jpg

Did you notice the "Modified by Gizmodo.com" watermark?

Their designs change a lot while metal has not been bent and this
graphic is obsolete. (The dome on top design is out, they want to put
parachutes there - at least this week.)

* I knew a guy from Copenhagen; he told me what happened to all the
citizens of that city that were guilty of collaboration with the Nazis
at the end of the war...it involved a lot of nooses and the city's lamp
posts.
"They told us we were Norse Aryans just like them...we were NOT just
like THEM, we were MORAL CHRISTIANS!".

That is not historically correct, which I hope is not a great shock to
you. Some that were armed chose to go down in a hail of bullets after
sniping at celebrating crowds, that was all. (As in other countries
there were girls getting their hair cur off in jeering crowds.)

--
Mvh./Regards, Niels Jørgen Kruse, Vanløse, Denmark

Niels Jørgen Kruse wrote:

Pat Flannery wrote:

The interesting part is the use of rollerons to stabilize it. I assume
they spin these up with compressed air prior to launch, and although
that would allow the gyros to pivot the fins, how much control authority
the fins have looks kind of iffy to me considering their small size.

I don't believe they were spun up for launch. The rocket was supposed to
rotate, just not too fast for the pilot. Rotation was their best hope of
canceling out bias and getting the thing to go straight up.

I watched the video of the debriefing event last saturday. Main points:

Tilting over was due to thrust vector being off axis by ~1.5 degrees.
Most of the tilting over happened just after clearing the rail and
largely stopped after the rocket started rotating. It was still going up
at abort.

Thrust oscillation must be a problem in the LOX feed because the
frequency is so low.

The cries of supersonic! were premature, speed was Mach 0.9 at abort.

The inertial navigation system agreed very well with data from the
doppler radar. It has enough processing power left over to do active
guidance too.

The booster had cameras of its own, but downlink was lost due to
interference from the newscopter.

In other news, they don't want to gamble on getting active guidance
ready for next launch season, so they are planning a dedicated launch
for parachute testing. To mess with people, they are shaping it like the
Apollo LES.

--
Mvh./Regards, Niels Jørgen Kruse, Vanløse, Denmark