Space Ship One Sept. 29th Flight

[propforce]

<font color="yellow"><i>Mike Melvill just told reporters gathered at the runway that it was pilot error that caused the unplanned roll during the rocket engine firing of today's launch. He said SpaceShipOne performed properly and he was never worried during the flight, knowing he could damp out the roll motion. Once he knew the 62-mile target altitude would be reached, he commanded the engine to shut down. The cutoff occurred 11 seconds early. </i></font><br /><br />I didn't think he would curse the engine in front of reporters <img src="/images/icons/wink.gif" /> But I am sure they will have intense discussions behind closed doors.<br /><br />Question for the more knowledgeable guys here. Right after the 'flame' went out on the hybrid rocket, I could still see white gaseous 'plume' coming out for approx 10~15 sec and it looked like was still producing thrust. I wonder if it was still burning on the hybrid or was it just a venting of nitrous oxide tank?<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[abq_farside]

Not knowing much about aerodynamics - <br /><br />Assuming he did not turn off engine when he did - Would not the roll have stopped once the he reached maximum altitude anyway (what ever it turned out to be)? With no force (engine shutdown) pushing it upward, the velocity of the vehicle would have been 0 at max alt. and I would assume, maybe incorrectly, that the roll would have stopped too.<br /><br />And on the way back down, with the roll stopped it seems it he would have been able to easy get it back under control. <div class="Discussion_UserSignature"> <p> </p><p><em><font size="1" color="#000080">Don't let who you are keep you from becoming who you want to be!</font></em></p> </div>

 

[centsworth_II]

<font color="yellow">"These really are staggering forces we're working with..."</font><br /><br />Given the forward speed, pitch would have been disatrous. As it is, the roll probably was not worse than experienced during a typical aerobatic manouver. The fact that it was unplanned is of course cause for concern. <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="yellow">"...if he had 11 more seconds of fuel then just think of how high he could have topped out at."</font><br /><br />I'm assuming that there was no worry of reaching escape velocity.<img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[dreada5]

<blockquote><font class="small">In reply to:</font><hr /><p>Would not the roll have stopped once the he reached maximum altitude anyway <p><hr /></p></p></blockquote><br /><br />No, I don't believe it would. There'd be nothing to stop it unless RCS was used.

 

[samilite]

Does anyone have the video of the ascend available yet? I tried to record it myself, but the video between release and gaining max altitude is missing. I guess the stream got very lagged during that time.

 

[rocketwatcher2001]

Well, there is something to be said about spin stability. A spinning rocket will go straight, for the most part........ <img src="/images/icons/smile.gif" /> <br /><br />*sigh* I normally don't like manned launches to be that dramatic. Going straight up, at mach 3, rolling roughly 180 degrees per second. At that point I'd want to be wearing my brown pants. <div class="Discussion_UserSignature"> </div>

 

[thermionic]

<br /> " At that point the attitude rates would not be a problem for the structure however they must be corrected before entry. "<br /><br /><br />I had thought that part of the intent of the shuttlecock configuration was that it would be self-righting, only stable with the belly down and fins up. I guess that isn't the case?

 

[dreada5]

It DID appear quite stable during descent in the shuttlecock configuration.

 

[propforce]

<font color="yellow"><i>At that point I'd want to be wearing my brown pants. </i></font><br /><br />Is that why the French Army wear them ??? <div class="Discussion_UserSignature"> </div>

 

[lunatic133]

Brown pants ... tehee.<br /><br />I know it sucks but risk is the name of the game :-/

 

[radarredux]

> <i><font color="yellow">*sigh* I normally don't like manned launches to be that dramatic. Going straight up, at mach 3, rolling roughly 180 degrees per second.</font>/i><br /><br />Reminds me of Neil Armstrong's Gemini 8 mission when a stuck thruster (or something) caused their craft to start a pretty serious roll.</i>

 

[centsworth_II]

<font color="yellow">"It DID appear quite stable during descent in the shuttlecock configuration."</font><br /><br />It does appear that as long as the craft survives the trip to space, it doesn't matter what it's attutude or motion as it reenters, it will regain a stable attitude due to the shuttlecock configuration. This looks to be a near failsafe method -- as long as there is no snag in moving the wings into the proper configurations as needed. <div class="Discussion_UserSignature"> </div>

 

[halman]

shuttle_guy,<br /><br />I have to wonder at the statement Melville made that the spin was his fault. Could he have decided to attempt some spin stabilization, and gotten into a feedback loop? Spinning the ship would be the best way to compensate for off-axis thrust without shutting the engine down.<br /><br />I also believe that the "shuttlecock" feature would save the ship from a disasterous re-entry, because the attitude would be corrected as soon as air pressure began to increase. If I remember from what I read years ago about the X-15 flights, the spin did not result in the vehicle desintigrating until it had fallen thousands of feet. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[halman]

RadarRedux,<br /><br />I believe that you are referring to the incident which occurred when the Gemini was docked with the Agena, and a thruster on the Agena stuck in the 'on' position. Armstrong attempted to correct, realized that he would use all his reaction propellant without being able to stop the yaw, which was spinning the two vehicles around the center of gravity, and undocked. After the Gemini was thrown clear of the Agena, Armstrong regained control. I wouldn't be surprised if there was a hole in his seat ripped out. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[thermionic]

My wife said she doesn't have anything scheduled for me on Monday. I might do a little driving this weekend, camp out in the desert for a night!

 

[bobvanx]

There are some places to stay that aren't far. And some interesting places, to visit. Just down the highway, towards LA, there's Vasquez Rocks State Park. I don't think overnight stays are allowed at that particular place, but you'll recognize the landscape from various Star Trek and Westerns.

 

[SpaceKiwi]

Wonderful news, congratulations to all concerned!<br /><br />Melvill seems to be accentuating the positive about it all. I imagine he is correct when he says it is easy to get some spin happening relatively easy when you are at that altitude. It seems like the RCS could use a little beefing up. What prospects for adding more gas to it? <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[wvbraun]

Congratulations to Burt Rutan, Mike Melvil and all the other people involved in this project. I'm glad everything was ok in the end despite the roll problem. One down, one to go.

 

[halman]

shuttle_guy,<br /><br />Perhaps I am mistaken, but it would seem to me that the tail booms would be aided in deployment by attitude deviations. Of course, they might be aided so much that they continue beyond the deployed position, but that would seem unlikely also, as they would be thrust to a 90 degree attitude relative to the center of motion. The hinges would probably be the point of failure, if one did occur. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[liquidspace2k]

I wonder if Scaled Composites are trying to fly Space Ship One more then the two times in the 2 weeks, just to show that they made it better reuseablity then what the X-prize needed. I believe they could fly it 3 or 4 times in a 2 week span.

 

[aaron38]

No, they're just trying to do the 2nd flight as soon as posible, so that if something were to go wrong and delay the flight, there's time to fix it before the deadline.<br /><br />Haven't they already said that SS1 is a museum piece as soon as it lands after the next flight?

 

[bobvanx]

I recall reading that, too. They wanted to build up a dataset. If the control problem is something his fancy CFD computer can't get a handle on, he just might need to fly it a couple of extra times before building hardware for Sir Richard.

 

[arobie]

Wow!! All of this is just awesome. I found out that the mission was a success during lunch. My friend and I were trying to keep up with the flight all day though school. We have a few cool teachers who let us check on the internet during school. <br /><br />Reading though the commentary on this thread, my heart stopped when the roll happened. I knew that it had happened, and I knew that it didn't cause tragedy, but still it was exciting. I've also now watched all the video I can of it. That roll looked very bad. <br /><br />I liked how Mike said the mission was perfect and how he called the roll a "Victory Roll". That's awesome! Melvill is just awesome.<br /><br />Looks like they will fly either on the day originally set, or a day earlier on Sunday. If it's on Sunday I can watch it.

 

[arobie]

<font color="yellow"><i>From Spaceflight Now: <br /><br />WEDNESDAY, SEPTEMBER 29, 2004 <br />1309 GMT (9:09 a.m. EDT) <br /><br />The crowds at Mojave are being told to stick around after today's flight for a "major announcement" concerning the X Prize Foundation's future.</i><br /></font><br /><br />What is this about?? Has anyone heard anything??