Space Ship One Tumbling

[selenite0]

I'm following the SS1 flight in progress. http://www.spaceflightnow.com/ss1/status.html

Apparently it went into a tumble at the end of the rocket burn but recovered as it began reentry. I was afraid this would happen, I'm glad they recovered from it. I think SS1's vertical CG isn't on the centerline, probably because they added extra mass to meet the X-Prize requirements without balancing it. So they had a steadily increasing pitch torque as the propellant burned off and finally couldn't hold it steady.

It's past the danger now. Should be an easy fix. They'll have to balance the payload before launch (which will be a pain to analyze) or have some active ballast (ie, a weight on a ropes and pulleys contraption) so they can adjust the CG in flight.

UPDATE: Okay, I'm now seeing a report that SS1 was rolling. If it was tumbling on the roll axis instead of the pitch axis CG would have nothing to do with it.

FURTHER UPDATE: jfoxdavis was watching the video and tells me the nose kept pointing up, so CG problems had nothing to do with the roll problem.

Never mind.

Comments

[icequeen-tpz.livejournal.com]

Damn, all of that in two weeks to win the X Prize!

[firedrake-mor.livejournal.com]

There's a Tom Smith song about that -- "The Worst Job There Is"that ends with the line "The ballast wants to land."

http://www.tomsmithonline.com/lyrics/worstjob.htm

In all things there must be balance, said my physics prof to me,
And in the days of sailing ships, the ballast was the key,
Some sand and garbage in the bilge are all you need at sea,
But things work slightly differently when you turn in zero-gee.
The ballast must be accurate to ten places, maybe more,
Whether you are dodging asteroids or just going to the store.

When the spaceships first used ballast, they tried everything in sight,
And inert materials at first worked out all right,
But when spaceships first went past light-speed, the laws of physics changed,
Gravitation pulled unequally, several ships were... rearranged.
They finally discovered that the ballast must float free,
To go where it's most needed -- so the ballast now is me.

I tried to be a Space Marine, but they wouldn't let me go,
My vision was myopic, my reflexes way too... slow,
And all my dreams of Space Marines and interstellar fame
Were dashed to Hell by defects in my undernourished frame,
But still I made it into space, although my job is dull,
For now I serve as ballast sealed up inside the hull.

Now inert, unliving ballast will not do the job -- instead,
They've got me in a Kevlar jumpsuit, pockets lined with lead,
The hyperdrive computer says where we'll need extra mass,
We accelerate to F.T.L. and inertia kicks my ass,
I bounce around between the seams, grabbing anything at hand,
Like a plane whose one wing tears and falls, the ballast wants to land.You've made, I think, a good guess about what happened, since, as I understand it, the only difference between this flight and the earlier one was the mass representing the two passengers and the extra fuel.

I noted the webcast was running about 10 seconds behind CNN, and my heart was in my throat during the rolls. I'll be waiting to hear Mike Medville's comments.

[selenesue.livejournal.com]

I got to work as early as I could but didn't seem to be able to see the webcast. When I plugged into the webcast site, all I got was an explanation of the prize, which is not what I was looking for, darnit. I'm glad all went well.