NASA Sounding Rocket Flight with Cameras

Hi all,

I stumbled upon this last night. [video=youtube;GLhaNd_H5bM]https://www.youtube.com/watch?v=GLhaNd_H5bM[/video] It's a sixteen minute video of a complete 2012 flight of a NASA Terrier-Black Brant sounding rocket as viewed from two cameras, one mounted forward and the other aft (and a synced ground camera at launch as well).

Some things that really fascinated me during the flight:

• The spin rate of the rocket after launch (wow, I had to avert my eyes to avoid getting sea sick!)
• How quiet it gets once the air density drops off.
• The mechanism by when the rocket stops spinning abruptly (1:28 into the video, I'm unsure exactly what it is).
• The final stage dropping away (About 1:40 in).
• When it starts spinning up again on descent.
• The return of sound.
• The deployment of the chutes (difficult to see as they're in the sun).
• The relatively soft landing.

Cool stuff.

There's no sound in the vacuum of space. So you heard the sound return as it enters atmosphere again.

An opposite force perpendicular to rocket airframe hull acting as a torque in opposite direction of rotation would stop the rotation of rocket. Perhaps an RCS unit with a slight gas thrust out of a nozzle. Or perhaps the angular velocity went to zero when the angular momentum was fully used and maybe it was a time warp in film by director's cut of film. The fins are spin stabilized. So in an atmosphere there are multiple force components allowing for a rotation by a force acting perpendicular to fin airfoil by a pressure difference by Bernoulli. If non airfoil there is still force by components of the angle of attack of fin having a lift greater than drag and the one of the force components acts as a torque on rocket hull this rotating it.

And the lift direction of fins is not representative of lift force on rocket by thrust. The fin lift is what rotates the rocket by force components.

Some sounding rockets spin because of precision-canted fins and others use spin motors. Active de-spin systems are used when the payloads don't want to be spinning when deployed.

Spin is required by the range operations for non-guided rockets to minimize dispersion. Around 6 rotations per second. The typical system to remove the spin uses masses on the end of cables (look up "yoyo despin") and often additional small thrusters if precision pointing is needed.

The spin up is usually done with fin canting. Some small sounding rockets historically have used "rifled" launch towers.

It certainly appeared to have some form of spin stabilization and de-spin technology on-board, as well as something to stabilize the payload which may be a gyroscope and what the humming was. I noticed that as soon as there was an interruption in the humming sound, on decent, that it started to spin again. Then when the humming came back it it stabilized, or it was just coincidental. It was interesting seeing their sequencing on recovery. If the altitude was correct it was roughly at 4.6KM that they deployed a drogue/pilot for the main (X-form) then the main deployed shortly after. It was also interesting to see their decent rate. Again if the monitor on the screen was correct it was 5 m/s on touchdown and appeared to fluctuate between 40-10 m/s while on main, which could be attributed to a combination of thermals and ground effect.

Interesting to see how the pros do this..great video!

Some stabilization systems use a counter-rotating mass for find-adjustment of the rotation. (That might be the "hum"). Feedback comes from rate gyros and another reference, such as a prominent star pattern (most accurate), or the Sun.

The de-spin thing is really what has piqued my interest.

At about 1:28, it stops spinning dramatically....the last stage is still attached, then you hear a click and see a band jettisoned, then the last stage falls away...something furls out and there is audio of something akin to outgassing and the payload stabilizes.

Wallops has a nice reference describing their capabilities and the current fleet of sounding rockets. https://sites.wff.nasa.gov/code810/files/SRHB.pdf

The spin is necessary to keep the rocket stable in direction when it is above significant atmosphere which the fins need in order to work. Interestingly, if you spin something like that it will eventually degenerate from the nice axial spin to an end-over-end tumble. Not sure what duration that would take on a sounding rocket. Objects will always want to rotate around the axis with greatest rotational inertia if given a choice.

Initial de-spin was a yoyo despin device by the sound of it, then likely a reaction wheel to steady from there.

I wonder what the total impulse was on the 2nd stage alone. 36 second burn time :eyepop:

And what about that recovery system? Talk about high speed deployment... even at high altitudes that's still got to be a lot of stress!

It looks like a yo-yo de-spin. I slowed down the video to 1/4 speed and grabbed this still at 1:26. It clearly shows one of the cables extended of the yo-yo just before being cut, I am guessing.

Some additional background information on the NASA Wallops sounding rocket manufacturing facility can be found here including the naming convention @ 10:00. @ 7:28 the guide also mentions that canted fins are an exclusive design choice for all of their rockets, based on price.

[video=youtube;IVfUM7HMPzM]https://www.youtube.com/watch?v=IVfUM7HMPzM[/video]

mpitfield said:

Some additional background information on the NASA Wallops sounding rocket manufacturing facility can be found here including the naming convention @ 10:00. @ 7:28 the guide also mentions that canted fins are an exclusive design choice for all of their rockets, based on price.

[video=youtube;IVfUM7HMPzM]https://www.youtube.com/watch?v=IVfUM7HMPzM[/video]

Click to expand...

Most may be but, in their users guide, they reference several vehicles, including the Terrier Improved Orion that can use spin motors. Could be that due to cost these aren't used much.

To all, thanks for posting these. I search for the originating channels and then subscribe if their channel consistently covers similar material:

LASP CUBoulder channel

https://www.youtube.com/channel/UCGLF2l0YJk4BC7zdRRfY9sQ/videos

Some of the NASA channels aren't nearly as active as they could/should be considering we're funding their activities. Can't even put a GoPro on your hardhat and upload it occasionally?:

NASA Wallops

https://www.youtube.com/user/NASAWallops/videos

Also, NASA too often tends to underestimate public interest in DETAILS. One of the Mars orbiters had a real time (as real time as possible from Mars) telemetry downlink web page that was beautifully done showing the status of all sorts of satellite systems.

For instance, anyone know of a single list of the current status of onboard systems/hardware for each of our two functional Mars rovers instead of having to read a bazillion periodic updates which don't include an all-encompassing list from what I've seen? I'd like to know what has failed or is operating marginally.