Black Arrow: The Lipstick Rocket - A Very British Space Program (video)
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Winston
Lorenzo von Matterhorn
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Small, but big enough to put the 146 lb Prospero into a high enough orbit that it's still there and, once again, with only US$85 million in 2017 dollars spent on the entire rocket program.
Prospero
https://en.wikipedia.org/wiki/Prospero_(satellite)
That and the recent Indian Mars orbiter program which cost a total of US$73 million makes me really wonder if we couldn't do our space efforts vastly cheaper, too, if we were to, for instance, eliminate vast layers of bureaucracy and manufacturer price gouging:
Mars Orbiter Mission (India)
https://en.wikipedia.org/wiki/Mars_Orbiter_Mission
Salvage-1
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Yup, and I believe that there were already plans to mate the Black Arrow to the Blue Steel booster. The Brits would have ended up with a fantastic, and cheap, launch system. Trouble is that the UK was still almost bankrupt after WWII and the reparations, and so things like the TSR2 and the Black Arrow lost out to 'cheaper' US alternatives, which ended costing over three times as much as the UK alternative would have.... politics at its best.
lakeroadster
When in doubt... build hell-for-stout!
Very cool rocket, and a great GDS candidate. I have a stand (way) off scale one built but unpainted with transparent fins. It was meant to be a stepping stone to a GDS version. I’ll post a pic when I get back to the farm if you’re interested.
lakeroadster
When in doubt... build hell-for-stout!
It's a cool looking bird for sure. I'd love to see some photo's of your model if you would be so kind.
I found this article today.. it has some great data: "a closer look at the Black Arrow rocket"
Sure thing. I’ll post the rough OR file for finned model as well.
Here’s one I posted earlier…
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Brilliant! A couple of weeks ago I saw one of the black Knight rockets in a museum which led me to read up about this family of sounding rockets and launch vehicles. As soon as I saw the black arrow I decided to try a GDS version although this type of design is a new thing to me. I was just going to start a new thread but then found this one!
I had got as far as cutting the pieces for a small version with a stock NC (which I will replace with a better scale version if I can make it fly!), rest is scratch. The lower section is 33mm BT and the upper 25mm which is not too far from scale. Haven't finalised the lengths yet.
The engine block slides in from the top and will be secured with a removable pegged thrust ring (I trialled this with a minimum diameter GDS test rocket and worked fine). There will be almost enough room for a mylar streamer recovery.
I just need to do the calcs for the exact location and area of the ducts then cut these and glue it all up.
As per most designs, there seems very little basis for estimating it's GDS stability (that's a different thread...) except conforming to the recommendations in PoF 379, so will definitely be an early morning heads up test flight!
If this one works then I'm hoping to scale up once it's possible to get hold of larger BT again...
I think the smaller scale is trickier because the motor mount takes up a decent proportion of the upper stage length, meaning the CG may not be as far forward as ideal for GDS. My formative GDS mindsim seems to think it feels ok, but probably just dum optimism.
I had got as far as cutting the pieces for a small version with a stock NC (which I will replace with a better scale version if I can make it fly!), rest is scratch. The lower section is 33mm BT and the upper 25mm which is not too far from scale. Haven't finalised the lengths yet.
The engine block slides in from the top and will be secured with a removable pegged thrust ring (I trialled this with a minimum diameter GDS test rocket and worked fine). There will be almost enough room for a mylar streamer recovery.
I just need to do the calcs for the exact location and area of the ducts then cut these and glue it all up.
As per most designs, there seems very little basis for estimating it's GDS stability (that's a different thread...) except conforming to the recommendations in PoF 379, so will definitely be an early morning heads up test flight!
If this one works then I'm hoping to scale up once it's possible to get hold of larger BT again...
I think the smaller scale is trickier because the motor mount takes up a decent proportion of the upper stage length, meaning the CG may not be as far forward as ideal for GDS. My formative GDS mindsim seems to think it feels ok, but probably just dum optimism.
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Decided to crack on and get this test model ready... Finished the centring rings and taper, modified the stock NC to make room for a streamer and allow cords to be stuffed inside. Calculated some nominal duct position and areas and did the cutting. These centre 2D from outlet of induction tube with area ~1100 mm2 which is approx D^2. Then whitewashed it so I can add details later if all goes well. No launch lug as the last one happily took off perched on the end of a rod.
It's got more or less the right look although by no means exact particularly the NC. Comes in a touch over 25 g so plenty of choice on powering, will probs start with a 1/2A3-2T (with an adapter) for a more constant thrust to see how straight it flies and give the ejection a chance before it tumbles back to earth. Hopefully will launch in the next day or so, possibly tomorrow but looking a bit windy.
It's got more or less the right look although by no means exact particularly the NC. Comes in a touch over 25 g so plenty of choice on powering, will probs start with a 1/2A3-2T (with an adapter) for a more constant thrust to see how straight it flies and give the ejection a chance before it tumbles back to earth. Hopefully will launch in the next day or so, possibly tomorrow but looking a bit windy.
lakeroadster
When in doubt... build hell-for-stout!
Are you planning to video tape the launch?
The consensus is that the rocket will go unstable as soon as the thrust stops... which should show up on a video.
I'm currently working on a BT-55 based GDS model also.
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You bet! But no promises as it will likely just be handheld phone camera.
I've been reading up on GDS and following a few threads (including yours!) so have a broad expectation including the "lofting" and post-thrust tumbling behaviour. Got a bit of a GDS bug at the mo and have been devising a few other test models to better understand the parameters. The small GDS test I did went off fine but had a different problem as the whole induction tube burnt away during thrust.
To counter this I have made the induction tube on this black arrow model quite a bit shorter and also painted the lower ~2cm of the inside in heat resistant paint.
Because this is a very light and small model I'm pretty happy that it would tumble recover altho would like to get the ejection working if I can because any larger model will need this.
lakeroadster
When in doubt... build hell-for-stout!
Good luck, looking forward to your flight report.
A little late back to this party... The OR file I promised in January for a finned Black Arrow. Mine is still unprimed sitting on the filing cabinet...
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Did a quick paint job and a few basic details, then did the test launch this morning on a 1/2A3.
Fairly successful given the very short thrust time but need to look at the video more carefully to see what it was doing stability wise straight after ignition. I'll upload the vid soon as I get a mo.
Fairly successful given the very short thrust time but need to look at the video more carefully to see what it was doing stability wise straight after ignition. I'll upload the vid soon as I get a mo.
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Here's a snippet of the launch, plus a couple of stills. I lost it on the screen after this point.
Some pretty major fishtailing going on, altho doesn't seem actually unstable.
I would like to index it versus the thrust curve to see where the BP peak thrust was. Because stability is only produced when the inductive gas velocity is high compared to absolute (model thru air) velocity, i have an idea that if acceleration during the peak thrust is sufficient that the induction/air velocity ratio during plateau thrust is low then stability is lost, or at least becomes marginal. This would likely be very early in the flight for this motor, possibly before it cleared the rod.
Next test is to try a motor with a longer and pref flatter thrust profile, like A3 or better B2. These should show more clearly what is happening with stability.
I am also going to compare the model parameters more closely to the stability conditions in PoF379, my guess is these may be marginal due to the difficulty in getting the motor far enough forward within the scale geometry, but this would be much better for a model at 3-4 times this size.
I also plan to add a small internal launch lug (at the moment it has none at all) to give it a truer lift off - I can't be certain it didn't ever so slightly snag on this test, which could be another contributor to fishtailing.
The model tumbled to ground before ejection but with no damage and no sign of any burn to the induction tube, the motor load/reload section was easy plus the GDS ignition method worked well for the second time.
Overall these points seem tentatively promising for a scale up.
View attachment TRIM_20220312_191809.mp4
Some pretty major fishtailing going on, altho doesn't seem actually unstable.
I would like to index it versus the thrust curve to see where the BP peak thrust was. Because stability is only produced when the inductive gas velocity is high compared to absolute (model thru air) velocity, i have an idea that if acceleration during the peak thrust is sufficient that the induction/air velocity ratio during plateau thrust is low then stability is lost, or at least becomes marginal. This would likely be very early in the flight for this motor, possibly before it cleared the rod.
Next test is to try a motor with a longer and pref flatter thrust profile, like A3 or better B2. These should show more clearly what is happening with stability.
I am also going to compare the model parameters more closely to the stability conditions in PoF379, my guess is these may be marginal due to the difficulty in getting the motor far enough forward within the scale geometry, but this would be much better for a model at 3-4 times this size.
I also plan to add a small internal launch lug (at the moment it has none at all) to give it a truer lift off - I can't be certain it didn't ever so slightly snag on this test, which could be another contributor to fishtailing.
The model tumbled to ground before ejection but with no damage and no sign of any burn to the induction tube, the motor load/reload section was easy plus the GDS ignition method worked well for the second time.
Overall these points seem tentatively promising for a scale up.
View attachment TRIM_20220312_191809.mp4
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