Level-3 high-performance design and build thread

New Ocean said:

Boosted darts still work for some applications:

https://en.wikipedia.org/wiki/Mesquito

You said 40 watts/cm^2 for 10 seconds. I gather that is only true for one specific rocket with one launch altitude and one motor design.

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The Mesquito was a development rocket. It is not operational. The NASA Sounding rocket program does not have a boosted dart in their current inventory. https://sites.wff.nasa.gov/code810/vehicles.html This is what the NASA Sound rocket program is and what it does today. https://sites.wff.nasa.gov/code810/files/SRHB.pdf

40 watts/cm^2 for 10 seconds is a good laboratory simulation for materials to be used for nose cones or fins on a riocket that will reach 100 km on a conventional trajectory: two stage APCP rocket with coast between stage ignitions, or single stage with a single or dual impulse burn.

I've mentionied in previous posts on TRF, 3 single stage 10" od rockets can reach >100 km: the 17' long Raytheon Patriot PAC-3 in a single burn; the 22' long S impulse CSXT GoFast rocket in a single burn and the 27' long S-impulse SugarShot-2-Space in a dual impulse burn. The common feature is a velocity M>5 @ 40 Kft. The integrated aeroheating load is ~400 J/cm2 over 10 seconds for each rocket. If you happen to have access to a 10 KW CW CO2 laser you can heat a 7" diameter area uniformly at 40 W/cm2 for a direct simulation.

Many sounding rockets traditionally use free obsolete military motors like the Nike, Terrier, Improved Orion, Talos. The Black Brants and the Malamutes are made for research and therefore are more expensive. Few useful payloads will fit in a dart and propellant is cheap compared to the cost of a launch so folks don't use darts for serious upper atmosphere experiments. The original darts were really cheap and used surplus motors. The traditional use of darts was to measure upper atmosphere winds via radar tracking the downard trajectory of a radar reflecting payload.

It's not that darts don't work, they just don't work as well as a conventional rocket for carrying usesul payload. aloft. The jobs they did do are not needed today, so they are technically obsolete and not used.

Bob

There are two amateur rockets that have gone to space, or nearly so. One was a conventional S rocket, the other was an R boosted dart. The boosted dart returned good video footage and could have carried modern electronics as well. In the hobby, boosted darts are a viable option. (Recent 100K attempt used one.) They certainly offer greater simplicity than a two stage rocket with a staging delay.

The previous point was that there are a wide range of flight conditions and one can modify them at will to manage heating. The surfaces that are most at risk, such as the fin leading edge, will not see some standard heating. The heating damage they experience is massively altered by even small changes in thickness, sharpness, and material not to mention flight profile.

My 3L3 flight is now up on the Tripoli records list. Thanks, Tom, Kevin and Ken.

https://www.tripoli.org/Membership/CompetitionsandRecords/LSingleMotorRecord/tabid/312/Default.aspx

That .kml file isn't compatible w/ the newer versions of google earth. You have to eliminate the spaces after the commas in the middle of the file, and eliminate the last comma at the end of each line in the file.

Thanks. I was wondering what happened with that.

Adrian A said:

My 3L3 flight is now up on the Tripoli records list. Thanks, Tom, Kevin and Ken.

https://www.tripoli.org/Membership/CompetitionsandRecords/LSingleMotorRecord/tabid/312/Default.aspx

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Congratulations Adrian..... I have looked at your designs considerably over the last year or so and have been inspired by your work..... I consider you a pioneer in min dia rockets. So glad to know your L3 was a success and a RECORD! THAT IS AWESOME....... would sure like to meet you sometime..... Your designs fascinate me.

Adrian A said:

My 3L3 flight is now up on the Tripoli records list. Thanks, Tom, Kevin and Ken.

https://www.tripoli.org/Membership/CompetitionsandRecords/LSingleMotorRecord/tabid/312/Default.aspx

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Congratulations on the record. Is the L115 a typo of L1115-P?

Thanks. That flight wasn't a level-3 cert flight, but it was testing out the design I plan to use in my L3 cert flight at BALLS this fall. If a bunch of things go right, I'll use a multi-stage 38mm rocket to see how high I can go as an L2 before going for my L3.

That would probably be a 4-stage, all Loki J1000's. Hehehehe...

I have tried and failed twice on a 3-stage 38mm attempt, and failed once on a high 2-stage. This weekend I'm planning to try a fast 2-stage 38mm shot, I600 to CTI J420 that should break Mach 3. I'll figure out what I'll do at BALLS after I see how this flight turns out. Previous sims with 3 maximal Js and long staging delays have gone over 70kft.

Actually, if it weren't so ludicrous, you would be allowed to have a full M impulse in multiple motors, so 8 J1000's would be the best. Perhaps 3-3-1-1, since you need liftoff thrust, and because a stack of 3-1-1-1-1-1 or 1-1-1-1-1-1-1-1 would never survive.

I just realized that I think there is a misunderstanding. Tripoli changed the rule so that you can no longer fly at twice your rated impulse with a 2-stage flight. So I would be limited to a full L before I certify on a single-stage L3 motor.

A K1085 could be a cool first stage, though. It has 2412 Ns so I'd have 2708 left over for 38mm stages.

Note what i've been suggesting: You should look at the Loki J1000, especially for a top stage: if it's already in rarified air, a faster burn will give less gravity drag (you don't need to use energy to lift propellant).

Adrian A said:

I just realized that I think there is a misunderstanding. Tripoli changed the rule so that you can no longer fly at twice your rated impulse with a 2-stage flight. So I would be limited to a full L before I certify on a single-stage L3 motor.

A K1085 could be a cool first stage, though. It has 2412 Ns so I'd have 2708 left over for 38mm stages.

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38mm really limits the size motor you can get commercially. Even with two 38mm stages you aren't going get up to that 2708 number...lol Kind of an interesting problem though. You could do *kind of* a boosted dart thingy with a 75mm first stage to a 38mm upper to get as close as possible to that 5120 NS number so to stay within the L2 ranks.

I like the idea though...see how high you can get within the L2 limitation.

Adrian, are you going to be at Airfest this year? I hope so, I enjoyed the peanuts at LDRS last year.

-Dave

It's 30% heavier and 25% longer with 20% more impulse. I'd need to sim it to see how it compares in a multi-stage rocket. It might be about a wash.

CarVac said:

Note what i've been suggesting: You should look at the Loki J1000, especially for a top stage: if it's already in rarified air, a faster burn will give less gravity drag (you don't need to use energy to lift propellant).

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It's 30% heavier and 25% longer with 20% more impulse. I'd need to sim it to see how it compares in a multi-stage rocket. It might be about a wash.

DAllen said:

38mm really limits the size motor you can get commercially. Even with two 38mm stages you aren't going get up to that 2708 number...lol Kind of an interesting problem though. You could do *kind of* a boosted dart thingy with a 75mm first stage to a 38mm upper to get as close as possible to that 5120 NS number so to stay within the L2 ranks.

I like the idea though...see how high you can get within the L2 limitation.

Adrian, are you going to be at Airfest this year? I hope so, I enjoyed the peanuts at LDRS last year.

-Dave

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It will depend on what kind of flight testing I need to do between Mile High Mayhem and Balls. The hospitality in Argonia is great, but the 10 hour drive each way takes some of the fun out of the trip overall.

And my sister calls me crazy at 3000 feet...