USC's rocket for suborbital attempt ground tested.

UTC doesn't have an aerospace department but several of the professors have aerospace phd's and have had actual experiences in industry. I hypothetically asked if they could design a scram jet. One said theoretically yes it would take a group of them given enough time and resources, however he said it would be a challenge to manufacture, more of a challenge to practically test, and then the theory doesn't always translate into a working functional engine the first try. There would be a knowledge gap for them where they would practically learn what the formulas don't cover the reality of it outside of a textbook or theoretical understanding. And they understand way more in depth than undergraduates do. They do regression models of solid fuel rocket motors and complex CFD. It's not just calculus, it's the understanding of theoretical boundaries and the practical implications that took many decades for some to master.

There's an inherent problem with college teams attempting very complex projects such as this, and it's that you only have your talent for a short period of time, and they don't have the time to devote 100% of their resources to the project. The mentor ends up spending a lot of time bringing the new students up to speed on the project, so only incremental progress is made over time, at best. I applaud their efforts, but making any significant progress in a reasonable amount of time is a huge uphill battle. The college mentors must be VERY patient people...

RGClark said:

Note well: reaching 100,000+ altitude with an amateur rocket is quite a significant achievement. Obviously, the average person could not accomplish this and it would not be easy to them!
But it is because those amateur rocketeers were able to accomplish this feat is why I say they can also make a rocket to reach the 100km von Karman line.

Click to expand...

Andrew_ASC said:

UTC doesn't have an aerospace department but several of the professors have aerospace phd's and have had actual experiences in industry. I hypothetically asked if they could design a scram jet. One said theoretically yes it would take a group of them given enough time and resources, however he said it would be a challenge to manufacture, more of a challenge to practically test, and then the theory doesn't always translate into a working functional engine the first try. There would be a knowledge gap for them where they would practically learn what the formulas don't cover the reality of it outside of a textbook or theoretical understanding. And they understand way more in depth than undergraduates do. They do regression models of solid fuel rocket motors and complex CFD. It's not just calculus, it's the understanding of theoretical boundaries and the practical implications that took many decades for some to master.

Click to expand...

An unusually cogent answer by Andrew! Well done!

eggplant said:

Huh? They fired Graveler 1 back in 2013 and it was a success.

[video=youtube;Ct8WDbmEOp0]https://www.youtube.com/watch?v=Ct8WDbmEOp0[/video]

Click to expand...

Must of been the first attempt at Graveler 2 then. I heard that they had blown up their most recent ground test at least. It was something to do with air pockets in the fuel grain.

The USC rocket propulsion lab (USCRPL) is now announcing they intend to make their attempt to suborbital space in April this year:

https://www.uscrpl.com/traveler-iii/

Advancing from a flight of 100k feet, to a flight of 100k meters in one year will be an impressive accomplishment if they succeed.

Ad Astra, USCRPL!

The efforts of the USC team reminds me of the efforts by the Maverick Civilian Space Foundation team. They are a group of professional engineers who instruct high school and university students in building and launching two-stage APCP rockets to reach 100,000 feet. Their rocket uses three clustered motors for the first stage and one motor for the second stage. The total propellant load is about 200 kg, like the SpaceLoft and GoFast suborbital rockets.

Each of the four Maverick motors composing their rocket have a ca. 50 kg propellant load. However, their rocket uses aluminum casings as indicated in this video:

California Academy of Math & Science Explorers Program - The Rocket Project.
[video=youtube;MutkJ0HKyA8]https://www.youtube.com/watch?v=MutkJ0HKyA8[/video]

This reduces the mass ratio and therefore the delta-v possible. BUT suppose the Mavericks used also carbon fiber casings for the 3-cluster first stage? Then the first stage alone might have sufficient delta-v for a suborbital space flight, as it would be larger than the USC rocket at a ca. 150 kg propellant load. You might want to use a fiberglass or carbon fiber cylindrical aeroshell to cover the 3-clusters though for aerodynamics reasons, as it would be traveling faster than the Mavericks original version not having to carry the heavy upper stage.

You would have to get the carbon fiber casings however. The USC team built their own carbon fiber winder. And you can find on the net examples of other amateurs who have built their own carbon fiber or filament winders. But one can be purchased for ca. $3,000 from the X-winder company.

It maybe though you want to use all four of the Maverick's motors clustered together. This would give a rocket of the same propellant size as the GoFast and SpaceLoft suborbital rockets. You would still need to give the motors carbon fiber casings to get the needed mass ratio and delta-v.

The 50 kg motors making up the Maverick's rockets are Q-class motors. Then actually two of them stacked one on top another would make up an R-class rocket, same as the USCRPL rocket. Then switching to carbon fiber casings may allow just two of the Maverick's motors to be used to reach suborbital space.

There are only a few Q-class motors that have been launched by amateur high power rocketeers. But if the USCRPL team succeeds, this suggests other high power rocketeers by using carbon fiber casings for their Q-class motors and stacking one on top of another making an R-class motor, they also could succeed at reaching suborbital space.

One other Q-class motor was the Qu8k motor that reached 100k feet:

https://ddeville.com/derek/Qu8k.html

The Qu8k motor had a 70 kg propellant load. Then two stacked would have a 140 kg propellant load, actually larger than the USCRPL rocket. Then it also given carbon fiber casing and stacked one on top of the other could reach suborbital space.


Bob Clark

ArchitectOfSeven said:

Honestly getting something like that into the air is so bulls*** hard as a student it's unreal. Over at UCLA we've been working on our first bi-prop rocket for almost 2 years with a huge and VERY well funded club and we are barely going for the first launch tomorrow. This is our second motor and fuel combination because we couldn't get decent performance out of the first design so we moved on to our current Ethalox bird. On that note, our performance values are still highly suboptimal and we will be lucky to crack 15k with a more likely apogee of ~10k. USC is making some serious magic happen with their project out there btw. Even then, Graveler 1 just made a huge crater so we'll see how their launch attempt goes. Wishing them the best. That SEB thing from Berkeley is a load of bs though. It's literally a bunch of marketing students with zero experience making rockets. They really need to stop insulting the community with their bs space race and actually do something of value. As cool as going to space sounds, doing that as a student is not very practical. There is way too much manufacturing and math skill required to expect undergrads to be able to do it within the short time they individually have.

Click to expand...

Just saw you guys at UCLA successfully launched to 12.5k feet:

https://mach5lowdown.wordpress.com/2018/03/12/rocket-project-at-ucla-launch-lox-ethanol-rocket/

Kudos! Getting a liquid-fueled bipropellant rocket to successfully launch is a significant achievement. You may beat out Berkeley for the first student biprop to reach the von Karman line.

Bob Clark

Okay, I read through this entire thread and all I see is everyone arguing and no one listening. I'm getting complaints about it and it doesn't seem to be accomplishing anything so I'm going to lock it.

Move along.

Nothing to see here...