USC's rocket for suborbital attempt ground tested.

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RGClark

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USC’s rocket propulsion lab for undergraduates has test fired an 8” R-class rocket:

https://mach5lowdown.wordpress.com/2018/02/26/graveler-ii-stats/



They intend to use this for a suborbital flight to reach the 100 km von Karman line for space. Anyone know the mass of the rocket? It may be comparable to the ca. 200 kg rocket made by Cesaroni for the SpaceLoft suborbital rocket.


I think once they succeed at this, breaking through the “not possible” thinking, it will be recognized that with staging small orbital rockets also are possible.


I like the safety steps the team uses for production of the large amounts of APCP propellant:


https://twitter.com/uscrpl/status/958427730231533568?s=21


Another university team is aiming for suborbital space using liquid-fueled rockets:


https://mach5lowdown.wordpress.com/2018/03/01/student-race-to-space/


Bob Clark
 
CTI UPA-264-C rocket motor:
  • Diameter: 10.45 inches
  • Overall length including payload adaptors: 119 inches
  • Propellant Weight: 412 lbs
  • Propellant Mass Fraction: 0.8
  • Delivered Sea-level Specific Impulse: 240 s
  • Burn Time: 12 s
  • HPR spec: ~450,000 N-sec S42000
 
Yes. That's the data for the GoFast amateur suborbital rocket and also for the booster used for the SpaceLoft XL commercial suborbital rocket. But the USC rocket has about half the total impulse of this rocket. It does use carbon fiber for the casing so it may still be able to reach suborbital space.

Bob Clark
 
Yes. That's the data for the GoFast amateur suborbital rocket and also for the booster used for the SpaceLoft XL commercial suborbital rocket. But the USC rocket has about half the total impulse of this rocket. It does use carbon fiber for the casing so it may still be able to reach suborbital space.

You said of the USC 8" motor: "It may be comparable to the ca. 200 kg rocket made by Cesaroni for the SpaceLoft suborbital rocket."
I was pointing out that it is not by posting the CTI specs.

Now you are saying of the CTI SpaceLoft XL motor: "That's the data for the GoFast amateur suborbital rocket".
It is not the same specs. Close, but the GoFast motor was less efficient and lower mass fraction.
 
Right. The USC rocket is an R-class rocket. I had never heard of an R-class before, which I assumed would be quite large. Given that the USC team intends to use this as a suborbital rocket, I assumed it was comparable in size to the GoFast and SpaceLoft rockets. However, it has half the total impulse. So it may actually be half-size.

Still, using carbon-fiber casing the USC team expects it to be able to reach the 100 km altitude line for suborbital space.

Bob Clark
 
Right. The USC rocket is an R-class rocket. I had never heard of an R-class before, which I assumed would be quite large. Given that the USC team intends to use this as a suborbital rocket, I assumed it was comparable in size to the GoFast and SpaceLoft rockets. However, it has half the total impulse. So it may actually be half-size.

Still, using carbon-fiber casing the USC team expects it to be able to reach the 100 km altitude line for suborbital space.

Did you not read the description of the USC Graveler II test motor and its purpose?
 
The ground test was to validate the Traveler III rocket they intend to use as a suborbital rocket.

Bob Clark
 
The USC rocket is an R-class rocket. I had never heard of an R-class before, which I assumed would be quite large.

You should know what that means, considering how much you've been posting everywhere on how easy amateur rocketry is.
 
You should know what that means, considering how much you've been posting everywhere on how easy amateur rocketry is.

My argument was any amateur or university team that reached 100,000+ feet could also build a rocket to reach the 100 km von Karman line for suborbital space. The USC team is about to prove that correct.

Bob Clark
 
My argument was any amateur or university team that reached 100,000+ feet could also build a rocket to reach the 100 km von Karman line for suborbital space. The USC team is about to prove that correct.

You are great at generalizations based on cherry-picked incidental observations without having done any of this yourself.

So, Bob, what does "R-Class" mean?
 
You are great at generalizations based on cherry-picked incidental observations without having done any of this yourself.

So, Bob, what does "R-Class" mean?

My point was to celebrate the accomplishments of amateur and university students working in high power rocketry. If that was taken as a criticism I apologize.

In any case, I think most people interested in high power rocketry will celebrate the success of the USC team if and when they succeed. Moreover, this will lead other university teams to follow on with their own attempts.

Bob Clark
 
My point was to celebrate the accomplishments of amateur and university students working in high power rocketry. If that was taken as a criticism I apologize.

In any case, I think most people interested in high power rocketry will celebrate the success of the USC team if and when they succeed. Moreover, this will lead other university teams to follow on with their own attempts.

Oh, why didn't you say so!? You are always posting about how easy this all is, belittling those who know how hard it is. (Especially on Arocket).

You should stop posting and start building something. Then go help a student team. You will learn along the way about the technologies and time-consuming tasks you think are simple and easy and cheap.
 
You should know what that means, considering how much you've been posting everywhere on how easy amateur rocketry is.

Don't waste your time trolling Bob. I helped found university rocket team for UTC last year, designed two supersonic multistage competition HPR rockets, and placed third nationally at SEDS which was a $4.5k inkling of this. We attempted a TRA record once. We drove to three states and had to integrate design fixes into designs after unsuccessful first test flight. Then we flew a different design which worked. 68 engineering college teams some from aerospace universities couldn't finish 3,000ft in two academic semesters. I could rant how I designed components most people told us were impossible to machine, or that we actually found ways to produce these impossible to machine parts with patentable features eventually despite how common naysayers wanted to belittle us. Bob here doesn't know how hard it is to get a drag coefficient of an object in solidworks from scratch at undergrad university level. How they have a 1" x 1" wind tunnel space de rated to Mach 0.8, and UTSI or NAS wants millions of dollars so you can get one number for one drag force equation at a Mach number way greater than 1 for an object that doesn't really exist yet outside of a one off prototype or a computer model. Then you've hit your technical limit of knowledge at undergrad senior year engineering and you have to ask industry experts with more efficient computing methods and probably 20+ years of hypersonics flow analysis research to take your models into fine mesh for three weeks because a military supersonic airfoil isn't fine mesh enough. They wanted Aerotech fuel specs. We eventually saw oblique shockwaves and supersonic exhaust gas plumes in particle effects on a PC screen. They called supersonic trivial then meshing took them weeks. Without all that effort we wouldn't have had info to start a structural analysis. Oh yeah CTI claimed everything was proprietary even casing threads. The research professors disliked CTI a lot from a technical info standpoint on fuel compounds to just simulate a model.
Had to assume sustainer was a boosted dart with other program specs at one point.
ANSYS only had 60 plus boundary layers with F600.314 not actual nice logos like front nosecone or trailing edge fin, it was such a frustration of a program that the professors were like let us use our hard codes from industry experience because it will take less time. We had technical knowledge to design nosecones, nozzles, casings, and open rocket to us seemed trivial except we lacked practical amatuer experience and the lack of practical flight experience was a horrific disaster and tedious learning curve process. Everything you amateurs call common sense we lacked. We made some mistakes on design. We had to learn from those mistakes. We pixy dusted an interstage at Mach 1.5 because we had never designed a rocket interstage before. Anybody who calls it easy is a nutcase. They don't even have a senior engineer student course load or an idea of what mathmatical h*** really is. 67% of the people next to you thought they were dumb and they already quit engineering path. You've got stubborn workaholic super seniors or Einstein wannabes left. Then the university itself will find ways to lawyer term any grant money into tax ident numbers even the professors can't retrieve at department level for simple raw material purchases for these engineering projects. The engineering department makes students raise funds. And they expect it in two semesters or a new engineering team is assigned with no experience. Engineer students sigh in relieve or pass out or get drunk at end of semester from the pain and misery. Then the communications people are all snotty and hyper and won't leave you alone after the university gets a headline story for months of effort. They like bob likely never had to use solidworks, ANSYS, FinSim, open rocket, or excel much or take calculus three or differential equations or controls. They never had deadlines with FCC\FAA\TRA paperwork and academia processes that require months of effort to achieve simple money transfers. No amount of rambling will convey the hardships by students.

A professor once said, you students have more leeway than I do about project funding. It was easier for us kids to use internship money in donations than it was for university to swap accounts or whatnot. These campuses are probably flipping out about mixing an R motor in a Chem lab, can't imagine what these guys and gals are going through. Likely hair loss and anxiety. If they fail senior design project they may have to take design courses sequentially again.

Task isn't impossible. It will take a lot of effort and will likely not succeed first attempt. There may not be a budget for second attempt. There's guys and gals with IREC team experience that can chime in. Basically I'd call it a slight miracle if it works as planned given how low experience the college teams are. The amateurs have more practical experience and they call this extremely hard.
 
My argument was any amateur or university team that reached 100,000+ feet could also build a rocket to reach the 100 km von Karman line for suborbital space. The USC team is about to prove that correct.

Bob Clark


Almost every post of yours makes the mistake of assuming nearly linear scaling in difficulty in rocket technology. In reality double the altitude is not double the cost and effort, it is likely to be closer to ten times or so. Read any of the posts and builds by those who have actually done it and you see that things that work perfectly fine at 10k will not when you get to 50k. Deployment charges, fins, parachutes and even the barometers usually used for deployment all rely on a certain atmospheric pressure to function as modeled and tested at ground level.


A very wise boss of mine likes to say "If it was easy, everyone would be doing it"
 
Bob Clark is actually an AI experiment. Like "ELIZA" but programmed to troll rocketry-related responses. Soon, he will be laughing uncontrollably, like Alexa started doing today.

Somewhere in the distant future, there will be a phrase "I was bobclarked!", and nobody will know where in the Helio system it came from!
 
Oh, why didn't you say so!? You are always posting about how easy this all is, belittling those who know how hard it is. (Especially on Arocket).

You should stop posting and start building something. Then go help a student team. You will learn along the way about the technologies and time-consuming tasks you think are simple and easy and cheap.

Actually, it is not intended to be that way. Belittling someone is saying they can not do something. I am saying they can do something.

The proof is in the pudding however. When the USC team makes their attempt, we can further judge how close they are to succeeding at making the suborbital flight.

Bob Clark
 
Actually, it is not intended to be that way. Belittling someone is saying they can not do something. I am saying they can do something.

When your target is amateur rocketeers helping to fill in your lack of knowledge, it is belittling to ignore their hard-earned experience by saying it is easy. At some point, only fools will reply to your statements. How many times will someone get "bobclarked" before they learn!

The proof is in the pudding however. When the USC team makes their attempt, we can further judge how close they are to succeeding at making the suborbital flight.

That is a nonsensical statement and contradicts your premise of how easy it is to scale to the next flight level. The USC group has been working for 10 years (that I know of) in difficult, incremental steps to get to this point. Orbital is at least 10x more difficult (plus non-technical parts of the equation that are show stoppers). Just on the technical side, that is 100 years more student effort. But, you will disagree based on frivolous arguments and baseless wishful thiking. And once again, another person in the known Universe will have been "bobclarked".
 
You should stop posting and start building something. Then go help a student team. You will learn along the way about the technologies and time-consuming tasks you think are simple and easy and cheap.

THIS

Please start a build thread... ANY build thread...
 
Bob Clark is actually an AI experiment. Like "ELIZA" but programmed to troll rocketry-related responses. Soon, he will be laughing uncontrollably, like Alexa started doing today.

Somewhere in the distant future, there will be a phrase "I was bobclarked!", and nobody will know where in the Helio system it came from!

John - you might be on to something. Today while I was plotting a plan set that was 500+ pages, I pulled up the Arocket archives. I've been pulling the time and date of every time the list has bee bobclarked (love the phrase) to see if there is a pattern.

Edward
 
You've got stubborn workaholic super seniors or Einstein wannabes left. Then the university itself will find ways to lawyer term any grant money into tax ident numbers even the professors can't retrieve at department level for simple raw material purchases for these engineering projects. They never had deadlines with FCC\FAA\TRA paperwork and academia processes that require months of effort to achieve simple money transfers. No amount of rambling will convey the hardships by students.

Preach brother! I mentor IREC teams and it can take two months to get funding to buy supplies. Oh, and then McMaster isn't a priority for campus delivery to sort, so it sits another two weeks. A couple of teams I've bought the materials for them, then invoiced the team for the amounts. I'll see my money back in 60-90 days, but at least the teams can actually get some work done.

Edward
 
...
A professor once said, you students have more leeway than I do about project funding. It was easier for us kids to use internship money in donations than it was for university to swap accounts or whatnot. These campuses are probably flipping out about mixing an R motor in a Chem lab, can't imagine what these guys and gals are going through. Likely hair loss and anxiety. If they fail senior design project they may have to take design courses sequentially again.

Task isn't impossible. It will take a lot of effort and will likely not succeed first attempt. There may not be a budget for second attempt. There's guys and gals with IREC team experience that can chime in. Basically I'd call it a slight miracle if it works as planned given how low experience the college teams are. The amateurs have more practical experience and they call this extremely hard.

I congratulate you on your experience and your successes in high power rocketry. Keep in mind the USC team is being instructed by the aerospace engineering professors at USC. Most of the top aerospace engineering departments like USC have professors who have experience designing and building rockets in industry. The professors already know how to do it. This is not a learning experience for them. They are instructing their students how to do it. It is a learning experience for the students.

If the USC team succeeds, then other top aerospace engineering departments could have student built suborbital space rockets by emulating their design.


Bob Clark
 
If the USC team succeeds, then other top aerospace engineering departments could have student built suborbital space rockets by emulating their design.


Bob Clark

...which no one was really arguing against. USC had this idea back in '05 or '06 and have been working towards it ever since. They made their first attempt in 2011 we have yet to see if they have worked out all of the issues. Other teams have been at it for 5+ years. There's a reason why many college teams have the goal of reaching the Karman line, and from what I can tell that reason is specifically because it isn't impossible. Not because it would be easy.

What people constantly argue with you about anywhere you show up in the amateur rocket scene is that you insist that all it would take to reach "orbital space" is a different mindset. Maybe you should try meeting some of the students who are actually working on this. The USC team drives out to FAR for motor mixing and tests, which means a 3 hour trip each way. That's the level of dedication these students are already putting in. What do you expect to change when/if their spaceshot works? Just because an orbital flight is the next step in some ladder of rocket progress doesn't automatically make it possible. Between Arocket and here, I think the amateur rocketry community is getting tired of explaining this.
 
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.
 
Even then, Graveler 1 just made a huge crater so we'll see how their launch attempt goes.


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

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

Thanks for that. I’m looking forward to reading about your progress. Liquid fueled especially bi-propellant rockets are a significantly greater technical challenge than solid rockets. Amateurs routinely make their own solid-fueled rockets to reach several thousand feet altitude. Not so for liquids. But they do have higher performance so I’m hopeful you or other university teams are successsful in reaching the goal.

Bob Clark
 
Thanks for that. I’m looking forward to reading about your progress. Liquid fueled especially bi-propellant rockets are a significantly greater technical challenge than solid rockets. Amateurs routinely make their own solid-fueled rockets to reach several thousand feet altitude. Not so for liquids. But they do have higher performance so I’m hopeful you or other university teams are successsful in reaching the goal.

That paragraph is proof you don't understand the comparable challenges or the scaling factors. Someone needs to tweak you AI algorithm.
 
Almost every post of yours makes the mistake of assuming nearly linear scaling in difficulty in rocket technology. In reality double the altitude is not double the cost and effort, it is likely to be closer to ten times or so. Read any of the posts and builds by those who have actually done it and you see that things that work perfectly fine at 10k will not when you get to 50k. Deployment charges, fins, parachutes and even the barometers usually used for deployment all rely on a certain atmospheric pressure to function as modeled and tested at ground level.


A very wise boss of mine likes to say "If it was easy, everyone would be doing it"

Easy is a relative term. To a Ph.D. level research mathematician calculus counts as “easy mathematics”. That is not the case for most people. My argument was that amateur and university teams that have reached 100,000+ feet altitude with their rockets have the capability to reach suborbital space. 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.

About the distinction between orbital and suborbital space, it’s commonly estimated to be 10 to 25 times more difficult on an energy scale. But that is for the same size payload. Sending a much smaller payload to orbital space would have about the same energy cost as a large payload to suborbit. About the cost in dollar terms it is a well known fact that the first stage of an orbital rocket makes up the bulk of the cost because of its much larger size. For instance for the Falcon 9 the first stage is 3/4ths the cost. Then use the suborbital rocket as the first stage of an orbital rocket but for a smaller payload. Following common cost principles for orbital rockets that first stage will make up the bulk of the cost.

Bob Clark
 
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