Finally Flying!

[Neil1993]

I attended the 10th Intercollegiate Rocket Engineering Competition 2 weeks ago and we finally got our rocket in the air! (This also explains why I haven't visited these forums in a while)

We launched to an altitude of around 10,000 feet (+/- 1000 ft) and the only problem we experienced was a sensor glitch in the commercial flight computer which probably resulted in an erroneous altitude reading.

We used an advanced carbon-thermoplastic airframe which was made via automated fiber placement and advanced honeycomb fins. Overall, pretty good for a rookie team.

The success is probably due to the fact that we have Captain Falcon on the nose.

[Frida Space]

Congratulations! Great job, really. Must have been a beautiful experience.

[RainDreamer]

preeeetty rocket. Should have put Jeb on the nose though, you will get to orbit.

[Reddragon]

Congratulations! Will you post a video about it? I'd definitely watch it!

[Neil1993]

preeeetty rocket. Should have put Jeb on the nose though, you will get to orbit.

There actually was a team that was sponsored by KSP and I think they did just that (but I'm not 100% sure). Unfortunately, their flight was appropriately Kerbal-esque. This is a

to a video of their launch.

Congratulations! Will you post a video about it? I'd definitely watch it!

Hopefully, it'll be out in the next few days. We're still putting it together.

Edited July 9, 2015 by Neil1993

[Endersmens]

There actually was a team that was sponsored by KSP and I think they did just that. Unfortunately, their flight was appropriately Kerbal-esque. This is a

to a video of their launch.

I feel horrible for the design team, but I laughed really hard at this. The fact that KSP sponsored them just tickles me.

Warning: DO NOT LET KSP SPONSOR A REAL LIFE ROCKET! XD

[Sampa]

welcome back, Neil! and that is fantastic news! Great job!

[Scotius]

Congratulations Sad to hear KSP team followed the proud tradition of Kerbal engineering. Oh well - back to the VAB.

[AngelLestat]

Congrats Neil, after so much wait and work, you (or your team) finally press the launch button.

How big was the rocket?

Video ? video ? Video??? come on, dont be lazy

[Nothalogh]

There actually was a team that was sponsored by KSP and I think they did just that (but I'm not 100% sure). Unfortunately, their flight was appropriately Kerbal-esque. This is a

to a video of their launch.

Oh hell, that's too funny

[ChrisSpace]

Congratulations. Are you planning any further launches?

[Neil1993]

Congrats Neil, after so much wait and work, you (or your team) finally press the launch button.

How big was the rocket?

Video ? video ? Video??? come on, dont be lazy

The rocket was a full 2.96 meters in height (or roughly 9' 9") and 0.104 meters in diameter (roughly 4"). Hopefully we can have a video this weekend, complete with epic music and even more epic footage. We're waiting for the competition to release footage they took with a drone before we finalize it.

Congratulations. Are you planning any further launches?

You bet we are! The competition takes place every year and we've already started on the next design.

[RainDreamer]

There actually was a team that was sponsored by KSP and I think they did just that (but I'm not 100% sure). Unfortunately, their flight was appropriately Kerbal-esque. This is a

to a video of their launch.

Ok...maybe we should put Val instead then. XD

Though makes me wonder if the KSP sponsored team is on this forum too.

[Neil1993]

Ok...maybe we should put Val instead then. XD

Though makes me wonder if the KSP sponsored team is on this forum too.

A rocket blowing up is nothing to be ashamed of. They were trying to build an advanced hybrid engine and, even for the pros, that stuff is pretty hard to get right. Just look at what happened to SpaceX recently.

They'll learn from the launch and the next time they fire it up, they'll probably be winning some awards.

[ChrisSpace]

Is your next rocket going to be more powerful or are you going with a similar design?

[RainDreamer]

Moar boosters!

[Neil1993]

Is your next rocket going to be more powerful or are you going with a similar design?

We're actually hoping to make a less powerful rocket. One of the defining characteristics of our design was the amount of composite materials used (excluding the payload which had to be heavy and the motor). We want to bring our composite design to the next level so that the next rocket can be light enough to switch down to a smaller motor yet still be able to meet mission objectives.

[RainDreamer]

ooh so better material, instead of better engine. We should have the option to branch research that way in KSP.

[Neil1993]

ooh so better material, instead of better engine. We should have the option to branch research that way in KSP.

How would that be integrated? researching something makes all parts lighter by an arbitrary amount? Or how about ability to choose the material used in a part, sometimes at the expense of strength (so ability to manage the strength-to-weight ratio of components).

Honestly, the material we used for the fuselage is so strong (Stronger than some steels) that we really didn't need to put too much effort into making sure things were structurally sound while still being light.

[SciMan]

Congratulations on the successful launch, and a very nice looking rocket!

(Hopefully) quick question.

Why are multi-stage rockets so uncommon in amateur rocketry?

Is there some big challenge with designing them that makes them too much trouble for the added performance?

Are they too complex or expensive?

Nobody wants to build them?

Some other reason I can't think of at the moment?

EDIT:

Just realized, it's entirely possible that I'm just not searching using the right terms. If anyone has a link that shows a multi-stage amateur rocket that uses large motors (NOT "Estes" black powder motors) in all stages, that would be much appreciated.

Edited July 11, 2015 by SciMan

[Neil1993]

Congratulations on the successful launch, and a very nice looking rocket!

(Hopefully) quick question.

Why are multi-stage rockets so uncommon in amateur rocketry?

Is there some big challenge with designing them that makes them too much trouble for the added performance?

Are they too complex or expensive?

Nobody wants to build them?

Some other reason I can't think of at the moment?

EDIT:

Just realized, it's entirely possible that I'm just not searching using the right terms. If anyone has a link that shows a multi-stage amateur rocket that uses large motors (NOT "Estes" black powder motors) in all stages, that would be much appreciated.

You pretty much named the reasons why. The fact is, if the job can be done better, more reliably and more efficiently with one motor, then why use two? in most cases, the equipment needed to make a multi-stage work just adds too much weight and complexity (if it's a rocket's like the ones we're playing with).

That being said, Mississippi state used a 2-stage rocket this year to propel their Advanced category entry to 23,000 feet. It was glorious

[magnemoe]

You pretty much named the reasons why. The fact is, if the job can be done better, more reliably and more efficiently with one motor, then why use two? in most cases, the equipment needed to make a multi-stage work just adds too much weight and complexity (if it's a rocket's like the ones we're playing with).

That being said, Mississippi state used a 2-stage rocket this year to propel their Advanced category entry to 23,000 feet. It was glorious

Military rockets tend to be single stage unless they reach space on Ap.

They are mass produced and performance is more important than cost. however they also have larger payloads.

Sounding rockets tend to be two stages, they often use an military rocket as first stage.

[Armchair Rocket Scientist]

Congratulations on the successful launch, and a very nice looking rocket!

(Hopefully) quick question.

Why are multi-stage rockets so uncommon in amateur rocketry?

Is there some big challenge with designing them that makes them too much trouble for the added performance?

Are they too complex or expensive?

Nobody wants to build them?

Some other reason I can't think of at the moment?

EDIT:

Just realized, it's entirely possible that I'm just not searching using the right terms. If anyone has a link that shows a multi-stage amateur rocket that uses large motors (NOT "Estes" black powder motors) in all stages, that would be much appreciated.

There are several significant challenges for multi-stage amateur rockets.

First, they are just flat-out more complex. There's two (or more) motors, two (or more) sets of electronics, etc. that can fail.

Second, the connection between stages is placed under very high loads during supersonic flight, and is difficult to build robustly.

Third, any motor that is "airstarted" needs a more advanced flight computer that can check that the rocket is flying close to vertical before igniting the motors. Why? If something goes wrong during the first stage burn, the second stage could ignite with the rocket pointing horizontally or even downward, which is extremely dangerous.

and

show what can happen if a simple timer is used to ignite upper stages. Either of those rockets could easily have killed someone.

However, there are some good examples of successful multi-stage flights.

is someone's 3 stager, and

is a 2-stage flight to over 100,000 feet. For reference, it would take 2-4 times as much total impulse to reach that altitude on a single-stage rocket.

[magnemoe]

There are several significant challenges for multi-stage amateur rockets.

First, they are just flat-out more complex. There's two (or more) motors, two (or more) sets of electronics, etc. that can fail.

Second, the connection between stages is placed under very high loads during supersonic flight, and is difficult to build robustly.

Third, any motor that is "airstarted" needs a more advanced flight computer that can check that the rocket is flying close to vertical before igniting the motors. Why? If something goes wrong during the first stage burn, the second stage could ignite with the rocket pointing horizontally or even downward, which is extremely dangerous.

and

show what can happen if a simple timer is used to ignite upper stages. Either of those rockets could easily have killed someone.

However, there are some good examples of successful multi-stage flights.

is someone's 3 stager, and

is a 2-stage flight to over 100,000 feet. For reference, it would take 2-4 times as much total impulse to reach that altitude on a single-stage rocket.

If you use solid fuel could you not use an fuse similar to the one who set off the charge on firework rockets.

its use an hole in upper corner so it ignites then the lower stage is burning the last part of its fuel so its TWR is tapering off.

At least for two stages an fail where the rocket is mot vertical would be just as dangerous for an 1 stage one designed to reach the same attitude. Anyway an abort system would simply be an device who cut the fuse.

Main problem would be to ensure clean separation, if its not clean it would be dangerous. and as you say it has to be solid before it separates.

[softweir]

If you use solid fuel could you not use an fuse similar to the one who set off the charge on firework rockets.

its use an hole in upper corner so it ignites then the lower stage is burning the last part of its fuel so its TWR is tapering off.

At least for two stages an fail where the rocket is mot vertical would be just as dangerous for an 1 stage one designed to reach the same attitude. Anyway an abort system would simply be an device who cut the fuse.

Main problem would be to ensure clean separation, if its not clean it would be dangerous. and as you say it has to be solid before it separates.

Not really. Consider:

It is very easy to ensure that a single-stage rocket is stable - the simplest way is to put enough fins at the bottom. Making multi-stage rockets stable is a lot trickier - to make the upper stages stable using fins, they have to be big enough to stabilise the upper stage, but those same fins will destabilise the lower stage.

Secondly, an upper stage is only stable *IF* it is moving fast enough when it ignites. If the lower stage loses thrust before the "fuse" burns through to the upper stage then the whole thing will slow down, and could already be tumbling before the upper stage ignites. Just as bad, if the lower stage propellant burns unevenly so the upper-stage fuse ignites too soon then the ignition of the upper stage will destabilise everything.

All these problems can be solved, but they either require genuine expertise, or else a lot of dangerous trial-and-error. For competions involving youngsters, single-stage is so very much safer!