Good points. My suggested approach did sort of assume you'd be starting
from nothing. That may well be the case - serious student rocketry
programs can come and go - but find out what if anything is already
going on - don't necessarily wait till you arrive there next fall either
- and depending on what's there, consider starting out as part of an
existing project.
Another point to explore: What's the existing safety culture? Are they
already comfortable with things like LOX handling and biprop test
stands? If so, within what limits? If not, you might well spend some
part of your first year working with the Academy engineering safety
people to find out and arrange to provide whatever procedural and
documentation and certification and
other-people's-projects-that-didn't-kill-anyone assurances they'd need
to support such. That process too would be significantly educational...
Henry
On 5/26/2019 11:28 AM, D K wrote:
First of all, see what they have done in the past. Successfully and unsuccessfully. Then see what the current projects are. Join a team as a grunt worker the first year. Learn the ropes at the Academy. Then evaluate what is possible to do and what you want to do. Find the intersection and work in that direction.
Don't go it alone and assume kudos and kumbiyas for your ideas as a freshman or sophomore. Demonstrate your abilities via hard work and dedication to this new group. Get a skin or two on the wall. Then start proposing. And progressing.
Doug Knight
On Sat, May 25, 2019, 5:51 PM Shepherd Kruse <shepherd.h.kruse@xxxxxxxxx <mailto:shepherd.h.kruse@xxxxxxxxx>> wrote:
I’m a student headed to the Air Force academy this Fall. I like
the thought process of going directly to liquids and spending all
the time and resources perfecting an engine. I’m hoping to get
backed by the Astro department and getting the rocketry program up
and running again. I’ve done a lot of work on my own, but as far
as success goes, what would you advise for me to focus on
potentially leading a USAFA rocketry team?
Regards,
Shepherd Kruse
On May 25, 2019, 1:04 PM -0600, D K <dougchar001@xxxxxxxxx
<mailto:dougchar001@xxxxxxxxx>>, wrote:
Having done student projects involving rocketry for the last 15
years or so, while none this big, this is a major accomplishment.
Students come and go administrations come and go, risk tolerance
of management varies, and interest at the institution can vary as
well. To work this long this hard and build upon the knowledge to
make it work is a major accomplishment in my opinion.
The caveat on student rocketry programs is one bad mistake, test,
flight can often ruin the whole program. Forgiveness for my
perspective is rare. Ending a multi-year program that affects
multiple students is not worth certain risks, IMO. Why liquids
are a completely different ballgame at University settings.
And the reality is in a university setting we're training
students to go out and work in different industries, oftentimes
not involving rocketry, especially in small programs such as
mine. Ultimately the student is more important than the rocket
not the other way around. The student is our real deliverable.
Why I'm only now starting to consider hybrids but at a very small
scale initially. And like the previous poster said you can do a
whole lot involving rocketry systems with solids as the propellant.
Doug Knight
On Sat, May 25, 2019, 1:58 PM Henry Spencer
<hspencer@xxxxxxxxxxxxx <mailto:hspencer@xxxxxxxxxxxxx>> wrote:
On Sat, 25 May 2019, Bruno Berger SPL wrote:
> Starting with a solid motor (eg a commercial one) is IMHO
not wrong. So
> you get your experience with the airframe, avionics,
telemetry, recovery
> etc before you maybe switch to liquids. The chance is great
that you
> will never fly something if you start with the development
of a liquid
> engine first...
The flip side of this, though, is projects that decide to fly
first with
solids and then switch to liquids, but die when they try to
make that
transition.
Whether starting with solids makes sense depends on your
goals. For sure,
getting something liquid working is a big hurdle. But if you
*must* jump
that hurdle to achieve your goals, flying with solids first
might not be
the best use of effort. For example, if your goal is a
system that does
DC-X-style powered landings, then learning how to do reliable
parachute
recovery (which is harder than it looks, especially given
that almost
every failure means building a new rocket) might be a costly
distraction.
Part of the problem is that there's a hidden mistake here,
lurking in
Bruno's own wording. Quite likely it *is* a mistake to start
with
development of a liquid *engine*, if your goal requires
development of a
liquid *propulsion system*. With solids, the engine pretty
much is the
whole propulsion system. With liquids, not so -- not even
close. People
seldom do post-mortems on failed projects, but I think a lot
of them would
show that the project died between "engine drawings complete"
and "first
successful firing", because getting the *rest* of the
propulsion system
working was planned to take a weekend, and after two 14-hour
days they
realized they were only getting started.
People who want a liquid propulsion system should not start,
as so many of
them do, by trying to design their ideal liquid engine.
Better to start
with the simplest and crudest engine possible, with no
intention that it
will ever fly, to get experience with plumbing, fluid
handling, controls,
ignition, plumbing, data acquisition, test operations,
plumbing, etc. :-),
before you maybe switch to a more sophisticated engine
design. Not least,
because that experience is going to change your ideas about
what the more
sophisticated engine should look like.
> for student projects it's important that you see results
soon to keep
> them motivated.
Agreed, and in fact I would omit "for student projects" --
seeing results
soon is important for any volunteer effort, and it sure
doesn't hurt for
investor relations either.
For low-budget projects with an inexperienced team and
nervous sponsors,
the dinospace dogma of all-up testing -- build and fly the
complete final
system the first time, and of course it will work -- is a
snare and a
delusion(*). Think incremental development and testing instead.
(* In fact, if you look at how the all-up concept developed
-- most
notably, its use for Project Apollo -- the people involved
didn't believe
for an instant that the first test was certain to succeed.
They tried for
it, they hoped for it, and they were prepared to exploit it if it
happened, but they were far from sure of it. The "and of
course it will
work" part got added later, by the ignorant and overconfident. )
Henry
