[SS-VehDev] Re: tasks, current

[william colburn]

Matt,

That was the original goal. It has been rather loose
it seems in organization. We should be receiving a
report from the head of each group as each milestone
is met.

We do have the overall vehicle specification and that
will be updated as specific limits are defined.

The in-progress analysis by Bob Krech will supply the
thermal inputs we need.

We've done the mission profile (Rich's SOARS file),
Hans has provided Cd, additional Mission profiles,and
Drag integral analyses. We have acceleration/time from
those runs.

We have flutter sim's and stability sim's for the fin
design.

Additionally we have a good line on internal
ballistics from Rich.

Pyro shock levels (ignition of each phase, NC
ejection, drogue release, and main chute ejection) we
can estimate from NASA doc's which I have on file.
Will forward those esp to those in charge of designing
the electronics. 

Snatch forces and g loads have to be computed as I
mentioned.

We are very nearly there in defining total mission
environment, have to add what we know into the overall
spec for all to access.

BC



--- Lakestake Rocketry <lakestake at gmail.com> wrote:

> Good evening,
> 
> As far as the "get inputs" goes shouldn't we (The
> VehDev team) be receiving
> comprehensive specifications from each team lead as
> to their requirements?
> We have our proposed starting point, but it would
> help in design if we knew
> the mass/space/temperature/shock requirements of all
> the parts we need
> to house/integrate with.
> 
> Once each team has prepared their proposals we can
> re-evaluate the design
> to see if we are still under mass and then tweak the
> airframe design to
> provide the needed concessions to each device.
> 
> Matt
> 
> On 10/26/05, Rich Nakka <richnakka at rogers.com>
> wrote:
> >
> > Three minor comments/suggestions:
> >
> > william colburn wrote:
> >
> > Here is my current list of tasks:
> >
> >
> > 3. Settle the launch lugs vs three rail tower vs
> > launch tube question.
> >
> >  Miraglia has some prelim CFD results for total
> drag with/without lugs. I
> > suggest he continue to refine the analysis, maybe
> look at smaller or less
> > obtrusive lugs.
> >
> > 5. Get inputs from Bob Fortune on the recovery
> system
> > volume needed. (150 lbm to recover at no greater
> than
> > 25 fps; require low altitude deployment of the
> main
> > and a drogue from 100K or so)Determine snatch
> forces
> > on drogue and main for purposes of designing
> > attachment points.
> >
> >  I suggest that a higher touchdown velocity should
> be considered, say
> > 30-40 fps. Since required chute area (i.e. mass)
> is inversely proportional
> > to velocity squared, increasing TD velocity to 30
> or 40 fps requires a chute
> > of 70% and 40% the size, respectively.
> >
> > Chute volume may not be a big problem. The chute
> ("fairing" ) portion of
> > the vehicle has been rather arbitrarily taken to
> be 2 feet (0.6 m). I
> > don't expect that lengthening the fairing should
> add much weight if it is
> > fabricated from carbon composite sandwich material
> or similar
> >
> >  6. Design NC removal system; I favor staying away
> from
> > BP for two reasons: altitude ignition (probably
> very
> > solvable) and dirty combustion products (maybe
> piston
> > ejection?)
> >
> >  Yeah... piston ! ;-)
> >
> > Richard
> >
> >
>