From: dlw@engr.ucf.edu (Chip Wuerz)
Subject: Re: altitude records (added reference and more info)
Organization: engineering, University of Central Florida, Orlando
Date: Thu, 23 Jul 1992 13:07:06 GMT

Records and Altitude Project Ideas
(To set the records straight and answer some recient questions)

********************************************************************

* * Some current records for NON-METALLIC NON-PROFESSIONAL Rockets: * *

Top two altitude holders:

1)	altitude -  24,771 feet 
	Percent Error on Track - 11.7%
	Set by   - Chuck Rogers and Corey Kline
	Location - Lucerne Dry Lake Bed, Lucerne, Ca.
	date     - June 1989, USXRL-89

2)	altitude - 22,211 feet
	Percent Error on Track - 5.3%
	Set by   - University of Central Florida
	Location - BlackRock Dry Lake Bed, Gerlach, Nv.
	date	 - August 1991, LDRS X

Highest Tracked Flight at Lucerne

	Kline/Rogers Team - 24,771 feet, 1989

Highest Tracked Flight at BlackRock

	University of Central Florida - 22,211 feet, Aug. 1991     

Highest Tracked Staged Rocket

	University of Central Florida - 22,211 feet, L750 to L750

Published notes on Chuck Rogers / Corey Kline Flight:
>> (Tripolitan Vol. 4 no. 00, December 1989)

New unofficial altitude record for nonmetallic high power/experimental 
type rockets.  Possibly highest tracked flight of an amature rocket
(metal or fiberglass construction) yet in the United States.  Korey 
Kline and Charles Rogers became the first recipients of the Rocket
Newsletter perpetual altitude trophy for the first flight to exceed
the previous record of 22,080 feet set with a metal rocket by the Fort
Team in May 1984.  The trophy will be awarded to the next team to 
exceed the current record.  Record is unoffical because of some 
uncertainty on the exact track.  The cloud of red carpenters chalk
ejected by the rocket was barely visible (because of a background of
white clouds at higher altitudes) and high wind speeds at 25,000 feet
dispersed the tracking cloud in only 3 - 4 seconds.  Trackers only
got a track on the general vicinity of the red carpenters chalk
in front of a cloud.  Before they could zero in the track, the red
cloud had disappeared.  The angles from the last position of the tracker
heads was used for the track, the error was only 11.7%.  The tracked 
altitude was within 3.2% of the postflight prediction (25,567 feet)
using the Rogers Alt4 altitude prediction program with the actual
liftoff weight of the rocket, and a preflight CD estimation from
program CD2.  Undoubtedly a valid track, but because of circumstances
considered an unofficial record only.  The Rocket Newsletter considers
this track an official record.
>> Rocket ws powered by an Ace Aeronautics L500-25, used built-in
>> delay and backup Moose engineering delay timer.  Rocket reached
>> an estimated mach 1.93, used 63 Deg swept fins to delay the peak
>> fin supersonic wave drag to mach 2.2.  Total impulse=3846 Ns,
>> Burn time=6.23 sec, wt=8.5lbs., length=62.0 in..  Rocket was
>> tower launch.


*** My note: L500 Ace Aeronautics, 2.125" X 40", Avg thrust 525.296 N
		total impulse 3272.59 Ns ***

*** My Note: unofficial means Tripoli unofficial.  Tripoli only recognizes
	tracks with less than 10% error.  (Chip Wuerz) *************


Published notes on University of Central Florida's Flight:
(The TRIPOLITAN ... AMERICAS HIGH POWER ROCKETRY MAGAZINE,
	OCTOBER/NOVEMBER 1991)

Highest tracked flight at LDRS-X / BALLS
Second all-time highest track of a non-metallic high power rocket.
University of Central Florida's research project and altitude attempt
to break the current high-power rocketry altitude record of 24,771 feet
set by the KLINE/ROGERS team in 1989.  Altitude attempt had been based on
3850 NS L-engine, new Vulcan L-750 engines deliver 3,000 (now known to be
less from motor testing results) newton seconds.  In an attempt to make
up power loss and to provide margin on the goal altitude of 25,000 feet,
the upper stage was delay-staged by several seconds.  Altitude predictions
computer simulation program predicted 28,500 feet.  Upper stage flew 
substantial trajectory, reaching apogee nearly 2 miles downrange.
Rocket used microprocessors / timer-controlled staging and ejection,
on-board flight data measurement package, and a radio beacon system to locate
upper stage.  Track was accomplished using red carpenters chalk.  Both
stages were recovered.

************************************************************************
	
* Simulation Software - RAS programs

Rogers Aero Space software is currently the best software that I
know of for simulating non-professional rocket flights.  It has its
limitations though.  For example, it assumes ideal drag (i.e. a smooth rocket). 
A good rule of thumb would be to subtract 10 to 15 percent off
the highest predicted altitude.

from jack@rml.UUCP (jack hagerty)

> I believe the record is a little over 24000 feet. As I stated in my response,
> there are two problems to be overcome in breaking that record. 1) it is just
> about mandatory for the rocket to attain supersonic speeds to reach these
> altitudes - they tend to shred at speeds approaching mach 1 due mainly to
> vibrational resonances. 2) It is hard to track the rockets at such high
> altitudes.

> If they can break the record at all, e.g. if the rocket holds together and
> they can track it, then breaking the record by 4x shouldn't be any harder
> than breaking it by 20%.

I agree with Jack in that it is just about mandatory for the rocket to attain
supersonic speeds to reach these altitudes.  This is due to the fact that
in order for the rocket to reach such heights it must have large motors and
be near minimum diameter.  The motors can only be so long, and must have at 
least a certain specific impulse in order to function properly.  So to have 
a higher total impulse in a smaller motor case you must have a higher specific 
impulse.

I disagree on the point that they tend to shred at speeds approaching
mach 1 due mainly to vibrational resonances.  This is true for most
paper rockets, but all of the sucessful high altitude projects that I 
know of use composite materials for the rocket structure (fiberglass is
most prevalent).  From past experiences it has been shown that a well
constructed fiberglass rocket can stay together up to about mach 2. 
So it is appearent to me that this is a barrier that other materials
are necessary to break (carbon fiber, kevlar, metal, ....).

* Tracking -

High altitude rockets are hard to track.  One of the most prevalent ways
used in our hobby is carpenters chalk.  The UCF project used one pound of
red chalk.  It looked about marble size from the ground (at 22,211 feet).
The parachute wasn't even visable through high power binoculars.

The University of Central Florida also uses a telemetry transmiter to
send information on the altitude.  We transmit information on temperature
and pressure.  By having this information for ground level and apogee,
the altitude can be accuratly determined.  The signal is also used
to point out the location of the substainer.  The reciever antenna is
a six element crossed polarized yagi array, designed for maximum gain and
directivity.

My case and point is, if you can't see it how can you find it?
In our case we use telemetry.
For the trackers to see it, use pounds of chalk!

One of the most important aspects of tracking is to have the chalk ejected
at apogee.  In order to do this we use a plugged substainer motor (the
delay columns are not that accurate, and are even less so for long delays).
A timer circuit is used for precision staging and ejection.

As far as breaking the record goes -  I feel it will be broken at the BALLs
launch, unless LDRS rules change.  
 
Rocket altitude varification - the method which is currently being
used is RAS simulations.  Up to this point the only valid tracks 
have to be taken optically by trackers.  I don't think they (Tripoli)
will except electronic tracks (yet). 

* Design considerations for high altitude -

Their is a trade off in the rocket designs.  A single stage rocket
has a much better chance to get the record because it is not as complex.
But, the two or more stage rockets have an advantage in that they can
drop off a lot of weight.  Now looking back on professional 
history, has any rocket made it to orbit using a single stage configuration?

Designing single and multistage supersonic rockets are a little tricker
than that of subsonic rockets.  For example, it has already been pointed 
out that the center of pressure changes. 
To make sure the rocket will still be stable when supersonic you need a 
more stable rocket to account for CP and CG migration.
Also, it is important note that most flight simulation programs use
subsonic formulas for various parameters and calculations.

Another major consideration is the additional recovery requirements 
for parachutes.  Randy Thomas from Paratech Parachutes has done a lot
of work on researching parachutes and made the comment that parachutes
behave differently above about 40,000 feet (air at 40,000+ feet?).  One 
also has to consider the drift from a rocket at such a high altitude 
(unless you want to recover your rocket in the next state).


I guess for a future analysis, I see more high tech electronics being used
like gyros.  Right now the altitude attempts are at the point of exceeding
the high power limits of Tripoli.  In the future either Tripoli will have
to up the motor limit or the altitude buffs will be in the realm of
amature rocketry (if they arn't already there)! 


Good Luck and I hope to see you at LDRS XI / BALLS.....
        This is the one you won't want to miss,

						Chip
						Tripoli # 681

Chip Wuerz                            Chip Wuerz
UCF high altitude rocketry projects   2272 King Johns Court
Electrical Engineering Dept.          Winter Park, Fl. 32792-2221
University of Central Florida
Orlando, Florida 32826

		

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