|
**IIn 2003
Shane Santi founded Dream. He's been studying optics since 1994
but used his first front surface mirror telescope when he was
10 years old, around the same time he started building and launching
rockets.
He lives in the details because of his desire to know what makes
things tick. He has an unquenchable thirst for not just knowledge
but discovery. Each time a question is answered, knowledge is
gained. Unique knowledge can lead to new approaches & solutions,
which in turn leads to deeper questions & even higher-level
understanding. It's at that point that discoveries start to be
made. Those who continue to ask questions, even 20 years on,
are the true subject matter experts. This specific drive can't
be taught because it requires a fire that comes from within. |
|
**Shane has
used his passion for complex systems to create a company that
focuses on installed performance, not promotional claims. In
fact the often large gap between promotional claims and actual
installed performance is the reason he formed Dream in 2003.
Small details matter and affect the final outcome of a system.
Optical systems are trying to achieve performance at fractions
of a wavelength of light. Details matter. Understanding countless
aspects of the system to unusual levels allows for abnormally
high levels of optimization. Shane's own goal is to offer a small
number of customers opto-mechanical structures, optics and full
systems that are truly modern, with unrivaled installed performance,
the highest throughput & the lowest possible maintenance. |
|
"Hello Shane, I can't
think of anyone who has delved as deeply into the mechanics of
optical systems as you have." |
|
- Dream customer |
|
|
**Around the
mid 1990's Shane read the first of many scientific papers (similar to 3rd paragraph
Answer 2 links) that quantified the much larger than expected
performance
losses associated with solid, front surface optical mirrors. Low stiffness supporting structures are another
historic area of performance loss. It became readily apparent
that many providing optical mirrors & systems were making
grossly over-reaching statements, since they ignored real-world
factors. If these main factors were dealt with, installed performance
could be noticeably better. |
|
Shane formed Dream in 2003 for three main
reasons; |
|
1.) Combine the complimentary technologies
of purpose-built carbon fiber & lightweight
mirrors, |
|
2.) Solve the century old problem of print-through
in lightweight mirrors and |
|
3.) Offer higher installed performance
instruments that typically required big aerospace and/or government
budgets, but at a much lower costs. |
|
|
**A more mechanically
& thermally stable total system can; slew faster, hold optical
alignment tolerances & optical surfaces to a higher, more
consistent performance level, in a dynamic mechanical (changing instrument angles) and thermal
(changing ambient temperature),
while being very close to thermal stealth. All of these, and
many more, combine to produce
instruments that break the pyschological norms
of what can be expected out of an instrument & for a given
aperture size. To believe these improvements have no benefit
is the same argument critics of G.W. Ritchey made 100 years ago.
Those without, will always try to minimize what they don't have,
but desire. This can be; products, experience and/or knowledge. |
|
"We shall look back and see how inefficient,
how primitive it was to work with thick, solid mirrors, obsolete
mirror-curves, ..." |
|
- George Willis Ritchey 1928 JRASC,
Vol. XXII, No. 9, November 1928. |
|
|
**In the years
just prior to starting Dream Shane recognized that he could
take aerospace composite technology and optimize it specifically
for the uniquely demanding thermal & mechanical tolerances
of modern opto-mechanical & electro-optical instruments.
The use of Invar rods to control spacing of optical components
requires two distinct & physically disconnected structures
instead of one. The more connections, the more likely stiffness
is lost, jitter is created & mass is increased; the opposite
of effeciency. Dream is making the instrument structures out
of a specific carbon fiber matrix that is athermal to the mirrors.
This provides incredibly stable optical performance of each mirror
because the mirror mounts, backplates, etc., are athermal, eliminating
the complexities that come with secondary "metered"
structures and of flexure-based mirror mounts. There's no need
for a metering structure because the whole structure matches
the mirrors already, by design. |
|
This focus on dealing with the source of
the problems has led to Dream's athermal
instruments which exhibit exceptional
mechanical stiffness & consistency. This inherently produces
an instrument with extremely low maintenance. They're ideal for
remote/robotic installations. The extensive use of Dream's CF
and CFSC™ in the mirror mounts, backplates, instrument
tubes, mounting plates, lens barrels & lens spacers, etc.,
is ideal because they have; |
|
****- low
mass, |
|
****- low CTE (Coefficient
of Thermal Expansion)
and |
|
****- extreme
stiffness. |
|
 |
|
|
**In 2001-2002
Shane discovered that standard composite companies had little
to no knowledge of optical systems, little to no knowledge of
stiffness (not strength)
and the extreme requirements that
come with them. They also had little desire to work with such
a demanding and difficult customer. This began a long
series of unexpected duties that Dream would have to bring in
house, in order to control and achieve the higher levels of performance
that Shane knew were possible compared to the status quo. The
benefit of the long years of R&D can be seen in Dream's in-house
designed & produced stainless steel inserts, the extreme rugged performance of Dream's
advanced composites (see
CFSC screwdriver video), the
low MSF errors
of its engineered, lightweight zeroDELTA™ mirrors and countless features that have been
developed for Dream's optical systems. Chasing real-world
performance has to be driven by a person
who understands why each parameter needs such critical control.
Otherwise no company would invest the additional time, effort
& expertise that is required to achieve higher level performance. |
|
**As soon
as space was leased in 2003 Shane designed the largest composite
oven that Dream continues to use to this day; 12' wide, 6' deep,
6' high (interior dimensions). It was upgraded in 2013 after
a decade of use. It can maintain a temperature tolerance of +/-1°F,
which is one magnitude tighter than normal aerospace composite
ovens. Dream's resin content is 20-40x more tightly controlled
than standard pre-pregs from a decade ago and 2-4x more tightly
controlled than current (2018) industry-leading space-qualified
prepregs. This unusual attention to detail has led to Dream's
actual and measureable performance gains. |
|
**Companies
are more recently using open-market carbon fiber in one or two
components of opto-mechanical systems but only 5-10% of the "carbon
fiber instrument" is actually carbon fiber. The other 90-95%
remain metals; old technology wrapped in a shiny new bow by the
marketing department. Look carefully and ask direct questions;
what percentage of the structural weight is carbon fiber? Are
all of the carbon fiber pieces load-bearing or are they in for
cosmetics/sales? How many use sandwich core? |
|
Dream's CFSC™ is used extensively
in the structures Dream produces.
Dream consistently averages 95% carbon fiber and only 5%
metals for the weight of the structures in its athermal instruments.
(no optics) |
|
|
|
**Shane began
researching lightweight mirrors of all types 25 years ago; thin
solid, solid conical, fused, frit-bonded, cast, etc. This was
brought on by his interest in understanding numerous types
of seeing, since seeing degrades installed
system performance. "Seeing" can come from numerous
sources and each source is often complex; mirror, telescope, observatory, ground effect, etc.,
are all individual forms of seeing that can do nothing but degrade
the installed performance. Understanding each source to a deeper level has
allowed Dream's products to break performance barriers and is
the reason Dream is now designing ground-up facilities. There's
no point in putting a high-performance instrument inside a facility
that will never allow it to be used to its full potential. |
|
One of Dream's 0.4m
instruments outperformed all other
instruments in a mulit-year
NASA program, with some of those instruments
being as large as 1m. This validates what G.W. Ritchey showed
100 years ago; quality of the total installed system matters far more
than aperture, when the other systems are ignoring fundamental,
centuries old thermal & mechanical problems. |
|
|
|
|
**Dream's advanced composites offer
extreme stiffness and produce an athermal instrument when combined
with Dream's zeroDELTA™
engineered, lightweight mirrors. Customers also use Dream's
CF & CFSC™ with zero-expanion
mirror materials because they offer higher stiffness, lower mass
and more closely match the mirror material than aluminum and
steel structures. This can eliminate the need for complex flexures
and metering systems, which bring their own errors to the mix.
Dream's systems achieve a much higher level of performance day after day, year after year,
while having the lowest maintenance. What many have considered
as performance limits due to their local atmospheric
seeing, is often traditional mirror seeing and low structure
stiffness; century's old problems that Dream has addressed directly
through knowledge & intelligent designs since 2003. |
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
The above strut is a prime example of the substantial
gains that Dream achieves with its optimized CFSC™ parts. The strut is 55.7" long,
weighs only 1.85 pounds and is shown in a 3-point bend arrangement
under 195 lbs of load. |
|
biomedical backboard, rigid backboard,
carbon fiber board |
|
carbon fiber structures for space,
carbon fiber space structures, cyanate ester, space qualified
carbon fiber |
|
|
rocketry, IRAC, Spaceport America
Cup, soundingrocket.org |
|
|
|
|
Other
Carbon Fiber Parts |
|
|
|
|
|
|
|
|
|
|
|
|
|
Dream's carbon fiber is also superb for zero-expansion
mirror materials like Astro-Sittal, Clear-Ceram, fused silica,
ULE, Zerodur, etc. Click below to see a carbon fiber structure
for a 25" Cassegrain that used ULE mirrors. |
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Connection points in any opto-mechanical
or electro-optical system are often the cause of a loss of stiffness
& therefore performance. This
page shows the pull-out strength of
Dream's stainless steel inserts used within Dream CFSC™ parts. |
|
|
|
|
|
|
|
|
|
|
|
|
|
"Your company does phenomenal work.
There is a lot of thought and heart that goes into your products.
Dream's engineering sets their lightweight mirrors apart from
competitors. Your engineering goes beyond the lightweight aspect.
You focus on actual performance!" |
|
- Ted Kamprath |
|
40+ years in professional
optics, using everything from $1m & $1.5m test rooms to 144"
Continuous Polishers. He's spent his career using the latest
in technologies, methods, materials & science finishing precision
optics. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Modern
Optical Metrology |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Knowledge is power. |
|
Ignorance a liability.™ |
|
