ON THE
EARLY RETIREMENT OF THE SHUTTLE
Launchspace Op Ed piece by
George W. Jeffs
·
A
Symbol: An in-space
ballerina and hypersonic flying
marvel, the Space Shuttle Orbiter is
almost impossible for others to duplicate and continues
to generate international admiration and respect for
U.S. technical capabilities.
· Full Potential Not Yet Realized: The
multi-functional Orbiter has performed "as designed" on
all assignments including reentry and a key role in the
International Space Station (ISS) assembly. Like any
new manned system, as crews and engineers become more
familiar (like a helicopter) performance "in the box"
improves and
extending-the-box opportunities are
identified. So far the Orbiter has operated generally
within the box.
·
Too
Young For Retirement: Each remaining
Orbiter has many missions and years of life remaining.
The Orbiter was designed for a
one
hundred mission life with a factor of
four (i.e. 400 flight potential). It has experienced
low flight rates and has not been structurally
overloaded (maximum loads occur during the boost phase
and high wind shear situations have been avoided through
pre-flight meteorological observations) and receives a
complete examination and any necessary refurbishment
between each flight.
·
The
System is Safe for Continued Manned Flights:
No critical failures have originated from within the
triply redundant Orbiter itself but like any spacecraft
designed for light-weight, it is vulnerable to abuse
(e.g. SRB O rings, ET insulation debris); these are now
known and addressable problems. The Space Shuttle Main
Engines (SSME)s were my principal safety concern through
the development years but their flight record has been
excellent and it may be that the integrity of recovered,
refurbished rocket engines is
as
good as or even better than new ones.
Some rocket engine incipient failures may lie undetected
in ocean graves.
·
Real Usability Through "Landing With Dignity":
Turnaround man hours are costly for the Orbiter, not the
least demanding being the heat shield preparation and
changes are continually being made to improve the
situation. Even so, this relatively light-weight, first
generation radiant heat shield is itself reusable and
obviates having to pay for a new vehicle and other
ancillary costs such as ocean recovery for every
flight.
Note: In depth reviews of "flown" Apollo
command modules concluded that second flights of the
hardware would be too costly at that time.
·
New
Space Initiatives Depend On The Orbiter For
Identification and Pursuit: The
on-orbit assembly option for a deep space manned system
became more viable upon completion of the International
Space Station (ISS) using the Orbiter. An "Orbiter"
segment of a deep space system would be used in assembly
activities, on-orbit transfers, tug functions and most
importantly for
the
crew Earth-to-orbit and orbit-to-Earth transfer.
Reliance on an Orbiter for re-entry would
eliminate configuration constraints on
size and shape and the weight of items such as
parachutes, heat shields and landing impact structure
and the energy needed to transport this otherwise
useless added weight throughout the entire deep space
mission. This approach essentially would trade-off
these advantages against the development of an
additional propulsion module for return from deep space
to high/low Earth orbit. The present Orbiter would be a
key mechanism in the early development of such an
on-orbit assembled system.
·
The
Shuttle Continues to Be An Intriguing Candidate For
"Commercialization": The system is
presently operational. Its payload-to-orbit delivery
and other capabilities are well documented. Its risks
are known and assessable for payload insurance and
crew-safety considerations and industrial elements are
already doing much of the work in many areas. Bailing,
leasing and/or other type of agreement for use of
government equipment (Orbiters, pads, control centers,
etc.) is probably feasible in some arrangement. Needed
is an industry, NASA-government, Congressional meeting
of the minds on all related elements including
government flight requirements, (e.g. ISS servicing) and
commercial pricing policies. If such a government
hand-off to industry could be affected it would, of
course, keep the Shuttle Program available for another
decade or two should presently unforeseen government
needs arise (even today it would be most
helpful to have Apollo supply and rescue
vehicles that serviced Skylab available for use on the
ISS).
· U. S. Taxpayers Have Not Yet Realized Their Full
Return-on-Investment (ROI) From the Shuttle System:
o It
really works; it is not just a briefing
chart promise.
o It has much life remaining and could be the key to
the identification and development of new systems.
o It is man-rated and safe--probably as safe as any
manned system will be-no others will get over one
hundred flights down the learning curve.
o The infrastructure is in place and operational and
has provided industry through extensive, hands-on
participation with the depth of training necessary to
assume total system accountability.
o To replace the Orbiter capabilities will take
decades and billions.
Decommissioning the Space Shuttle should be postponed
indefinitely.
George W. Jeffs is the former President of Space and
Energy Operations [including Shuttle Orbiter,
Integration and Space Shuttle Main Engines (SSMEs)] at
Rockwell International. He is also the former President
of the Space Division, North American Aviation-Rockwell
International [including Apollo Command and Service
Modules and the Space Shuttle Orbiter]. He is also a
helicopter and fixed-wing pilot with multiengine and
instrument ratings.
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