Commercial
Space Shuttle Freighter
Key to 21st Century Space Transportation
Developed by Concerned American
Aerospace Engineers
Interested members of the aerospace community please contact: ( caae@wt.net ) Nelson
Aerospace Consulting
3
2020
Executive Summary
The Commercial Space Shuttle Freighters
is designed to: support near earth space transportation requirements, provide
the capability for deep space exploration, support mankind’s need to obtain
deep space resources, provide rapid response to deep space threats, and
establish populated safe havens in deep space. Affordable and sustainable space transportation for the
21st century must be based on commercially operated reusable
launchers and space based vehicles. This requires a space transportation
system that has the capability to return commercial quantities of near-earth
and deep space resources to the Earth’s surface…a commercial space shuttle
(CSS) freighter. The CSS freighter using
the decommissioned Space Shuttle’s configuration has the potential to reduce
the mission launch cost to $50 million. The launch cost will be significantly
lower than those of an expendable launch vehicle, primarily because of
eliminating the manufacturing of expendable stages, capability to increase
flight rate, and lower insurance costs because of the increase reliability.
The CSS freighter uses the
orbiter airframe profile, fly back boosters and will be autonomously operated.
Crews will be flown only on missions requiring their presence for mission
support. For these missions, they will be provided escape pods which provides
protection for launch, on-orbit, and entry anomalies. There are no piloting
requirements. Launch pad assembly of the freighter will reduce operations cost
and turnaround time. Rapid turn-around is a unique CSS freighter feature which
reduces operation’s cost, provides the capability for timely intercepts of
threating asteroids/comets, and supports USAF rapid deploy missions.
No
NASA support will be required for the operations of the CSS freighter or space
based vehicles. NASA’s role in space transportation will be to develop advanced
technologies and concepts for the space freighters and space based vehicles
needed for near earth and deep space operations. NASA, however will/or can be in charge of research space probes
delivered by the CSS freighter transportation system.
The payload delivery capability,
landing weight limits, and launch cost of the CSS freighter will establish the
design boundaries of the future space based vehicles. The CSS freighter’s
operational capability will be the cornerstone for planning and development of
the 21st century’s space transportation system.
CSS Freighter Design Reference
Mission
· Deliver and return 20
metric tons to and from a circular orbit of 240 nm at an inclination of 28.5
degrees.
· All mission phases
conducted by autonomous operation with ground control backup flight guidance.
· Provide escape pods
for up to 4 passengers. Passengers will have no flight control authority.
· Provide 4 days
nominal on-orbit operation plus 8 days in power down mode for contingency
passenger retrieval. Dormant (no passengers) on-orbit systems will be designed
for 60 days in gravity gradient attitude for repair or retrieval of disabled
freighter.
· Orbiter return to
launch status will not exceed five days.
Business Model
The business model considered by
Lockheed Martin for the VentureStar commercial launch
vehicle fleet may still be the best option. Lockheed Martin proposed to build and
operate a minimal commercial fleet of vehicles. One cost estimate for the fleet
was $8 billion in 2014 dollars. NASA and other U.S. government customers would
guarantee a specific number of payloads (launches). Unfortunately, the VentureStar had unsolvable development problems and never
obtained operational status.
This is a similar business model to
that the USAF has with United Launch Alliance. However, the extreme operating
cost and low flight rate of their expendable launch vehicles has made this a very
expense business contract.
CSS Freighter Development Concepts and
Operational Cost Analysis
Development
and operation estimates have been made for the commercial space shuttle (CSS),
using NASA data. It was estimated that a CSS fleet of 3 launchers
could be developed for $9 billion. Annual operations cost was estimated to be
$820 million.
Basically,
this plan requires that the government (NASA/USAF) annually purchase enough
launches to meet the space launch company operations expenses. Any launch position not needed by the
government could be released to the private sector. In 2018 there were 35 launches that could
have been flown on the CSS. The CSS
operator would only have to capture 17 to achieve a break-even $50 million
launch operation cost. With the CSS unique capability to provide payload
return, this is a very achievable goal!
Note: There
were 114 space launches in 2018, of which 35 could have flown on the CSS. At an annual operating expense of $820
million, the CSS operator
would only have to capture 17 of those flights to achieve a break-even $50
million launch operation cost.
Following is a
description of existing technologies and improved operations procedures that
make the CSS freighter cost competitive:
Flight Operations
(FLT OPS)
The CSS freighter flight operation
costs are reduced by removing civil service support. Additional FLT OPS cost
reductions are made by the following innovations:
· Orbiter Configuration: The airframe exterior will not be significantly
altered. However, since no crew windows will be required a ballistic nose cone
similar to that of the X-37B will be investigated. Composite material will be
used to reduce weight as was accomplished for the Boeing 787. Composite material can reduce the orbiters weight by 20 percent
(approx. 15,000 lbs.). Initially this weight saving should be used to
reduce landing loads and the size of the external tank or elimination of the
tank. Composite materials are expected to reduce the maintenance costs.
Consider X-37B Nose Cone Configuration
· Integrated Vehicle Health Management System (IVHM): A major contributor to the high costs of current space
vehicle systems is the operations, maintenance, and infrastructure portion of
the program’s total life-cycle costs. Incorporation of IVHM with distributed
remote health nodes, fiber optic distributed strain sensor, and fiber
distributed data interface communications components will result in significant
program life cycle savings by improving reliability and lowering operational
costs. Computer technology has advanced to the state that an onboard IVHM
computer system can verify the status and control all vehicle systems. It has been proved to be extremely effective
on modern aircraft and spacecraft. The ground and flight software developed for
the Lockheed Martin VentureStar and X-37B could be a
baseline design for reducing the cost and development time of the IVHM system.
· Modular Flight Subsystems: Subsystems must be a modular
concept, designed for unconstrained replacement. The spare parts operation must be based on
modular replacement of the subsystem.
Modular replacement is required to reduce the time for replacing flight
failed subsystems from days to hours.
Modular replacement designs must consider launch pad and on-orbit
replacement of failed equipment.
· Orbiter Propulsion: All Hydrazine is removed from the orbiter. The attitude control propellant is replaced
with a “green” propellant such as AF-M315E.
The orbital maneuvering system for major altitude changes is a hybrid
engine with liquid oxidizers and a solid fuel such as hydroxyl-terminated
polybutadiene (HPPB). These fuels
decrease processing time and increase safety. The Dream Chaser hybrid rocket
motor is being considered to replace the orbiter’s hydrazine OMS.
· Thermal Protective System (TPS): The NASA Space
Shuttle TPS is not acceptable. However,
the TPS is not believed to be a development issue with the current available
materials. Use of metallic tile, mechanical fasteners, carrier panels,
carbon-carbon, rigid ceramic and other current technology will be considered.
The TPS must be able to withstand impacts and/or be repairable on-orbit. The vehicle health monitoring system will
monitor the TPS for any breach. On orbit repair of TPS will be developed.
Other
TPS considerations:
· Toughened unipiece fibrous re-enforced
oxidation-resistant composite, (TUFROC), to cover the wings’ leading edges.
· Toughened unipiece fibrous insulation,”
(TUFI), to replace ceramic tiles and reduce weight.
·
Design a robotic flight vehicle
system to repair on-orbit TPS failures.
Lockheed
Martin VentureStar TPS
IN-FLIGHT
TPS INSPECTION AND REPAIR:
In-flight inspection using the
integration of thousands of sensors into a pattern of fibers located in the TPS
will provide real-time structural health of the freighter. Any breach in the
TPS will be repaired by an on-board free fly spacecraft designed for
multi-purposes repair.
TPS repair kits fall into two basic categories, mechanical or chemical.
Mechanical repairs systems rely on prefabricated materials and fasteners.
Chemical repairs rely on materials that are applied in a raw form and develop
into a chemical adhesive bond to the TPS.
· Electrical Power System: Consist of solar arrays and ion
batteries and/or an Electric Auxiliary Power Unit (APU) system designed to replace
the Orbiter’s existing Hydrazine APU. The Electric APU consists of a battery,
associated 270-volt power, distribution and control, electro-hydraulic drive
unit, and cooling system. Electromechanical
Actuators (landing gear, body flaps, elavons,
gimbals) will be designed for those functions.
X-37B Solar Array
Electric Auxiliary Power Unit
CSS Freighter Passenger Escape
Pod
The CSS will transport passengers to
and from space in pods. Escape pod weigh is estimated at 700 pounds per pod.
The pods provide protection for all phases of flight. At launch pad abort and
lower altitudes escapes, a ballute deploys to slow the pod for parachute
deploy. The pod’s life support system provides on-orbit safe haven in the event
the cabin pressure is breached. Target lifetime for life support is 20 days to
allow for on-orbit rescue. Pods are located behind the nose cone heat shield
wake to reduce excessive thermal loads in the event of a Columbia type entry
failure. The pod is also equipped with a heat shield system. The pod must be a
“smart pod” ... it must have knowledge of the environment.
Launch Operations
Removing
civil service support significantly reduces launch operations (OPS). Additional launch cost reductions are
made by the following:
· The CSS freighter will consolidate ground and flight
operations at the launch site. The
support launch team personnel will be responsible for both preflight and flight
operations.
· Pre-Mission Planning:
Flight planning design computer programs have been developed that
incorporate common databases, total vehicle environment modeling, and internal
iteration processes. These flight design
computer programs (incorporating sequential quadratic programming) have reduced
the flight design from months to a few days and significantly reduced manpower
requirements.
· Launch Vehicle
Assembly: Launch pad assembly of the CSS will reduce operations cost and
turnaround time. The assembly complex will be on rails and be moved away from
the launch platform prior to launch. The orbiter will be prepared for launch in
a hangar facility and towed to the launch site for assembly. The freighter’s
launch complex will be like the Vandenberg SLC-6 (Slick Six), however it will
be designed for freighter launch operation. There has never been a shuttle
launch complex specific designed for space shuttle operations.
·
Assembly
Pad Preliminary Design Requirements:
· Building will meet locality wind loads limitations.
· Cooling tower water will be recycled.
· External building dimensions will support one
freighter.
· Meet safety operation for current shuttle launch
constraints (open building segment configuration).
Encapsulated Payloads:
Payloads will be
"encapsulated" cargo; that meets the power supply and berthing
configuration requirements.
The CSS will not serve as an on-orbit payload service platform. The CSS
freighter is a "ship and shoot" and retrieval cargo operations.
Nominal mission operation will not exceed 7 days. Payloads will have an
allotted power usage limit.
Orbiting Processing Building:
·
No significant
change is expected for the building’s external configuration or floor
space. Internal layout is TBD by the
selected orbiter systems. Note:
It is not a frim requirement to use any exist NASA facilities for CSS freighter
operations.
Fly-back
Boosters:
Reusable
fly back boosters will significantly reduce operations costs and increase
reliability. SpaceX successful recovery of
the Falcon first stage has proven that the booster recovery capability
exists. It may be possible to use a
version of that stage.
Civil Service:
NASA
will not at any time be an operator of the CSS Freighter.
External Tank (ET):
It
is expected that the composite cryogenic tank will be available and reduce the
manufacturing costs. Manufacturing cost,
not payload to orbit will be determining factor in the design of the CSS
freighter external tank. The freighter
thermal protective system must be impact resistant and on orbit repairable
which permits the removal of the foam insulation from the ET. Reversing the hydrogen and oxygen tanks
should be revisited. It is possible that the CSS freighter will demand higher flight
rates, permitting more than one external tank manufacturing supplier. Tank
manufacturing should be within trucking distance of the launch site. The external tank can also be a storage
container for near earth and deep space requirements.
18 ft. (5.5 m.) Composite Cryogenic tank
The composite cryogenic tank is expected to reduce the tank
weight by 30 percent and have a 25 percent cost saving over the external metal tank which results
in a launch cost reduction of approximately $13 million.
Note: A vehicle
sizing study must be conducted to determine if the external tank requirement
can be eliminated.
Government Furnished
Equipment (GFE):
No GFE is required except that required
for range safety.
Logistics (LOG):
Logistics cost includes network, facilities overhead, and
administration costs are averaged for 12 annual flights. This cost is
significantly reduced as flight rate increases.
Space Shuttle Main
Engine (SSME):
The existing engine will be used for the initial CSS
freighter. For future use the engine
could adopt extensive use of integrated health monitoring and single cast
construction of large components. High
pressure pumps could be incorporated that can be flown 50 times before
overhaul. Studies have projected that an
advanced engine can be turned around in 58 hours as compared to the current
time of 160 hours.
Miscellaneous (MISC):
Miscellaneous includes the cost of propellants and vendor supplies.
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Commercial
Launch Market for CSS Freighter
The
predicted average commercial medium to heavy launches for the next 10 years is
11 per year. However the CSS freighter
has the potential to increase the market by offering the unique capability of
satellite on-orbit checkout before release and returning faulty satellites for
repair. Once the space tug is
operational, satellites can be serviced on-orbit or retrieved. The Freighter can offer tourist flights to reduce
cost of cargo delivery.
It is recognized that economic
conditions will dictate the launch market; however significantly lowering the
launch cost will attract other unidentified users
The
Space Transportation Plan for the 21st Century
Commercial Space Shuttle Freighter and
Space Based Fleet
“To get somewhere... we have to know where we’re going!”
Ed Stein’s 2012 caricature captures the path
of this nation’s manned space flight. The Space Based Transportation Plan can
change that Path.
Space Based Transportation Plan
The following chart outlines the development
and operation of the CSS freighter that enables the construction of a space
based fleet. The stair step approach provides a long range plan for obtaining
needed technologies and space vehicle development. Each step is a building
block for the next phase of development. It allows the next phase to begin
before the previous step is operational. For example the space based transport
stage (Trans Stg.) commonly referred to as a space tug, can be started before
the CSS freighter becomes operational. The Lunar Transfer vehicle can be used
as cis-lunar transfers or asteroid/comets interceptions. The modular system design
permits in-space subsystems upgrades.
Space Based… Space Tug to Space
Cruiser
The space transportation system for the 21st century must be developed
as an evolutionary process using "space based" vehicles. The initial
space based vehicles would be small unmanned vehicles supporting robotic
missions. The development schedule for large crewed spaced based vehicles will
accelerate or decrease as the funding and needs for space exploration
requirements dictate.
Space based tugs must be a top priority for
the space transportation system. They are a key factor for reducing mission
cost and increasing mission success. Tugs can be supplied by the CSS freighter
and expendable launch vehicles. Tugs can support near earth, lunar, and deep
space missions. The
first step to a “Star Trek Enterprise” space cruiser is the unmanned space
based tug. NASA’s future is in the development of these space based vehicles to
be operated by the commercial sector.
Future space based tugs can conduct the
following missions at significantly reduced operation cost and reduced chance
of mission failure:
Deep space missions could be designed for a thermal
aero-brake entry system. The aero-brake conducts several skip entry maneuvers
to slow to low earth orbit velocity where the CSS freighter rendezvous with it
for cargo retrieval and deploy. The NASA proposed VASIMR plasma rocket and
NERVA nuclear engine are concepts for deep space propulsions systems.
However,
these future concepts will remain paper studies until the launch cost to orbit
is significantly reduced. There must be a defined affordable
launch mass capability before any deep space transportation vehicle can be
developed. The CSS freighter is the first step to deep space operations.
Justifications
for space based vehicles:
1.) Space based vehicles are the logical and mandatory requirement in the
establishment of a baseline concept for a cost efficient advanced space
transportation systems. Lifetime of these vehicles would be expected to be 10
to 20 years and therefore would significantly reduce the cost of deep space
transportation.
2.) Development of space based vehicles provides an exciting and meaningful
endeavor for NASA and its contractors.
3.) Space based vehicles will reduce the orbital debris problem.
4.) The inert weight of the expendable upper stage would not have to be
orbited.
5.) Provides a test platform for testing and recovering hazardous advance
concept space engines (nuclear, toxic, etc.).
6.) Of particular interest is the capability to provide affordable access to
unmanned space commercial laboratories and space manufacturing facilities.
Why
Expendables Launch Vehicles are Obsolete
Expendable
launch vehicles suffer from an unsolvable problem…every launch is the first
test flight which can have unknown flight terminating manufacturing
defects. Only reusable launch vehicles
like the CSS freighter can solve this problem!
History
of Expendable Launch Vehicle Failures
FAA
data
Expendable
launchers have a historical flight rate of around 5 percent. Reusable launch vehicle has the potential to reduce
the flight to less than 2 percent. The
CSS freighter has the capability to save the payload and the vehicle in the
event of a flight terminating failure and return to the land…in addition to
significantly lower launch cost. To
continue development of expendable launch only invites more failed launch
programs.
CSS
Request for Proposal
NASA
can initiate the CSS program by issuing a Request for proposal (RFP) for launch
services.
Initially the CSS contractor would be asked to provide launch service to
LEO. Expanding the system to support
deep space based vehicles would follow.
NASA would have a backup to the Space Launch System without effecting
the progress or present a challenge to those who still believe this failing
program will prevail.
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Coordinator’s
Biography and Contact Information
Don A. Nelson is
an aerospace consultant and writer. Mr. Nelson retired from NASA in January 1999
after 36 years with the agency. He participated in the Gemini, Apollo, Skylab,
and Space Shuttle Projects as a mission planner and operations technologist.
Mr. Nelson was a supporting team member for the first rendezvous in space,
first manned mission to the moon, first manned lunar landing, and the first
flight of the Space Shuttle. During his last 11 years at the NASA Johnson space
Center, he served as a mission operations evaluator for proposed advanced space
transportation projects. Mr. Nelson is a graduate of Southern Methodist
University School of Engineering. He is a certified private pilot and holds a
Phase VI Pilot Proficiency Wings
award from the Federal Aviation Administration.
Mr. Nelson is the author of: “NASA New Millennium Problems and Solutions” and “The NASA letters.”
For information or to
offer support contact:
Email:
caae@wt.net
Mail:
Nelson Aerospace Consulting
1407 Moller Rd
Alvin TX 77511-3248