NASA STS Recordation
Oral History Project
Edited Oral History Transcript
Donald L. McCormack
Interviewed by Jennifer Ross-Nazzal
Houston, Texas – 24 March 2011
are written answers to questions provided by Donald L. McCormack for
the NASA STS Recordation Oral History Project.
Please give us a brief overview of your career with NASA.
I started my career supporting the Space Shuttle Program (SSP) with
Rockwell International in 1984. I was an Orbiter thermal control system
(TCS) engineer, and our primary responsibility was to work with mission
planning and operations personnel to develop Orbiter attitudes and
durations that were thermally acceptable for the Orbiter structure
and its systems. We would also provide real-time mission support.
In 1991, I left Rockwell and joined NASA in what was then called the
Orbiter and GFE (Government Furnished Equipment) Projects Office as
a Mission Evaluation Room (MER) manager. The MER provides engineering
support to the flight control team during Space Shuttle missions.
I worked as a MER manager for about twelve years and supported fifty
flights as a MER manager. Following the Columbia accident (STS-107),
I moved to the SSP Flight Operations and Integration Office where
I served as the Deputy Manager from 2004 through 2008. In 2008, I
was moved to my current job in what is now called the Orbiter Project
Office where I am the associate manager. Back in 2000, I was assigned
the task of Ferry Operations manager and have maintained that task
to this day. I have led the planning of thirty-five ferry missions
and the execution of ten.
Describe for us how an Orbiter is prepared to be ferried from Edwards
Air Force Base, California, to Kennedy Space Center (KSC), Florida.
How many people are involved in the preparation? How long does it
take to prepare the Orbiter before it is placed in the mate/demate
device? When is the tail cone placed on the Orbiter? Why is it attached
to the Orbiter? What is the most challenging aspect of preparation?
Following a landing at the Edwards Air Force Base, once the convoy
operations are completed on the runway, the Orbiter is towed to what
is referred to as Shuttle Area A at the Dryden Flight Research Center,
which is located at Edwards. Upon arrival, the Orbiter is towed into
and “spotted” in the mate/demate device (MDD). What then
begins is a planned seven day period of preparations for the ferry
mission, which we refer to as a turnaround operation. Note that in
addition to being outfitted with the equipment needed to mate the
Orbiter to the Shuttle Carrier Aircraft (SCA), the MDD provides platforms
from which work to prepare the Orbiter for ferry can be performed.
The “big operations” that are performed during turnaround
are Space Shuttle main engine (SSME) drying which consists of a dry
nitrogen purge of the SSMEs to remover moisture; power reactant and
stowage distribution system (PRSD) off-load to remove the cryogenic
oxygen and hydrogen from the PRSD tanks as well as fuel cell purging;
de-stowing the crew module to remove middeck payloads, the extravehicular
mobility units (EMUs), and various other equipment; installing mechanical
locks on the SSMEs and the elevon flight control surfaces to lock
them into the position required for ferry; draining a small quantity
of propellant from the orbital maneuvering engine (OME) ball valves
to prevent seal deterioration; tail cone installation for the reduction
of aerodynamic drag; and finally, raising the Orbiter to then be lowered
into position for mating to the SCA.
Since we no longer plan to land at Edwards, the team there for landing
consists of only thirty or so people. Those folks perform the convoy
operations and the initial turnaround operations, which include establishing
purge and cooling to the vehicle, towing the vehicle to the MDD where
it is jacked and leveled in addition to performing some initial operations
to safe the Orbiter. In the meantime, a larger turnaround team is
deployed from the Kennedy Space Center and typically arrives about
twenty-four hours after landing. This deployment brings the total
turnaround team size to about 150 people to support an around-the-clock
operation. The turnaround plan shows that the effort will take seven
days barring any delays due to weather or technical difficulties.
Typically the Orbiter is mated to the SCA and ready to be ferried
within seven to nine days of landing.
There are several operations that can be challenging but the most
consistently challenging operation in preparing the Orbiter for ferry
is the installation of the tail cone. It’s a large structure
that’s attached to the Orbiter’s base heat shield at eight
attach points. Moving the tail cone into position and aligning it
for attachment is very challenging. This operation typically takes
two to three shifts to complete. Installation of the tail cone is
one of the last operations performed prior to the actual mating of
the Orbiter to the SCA. The operation typically begins about five
days after landing. The purpose of the tail cone is to improve the
aerodynamic performance of the mated vehicle.
Walk us through the process of attaching the Orbiter to the SCA. How
is attached? How long does that process take? Does the process differ
based on which Orbiter is placed on top of the SCA? If so, how?
As its name implies, an Orbiter can be mated to or demated from an
SCA in the MDD. The MDD has a cantilevered structure that is equipped
with a moveable frame, called a sling, that attaches the Orbiter at
four locations. Those four locations, two forward and two aft on the
sides of the Orbiter’s mid fuselage, are the same four locations
used to lift the Orbiter when it is mated to the ET (External Tank)
in the VAB (Vehicle Assembly Building). The sling is attached to three
hoists that act in unison to lift, or lower, the Orbiter. The sling
is attached to the Orbiter early during the turnaround operation and
remains attached until it is removed after the orbiter is mated to
Once the Orbiter is ready to be mated it is raised about fifty feet
and the SCA is towed into the MDD. The Orbiter is then slowly lowered
onto the SCA and two large aft attach bolts are installed and the
forward attach fitting is mated. Note that the three attach locations,
two aft and one forward, are the same three locations used when the
Orbiter is mated to the ET for launch. The mate process typically
takes about twelve hours, and the process is the same for each Orbiter
in the fleet.
Please describe the flight readiness review process, once the SCA
and Orbiter have been mated. How long does an FRR take? Who is at
One to two days prior to the initiation of a ferry mission a ferry
flight readiness review (FRR) is held at Dryden and supported by teleconference
from KSC and JSC (Johnson Space Center, Houston, Texas). The review
is chaired, from Dryden or KSC, by the manager, Launch Integration
who is ultimately responsible for ferry operations. The key players
on the review board are representatives from KSC Shuttle Processing,
United Space Alliance Ground Operations, JSC Aircraft Operations (SCA
flight crew), JSC Orbiter Project Office, Human Space Flight Support
Office (Department of Defense personnel), JSC Flight Operations and
Integration (payload), JSC Safety and Mission Assurance, and the Ferry
Operations manager. The review typically takes one to two hours.
The objective of the review is to determine the flight readiness of
the SCA and the Orbiter, the flight readiness of the Pathfinder aircraft,
the readiness of the ferry flight support equipment, the readiness
of the ferry flight personnel (flight crews, aircraft maintenance
personnel, Orbiter support personnel, Department of Defense support
personnel), and the readiness of en-route support bases. During that
review we also look at the planned route and take an initial look
at the weather forecast.
What are the key considerations that are made before a flight is scheduled?
Is the flight path the same every time or are adjustments made as
weather or other issues are encountered?
I’d say the primary consideration is the determination that
the aircraft and support equipment, the ferry flight personnel, and
the en-route support bases are ready to support the mission. This,
of course, is formally done during the ferry FRR. So, we review the
issues that may have arose during the turnaround period and ensure
that the team is comfortable with the resolutions of those issues.
Another key consideration is the flight plan. There are about twenty
military bases that are trained to support ferry operations. These
bases are primarily located across the southern third of the U.S.,
so the flight path is always in that region of the country. In the
planning phase of a mission, the selection of the bases we will use
is primarily based on SCA performance. That is, what route makes the
most sense from an efficiency standpoint given the capability of the
SCA for the given Orbiter and the time of year. Occasionally we will
select a route that will allow for a special event, such as a flyover
or to perhaps utilize a base that we have not used in a long time.
With all that said, the ferry operation is extremely dependent on
the weather. Therefore, the weather ALWAYS drives when we fly and
the route that we take. The Orbiter absolutely cannot be flown through
rain. Significant Thermal Protection System (tile) damage can occur
with only brief flight through rain, even light rain. In addition,
we work very hard to try to avoid rain when on the ground at a stopover.
Our rules allow for light rain, but I prefer encountering no rain
en route. The vehicle does leak, and water in the vehicle upon arrival
at KSC drives additional work. Obviously, severe weather, for example
lightning and hail in a thunderstorm, could damage the Orbiter on
the ground and needs to be avoided.
Other constraints we manage are the ambient temperature and pressure
that the Orbiter can be operated in during flight. The minimum temperature
is 15 degrees Fahrenheit and the minimum pressure is 8 psia (pound-force
per square inch absolute). These limits result in the flight altitude
generally being in the range of 11,000 to 16,000 feet depending on
the time of the year.
So, once we complete the ferry FRR and a go is given to ferry, we
select a day that we can start the mission based on the weather forecast.
Before every flight leg of the mission, a weather briefing is conducted
to determine if the flight can proceed.
How many pilots and flight engineers typically fly onboard the SCA?
Is there room for others or is the team limited by the weight of the
On end-of-mission ferry flights, there are two pilots and two flight
engineers onboard the SCA. That is, essential personnel only. There’s
certainly room for others and weight is not the reason that we limit
the number of people in the SCA. When an Orbiter is ferried following
a spaceflight, there are still hazardous fluids on board during the
ferry to KSC. Although unlikely, there’s certainly the potential
that a leak could develop creating a hazardous environment around
the SCA. Exposing nonessential personnel to that hazard is not acceptable.
Each member of the SCA crew is trained to use and equipped with a
portable breathing apparatus so that they can safely depart the SCA
following landing in the event of a leak.
Will the weight of the Orbiter vary by mission and what the crew has
brought back from space? What complications, if any, does this pose
for the return flight?
Yes, the weight of the Orbiter varies by mission primarily by what
is returned in the Orbiter’s payload bay. For example, if the
mission delivered a large ISS (International Space Station) module
or a large satellite, the Orbiter would return with essentially an
empty payload bay and the ferry weight of the Orbiter would be on-the-order-of
195,000 to 205,000 pounds. If the mission had a Spacelab module in
the payload bay or an MPLM (Multi-Purpose Logistics Module), the ferry
weight would be on-the-order-of 220,000 to 230,000 pounds. The heaviest
Orbiter that we’ve ferried was Discovery after the STS-114 mission,
which had an MPLM in the payload bay, and that vehicle weighed almost
228,000 pounds. So, all of the end-of-mission ferry flights can be
bounded by a weight range of about 195,000 to 230,000 pounds.
It should also be noted that when the Orbiters were initially delivered
to KSC or were ferried to Palmdale, California, for maintenance, their
weights were in the 150,000 to 160,000 pound range.
I don’t know if I’d call it complications, but the weight
of the Orbiter clearly affects the ferry mission by the impact it
has on SCA performance. The performance of the SCA is primarily impacted
by the weight of the Orbiter, field elevation, ambient air temperature,
and runway length. So, it can be more challenging ferrying a 228,000
pound Orbiter in August than it is a 195,000 pound Orbiter in January.
The latter case would result in better SCA performance and that additional
capability can provide more operational flexibility and make the mission
easier to execute.
What role does the Pathfinder play in the ferry flights? What type
of plane is the Pathfinder, typically?
The Pathfinder does two things for us. It provides weather reconnaissance
and it transports the ferry flight team and the required ferry support
When we ferry in the winter, there are requirements to provide a heated
purge to the Orbiter at overnight stopovers. The Orbiter requirement
is to provide the purge if the overnight temperature is expected to
be below forty-five degrees Fahrenheit in excess of four hours in
order to mitigate the risk of reaction control system (RCS) thruster
leaks. In addition, payloads in the Orbiter payload bay may have purge
requirements as well. So, when purge is likely to be required, we
bring specialized purge equipment with us. Over the years, we’ve
used either a USAF (United States Air Force) C-141 or C-17 to transport
the purge equipment and therefore be used as the Pathfinder aircraft.
When purge equipment is not required, we typically use a NASA JSC
aircraft. We’ve used the zero-G aircraft, which was a KC-135
up until a few years ago, and is currently a C-9. We’ve also
used a USAF KC-135 on several occasions. These aircraft are somewhat
less expensive to operate than the larger cargo aircraft and still
work well in transporting the ferry team.
As far as weather reconnaissance goes, there’s always an experienced
SCA pilot in the Pathfinder, either in the middle seat of a USAF aircraft
or in the middle seat or flying a NASA aircraft. The Pathfinder takes
off prior to the SCA and proceeds out to 100 or so miles ahead of
the SCA. If the weather is severe clear en route, the weather reconnaissance
role of the Pathfinder is easy. If there’s weather en-route,
that was deemed acceptable to conduct the ferry flight yet we knew
would require some maneuvering en route or had the potential to unexpectedly
develop into something more difficult to deal with, the weather reconnaissance
role of the Pathfinder would be more challenging.
The SCA pilot in the Pathfinder is in radio contact with the pilots
in the SCA and provides the necessary guidance to safely navigate
through more challenging weather conditions. Note that we always have
a weather alternate for each leg that can be utilized in the event
of a blown forecast. In my experience, we’ve never used the
How long does the trip between California and Florida typically take?
With good weather and a light Orbiter, that’s of course a relatively
light Orbiter, the trip can be made with two flight legs in one day.
That has actually been accomplished on several occasions. However,
with bad weather, a mission can stretch out to four days and more.
I’ve had one that took seven days from the time we were ready-to-ferry
to the time we arrived at KSC. Typically, a flight is accomplished
in three to four legs flown over a period of two to three days.
How often do the pilots stop to refuel or rest? Where do they stop,
at commercial airports? At military bases? Are there requirements
for these facilities? If so, please explain.
This question has essentially been answered in the course of answering
previous questions. The SCA takes on some amount of fuel whenever
we stop. The amount will be determined by the SCA performance requirements
of the next leg. Typically we’ll rest overnight (RON) one or
two times during a mission. We’ll stop either due to weather
or a lack of daylight. We have a requirement to fly only during daylight
hours due to the requirement to see and then avoid flight through
As previously mentioned, there are twenty or so military bases that
are trained to support our mission. In addition to that training,
they have the ground support equipment to support our requirements
and they have agreed to provide transportation and reserve lodging
for the ferry flight team at RON stopovers. The requirements are essentially
those things typically required for aircraft, such as fuel and power.
In addition, we require that they have man-lifts that allow our technicians
to access the vehicle to establish purge and if necessary repair any
damage that may have occurred to the Orbiter in flight.
There are two commercial airports that have also agreed to support
ferry operations. Rick Husband International Airport in Amarillo,
Texas, has been used twice in recent years as a refueling stop. The
other, Orlando International, Florida, has never been used and would
likely only be used as a weather alternate. In addition, we have used
Ellington Field in Houston on several occasions during initial delivery
or maintenance ferry missions.
Are there other safety precautions taken when the SCA lands at an
airport, military base, or KSC? Please explain. What type of security,
if any, is required for the Orbiter when the plane lands to refuel?
Upon landing, the SCA is typically taxied to a location where a safety
assessment can be performed. Depending on the airfield, the location
might be where it will be parked for refueling or RON, or it can be
at a location where hazardous cargo is parked. The safety assessment
is performed by KSC personnel on the ferry team and consists of toxic
vapor tests and visual inspections performed at ground level. Once
the environment is declared safe, the SCA is parked, if it wasn’t
at its park site already, and the SCA flight crew is given clearance
to depart the aircraft.
If it’s simply a refueling site, the base security personnel
remain stationed at the aircraft until refueling is completed and
the SCA is ready for departure. If it’s a RON stopover, as they
are trained to do, base security personnel establish a restricted
area around the SCA. This is done under the guidance of the KSC security
personnel on the ferry flight team. The restricted area is established
by setting up a perimeter that is at least 200 feet from the SCA—wing
tips, nose, and tail. Ropes and stanchions are used, and there is
a single controlled entry point. Military personnel control the entry
point and monitor the restricted area. The ferry team has special
badges that allow them access to the area. In addition, lighting is
provided to keep the area illuminated overnight. Bottom line, there
are young men with weapons at the SCA at all times. Unauthorized access
to the SCA and Orbiter would be difficult and unwise to attempt.
Note that the primary reason that we have security personnel on the
team is the unlikely event where we would land at an untrained military
base or a commercial airfield. In those cases, the ferry team security
personnel would work with the airfield security personnel to provide
the security that is required.
How much fuel is used during a ferrying flight?
Obviously, the total ferry flight time will depend on the route and
the number of legs flown. More fuel is burned during takeoff and climb
to altitude so the amount of fuel used will increase with the number
of flight legs. However, for a typical ferry flight from Edwards to
KSC, the total flight duration is about seven hours. The average fuel
burn for the SCA during a ferry flight is about 5750 gallons an hour.
So, the amount of fuel used during a ferry flight is about 40,250
gallons (269,675 pounds). Incredibly, the total amount of fuel burned
during a ferry mission weighs more than the Orbiter.
During these stops do the pilots meet with the media or chat with
the public? Is the public given an opportunity to view the SCA when
the Orbiter is on top of the 747? The SCA has flown several flybys
at JSC, who decides what locations will be able to see the SCA in
A representative from the KSC Public Affairs Office (PAO) is a member
of the ferry flight team and they work directly with base PAO personnel
to arrange for interviews with the local media upon arrival. If it’s
a refueling stop, the pilots typically don’t have time to talk
to the media, and questions at those stops are typically handling
by the ferry team’s PAO representative. However, either the
manager, Launch Integration, if he’s with the mission, the ferry
manager, or one of the pilots will try to make time for a short interview.
If we’re at an overnight stopover, typically one of the pilots
and one of the managers will do an interview with the media. Interest
has grown during the most recent ferry flights and during the STS-128
ferry flight, we actually had a reporter and photographer from the
ABC affiliate in Houston travel with the ferry team.
As for the public, the viewing opportunities are limited. Depending
on the base, there are opportunities for some limited viewing from
the perimeter fences. We typically do not make special arrangements
to allow on base access to the public during post-mission ferry flights.
There have been a few occasions, like during the initial deliveries
of Atlantis and Endeavour and ferry flights of an Orbiter to Palmdale
for maintenance, where we landed at Ellington Field and allowed the
public access for viewing. In those cases the Orbiters were inert,
did not have hazardous fluids on board, allowing for a safe environment
for the public.
Flyovers are considered when a request is made by someone within the
Agency or the government (federal or a state). One thing we make clear
is that a flyover is only performed if it can be done so without adding
a flight leg or adding an extra day to the mission. So, for example,
if a flyover of JSC is being considered but the weather dictates a
flight path to the north of Houston and the flyover could only be
accomplished if the mission is delayed, the flyover would be cancelled.
How frequently is the Orbiter checked for damage on the return flight?
Has the Orbiter ever suffered damage during a ferrying flight? If
so, please explain.
Following each flight leg of a ferry mission, the Orbiter is visually
inspected for damage. Occasionally, minor tears to blankets or other
components of the Thermal Protection System are observed. On rare
occasions, the observed TPS damage is repaired as a precaution to
mitigate further damage to the Orbiter and to alleviate a debris concern
for the SCA. The repairs that have been done in the past have been
minor and usually consists of removing the damaged material.
The most significant damage that an Orbiter has ever experienced during
ferry occurred back in 1985. The Orbiter was Columbia, and it was
being ferried back to KSC following a maintenance period in Palmdale.
The report indicated that on the final leg of the mission, from Offutt
Air Force Base to KSC, the SCA was flown through light rain for an
estimated ten to twelve seconds. The Orbiter sustained significant
tile damage, especially to the tiles on the forward reaction control
system module and on the tiles around the windows. As I indicated
earlier, flying through rain absolutely has to be avoided as significant
damage can occur costing millions of dollars to repair and taking
the Orbiter out-of-service for a significant period of time.
On another occasion, and I have no detailed information on this one,
the Orbiter sustained a bird strike on takeoff from KSC and about
a dozen tiles were damaged or lost.
The most common detrimental effect that occurs during ferry missions
is something I alluded to earlier and that’s caused by water
intrusion that occurs either while the Orbiter is in the MDD at Dryden
or while on the ground during the ferry mission. The Orbiter does
leak, primarily around the payload bay door seals, and water leaking
into the vehicle has the potential to damage components and thermal
insulation blankets or lead to corrosion. So, during the ferry mission,
we try hard to avoid rainfall on the ground.
When the plane finally lands at KSC, how is the Orbiter demated from
the SCA? Where is it taken?
Upon landing at KSC, once the safety assessment is completed and the
SCA is shut down on the ramp at the SLF (Shuttle Landing Facility),
the mated vehicle is towed in to the MDD. The MDD at KSC is similar
to the one at Dryden. Typically, within about sixteen hours, the Orbiter
is demated from the SCA and towed into its Orbiter Processing Facility
How much does it cost to ferry the Orbiter from California to Florida?
This is one of the media’s favorite questions and probably my
least favorite to answer mainly because it can’t be answered
with a single number and without some explanation. If you look at
just the marginal cost of a single ferry flight, it’s about
$400,000. That includes primarily the flight hour costs of the SCA,
the flight hour costs of the Pathfinder, and the travel and per diem
costs for the ferry flight team. That cost is a good estimate but
it will vary depending on the duration of the mission, the aircraft
used as the Pathfinder, and other factors. However, that does not
include the cost to actually maintain and operate the SCA, which is
significant and will vary from year-to-year depending on the maintenance
In addition, whenever a landing at Edwards occurs, a large team from
KSC is required to travel to Dryden for a week or more to perform
the turnaround operation. This expense, the largest part of which
is a contracted amount that the SSP pays to the United Space Alliance,
is also significant and not included in the ferry flight cost number
provided above. So, if you look at the total cost of landing at Edwards
incurred by the SSP, it’s on the order of $2 million.
How many times has the Shuttle landed at Edwards and had to be ferried
So here we are, STS-133 just landed at KSC and we have two flights
remaining, STS-134 and STS-135. As of this time, fifty-four missions
have ended with landings at the Edwards Air Force Base and one ended
with a landing at White Sands Space Harbor in New Mexico. So an Orbiter
has been ferried fifty-five times following a landing at a site other
than KSC. Columbia landed at Edwards twelve times and the one time
at White Sands, Challenger landed at Edwards seven times, Discovery
fifteen times, Atlantis thirteen times, and Endeavour seven times.
How many times has the SCA flown the Orbiters to Palmdale? If the
Shuttle needed to go to Palmdale, do you land there or at Edwards?
If the pilots land at Edwards, how is the Orbiter taken to Palmdale?
The Orbiters were taken back to Palmdale eight times for maintenance
periods. Columbia made four trips back to Palmdale; Atlantis made
two, and Discovery and Endeavour each made one. On its first trip
back to Palmdale in 1984, Columbia was flown to and from Edwards.
It was demated and mated at the Dryden MDD and towed to and from Palmdale.
In the late 1980s, after the Challenger accident, a device called
the Orbiter Lifting Fixture (OLF) was assembled at Palmdale and was
used to mate and demate an Orbiter to the SCA during the remainder
of the program. Note that the OLF was going to be used at Vandenberg
Air Force Base, California, until the decision was made to cancel
West Coast launches after Challenger (STS 51-L). The OLF was first
used at Palmdale for a mating operation for the initial delivery of
Endeavour. For the initial delivery of each of the other Orbiters,
they were towed to Edwards and mated using the MDD at Dryden.
I understand that Enterprise was ferried to England and also Paris
for the air show. What challenges, if any, did flying over the Atlantic
The ferry flight of Enterprise to Europe for the Paris Air Show took
place in May and June of 1983. Obviously that was well before my time
and quite frankly, I know very little detailed information about that
flight. From what I do know, it must have been a fascinating trip.
The SCA and Enterprise departed Edwards on May 16 and flew approximately
twenty flight legs including several short flights at the air show
in Paris over the next thirty days. On the way to Europe they made
stops in Colorado, Kansas, and Ohio in the U.S. They followed what
I refer to as the northern route where they made a stop at Keflavik,
Iceland, before arriving in England. They arrived in Paris on May
24 and were at the Paris Air Show until June 5. While in Europe, they
also made appearances in Germany and Italy. On the way home, they
followed a similar route and made additional stops in the U.S. in
Illinois, Washington D.C., and Texas before arriving back at Edwards
on June 13.
Now, with all that said, I suspect the flight was somewhat easier
than what we do today. First of all, Enterprise did not have most
of the internal components required for spaceflight and obviously
did not have a payload. As a result, she only weighed 126,600 pounds,
well less than a post-mission Orbiter. So, the SCA could carry a lot
more fuel and therefore had much better range. In addition, since
the vehicle was inert and was never intended for spaceflight, I’m
sure they didn’t have the temperature and pressure driven altitude
restrictions we have today for a post-mission ferry flight. Flying
higher, I suspect up to 20,000 to 25,000 feet, would have improved
the SCA’s range even more and would have resulted in a greater
capability to avoid weather. In addition, since it didn’t have
the Thermal Protection System used on the spaceflight Orbiters, I
believe it was less sensitive to flight through rain, although I suspect
they still tried to avoid it. All in all, as I stated above, I suspect
it was a somewhat easier mission to execute even though it was a very
lengthy mission, in miles and duration. And besides, they got to spend
about ten days in Europe with an Orbiter mated to a 747. I suspect
they were like rock stars.
Are there any particularly challenging or memorable ferry flights
that jump out in your memory? If so, would you share those details
They are all challenging and memorable. I’d say the most challenging
and memorable was what turned out to be a simultaneous duel ferry
mission back in 2001. I’ll try to give a brief summary of that
somewhat complex event.
Columbia was at Palmdale for what turned out to be its last maintenance
period. It was scheduled to be ferried back to KSC in late February
using SCA 905. As luck would have it, the STS-98 mission ended with
Atlantis landing at Edwards on February 20, 2001. So, turnaround processing
began immediately on Atlantis while discussions ensued as to how these
two ferry missions should be accomplished. Guidelines were established
to assist the decision making process. These guidelines were basically
that the Columbia ferry could not interfere with the Atlantis ferry,
since Atlantis would be flown again sooner, and that neither ferry
mission could interfere with the launch of the STS-102 (Discovery)
mission, scheduled for March 8. However, after careful evaluation,
it was determined that two independent ferry missions could be accomplished
with the equipment and personnel assets that were available. Atlantis
would be ferried using SCA 911. With independent missions, both Orbiters
could be returned to KSC as soon as possible.
Early during the turnaround processing of Atlantis, it appeared that
the Columbia ferry would be completed several days prior to the time
the Atlantis ferry would be ready to start. However, if you’re
ever going to see an extended period of rain in the high desert region
of California it’s going to be in the late winter months, and
that’s exactly what happened. Overcast conditions with periods
of light to moderate rain delayed the start of the Columbia ferry
flight and by the time the mission was able to start, Atlantis was
ready to go as well.
So once again, as luck would have it, by the time the weather allowed
the Columbia ferry flight to start, Atlantis was ready to be ferried
as well. On March 1, 2001, the first simultaneous ferry flights in
the history of the SSP began. I was with Columbia and my good friend
Denny Gagen, the NASA KSC Ground Operations Manager (GOM) at Dryden
was leading the Atlantis ferry mission. Jim [James D.] Halsell, the
Manager, Launch Integration and the SSP person ultimately responsible
for ferry operations was traveling back and forth between both missions.
The three of us had worked together closely in the planning of these
missions and would continue to do so during their execution.
On the first day of the mission, Columbia was flown to Dyess Air Force
Base in Abilene, Texas, and Atlantis was flown to Altus Air Force
Base in Atlus, Oklahoma. Both missions were held up there while we
waited for the same slow moving low pressure system that had caused
the delay in California to clear the area across the southeastern
region of the country. Atlantis and Columbia finally arrived in Florida
on March 4, twelve days after Atlantis’s landing at Edwards
and seven days after Columbia was ready-to-ferry. Atlantis went to
the KSC SLF and Columbia went to the skid strip at the Cape Canaveral
Air Force Station. Columbia went to the skid strip because with the
STS-102 launch preparations that were on-going at KSC, the ramp at
the SLF could not accommodate both SCAs at the same time. Following
the demate of Atlantis and the departure of SCA 905, Columbia made
the short hop to the SLF on March 5.
There are so many details I could add, and probably a few I’ve
forgotten, but needless to say, it was a “challenging and memorable”
Describe the SCA and what modifications were made to the plane so
that it could ferry the Orbiter. Where is the SCA typically housed,
at Dryden, JSC, or KSC? How often is the SCA is flown without the
Orbiter? Would the number of crew and/or passengers change as a result?
I know that you’re also talking to one of the SCA flight engineers
and he’d be much better at answering this question than I. However,
I’ll provide a very high level summary of the SCA and the major
modifications that were required to support ferry operations. An SCA
is a modified Boeing 747-100. The most obvious modification from the
outside of the aircraft are the struts that were added for the attachment
of the Orbiter. Another obvious modification are the two vertical
stabilizers that were added to the ends of the standard horizontal
stabilizer. These were added to provide additional directional stability.
Inside the aircraft there’s a dramatic modification from a 747s
commercial configuration. Aft of the forward doors, all of the standard
internal furnishings, seats, overhead bins, etc. were moved to reduce
the weight of the aircraft. What you see is the green painted structure
of the aircraft fuselage. It’s a very interesting look into
aircraft construction. Finally, a less obvious modification was the
addition of redundant power supplies and cabling to provide electrical
power to the Orbiter as well as the SCA instrumentation required to
monitor these devices. The power supplies are primarily used to power
Orbiter fluid system heaters and water coolant loop pumps during ferry
There are two SCAs, and they are housed at Dryden.
On average, I believe the SCAs are flown about once a quarter. (Again,
a better question for a flight engineer). Those flights are for maintenance
or systems checkouts or for flight crew proficiency. Where there are
strict rules regarding the number of persons in the SCA during an
Orbiter ferry flight, those rules do not apply for SCA flights for
maintenance or systems checkouts or for flight crew proficiency. For
those flights, those particular missions define the crew size. With
the seating still available in the aircraft, it can accommodate about
How many SCAs has NASA had over the years? How many are in service
The first SCA was SCA 905, and it was the aircraft used during the
Orbiter Approach and Landing Test (ALT) Program performed at the Edwards
Air Force Base in 1977. There were eight captive test flights using
the Orbiter Enterprise and five free flights where the Enterprise
was released from the SCA. After the ALT Program was completed, the
SCA was modified to its ferry flight configuration, which was primarily
a modification to the forward attach hardware. SCA 905 was modified
from a 747 owned by American Airlines. The modification was done for
NASA by the Boeing Corporation.
After the Challenger accident, the SSP decided to add a second aircraft,
and SCA 911 was added to the fleet. SCA 911 was modified from a 747
owned by Japan Airlines. It was also modified by Boeing. Interestingly,
the first ferry flight using SCA 911 was for the initial delivery
of Endeavour to the KSC.
Both aircraft are in service today.
How many SCA pilots work for NASA? Do they also fly other NASA planes?
Currently, there are only three SCA pilots that are qualified to support
ferry operations. During my tenure we’ve had up to six pilots
available for ferry operations and I’ve worked with nine different
pilots over the years. But as the SSP winds down, that number has
dwindled. I’ve seen many very qualified SCA pilots retire over
that past six to seven years. However, the guys left should be all
we need to support the remainder of the SSP and deliver the Orbiters
Yes, the SCA pilots fly other aircraft, typically several.
Is there anything else about ferrying operations or the SCA we might
have overlooked that we should know about?
I’ve got to compliment you on your questions. They’re
actually very good and I believe they’ve allowed me to cover
ferry operations pretty thoroughly.
I would like to add that it’s been my great pleasure to be involved
in Orbiter Ferry Operations. I actually consider it the best job I’ve
had in my NASA career. It’s a fascinating operation, and I’ve
always considered it a privilege to play a small part in transporting
these incredible vehicles across the country. The Orbiters are the
most capable spacecraft ever built and are likely to retain that title
for many, many, years to come. The people I’ve worked with are
true professionals that are very good at their jobs and take pride
in what they do. It’s been fun.