Mama said papa ain't no negroid, he sure weren't, his mama weren't getting them beers though...
The End Of US Manned Spaceflight Looms Ever Closer
The
US manned space program has at best only a few more years of missions
left in it, until its cost, complexity and design flaws results in
another failure that grounds all US manned launches until a new
transport system is designed and built. |
by Jeffrey F. Bell
Honolulu - Jul 10, 2003
Once again, NASA has proposed to develop a replacement
for the troubled Space Shuttle. This year's project goes by the
ungrammatical moniker "Orbital Space Plane". An interim version of OSP
called the CRV (Crew Rescue Vehicle) to be developed by 2010 will take
over the International Space Station lifeboat task now done by Soyuz.
An improved OSP called the CTV (Crew Transfer Vehicle) will assume the
ISS crew exchange task now done by Shuttle in 2012. To minimize
development costs, the OSP will be launched on one of the new EELV
family of expendable boosters, Delta 4 or Atlas V.
Sound familiar? It should. The OSP is only the latest of many "Shuttle
replacement" programs that have all failed dismally. A close look at OSP
shows that this program is also doomed to failure due to fundamental
technical defects. It's no surprise that such usually reliable NASA
boosters as "Space Coast" Congressman Dave Weldon and aerospace lobbyist
Lori Garver have publicly attacked OSP.
Most critics have focused on the suspiciously low development costs, or
the embarrassing gap between 2006 and 2010 in which no ISS lifeboat is
planned. In fact, the basic concept of the program is so stupid that
every knowledgeable person involved in it must be perfectly aware that
it will never fly.
The basic problem is that the OSP, as currently defined, must carry such
heavy mass penalties in the form of wings, wheels, and various escape
systems that its performance will not be much better than the Dyna-Soar
design of 40 years ago.
Because it cannot carry any of the supplies needed to sustain its
passengers once they arrive at the ISS, it will not reduce the number or
expense of Shuttle missions needed to support the International Space
Station, and will not provide "assured access to space" as NASA claims.
Instead OSP will force NASA to simultaneously fly two very expensive
man-rated vehicles at a time when it is financially unable to support
even one, and will double the risk of long stand-downs in ISS operations
due to lack of either replacement crewmen or the supplies needed to
keep them alive.
The Shrinking Spaceplane Mystery:
The original OSP concept
envisioned a 7-seat vehicle which could rescue or exchange the entire
ISS crew in one sortie. (NASA's proposed Budget Amendment of 14 November
'02 said "as many as 10".) The Level I requirement document reduced
this to "at least 4" persons.
This major decline in the OSP's basic performance measure was widely
criticized. Although I have not seen an official justification for the
4-seat requirement, it appears to be based on an agreement among ISS
users that NASA will be responsible for escape and exchange only of the
non-Russian ISS crew members, with the RSA continuing to support 2 or 3
Russian crewpersons with 2-3 Soyuz TMA flights per year.
However, a later NASA document "interpreting" the Level I requirements (
online reference)
has gone mostly unnoticed. In this 'interpretation" the requirement for
"at least 4" seats in OSP has been changed to a "system requirement"
that can be reached using multiple spacecraft instead of only one!
Presumably, proposals for 2-seat or even 1-seat spacecraft would be now
considered acceptable under this bizarre "interpretation" of the "at
least 4" requirement.
I know of no other aerospace program in which the basic performance goal
has been lowered by a factor of FOUR in the first few months! This
isn't just a question of being "a step backward from Shuttle" (or even
from Soyuz), but fundamentally wrecks the economics of the program. Even
in the CRV mode, a 2-seat OSP is an extremely dubious proposition.
The normal configuration of the station would then be one in which two
OSPs and a Soyuz would occupy three docking ports, oriented in such a
way that all three lifeboats could be manned and pull away from the
Station in any desired order, while leaving other ports free for CTV or
supply vehicle docking.
In the CTV mode, the 2-seat OSP would be heavily burdened by the
irreducible overhead of basic nav, comm, and docking equipment that
cannot be scaled down. So by cutting the seating in half, NASA has much
more than doubled the annual cost of rotating ISS crews.
NASA has not given any reasons for this extraordinary lowering of the
bar that the three competing contractor teams have to reach. The most
likely explanation is that preliminary studies have revealed a 7-seat or
4-seat spaceplane turns out too heavy to be launched on Delta 4 or
Atlas V, when all necessary requirements are met.
To see what kind of problems they may have found, let's compare it with
the previous, now-cancelled design for a 6-seat Station CRV, the X-38.
The X-38 was very narrowly tailored for the CRV requirement. It lacked
most of the systems needed for independent flight, since it was to be
carried into orbit inside a Shuttle and docked to the ISS with the aid
of the Canadarm2. The ECS supported 6 persons for only 9 hours, the RCS
used compressed nitrogen, avionics were highly simplified, there was no
rendezvous and docking gear, landing used a simple solid retrorocket,
parachute and skids.
There was no question of reusability since it was an emergency lifeboat,
and since it would only be used once or twice in the lifetime of ISS
high reliability was unneeded.
Now let us imagine a CTV version of the X-38. Clearly, a lot of stuff
needs to be added: radar, computers, control rockets, fuel, instrument
panel, a window to look out of, a docking mechanism that can tolerate
significant misalignments and shocks, more O2 and N2 tanks, more CO2
scrubbers, real thermal control, extra batteries.
Many of these systems need to be duplicated to provide sufficient
reliability for routine flights, and everything needs to be reusable
with minimal maintenance between flights. There just isn't volume for
this stuff in X-38 (or any winged vehicle of its approximate size and
weight) without throwing out some of the seats.
Of course the controlling factor in all space operations is mass. To see
how bad the mass problem is, let's look at the rich and depressing
history of previous unsuccessful orbital spaceplane designs:
Table I: Actual and Proposed
Space Station Ferry Vehicles
(Ballistic
Capsules in Italics):
Project Designed
Capacity: Masses: R&D Cost
Name by in Booster Crew+Cargo Landing/Launch/
+LES (FY02 $)
--------- ----- ---- ------------
---------- ----------------------- --------
X-20 D-Soar USAF 1963
Titan IIIC 1 + 450kg 5165/ 6525kg
Gemini NASA
1964 Titan II 2 +
0kg 1910/(no LES)
Big Gemini USAF
1967 Titan IIIM 9 + 2500kg / 15600kg
Shuttle NASA 1981 Shuttle
7 +12500kg $27B
Hermes ESA 1984 Ariane
6 + 4600kg 15000/ (no
LES)
$2.4B
Hermes ESA 1987 Ariane 5
3 + 3000kg 21000/ (no
LES)
Hermes ESA 1991 Ariane 5G
3 + 3000kg 23000/ $10.1B
HOPE NASDA 1987 H-2 4 + 2000kg 13000 /
22000kg $4.9B
HL-20 NASA 1997 Titan III
8 + 0kg 11600/ 16300kg
HL-42 NASA 1997 NLS
4 + 4300kg 13365/ 21093/
28725kg
OK-M USSR 1986 Zenit
2 + 2000kg 10200/ 15000/
Zarya USSR
1986 Zenit 6 + 1500kg 12000/ 15000/
X-38+ CTV NASA 2002 Titan IV
6 + 0kg /~16000kg
Merkur CRV USSR 1975 Proton
3 + 50kg 4250/
X-38 CRV NASA 1996 Shuttle
7 + 0kg 7300/
8163/(no LES) $0.5B
X-38 CRV NASA 2002 Shuttle
6 + 0kg 9072/(no LES) $1.5B
Apollo CRV NASA
1967 Shuttle 6 +
0kg 4500/(no LES)
Soyuz TMA USSR 1967 Soyuz
3 + 350kg 2900/
7150/
Progress M1 USSR 1978
Soyuz 0 + 2230kg -- /
7150/(no LES)
The real killer in Table I is the column labeled "+LES"; these are the
total launch masses inclusive of a Launch Escape System capable of
boosting the spaceplane quickly away from an exploding booster during
max-Q.
This is an invisible element in most spaceplanes, usually tucked away in
an "adapter section" between the spaceplane's tail and the top of the
booster. Since this adapter/escape module is dumped immediately on
reaching orbit it is often not included in the vehicle's "total mass".
However, in those designs where I have been able to isolate its
contribution to the total launch mass, it is on the order of %20-30!
(The classic "escape tower" used on most ballistic spacecraft is also
surprisingly heavy, but it usually is jettisoned after max-Q, so its
entire weight is not subtracted from the payload.)
The performance penalty is so great that many spaceplane designers have
tried to recover some of it by mounting the escape rockets on the
outside of the spaceplane or the adapter and firing them during every
ascent after they are no longer required for escape.
This introduces a host of other problems, the worst one being that an
extra failure mode is introduced into every launch. The European Hermes
mini-shuttle omitted escape rockets completely, relying only on ejection
seats even after the Challenger accident.
Since increased crew safety is allegedly a major reason for OSP, it is
inconceivable that it will not incorporate a full-capability LES. The
huge performance penalty of carrying this heavy module all the way to
orbital velocity is the main reason that a 6/7-seat winged CTV cannot
possibly be launched on a medium-lift booster like the Delta 4, and even
a 4-seat version would be marginal.
In fact, shortly before X-38 was cancelled, a modified version was
considered for the CTV requirement, and the proposed boosters were
Ariane 5 and Titan 4, suggesting that the project engineers expected the
9-tonne CRV version to bulk up to ~16 tonnes when upgraded to perform
the CTV function and fitted with a LES module. So OSP cannot merely be
"X-38 on a stick"; it is a different and much heavier beast.
Another lesson from the dreary history of orbital spaceplanes is that
the R&D costs are usually underestimated. The Hermes Euro-OSP
quadrupled in cost over seven years, and X-38 tripled in six. The idea
that one can design and test a new manned vehicle roughly half as
complex as Shuttle with a budget only %2-5 as big is clearly a fantasy.
The tyranny of wings:
Several semi-ballistic orbital ferry
designs are included in Table I to show just how much we are paying for
the dubious benefits of wings and runway landing. One of the main
reasons X-20 Dyna-Soar was cancelled in 1964 was that Gemini provided
the same capabilities on about one-third the total launch weight.
The Soviet designs OK-M and Zarya, 2-seat winged and 6-seat ballistic
CTVs designed to fit the same mass limit, show the same factor of three.
A modified Apollo CM was proposed to meet the 6-seat CRV requirement on
about half the weight of X-38. Given today's huge launch costs, what
possible reasons exist to justify launching two or three times the
necessary mass? Many years of Shuttle flights have give some people the
idea that reusable spacecraft must have wings, but in fact the only
reason the Shuttle has wings is a long-forgotten USAF requirement.
It is perfectly feasible to put a new ablative heat shield on a
semi-ballistic vehicle and reuse it. The Gemini 2 capsule was actually
refurbished and reflown in 1967 as part of the Air Force MOL program.
The Chelomei Design Bureau in the USSR also reflew several examples of a
fully reusable 3-man ballistic space station CRV called "TKS-VA" or
"Merkur" in 1977-83.
Another myth is that a water landing would require borrowing a carrier
battle group from the Navy. For regular scheduled CTV landings near KSC,
NASA could use its two dedicated recovery tugs which lie idle at Port
Canaveral between the occasional Shuttle SRB recovery missions.
Apollo missions regularly landed within 2nm of the predicted point, so
it should take less than an hour to hoist the spacecraft aboard and hose
it off with fresh water. For emergency CRV landings, existing search
and rescue organizations would be adequate.
The feasibility of a ballistic design for OSP was demonstrated by ESA in
1998, when they flew and recovered a prototype Station CTV called
"ARD", which was an %80-scale Apollo CM with modern avionics and
recovery gear. Curiously, NASA recently completed a study (
online reference)
of an Apollo-based OSP design, which does not mention either Gemini 2R,
Merkur, or ARD, but instead repeats all the standard anti-ballistic
myths.
This is another example of the fact that airplane pilots, who all have a
gut feeling that the ballistic spacecraft concept was an unfortunate
diversion from the "correct path" of gradually developing airplanes into
spaceships, dominate NASA's manned program. (Actually, Table I suggests
that this approach makes as much sense as gradually developing steam
locomotives into airplanes.)
Although Sean O'Keefe has said that ballistic designs are acceptable in
the OSP competition, it is unlikely that any of the three industry teams
will propose one. They have received plenty of hints from lower-level
NASA pilot-officials, pilot-astronauts, and even some pilot-Congressmen
that only a winged, streamlined, Shuttle-like design with sticks and
rudder pedals will satisfy them.
The Space-Tech Vacuum.
"But surely all the technological
advances made since Dyna-Soar/Shuttle/Hermes will allow OSP to be much
faster/better/cheaper," some of you are saying. Whenever anyone says
this, I demand that they name those technological advances. Nobody is
ever able to, since there haven't been any since about 1964, when NASA's
narrow focus on the Moon Race caused them to stop funding basic
rocketry research.
What little progress has been made is the gradual reduction in the cost
and failure rate of expendable boosters, demanded by and funded by the
comsat industry and the DoD. If you look at the current technological
shelf that the OSP design teams can pull components off of, it has
pretty much the same stuff on it that the Dyna-Soar team had in 1964.
(The X-38 did employ the most advanced technology now available, and one
can see from Table I that no major improvement in performance
resulted.) And it is just not possible to propose to develop anything
new within the cost and budget constraints of the program.
Of all the Shuttle replacement programs, it was the ones that tried to
develop new technology (X-30 and X-33) that failed most spectacularly,
and the one that stuck with low tech (DC-X) that actually flew. New
technology in an area as specialized as space flight just doesn't
appear; it requires years of sustained effort by large numbers of
scientists and engineers at a cost of billions of dollars.
And NASA has not been willing to spend billions of dollars on anything
except the "operational" programs, Shuttle and Station. This is the
reason our astronauts are flying in Russian capsules and Atlas V will be
launching our satellites with a Russian engine. Until NASA makes a
major shift in its priorities from current operations to long-term
research, don't expect any new technology like aerospike or
tri-propellant engines to arrive.
The feeble EELV:
So if a full-sized winged OSP would weigh at
least 16 metric tons, which of the many proposed versions of the two
EELVs are powerful enough to handle it? Another table is useful here:
Table II: Possible EELV
booster configurations
(existing boosters in italics for comparison):
Name of # of Cost per Payload to
Booster engines
Launch LEO / ISS /
GTO
---------------- -------
--------- ------------------
“Single-barrelled” medium-lift
versions:
Delta 4M 2
$90M(FY99) 8600/ 8400/
3900kg
Atlas V 501 2
10300/ 9900/ 4100kg
Delta 4M+ (5,2) 2+2SRB
$100M(FY90) 10300/ 9900/
4350kg
Delta 4M+ (4,2) 2+2SRB
$95M(FY90) 11700/11400/
5300kg
Atlas V 511 2+1SRB
12050/11700/ 4900kg
Atlas V 401 2
$77M(FY98) 12500/12100/
5000kg
Delta 4M+ (5,4) 2+4SRB
$110M(FY90) 13600/13100/
6120kg
Atlas V 521 2+2SRB
13950/13500/ 6000kg
Ariane V 2+2SRB $180M(FY00)
16000/ kg
Atlas V 531 2+3SRB
17250/16700/ 6900kg
Titan IV 5+2SRB $400M(FY97) 17700/17200/
Atlas V 541 2+4SRB
18750/18200/ 7600kg
Atlas V 551 2+5SRB
20050/19450/ 8200kg
“Triple-barrelled” heavy-lift versions:
Delta 4H 4
$170M(FY99)
/23800/13130kg
Atlas V HLV 4
$170M(FY98)
25000/24250/12650kg
This table reveals that the two competing medium-lift versions of EELV
are not really interchangable, even though they are similar in size and
appearance. The basic kerosene/LOX core stage of Atlas V is much more
capable than the LH2/LOX core stage of Delta 4, due to the lower energy
density of liquid hydrogen.
Delta 4M could not even lift the basic ~9100kg X-38 CRV vehicle, without
the extra systems and modules needed for the CTV mission. When
augmented by the maximum numbers of strap-on solid boosters, payload to
the ISS orbit of Delta 4M+ is only 13100kg while the similar
configuration of Atlas V can tote 19450kg.
So to maintain any semblance of competition between Boeing and
Lockheed-Martin in producing the manned versions of these boosters, the
total launch mass of OSP, complete with all adapters, must be limited to
13000kg, not the 16000-17000kg that was the limit for Hermes or X-38+.
In fact a more desirable goal for both cost and safety reasons would be
to launch on the purely liquid-fueled versions of both boosters. Could
it be that the rapid decline in the seating capacity of OSP is an
attempt to meet this goal -- or maybe to cover up the fact that some
senior NASA official made a dumb mistake in judging the launch mass
needed?
Launch safety issues:
A simple way to make OSP bigger would be
to launch it on the "heavy-lift" or "triple-barreled" versions of Delta
4 and Atlas 5 which can lift about 24000kg.
In fact, many NASA graphics do show the OSP mounted on these much more
capable boosters. But this option would raise both the cost and the
launch failure rate. The OSP Level I Requirements includes an "increased
safety" requirement for the survival of crews, but this is irrelevant.
The basic limitation on the operational lifetime of Shuttle, OSP, or any
reusable spacecraft is not the loss rate of crews, it is the loss rate
of spacecraft.
Astronauts, after all, are easily replaceable. The number of
overqualified applicants vastly exceeds the demand. But the OSP vehicles
will be expensive, hand-built national treasures that simply can't be
thrown away.
Just imagine what would have happened if the Shuttle fleet had actually
flown the advertised 50 times a year -- at a loss rate of 1 in 60
flights, we would have run out of Orbiters long ago. The same logic
applies to OSP, only more so because Delta 4 and Atlas 5 are cheap,
non-man-rated commercial boosters whose reliability goal is only 98%.
Furthermore, Delta 4H and Atlas V HLV are both likely to have launch
failure rates about double those of their medium-lift versions.
Experience has shown that reliability of boosters scales directly with
the number of stages and the number of non-redundant engines on each
stage.
Both heavy-lift boosters have bad configurations from this perspective.
The 1st stage is made up of three engines fed from independent tanks, so
even a non-catastrophic shutdown of any engine is non-survivable. Both
EELV-Hs are effectively 4-stage boosters from a reliability perspective.
Now the old 2-stage versions of Delta and Atlas have a combined recent
failure rate of ~%1.6, consistent with the rule of thumb that any
individual stage fails a little less than %1 of the time.
This implies that the Delta 4H and Atlas 5H will fail on about %3 of
launches, three times the rate of Shuttle. Even if the LES rockets the
OSP away from the booster blast, it is left gliding down toward the
Atlantic ocean with approximately the subsonic L/D of a brick. Many
studies of spaceplanes have shown that they can't survive high-speed
high-AOA water landings. Clearly we can save the crews with ejection
seats (more weight and volume lost!), but probably not the vehicles.
Now the baseline requirement for the CTV is to relieve the 4
non-Russians on the ISS every four months. So, we have a choice of
launching 6 times a year with 2-seat CTVs and splashing one every 10
years, or launching 3 times a year with 4-seaters and... splashing one
every ten years.
Apparently, NASA has decided to minimize its losses by choosing the
2-seat option. This is consistent with the announced plan to fly
Shuttles with 2-man "kamikaze" crews.
There has already been discussion of reducing the failure rate by
developing a special "man-rated" version of the EELVs. This is unlikely
to work. A vast amount of effort was put into "man-rating" the shuttle,
and the overall failure rate is still %2. And the whole basis of using
an expendable booster is that they are cheap.
The basic Atlas V costs only a little more than the $60M Shuttle
external tank! Introducing special safety requirements for the OSP
boosters will run up the expense and introduce many operational
complications.
Others have suggested providing a "Return-To-Launch-Site" abort
capability in the OSP which would allow it to fly back to Florida
instead of splashing in the Atlantic.
Of course this isn't easy -- otherwise we would already have it with the
Shuttle. Any reasonable spaceplane design just doesn't have the gliding
range to get back to KSC or even the East Coast after an abort, after
it makes the needed high-speed turn. RTLS abort means burdening the OSP
with turbojet engines and fuel for a powered atmospheric cruise.
Again, this option was considered for Shuttle Orbiter and rejected due
to severe weight penalties and the complications involved in protecting
the turbojets during reentry. But the cut in required seating to 2 may
be a way of letting the contractors explore the costs of this option.
Another safety problem specific to winged OSP concepts is that the
return vehicle's wings are at the wrong end of the launch stack and make
the combined vehicle aerodynamically unstable, like an arrow with its
feathers at the front. Von Braun's 1952 Ferry Rocket used massive,
draggy tailfins to restore static stability, as did the Air Force's
X-20A Dyna-Soar spaceplane of 1963.
Nowadays we have mastered the art of flying unstable aircraft like B-2
with automatic control systems that quickly counter any tendency to swap
ends. This principle could be applied to the EELV+OSP stack -- if the
engines can be gimbaled far enough and quickly enough, and if
appropriate control software is written and debugged.
In either case, the EELV used to launch OSP will be considerably
different and more expensive than the current version. (NASA has chosen a
third solution for the X-37 in deciding to launch the vehicle inside a
standard cylindrical payload shroud. This would be unacceptable for a
manned vehicle because it would delay escape from an exploding booster.)
For all these reasons, it is clear that an acceptable level of crew
safety can only be achieved with a semi-ballistic water-landing vehicle.
But I don't have to rely on hypothetical arguments here - the dismal
quality control in the Russian space industry has given us living proof
in the large number of Soyuz passengers who have emerged bruised but
alive from a horrifying series of mishaps that would have killed them if
they had been in a "flying Ming vase" like the Shuttle or a winged OSP.
Ground ops and scheduling:
Little attention has been given to
the problems raised by having the manned program share launch facilities
with one (or both?) of only two US satellite boosters.
The EELVs will also be handling a variety of high-priority military
payloads, and also carrying the US flag in the highly competitive
commercial launch market. Right now in the aftermath of the Telecom
Bubble, Boeing and Lockheed are desperate for government launches to
fill up their suddenly empty commercial order books. But the situation
might be very different in 2012-2020.
The demand for 6 Medium or 3 Heavy EELV boosters per year, probably in a
special man-rated configuration, might prove onerous. Currently, the
Russian factory making the RD-180 engine for Atlas V is contractually
obliged to deliver only 10 engines per year through 2012, suggesting
that the whole EELV program is scaled to a total of ~20 Medium or ~6
Heavy launches/year.
And if Shuttle-like extra safety requirements are imposed, there are
sure to be many delays in OSP launches, tying up the pads for long
periods. I forsee the EELV program becoming as overstrained as Shuttle
was in the period just before 1986 when NASA, DOD, and commercial
payloads were stacking up in hangars -- and we all remember what that
schedule pressure led to.
Orbital Debris:
Little attention has been given to the problem
of orbital debris impact on the CRV while docked to the station. An
unnoticed impact on the OSP's wings, nose or belly during its years of
orbital storage could doom the crew during reentry. Studies of the
debris threat to Shuttle have shown that its thermal protection is very
vulnerable. At the current level of threat, a Shuttle docked to the ISS
for 20 years has a ~%70 chance of being disabled by space junk.
While 1 big OSP or 2 small ones will make a smaller target, the debris
population is increasing at about %4 per year. NASA is concerned enough
about this rising threat that the manned sections of ISS are fitted with
thick multilayered "space armor" to protect them from debris up to ~1cm
across.
The CRV version of OSP needs to be armored against impacts at least as
well as the pressurized portions of ISS itself, and the armor must be
quickly jettisoned before an emergency reentry. This feature is
especially difficult to incorporate into winged or lifting-body
configurations due to their high surface/volume ratio.
The real need:
The OSP requirements concentrate entirely on
the CRV and CTV tasks. But there are other tasks essential to
maintaining the baseline 7-person crew on ISS which are not mentioned.
They include:
A) the general supply task now done by Progress.
B) the water supply task. Even with 3-man crews, Progress M1 supply
flights have been unable to supply enough drinking water to ISS (the
dedicated water tanks on the Progress M version were replaced by more
rocket fuel capacity). The Shuttle assembly flights used some of their
surplus mass capability to make up for this deficiency. This water
shortage is the main reason the ISS crews have been cut back to 2 during
the Shuttle stand-down.
C) the orbital reboost task. The Station is constantly losing velocity
and altitude due to air drag on its gigantic solar panels. It must be
given periodic pushes by its own thrusters or some attached vehicle. The
mass of fuel which must be lifted to ISS gets larger each year as
station mass and drag area rise (and as the Earth's atmosphere expands
in the later part of this decade due to the solar cycle). Even with the
current mini-ISS, the fuel capacity of Progress and Soyuz proved
inadequate and Shuttles burning their excess OMS fuel supplied much of
the reboost.
It is estimated that the completed ISS will require about 70,000kg/year
of supplies when fully manned (Space News, 21 April '03). What vehicles
will be available to lift this load?
Table III: Capacity and Flight Rate of Proposed ISS Supply Vehicles
Supply Funding Total Launch Flight
Rates: Up Likely
Vehicle Agency
Mass Vehicle NASA Plan
Reality Cargo Cargo/yr
----------- ------
------- ------ --------- -------
------- -------
Soyuz RSA 350kg Soyuz
] 2/yr 350kg
700kg
Progress
M1 RSA 7150kg Soyuz ]
7-12/yr 4/yr 2200kg
8800kg
HTV NASDA 15000kg Ariane 5G
2/yr 0.5/yr 7000kg
3500kg
ATV ESA 20500kg H-2
2/yr 0.8/yr 10000kg
8000kg
Shuttle NASA
Shuttle 5-7/yr 4/yr
12500kg 50000kg
The maximum emergency flight rates assumed by NASA in column 5 are
fantastically optimistic. The RSA has recently averaged 2 Soyuz and 4
Progress flights a year, but is contractually obligated to supply only 2
Soyuz and 3 Progress per year through 2006. The European Automated
Transfer Vehicle is budgeted to be produced at a rate of one vehicle
every 15 months, and is to be launched on the troubled Ariane 5G
booster. The Japanese H-2 Transfer Vehicle is a paper concept and the
future of its H-2 booster is even more doubtful.
Even if they proceed on schedule, these new vehicles will never do more
than keep the European and Japanese crewpersons supplied with truffles
and sushi. Most importantly, the Shuttle flight rate has declined from
~7/yr in the mid-90s to ~4/yr today, while the budget has fallen ~40%
and is scheduled to drop further in the current 5-year budget plan. So I
have drawn up a more realistic flight schedule in Column 6 and a
possible cargo budget for ~2010 in Column 7.
This exercise reveals that %70 of the total cargo (and 100% of the US
cargo) delivered to the completed ISS must still be delivered by
Shuttle. So it will be necessary to continue flying Shuttle missions at
the current rate even after OSP takes over the crew exchange mission in
2012.
ISTP: Inevitable Spaceflight Termination Plan.
NASA's current plan is to fly these supply missions in a "kamikaze mode"
with only two volunteer pilots on board. This implies no reduction in
the onerous safety requirements on Shuttle operations and no reduction
in the huge cost. Indeed, the Columbia Accident Investigation Board is
likely to call for even more expensive testing of the ageing orbiters
between flights, which will run the costs up even more.
Even if the Shuttles are converted to unmanned operation like Buran and
reduced safety standards are accepted, they will be hugely expensive
relative to our foreign partners' truffle-cans and sushi-cans. So where
is the budget wedge to operate OSP coming from? Imagine NASA in the
1980s trying to operate the Shuttle, while still flying 4 Apollo
missions every year.
Furthermore, NASA's Integrated Space Transportation Plan shows continued
R&D for a true Shuttle replacement vehicle. There just doesn't seem
to be any way these three manned programs can be supported
simultaneously without a massive increase in the NASA budget.
But the real danger of continuing to rely on Shuttle as a grossly
inefficient medium-lift cargo vehicle is: What happens after the
inevitable next crash? The loss of Columbia does not impact ISS assembly
and supply in the short term, since this orbiter was overweight and not
adapted to dock with ISS.
But in the long term it was planned to upgrade Columbia to full ISS
support configuration to cope with the growing supply demand. Another
Orbiter loss will bring the fleet down to two, except when one of them
is in overhaul (at least %50 of the time). Can the necessary 4 ISS
supply flights per year be maintained with a 1.5FTE orbiter fleet? Has
NASA even studied this problem?
This analysis leads to the question: what exactly will we gain by
developing the CTV version of OSP? Why does this task need to be
unloaded from the Shuttle, which is going to be flying to ISS every
three months anyway? If the Shuttle is too dangerous for a seven-person
crew, isn't it too dangerous for a 2-person crew?
And won't the inevitable deaths of 2 astronauts on a mere cargo-carrying
flight which the other ISS partners are all flying with safe unmanned
vehicles be just as traumatic at the Challenger and Columbia tragedies,
and result in a similar hiatus in vital supply missions to ISS? So
OSP-CTV will be grounded anyway, despite its superior (and expensive)
safety systems, because its passengers will have nothing to eat or drink
when they arrive at the station (except whatever truffles and sushi our
gallant allies can spare).
Clearly, the OSP by itself does not provide "assured access to space".
The USA needs to also design (or buy) an unmanned spam-can supply
vehicle adapted to EELV launch, to replace the Shuttle in its
cargo-carrying role.
This need is even plainer now that the true state of deterioration in
the remaining Orbiter fleet is becoming clear. Yet no money is budgeted
in the Integrated Space Transportation Plan for this vital vehicle! In
fact, NASA has terminated funding for the Assured Access to Space
program, the only current program which might have produced such a
vehicle.
Grasping at straws:
The obvious inadequacies of OSP are
inspiring many proposals for "faster/better/cheaper" ways to achieve the
program's objectives. Unfortunately, most of these ideas are as
ill-founded as OSP. Many of them involve reducing the already
inefficient flight rate of the Shuttle, or assigning it new roles that
it is quite unsuited for.
Typical of these desperate ideas is a proposal to put Shuttle on
"standby" status for occasional special loads. This is a fantasy, since
the Shuttle program relies so much on highly skilled manpower that it
can't be turned on and off at will.
Another unworkable concept is to use Shuttles as the CRV by leaving them
docked to ISS during each crew's 4-month deployment. This proposal
would knock us down to a 2-orbiter fleet just like another crash (except
it will cost more because there would still be 3 orbiters to maintain).
Furthermore, the large and fragile target that the Orbiter presents to
space debris would require that all external surfaces be inspected
frequently for impact damage. And if dangerous damage IS found, what do
we do about it? The Shuttle lifeboat proposal would merely accelerate
the ongoing decline in the Shuttle fleet and hasten the black day when
the US loses its manned space capability completely.
What is to be done?
Fundamentally, the NASA manned program
today is in exactly the same situation described in a prescient OMB
report written back in 1969, during the planning stages of Shuttle:
The critical problem with manned space flight is that no one is
really prepared to stop manned spaceflight activity, and yet no defined
manned project can compete on a cost-return basis with unmanned space
flight systems.
In addition, missions that are designed around man's unique capabilities
appear to have little demonstratable economic or social return to atone
for their high cost. Their principal contribution is that each manned
flight paves the way for more manned flight...
NASA equates progress in manned space capability with increased time in
space, increased size of spacecraft, and increased rate of activity. The
agency also insists upon continuity of operational flight programs,
which means we must continue producing and using current equipment
concurrently with development of next generation systems. Therefore, by
definition, there can be no progress in manned space flight without
significantly increased annual cost.(Quoted in Heppenheimer, THE SPACE SHUTTLE DECISION)
NASA has repeatedly tried to get out of this self-inflicted trap by
conning someone else to develop Shuttle II out of their pocket (X-30:
Air Force, X-33: LockheedMartin, OSP: the comsat industry). This idea
has failed every time.
In an ideal world, it would be time to try another option: Stop Shuttle
flights, stop the Space Station program, and divert the money absorbed
by the marching army of Shuttle/Station workers into real research on a
real spaceship.
Of course, this would require serious thought and public debate on what
kind of spaceships we need, instead of just replaying the obsolete 1952
Von Braun plan over and over again. It would require the Bush
Administration to show the same kind of resolution in standing up to our
"international partners" on space policy that it has shown on
insane-dictator-control policy.
It would require Congress to actually adopt the role of skeptical
overseer of public expenditure that it plays in all other areas of
government activity. It would require everyone to admit that 14 Shuttle
astronauts really did die for nothing.
Before Columbia, these things were off the table. But right now,
influential people are starting to consider them. There is, however, one
wild card that nobody seems to be talking about: the impending launch
of the first Chinese astronauts.
Since many people still think that manned space flight is some kind of
measure of national power (thank you, Nikita Khrushchev!) the first
Chinese flight will produce another Sputnik Shock and pressure to
continue a spectacular US manned program. will be irresistible. So it is
more likely that NASA will be allowed to continue assembling the
International Space Station at a glacial pace.
A Modest Proposal
Even if we can't get the Space Station millstone lifted from NASA's
back, we can at least get it off the present suicidal course of flying
the decaying Shuttles around in circles until they have all crashed. I
propose the following program:
- Inspect the Apollo Command Modules currently in museums for
heat-shield damage that would prevent them from surviving a second
reentry from orbit. The CMs that never left LEO should still have well
over 50% of their ablative material remaining. Choose the two best of
the lot and refit them as 6-seat CRVs, along the lines of the 5-seat
conversion planned for the unflown Skylab rescue mission. (The panel of
superannuated engineers that studied this option for NASA raised several
objections, but none of them seem to be show-stoppers.) The converted
Apollos should be ready by the time the current CRV contract with the
RSA expires in 2006, and one or both will be carried up to ISS on a
Shuttle flight.
- Begin negotiations with Daimler-Chrysler for the purchase
of a NASA version of the ATV truffle-can cargo ferry, adapted for launch
on EELVs. To make the negotiations more competitive, start studies of
an all-American spam-can design to meet the same performance goals.
Study a tug version of ATV that could deliver ISS modules without
risking lives.
- Change the OSP program specification to eliminate all
CRV-based requirements and require that all proposals include 4 or 6
seats and use the proven Gemini or Apollo semi-ballistic configurations,
with crew safety assured by an escape tower. Emphasize this by removing
"plane" from the program name, and stopping the recruitment of airplane
pilots as astronauts. Consider using the weight saved for a disposable
cargo module. Allow non-reusable designs if they turn out to be cheaper.
Ask RSA and ESA to provide full data on the Merkur and ARD ballistic
ferry vehicles.
- Reprogram the billions of dollars now being budgeted by the
Air Force for direct subsidies to the Delta 4 and Atlas 5 contactors
towards the purchase of actual boosters for ISS supply missions.
What I can tell you country boy is ship vs ship he was...
McVicar - Roger Daltrey (The Who)
http://www.youtube.com/watch?v=OgkNkqlKMTw/
