SpaceX August-September 2004 Update

Falcon I on
the Launch Pad!
The Falcon I actual flight vehicle is now on the SpaceX launch
pad at Vandenberg Air Force Base (near Santa Barbara, California).
This is a huge milestone for our company and is the result of
a monumental effort by everyone here.

Below are
a series of pictures showing Falcon being erected by the mobile
launcher on to the quadropod hold down fixture. Time to rotate
vertical is about 15 minutes, although we should be able to reduce
this to only a few minutes once we-re comfortable with the
process. The white building on the launch deck (shown in pictures
four and five) is the retractable hangar, which provides shelter
to technicians for final checkout and satellite integration. It
moves back on rails shortly before launch. Note the new carbon
fiber inter-stage and the ablative covering the forward portion
of the payload fairing.

Falcon on mobile launcher ready to rotate vertical

About halfway to vertical (the telescoping hydraulic ram is now
visible)

Vertical and fixed to the hydraulic launch hold down clamps

Perspective looking straight down the flame trench

Oblique view (white structure on the deck is the retractable hangar)

Side view (large tank in the foreground contains the liquid oxygen
propellant supply)

The remaining
milestones are (not necessarily in this order):

1. Complete
the formal flight qualification program for the engines.
2. Receive range safety approval to launch.
3. Do a full vehicle hold down firing on the launch pad as a final
verification.
4. Integrate the TacSat-1 satellite.
5. Launch to a 500km orbit

At this point,
it looks like the first available launch window that works for
both SpaceX and Vandenberg is mid to late January.

Mobile
Control Center
We built our control center in a trailer for maximum flexibility,
which means we don-t need to spend capital building up this
capability at each range. It also minimizes the ongoing overhead
costs of having to pay rent or maintenance for a control center
when we only use it for a few weeks at a time during launch.

The MCC contains
up to twelve personnel and is fully self-supporting with its own
generator, UPS and air-conditioning. It contains everything necessary
to interface with the Air Force Base, all voice and data com,
vehicle telemetry displays, etc.

Inside of Mobile Control Center

Outside of Mobile Control Center

Launch Manifest
Every update going forward will have the expected launch schedule,
but showing only firm contracts for which we have received a deposit.
There are a lot of discussions underway with potential customers
and I expect that in 2006 we will manifest at least four flights
again, with volume picking up significantly above that in 2007.
It will take a few years for the satellite market to adjust to
the availability of a low cost launch vehicle.

Falcon
V Progress
The information on Falcon V that has been on the website for several
months is now significantly out of date. Following discussions
with customers, we decided earlier this year to make some important
changes.

We are switching
from a dual Kestrel upper stage to a single Merlin upper stage.
This has a major effect on mass to orbit due to improved mass
fraction, higher specific impulse and better staging efficiency.
The improved mass fraction results from having a pump-fed upper
stage with thin tank walls and low helium requirements vs. pressure-fed
with thick tank walls and high helium requirements. The higher
specific impulse comes from the much higher chamber pressure of
Merlin and much higher expansion ratio. The Merlin vacuum specific
impulse is expected to be 340s vs. 325s for Kestrel.

Other changes
not included in prior numbers will also boost payload to orbit.
During the development process, the Merlin engine has show itself
capable of at least an 80,000 lb sea level thrust vs. the nominal
72,000 lb. Also, both the inter-stage and fairing will be made
from a carbon fiber sandwich composite (vs. just the inter-stage
in Falcon I), improving mass fraction. Following completion of
the Merlin 1 qualification, we will begin work on a Merlin 2 with
a sea level thrust target in excess of 100,000 lb as well as a
slight increase in Isp.

The estimated
payload to orbit with the Merlin 2 engine, including both an Isp
and mass fraction sandbag, is as follows:

The above
performance to GTO & escape can be improved significantly
and the burnout g load reduced by using a kick stage, such as
a Star motor from ATK. Note, the initial version of Falcon V,
which is expected to launch in late 2005, will have approximately
20% less capability than the above numbers (official update to
the website coming shortly). These performance numbers are applicable
to launches occurring in late 2006 when the Merlin 2 engine upgrade
is flight ready.

I expect the
Falcon V development to be considerably faster and easier than
the Falcon I development, because it uses most of the same components.
Unlike Falcon I, where we had to develop two complete engines
from scratch, Falcon V in its initial version requires only minor
adjustments to the existing Merlin engine. The avionics are the
same as Falcon I and the airframe architecture on Falcon V is
just a wide body version of Falcon I. Also, most of our launch
site infrastructure and the environmental permits already accommodate
both vehicles.

Noteworthy
items on the Falcon V development:
1. The upper stage Merlin engine is in the fabrication cycle and
should be complete in a few months, except for the vacuum skirt
extension.
2. LOX and RP-1 manifold parts for the five first stage engines
are done.
3. Our custom-made friction stir welder, which will be used for
the Falcon V tanks, has arrived and is producing excellent welds
with literally zero defects.
4. Spin form tooling for the tank domes is on order and expected
in January.

Elon

TECHNICAL
UPDATES

Propulsion

The past few
months have mostly consisted of testing and retesting the engines.
As reported earlier, we noticed cracks developing in the cast
aluminum fuel manifold. As a result, we decided to switch to inconel,
a nickel-chromium-iron alloy that has several times the strength
of cast aluminum and even greater toughness, at the cost of a
few extra pounds of mass. The area under the stress-strain curve
(definition of toughness) for our inconel manifold is an order
of magnitude greater than the aluminum casting.

Testing at
this point is focused mostly on ablative life and making sure
that we are not at risk of burning through the chamber wall. Depending
on how this goes, we may need to increase film cooling to the
engine walls and sacrifice a few seconds of specific impulse.

Maximum thrust
achieved so far during testing of Merlin is 81,000 lb and in fact
the engine has to be detuned to bring thrust down to within specifications
for Falcon I. This is quite good news, because we have been able
to build that extra thrust into the Falcon V design and boost
payload well above numbers currently advertised on our website.

Structures

Launch
Pad
All major launch pad construction is complete, including concrete,
steel work, propellant supply tanks, launch mount, etc. We also
built a retractable hangar on the upper deck to provide shelter
to people working on the rocket during final checkout and integration
of the satellite. This rolls back on rails just prior to launch.

As shown above
in launch pad pictures, LOX and RP-1 tanks sit on either side
of the launch deck, along with helium pressurant and nitrogen
purge supply tanks. Pad electronics are in a small room under
the launch quadropod. The work remaining consists mainly of finishing
the electrical and communication wiring, as well as the plumbing
from the supply tanks to the vehicle.

Our pad infrastructure
is probably more than an order of magnitude less complicated than
most other US facilities and bears a closer resemblance to the
current Russian/Ukrainian approach or the early US Thor architecture.
In fact, we drew some of our ideas from an old Thor rocket and
its mobile launcher that are sitting in a museum at Vandenberg.
It is not clear to me why those ideas were abandoned.

Mass Improvements
We have made significant mass savings in first stage, particularly
in the inter-stage structure. By moving from an aluminum design
to a carbon fiber composite design, we cut the weight of the inter-stage
in half. Now, we started with a poorly optimized aluminum design
and then moved to a really optimized carbon fiber/honeycomb design,
so ordinarily you would not see that much of an improvement. The
icing on the cake here is that it actually costs us less to build
the carbon fiber inter-stage than the aluminum one! Long term,
we will probably switch our aluminum fairing design to composite
as well.

Other areas
of first stage mass improvement:
– Parachute recovery system mounts
– Helium bottle mounts
– Pressurant plumbing changed from steel to titanium
– Separation rings
– Thrust skirt
– Removal of an unnecessary ring at the base of the vehicle
– New (and better in every way) pre-valve design
– Thinner slosh baffles
– Thinner tunnel covers
– Thrust frame changed from steel to titanium
– Gimbal joint changed from steel to titanium

Some parts
of the main engine have grown in mass, but the net effect is that
we are likely to meet our propellant mass fraction target of 94%
for the first stage, including the inter-stage and recovery system.
This is among the best mass fraction numbers for any boost stage
and is particularly good when considering that our first stage
weight incorporates a recovery system and increased design margins
for reusability.

Avionics

We integrated
our full suite of avionics with the aluminum honeycomb support
structure, which located just below the fairing. This was then
mounted to the flight vehicle for transfer to Vandenberg. After
ironing out a few nits, communication through the umbilical cable
from the Mobile Command Center to the vehicle flight computer
worked flawlessly. We were also able to obtain a very precise
alignment of the vehicle using a theodolite.

Below is a
picture of the avionics tray nearing final assembly. The upper
half contains vehicle avionics necessary for guidance & control
and transmission of telemetry & video. The lower half contains
a completely independent flight termination system that will be
used by range safety to terminate thrust in an emergency.