Status Report

SpaceX Update 9 May 2003

By SpaceRef Editor
May 9, 2003
Filed under , ,

Much has

happened in the past few months, so there is a lot of good information

in the update below. We have had several successful firings of

the Falcon main engine (named Merlin), the first stage is almost

complete, the second stage is in fabrication, our prototype fairing

structure is done and a lot of the small, but important pieces


In March,

we ran a three day Falcon design review for potential customers

and the regulatory authorities, which seemed to be very well received.

Representatives from NASA, the Dept of Defense and several commercial

satellite builders were present on the customer side. On the regulatory

front, we had Air Force Range & Safety and the FAA in attendance,

and I would like to thank both of those organizations for their

continuing support in helping us move Falcon through the regulatory

approval process.

At this point,

we have a verbal launch commitment from a Dept of Defense customer

and a written launch commitment from an international government

customer. While still preliminary, this seems to confirm that

there is at least modest demand for launching small satellites.

We are starting

to have more definite numbers for the payload capability of Falcon

and indications are that it will do at least 1,250lbs (570kg)

to 200km LEO from Cape Canaveral. This is 25% above our initial

target of a 1,000lb payload capability. Pricing for the Falcon

remains constant at $6 million per launch.

Also, starting

in Q4 2004, SpaceX will offer Falcon with two liquid strap-on

boosters in a configuration similar to Boeing’s Delta IV

Heavy. Falcon’s capability to LEO would increase substantially

to above 4000lbs (1820kg) and enable GTO payloads of approximately

1300lbs (590kg). Pricing and final payload capabilities are not

yet determined and a more formal announcement will follow in coming


I have been

asked several times whether we intend to pursue human spaceflight.

The answer is that SpaceX will definitely pursue that market in

the long term. In fact, part of the reason why we have spent substantial

capital on reliability — some would argue more than is necessary

for satellites — is that we would like Falcon to be safe enough

for human transportation. However, we believe it makes sense to

prove reliability with satellites before putting people on the

rocket. 99% reliability is considered exceptionally good in the

satellite delivery world, but is not very satisfactory for people.

Over the next

several months, everyone at SpaceX will be heads down working

hard towards our first satellite launch. Before too long, we should

be able to release details of those launch plans and the partnership

that has come together to make it happen.


Merlin at full thrust with a copper chamber

Merlin with a flight weight ablative chamber

After several

weeks of testing, we are at about 94.5% combustion efficiency

on a copper heatsink chamber. We will be firing with an ablative

chamber in about six weeks, once we correct an issue with the

metal insert that joins the injector head to the chamber. That

should bump that up efficiency by a few percentage points and

put us above our target of 96%. Including gas generator losses,

vacuum specific impulse would then be about 310s with a modest

expansion ratio.

Merlin Turbo-pump

Also in May,

we expect to run the Merlin turbo-pump and verify pressures &

flow rates. As mentioned before, our approach is a gas generator

cycle, single shaft, single turbine wheel combined LOX/kerosene

pump. Like the rest of our development, all components except

those used for calibration are at or near flight weight. At 150lbs,

the turbo-pump may be the best ever pump in its class for thrust

(max 85,000lbf vacuum) to weight.


Stage Primary Structure Arrives

Despite delays due to the transport company truck breaking down

on the way to pick up the first stage in Wisconsin, it arrived

in time for the design review in good shape. Our shipping fixture

with additional bracing from Spincraft did a great job of supporting

the stage against lateral loads from the road. We could measure

no meaningful deviation from circularity when it arrived, despite

the fact that it was shipped unpressurized. This was actually

an important practical test of structural stiffness as compared

to an Atlas II/III, which requires pressure stabilization in transit

to maintain its shape.

Falcon 1st Stage Primary Structure


Ring, Satellite Adapter Cone and Separation System

The vehicle avionics and flight termination system (apart from

the linear shaped charges) are mounted on the cone, which is in

turn mounted to the top of the second stage. On top of the cone

is the satellite release system. We have decided to use a low

shock, non-pyrotechnic device called Lightband, with essentially

zero debris that could contaminate a satellite or spacecraft’s


Payload Adapter and Satellite Release System on Mounting Tool


Stand Instrumentation and Setup in Texas

The Merlin horizontal pressure fed test stand is now fully set

up at our propulsion testing facility in Texas. You can see it

on the left under construction in this picture taken in February

during a cold snap (that is ice on the ground). The large white

pressurant ball, formerly used for wind tunnel tests, is made

of one foot thick steel and weighs about 35 tons. In the middle

of the picture is the vertical test stand for Merlin and to the

right is the Kestrel vertical test stand.

This is intended

to be a world class stand on par or better than those in use by

Boeing or Northrop, so it is quite expensive and a lot of work

to build and check out. In the end, however, we should be able

to characterize very accurately the flows, pressures and temperatures

throughout the thrust chamber assembly and fine tune the injector

for maximum efficiency.


Test Stand Instrumentation and Setup in Texas



The tooling for joining the fairing skin panels, ring frames and

stringers has been built and both fairing halves assembled. Our

small construction crew, most of whom are former Boeing veterans

from Huntington Beach, are doing a great job. They’ve built

dozens of fairings in the past for everything from Delta II &

IV to the Titan IV.

The first

unit is an engineering prototype, which we will place in a test

harness and verify all the expected load cases. Depending on how

well the physical testing compares to our finite element model

predictions, we will consider reducing the aluminum skin thickness

in follow on units.

SpaceRef staff editor.