The SpaceX Archive
January, 2004 Newsletter

December 2003

Falcon I Unveiled

The official unveiling of Falcon I took place this past month outside FAA headquarters in Washington DC. Patti Grace Smith, the head of the FAA space division, was kind enough to say a few words and Dana Rohrabacher, Chair of the House Space Subcommittee, provided some remarks via letter in support of SpaceX. Following the unveiling, a reception and dinner was held at the Smithsonian across the road.

We were able to truck the whole 70 ft long vehicle and mobile launcher/erector all the way from California over standard highway routes without a problem. The trip took about five days in each direction. So, in addition to giving the people in DC an opportunity to see the rocket first hand, this event also served as a key logistics test for moving Falcon over long distances.

The only hairy moment occurred when a railroad crossing boom suddenly came down and hit the rear end of the first stage. The truck driver was moving very slowly over the railway tracks to avoid jolting the rig, when suddenly the train alarm went off and the boom came down. Fortunately, the impact was light and the tank was undamaged.

Falcon V Announced

The biggest news we had to announce was Falcon V, the medium lift upgrade to Falcon I. Now, I would be the first to concede that there is something presumptuous in announcing an upgrade before we have even launched the initial product. The reasons for this are twofold:

  1. The mission lead times to manifest spacecraft on rockets are incredibly long — two years would ordinarily be considered fast. Only in rare situations and with special organizations like the Office of Force Transformation and the Naval Research Laboratory can one do better than that. This means potential customers need to know the upgrade path as soon as we do.
  2. Since Falcon V uses the same engines, structural architecture (with wider body) and avionics/guidance, the development risk is actually quite low and well understood. As such, we are very confident of being able to execute a first launch in 2005.

Falcon V is intended to compete for missions that currently fly on Boeing’s Delta II or the low end of Delta IV and Atlas V. The performance targets and standard payload fairing dimensions are given on the Falcon Overview page. Per standard SpaceX practice, the stated performance numbers for Falcon V are intentionally lower than our calculations indicate. Once a flight unit has been built and weighed with all secondary structure in place, they will be adjusted upward.

SpaceX plans call for a long term heavy lift vehicle development. I should be clear that Falcon V is not it. The heavy and super-heavy will be a different line of launch vehicles than Falcon and will make use of a significantly larger main engine. Merlin and Kestrel will constitute upper stage engines for that vehicle line.

Falcon V makes significant strides towards furthering the ultimate SpaceX goal of improving cost and reliability by a factor of ten. The cost per pound to orbit would be about $1300 at the $12M plus range fees launch price. For a production rocket, that would constitute a new world record, excepting only limited use military hardware from the former Soviet Union. With further improvements in performance, I expect we can break the $1000 per pound barrier within a few years of Falcon V’s first launch.

Although we have not yet built F-V in its entirety, we do know how much the engines, avionics and a similar (albeit narrower) structure cost. As such, I can say we have extremely high confidence in the F-V price.

As far as reliability, one could reasonably argue that the ability of F-V to lose an engine at any stage of flight and still complete a successful mission is the biggest launch vehicle reliability improvement in decades. The last time that capability existed was with Saturn V (Shuttle can lose an SSME in some cases, but obviously not a side booster). On two Saturn V flights, Apollo 8 and Apollo 13, an engine failed, but the missions safely made orbit thanks to the engine out capability.

As intuition might suggest and [a study] by Aerospace Corporation shows, engine problems are by far the largest cause of rocket failure. The bizarre thing is how engine failure risk is dramatically exacerbated by multi-engine launch vehicles that require every engine to work flawlessly. What rational person would board a 747 if a failure of any of its four engines at any point in flight meant certain death? If you are someone who would board such a plane, seek help immediately.

— Elon

TECHNICAL DEVELOPMENT UPDATES

Propulsion

We continue to iron out the bugs in the turbo-pump. It appears that design life issues related to bearing cooling and inter-propellant seals have been put to rest. This was one of our biggest concerns in propulsion, since a failure could occur randomly after liftoff even if all parameters showed green in the hold-before-release phase.

Fuel impeller performance is lower than we would like, but still within an acceptable range for flight. The only showstopper right now is suction specific speed on the LOX impeller. Compensating by increasing tank pressure would partially, but not fully solve the problem. We have brought in some retired Rocketdyne engineers as advisors and are working on two slightly different design solutions in parallel. Both solutions should work, but one may perform better than the other.

It will be February before the turbo-pump goes back on the test stand for hopefully the final test series. That will allow us to integrate the three main engine sub-systems (thrust chamber, turbo-pump and thrust vector control) and attach them to flight tanks for the stage hold down test in late February.

In the meantime, we will put an upgraded version of Merlin on the horizontal test stand and see if higher combustion efficiency can be obtained.

This year, we will also be moving from a single propulsion team to a dual propulsion team, as a result of some excellent new hires. It won’t quite double our rate of progress, but something like a 50% improvement should happen.

Strategically, one of our goals in propulsion is to build up a world-beating turbo-pump development team. If you or someone you know is among the best in the world at designing & building turbo-machinery (with the track record to prove it), please encourage them to send in their resume. Note, advanced turbo-machinery development experience is important, but not necessarily rocket turbo-pumps. As an incentive, SpaceX provides a $2500 referral fee to anyone who refers an employee we hire.

Structures

Unfortunately, the first stage structure shipped to our propulsion development facility in Texas for stage hold down testing did not pass SpaceX quality assurance. Despite being x-rayed and die penetrant inspected prior to shipment, on close inspection certain of the welds were below our quality requirements.

The tank has been shipped back to the subcontractor to have a section cut out and replaced. A weld repair could have been attempted, but that would have been an unnecessary risk.

The vertical stand is now fully outfitted, instrumented and plumbed for the stage hold down test. Note the box support structure for the tank for protection against the hurricane class winds occasionally seen in this part of Texas. On top of the old test stand built by the US Navy for missile testing, we have rebuilt the flame duct, poured a new layer of high temperature concrete and installed a high pressure water deluge system.

In between the first stage engine and the tank structure are thrust measurement devices on all axes. This allows us to very accurately calibrate thrust as well as side loads through the full gimbal range.

Avionics

Several key components finished testing in December, including the command receiver and the C-band tracking transponder. We also assembled the armada of signal amplifiers for vehicle data acquisition and placed them in their mount plates. For its maiden flight, Falcon I will be instrumented to the hilt. Those pressure, temperature and accelerometer data feeds are then transmitted back over the S-band downlink.

Attack of the amplifiers

One thing is for certain — we will know the location of our first stage when it lands several hundred miles downrange in the Pacific about 20 minutes after launch. There are seven methods of location:

  1. Ballistic projection past loss of radar signal
  2. GPS coordinates via the S-band telemetry stream
  3. Spotter plane sighting
  4. Recovery boat sighting
  5. Radio beacon
  6. Sonar beacons (two)
  7. Additional GPS tracker communicating over the GlobalStar satellite network (ET phone home)

The recovery system sub-assembly, including 75 ft main parachute, drogue parachute and 10,000 lb mortar are now fully assembled and attached to the square beam mount. This will be placed in the inter-stage, just above the first stage tank. The parachutes will actually sit partially inside the nozzle of the second stage engine.

In the worst case scenario, we’ll recover two pieces of scorched aluminum with sonar beacons attached to them. Best case, it will come in completely intact and everything is reusable, apart from the low cost ablative portions of the engine. Reality for the first few recoveries will probably be somewhere in between, but I suspect it will be closer to the all intact scenario.

Prices for Falcon I and Falcon V currently ignore the possibility of recovery. If the recovery economics work out and we are cautiously optimistic of that being the case, customers can expect a modest reduction in the cost of each.