Tuesday, January 13, 2015

SpaceX Pads Its Lead

Coming soon to the Cape's Pad 13 ... A test flight of the reusable Falcon 9 at the SpaceX test site in McGregor, Texas. Video source: SpaceX YouTube channel.

A rather poorly kept secret became public on January 6 when Florida Today published an article about SpaceX planning to use the inactive Pad 13 at Cape Canaveral Air Force Station as a landing pad for the Falcon 9 booster.

The environmental assessment for that use appeared online when NASASpaceflight.com posted a link to the draft report on the Patrick Air Force Base web site.

Also available at this link (in case the original disappears), the report was prepared for SpaceX and the U.S. Air Force in October 2014 by Gator Engineering and Aquifier Restoration, whose illustrations appear below. SpaceX was a prior G.E.A.R. customer in 2013.

The report not only reveals the company's plans for Pad 13, but lots of details about its operational strategies as well as the near future for the Falcon Heavy.

The below information is directly from the report. Page references are to the PDF number, not the section/page number in the report.

Page 8 states that SpaceX is working towards a “5-year real property license” from CCAFS for the facility, which seems a bit short compared to the 20-year lease with NASA at Kennedy Space Center's Pad 39A.

Pad 13 as it currently appears on Google Earth. Click the image to view on Google Earth at a higher resolution and scroll the vicinity.

Page 10 states the purpose for the SpaceX project:

The purpose of this action is to provide a [Reusable Launch Vehicle (RLV)] landing area by constructing a landing pad and associated supporting infrastructure for landing operations of the Falcon 9 or Falcon Heavy vehicle in order to reuse it for future launches. This purpose continues to support SpaceX’s over-all missions for NASA and the USAF. The action continues to fulfill the United States’ expectation that space transportation costs are reduced in order to make continued exploration, development, and use of space more affordable. The Space Transportation section of the National Space Transportation Policy of 1994 addressed the commercial launch sector, stating that “assuring reliable and affordable access to space through U.S. space transportation capabilities is fundamental to achieving National Space Policy goals.”

This action is needed in order to increase the effective and cost efficient operation of space flight by providing a truly returnable, re-usable space vehicle close to the location that it was launched from. The need for the Proposed Action is also in line with NASA’s Space Act Agreement (SAA) and the FAA’s Office of Commercial Space Transportation mission, which is to continue to support of the U.S. goal of encouraging activities by the private sector to strengthen and expand U.S. space transportation infrastructure. The Proposed Action would provide greater capability in its mission to support the ISS and other commercial enterprises. Demand for launch services has increased over the past 20 years and the demand projections indicate that this would continue into the foreseeable future. In order for the United States to be competitive, the cost and frequency of launches needs to keep pace with world demand.

These national needs are cited throughout the document as critical justifications for the project.

Page 15 states:

“The scope for this EA is limited to the landing of the first stage of a Falcon 9 vehicle, or a Falcon Heavy single first stage, at LC-13, and the activities to support redeveloping LC-13 into a landing location. This EA does not include a multiple booster landing scenario since only one booster will be landing at this facility during a landing event.

Conspicuous by its absence is the crew version of the SpaceX Dragon, known as the V2. One would presume that Pad 13 could also be used for aborts or returns from orbit, but that is not mentioned. The Dragon V2 will launch atop the Falcon 9 at KSC's Pad 39A, but after orbital flight it would land whereever orbital mechanics permit.

A May 2014 promotional film showing computer animation of a Dragon V2 flight. Video source: SpaceX YouTube channel.

The above May 2014 SpaceX promotional film shows the V2 landing at a pad near the CCAFS runway, called the Skid Strip. That pad currently does not exist. Presumably the CGI is just for illustration and is not an actual plan. Perhaps another environmental assessment will be required if Pad 13 is used for V2 landings — or SpaceX may seek another location closer to the NASA side of the Cape that would return the crew to their headquarters facility in the KSC industrial area.

The report states in several places that only one of the three Falcon Heavy boosters will return to Pad 13. The others would be recovered down-range, presumably on the SpaceX Autonomous Spaceport Drone Ship.

The SpaceX Autonomous Spaceport Drone Ship. Image source: Elon Musk on Twitter.

According to page 16, “It is anticipated that the stage would return to the landing pad within approximately 10 minutes after lift-off. Preliminary trajectory analysis indicates that a point directly beneath the vehicle at stage separation falls approximately 16 nautical miles from the launch site.”

The site would have a 200 foot by 200 foot square primary landing pad, with four 150-foot diameter contingency pads around its perimeter. Page 17 states, “The contingency pads would only be utilized in order to enable the safe landing of a single vehicle should last-second navigation and landing diversion be required. There are no plans to utilize the contingency pads in order to enable landing multiple stages at LC-13 during a single landing event.”

The main pad and contingency pads. Click the image to view at a higher resolution.

Page 17 continues:

At the location of the former blockhouse, a steel and concrete “stand” would be built to secure the Falcon stage during post-landing operations. The stand would consist of four Individual pedestal structures which would be transported to site and bolted to a concrete base. Each of the four pedestals, would weigh approximately 15,000 lbs, and would be 107 inches tall and 96.25 inches wide. A mobile crane would lift the stage from the landing pad, and transport and place it on the stand. Activities such as allowing the landing legs to be removed or folded back to the stage (flight position) prior to placing the stage in a horizontal position would occur there.

Worried about the stage going off course? Page 19 addresses that concern:

The guidance, navigation, and control system of the Falcon vehicle is triplicated such that the system is one-fault tolerant. The system consists of three inertial measurement units, three GPS receivers, three flight computers, and thrust vector control on the first stage. A destructive Flight Termination System (FTS) would also be active ...

The location of support facilities proposed for Pad 13. The report does not provide an explanation for the numbering. Click the image to view at a higher resolution.

For those who miss the twin sonic booms that heralded the return of the Space Shuttle orbiters, the report notes in several places the potential for a sonic boom as the Falcon 9 returns. But the boom is expected to occur about 30 miles out over the ocean.

The expected sonic noise pattern for a Falcon 9 RLV flying back to LC-13 from an approximate trajectory of between 040 degrees and 060 degrees. Click the image to view at a higher resolution.

Pages 64-65 of the report discuss the sonic boom potential in detail.

The maximum focus boom would be 3psf or less and occur beyond over the ocean 30 miles from the coast. CCAFS and the Daytona Beach area may experience a slight over pressure of up to 1 psf, but generally about .4 psf or less ... Based on the discussion above, sonic boom effects from landing operations at LC-13 would be less than other launch actions and would not cause a significant noise impact in sensitive areas.

SpaceX attempted to land its Falcon 9 on the drone ship on January 10. A shortage of hydraulic fluid resulted in a “hard landing” but the F9R did reach its target. SpaceX has indicated it intends to try again with its next launch, currently scheduled for January 29.

As fun as it is to watch SpaceX try to land on the ship, it's only part of a larger strategy to bring back rockets to Pad 13 so they can be refurbished, refueled and flown again.

It's been a long time since the Cape was the epicenter of aerospace innovation. The glory days are about to return, thanks to SpaceX.

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