SpaceX the Alan Notes

SpaceX believes they have “all the necessary pieces” to achieve a full recovery of the booster stage, with the next launch of their Falcon 9 v1.1 set to test another key technology towards that aim, via the debut of landing legs on the aft of the first stage. While there is a low likelihood SpaceX will be able to recover the first stage of the CRS-3 Falcon 9 from the water, the returning booster will attempt to deploy its landing legs during its descent.

SpaceX CRS-3:

The NET (No Earlier Than) March 16 launch of the Falcon 9 v1.1 has a primary objective of lofting the next Dragon spacecraft (CRS-3/SpX-3) into orbit for her journey to the International Space Station (ISS).

Preparations are continuing with the processing and integration of the spacecraft and launch vehicle at SpaceX’s SLC-40 facility located at Cape Canaveral in Florida.

As recently revealed by NASASpaceFlight.com – via comments made by Tom Mueller, Co-Founder and VP Propulsion for SpaceX – the decision was taken to install four landing legs on to the aft of the F9 v1.1 first stage. The potential for this launch to include the innovative legs was known for some time. However, the actual decision to integrate the legs on the CRS-3 F9 was not confirmed until deep into the rocket’s flow.

Just days later, SpaceX CEO Elon Musk tweeted a couple of photos showing the legs as installed on the rocket, confirming the company is ready for the next milestone towards the rocket becoming fully reusable.

Both NASA sources, and SpaceX officials, note the addition of the legs on the rocket will incur no impact to the primary goal of lofting Dragon into orbit on its resupply mission to the ISS.

toward the ultimate goal of returning the first stage back to Earth for reuse.

These events occur after staging, with the first stage booster rotating 180 degrees via Reaction Control System (RCS) thrusters, prior to the re-ignition of three of the booster’s nine Merlin 1D engines.

This “boost back” maneuver, as it will be known when the stages eventually return to a designated landing site, currently targets an area over water, allowing a safe testing zone to refine control of the returning stage, prior to the eventual landing attempts on terra firma.

“Extended and precise high altitude reentry burns have occurred (on previous Falcon 9 v1.1 missions) that are similar to a boost back, but we did not attempt to bring the rocket close to land, ” noted SpaceX Spokesperson Emily Shanklin in a series of responses to NASASpaceFlight.com

The first stage of the Falcon 9 v1.1 that successfully lofted the CASSIOPE satellite managed to conduct its three engine burn, allowing for reentry.

However, the stage started to spin during its return, causing the fuel to centrifuge. According to Mr. Mueller, the baffles in the tanks were not designed for those stresses, causing debris to get into the engines, resulting in them shutting down prematurely. The stage was lost when it impacted the Pacific Ocean.