To commemorate their greatest accomplishment to date with the Starship, SpaceX has released a recap video of the SN8 high-altitude flight. This was the 12.5 km hop test that took place on December 9th, 2020, which saw the SN8 prototype ascend to an altitude of 12.5 km (7.8 mi), conduct a “belly-flop” maneuver, and return to the launch pad. While it didn’t quite stick the landing, the test was a major milestone in the development of the Starship.
The flight test came after multiple static fire tests were conducted with previous prototypes (the SN1 through SN5), and a series of 150 meter (~500 ft) hop tests with the SN5 and SN6. On October 20th, 2020, another successful static fire test was conducted with the eighth prototype (SN8) using three Raptor engines. With the engines and design validated, the company prepared to conduct its first high-altitude test in December.
The two minute-twenty second video captures the highlights of the test by merging footage from the many different cameras that were recording that day. This included a series of external cams (including a drone cam that follows the SN8 all the way up) cams inside the engine compartment, one on the landing pad, and fuselage-mounted cams.
It begins by showing the engine ignition and the ascent, with all three Ratpor engines producing a trail of orange-blue flames – which is the result of its liquid methane and liquid oxygen (LOX) fuel being burned. This is followed by the engine cutoff, where the three Raptor engines disengage (one at a time) as the SN8 nears its apogee of 12.5 km.
In slow motion, we then see the SN8 turn on its side and watch its fins adjusting for the “belly-flop” maneuver. This portion of the test was meant to validate the prototype’s aerodynamic surfaces, which the Starship will rely on to manuever and shed speed while making an atmospheric reentry. The descent is captured from multiple angles using the drone cam and the fuselage cam.
Then comes the “flip manuever,” where two of the Raptors reignite and gimbal in order to bring the tail around for landing. This is shown from both the side (drone cam) and the ground. The engines them flame up for the landing burn, but fail to slow the SN8 down enough for it to make a soft landing. The touch down and Rapid Unscheduled Disassembly (RUD) – aka. explosion – ensue.
This was due to a fuel line pressure issue, which the ground crews quickly identified after the test was complete. Shortly thereafter, Musk took to Twitter to share what they had learned:
“Fuel header tank pressure was low during landing burn, causing touchdown velocity to be high & RUD, but we got all the data we needed! Congrats SpaceX team hell yeah!!”
Despite the fiery ending, all of the key systems and surfaces involved were validated. These included the ascent, the switchover from the tail to the header fuel tanks (once SN8 reached its apogee), and the precision flap manuever that allowed for a controlled descent. Meanwhile, the crews obtained all the data they needed about the issue that prevented a soft touchdown and will be using it to inform the next round of tests.
The video then ends with the caption that reiterates the successes of this first-ever high altitude flight test:
“SN8 DEMONSTRATED A FIRST-OF-ITS-KIND CONTROLLED AERODYNAMIC DESCENT AND A LANDING FLIP MANEUVER. TOGETHER THESE WILL ENABLE LANDING WHERE NO RUNWAYS EXIST INCLUDING THE MOON, MARS AND BEYOND.
“NEXT UP: SN9.”
Speaking of which, all indications are that Musk plans to conduct a hop test with the SN9 and others in the coming weeks. These include Notices to Airmen (NOTAMs) issued by the Federal Aviation Administration (FAA) for the airspace around Brownsville, Texas, and road closure notices issued for Cameron Country around the Boca Chica test sight.
These have since been extended, with new NOTAMs issued for next Wednesday and Thursday (Jan. 13th and 14th) from 08:00 AM to 06:00 PM local time (CST) – or 06:00 AM to 04:00 PM PST; 09:00 AM to 07:00 PM EDT. Similary, new road closures have been announced for State Highway 4 and Boca Chica Beech in Cameron Country for Monday to Wednesday (Jan. 11th to Jan. 13th).
The SN9 has since been rolled out onto the landing pad and conducted its first static fire test earlier this week (Wed. Jan. 6th). Unfortunately, the test was aborted after a very brief firing and another is likely to happen this coming week before any hop tests are attempted. Meanwhile, the SN10 has been stacked and integrated inside the High Bay and will be ready to roll out as soon as the SN9 has been put through its paces.
The SN11 and SN12 are also being assembled inside the facility’s Mid Bay, with the SN11 almost finished and just in need of its nosecone. Musk has also hinted that he and his crews at the Boca Chica facility will be testing the SN9 and SN10 (and subsequent prototypes) simultaneously. This was in response to a tweet by RGV Aerial Photography (@RGVaerialphotos), which conducts weekly flyovers to take pictures of the Boca Chica facility.
The image in the tweet shows the SN9 on the landing pad, with an earlier picture of the SN8 added (using Photoshop) on the adjacent pad. The image is captioned with a question for Musk: “With SN10 nearly complete and repairs being done at the landing pad, do you think this is something we will get to see in the next few weeks?” To this, Musk tweeted a reply of, “Yes.”
2021 is going to be an exciting time for SpaceX, commercial space, and space exploration in general! While the year has seen its share of bad news already, it looks like there are some serious bright lights on the horizon!