BOCA CHICA, TX – Yes! Starhopper, finally, with the big hop!
The big headline for the past couple of weeks has been the SpaceX Starhopper, because it finally completed it’s big hop! If you’re just coming up to speed, the Starhopper is the first step in the development of SpaceX’s much larger Starship and Super Heavy rockets. You may have previously heard this referred to as the BFR or the Big Falcon Rocket. Prior to the most recent flight, the FAA had granted SpaceX the ability to complete unlimited flights tests to an altitude up to 25m and they have utilized that flight permit to perform 3 flight tests so far. Two of them were pretty small, just a couple of centimeters off the ground and one was a little bit larger at 59 ft or 18m. For the past couple of weeks, we’ve been waiting for SpaceX to complete the much larger 200m test, although the waiting dragged on while SpaceX and the FAA tried to come to an agreement on what the safety parameters would be so that the FAA could issue SpaceX a safety approval.
The FAA finally did issue SpaceX authorization to perform one much larger hop, and only one much larger hop. This isn’t really much of a big deal, because Elon Musk has stated many times in the past that this would be the final flight test for the Starhopper platform anyways. After this, SpaceX is intending to move on to their much larger orbital prototype for the Starship rocket and the Starhopper platform will be converted into a vertical test standfor their new Raptor engines.
This flight was allowed to hold up to 30 metric tons of fuel and it was permitted to fly to an altitude of 150m. Which is just shy of 500 ft. Now originally, this flight was billed as a 200m flight test or about 650 ft, but it appears that the FAA wanted to put a little bit of a cap on that, presumably for public safety reasons. Don’t forget that the Boca Chica launch site down in Texas is only about 1.5 miles or 2.5 kilometers away from the nearest town. For comparison, when I attended my two NASA Social events down in Cape Canaveral, Florida, we had a prime viewing area, which was still about 2.9 miles or a little less than 5 kilometers away from the launch site and that was as close as anybody could get! So there are residents and houses that are less than half the distance that I was allowed to be at and they are not completely clear of all risks. So much so that local authorities down in Boca Chica Village handed out flyers to their residents urging them to stay out of their houses for fear that an overpressure failure event could break their windows and blow glass into their houses.
When it came to the test flight itself, it wasn’t without drama. The first flight attempt came later that day on Monday, August 26th, but it was aborted just 0.8 seconds after ignition when… well, ignition didn’t happen. Elon Musk mentioned on Twitter that the igniters that actually do the ignition of the Raptor engines didn’t actually ignite. The new Raptor engines that SpaceX is developing for their new Starship and Super Heavy rockets not only uses a new fuel mixture, but it also uses a new, or rather just a different, ignition process. You may be familiar with the Falcon 9 rocket which uses a pyrophoric chemical ignition process made up of the chemicals triethylaluminum and triethylborane or TEA-TEB. This is the iconic green flash that we see at the engine bells when the first and second stages of the Falcon 9 ignite and the TEA-TEB instantly combusts with oxygen and ignites the engine. The Raptor engine, however, uses methane and a spark plug igniter system. A spark plug ignites a little blow torch and that, in turn, ignites the main combustion chamber and it appears that those spark plugs didn’t actually operate. We did see cryogenic fuel pouring out of the engine bell, but no ignition whatsoever and the test was promptly aborted.
The actual flight itself took place on Tuesday, August 27th, the very next day, and it was amazing! WAY better than I expected it to be. That awkward little flying water tower with legs, lifted off, traveled to an altitude of about 150 meters or a little less than 500 ft, added in a roll program before it finally had a soft landing on the adjacent landing pad just a few meters away. The test itself seems to be a major success for SpaceX, but it wasn’t perfect. We did see a composite overwrapped pressure vessel, or COPV, liberate itself from the Starhopper and it landed a little ways away, just after landing. That’s not supposed to happen, but it’s really a non-issue, because for this test to be successful, it really just needed to launch and land. From point A to point B – mostly in one piece.
So this appears to give SpaceX the green light to move on to the next stage of development which is orbital prototype for Starship. That much larger prototype could be flying as early as a month or two from now and will start with some suborbital flights before moving on to actual orbital test flights.