SpaceX is getting closer to the day when it will be able to make good on its promise of conducting regular missions to orbit, the Moon, and to Mars. At the heart of all this is the progress they are making with their Starship and Super Heavy launch system. In recent weeks, Musk’s commercial space company conducted two successful 150 m (500 ft) hop tests with the SN5 and SN6 prototypes at the Boca Chica launch facility in southern Texas.
Based on the latest announcements to come out of SpaceX, it appears that this recent string of successes has emboldened Musk and his company. Previously, Musk indicated that he was planning on making several more small hop tests and that the SN8 would attempt a 20 km (12 mi) flight sometime next year. More recent indications, however, suggest that Musk wants to conduct this high-altitude test before the end of October.
The first indication came in the form of a Notice to Airmen (NOTAM) issued by the Federal Aviation Administration (FAA) last week (Wednesday, Sept. 9th). The reason for this notice, according to the FAA, was “to provide a safe environment for space operations,” which would remain in effect from 03:45 am UTC (11:45 am EDT; 08:45 am PDT) on Sept. 9th, to 11:59 pm UTC (07:59 pm EDT; 04:59 pm PDT) on Oct. 31st.
A notice advising pilots and aircraft to avoid the region above Boca Chica for almost two months straight would indicate that SpaceX plans to do some rigorous flight testing. At the very least, it would be seen as an indication that Musk was hoping to conduct more small hops using the SN5 and SN6 (as he had previously stated) as well as a second cryo-proof pressure test – this time with the SN7.1 tank.
However, the next indication came from Musk himself via Twitter just two days ago (Saturday, Sept. 12th), where he stated that the “SN8 Starship with flaps & nosecone should be done in about a week. Then static fire, checkouts, static fire, fly to 60,000 ft & back.” The SN8 will also be equipped with three Raptor engines, though it’s not yet clear if they will be SN27s or the newer SN29s.
The most challenging aspect of this test will be the landing portion, which will consist of the vehicle shutting down its engines and “belly-flopping” towards the ground. The purpose of this will be to see if the maneuvering fins and aerodynamic surfaces will allow the Starship to glide back to its landing site. Ground crews will then attempt to relight the engine during the last few seconds and swing the aft back around for a soft landing.
To be clear, 60,000 feet (18,288 meters) could just be a rough number and not represent a reduction in the target altitude. Either way, it is clear that the company is focused on getting the SN8 ready to make their highest hop test to date. The SN8’s fuselage was recently assembled inside the Mid Bay at Boca Chica and the aft fins are currently being installed. Meanwhile, the nose cone is inside the Windbreak facility waiting for the final assembly.
Meanwhile, it’s not clear what SpaceX plans to do with the SN5 and SN6, whether they will be scrapped, used to make additional hop tests, or for some other purpose. However, both prototypes served their purpose, allowing SpaceX to test out various iterations of the Starship design and acing the cryogenic load test, the static fire test, and the hop test.
Another important milestone that will be happening soon is the pressure test of the SN7.1 tank. Like it’s predecessor, this tank will be pressurized with cryogenic liquid nitrogen until it experiences a blowout. Once again, the purpose of this is to test the effectiveness of the steel alloy (340L) and the manufacturing techniques used to create all of the latest Starships variants.
That event is expected to happen later this week and will be the final hurdle before the SN8 is rolled out and run through final preparations before making its high-altitude hop. These will include two static fire tests of its three Raptor engines and a full system and structural check in between. Since this will be the first static fire three Raptor engines together, those tests will also represent a milestone.
“One way or another, excitement guaranteed!” Musk added. “Support of greater Boca, Padre, Brownsville community is very much appreciated.”
Top Image Credit: @ErcXspace
Further Reading: NASA SpaceFlight, FAA