Will the Starship Make a 15 km Hop Test on Wednesday?

Update: According to FAA flight restrictions that were redacted yesterday (Dec. 3rd), the date for the hop test has since been moved to Monday, Dec. 7th, at the earliest. The altitude of the test has also been dropped from 15 km to 12.5 km (41,000 ft).

SpaceX has really hit its stride lately! Throughout the Summer of 2020 and well into the Fall, the company has experienced a string of successes with the construction and testing of its Starship prototypes. This has included multiple cryogenic load tests, static fire tests, test tank pressure tests, and even two 150 m (~500 ft) hop tests. And now, it looks like SpaceX could be making its first high-altitude flight test as early as tomorrow!

This test will see the first Starship prototype with three Raptor engines (SN8) fly to an altitude of 15 km (9.3 mi) before returning home safely. The engineering teams will be using this test to validate the Starship maneuvering fins as well, conducting a “belly-flop” maneuver that will see how the spacecraft’s aerodynamic surfaces allow it to make controlled landings on bodies that have an atmosphere.

The possibility that this test could take place this week was floating by Elon Musk via Twitter over the weekend. The news came as a response to a comment by Michael Baylor of NASASpaceFlight.com, who shared news of an alert notice to the residents of Boca Chica. These are issued in advance (along with notices of road closures) in the event of a static fire or flight tests being conducted at SpaceX’s South Texas Launch Site.

The alert, the full text of which you can read here, specified that:

“SpaceX will conduct Space Flight Activities on November 30, 2020 from 7:00am to 9:00pm. Approximately 10 minutes prior to the activity, you will be provided notice by the sounding of a police siren in Boca Chica Village. There may be more than one instance during that time period where you will hear a siren notification.”

The notice also warned that a malfunction during testing could lead to a possible “overpressure event” that would break windows. As such, it was recommended, but not required, that residents and their pets vacate their houses in the village for the duration of the activity, or at least wait outside once they heard the police siren and stay there until given the all-clear.

Baylor also stated that flight restrictions were still pending, which would indicate that the flight test (already expected to happen this week) had been given the green light. In response, Musk tweeted that only a static fire would be taking place yesterday (Nov. 30th) and that the long-awaited flight test would occur no sooner than tomorrow (Dec. 2nd).

This coincides with a Public Notice for Cameron County that indicated a series of temporary closures for State Highway 4 and Boca Chica Beach. This includes one closure with a primary date of Nov. 30th (7:00 am to 6:00 pm), with secondary dates running from Dec. 1st – 2nd (8:00 am to 5:00 pm). Another was scheduled for Dec. 3rd (primary) with Dec. 4th and 5th (all from 8:00 am to 5:00 pm).

A third and final closure is scheduled for and again from Dec. 7th – 9th, with the primary (Dec. 7th) running from 8:00 am to 5:30 pm, and the secondary dates running from 8:00 am to 5:00 pm. According to Cameron County Judge Eddie Travino Jr., the closures were issued in “connection with space flight activity, now or in the future.”

The SN8 was officially cleared to commence preparations after its latest successful static fire test last week (Tuesday, Nov. 24th). This was the fourth static fire test performed by the SN8 and the second test using three Raptor engines. The first three-engine test took place in late October, which was followed by the SN8 finally having its nose cone and flaps installed.

With that latest milestone complete, Musk stated via Twitter that a flight test would be happening this week.

“Good Starship SN8 static fire! Aiming for its first 15 km / ~50k ft altitude flight next week. Goals are to test 3 engine ascent, body flaps, transition from main to header tanks & landing flip.”

If all goes according to plan, the SN8 will cut off its engines shortly before reaching its maximum altitude. Once the descent phase begins, the spacecraft will turn its hull towards the ground and glide towards the landing pad, relying solely on its fins to control its fall. The ground crews will relight the engine during the last few seconds and swing the rear section back around for a soft landing.

According to past statements, Musk hopes to follow this up with a suborbital flight sometime next year. This would see a Starship fly to an altitude of 200 km (~125 mi) using six Raptor engines (three optimized for sea-level thrust and three optimized for the vacuum of space). Meanwhile, work continues on the Super Heavy booster element of the launch system, which will have no less than 28 Raptor engines.

As always, things never seem to happen precisely on schedule. But they are happening and getting ever-closer to the point of culmination. In a few more years, we may very well be seeing the Starship making regular trips to orbit, flying passengers from one continent to another, bringing payloads and people to the Moon, and maybe even establishing a colony on Mars.

Further Reading: Teslarati