They say, “The third time is the stimulus.” That was largely the case today when SpaceX made its third attempt at a high-altitude flight test at its launch facility in Boca Chica, Texas. As in the two previous attempts, a Starship prototype (SN10) with three Raptor engines flew to an altitude of 10 km, performed a descent maneuver with “belly flop” and then returned to the launch system.
As with previous high altitude tests, the SN10 successfully launched, peaked and validated the control fins and aerodynamic surfaces. However, unlike previous tests, the SN10 was able to slow down and stay upright enough to make a smooth landing. While the prototype exploded a few minutes after landing (apparently due to a methane leak), the flight was a complete success!
In the month that had passed since the last flight, the ground teams at the SpaceX South Texas launch site near Boca Chica were preparing for their third attempt at a high-altitude flight. After much anticipation, March 3rd was chosen as the earliest date for a start attempt. Originally, Elon Musk and the Boca Chica crews had hoped to take off at 9:00 a.m. CST (7:00 a.m. PST; 10:00 a.m. EST), but the flight was canceled.
The termination occurred almost immediately after the engines ignited when the automated safety systems switched on. Not long after, Musk went to Twitter to explain why this had happened and tweeted, “Start the demolition at the slightly conservative high thrust limit. Increase the thrust limit and recycle the propellant for another flight attempt today. “
After a few hours of preparation, they made a second launch attempt at around 5:14:45 p.m. CST (3:14:45 p.m. PST, 6:14:45 p.m. EST). The flight began with the SN10 firing all three Raptor engines and taking off smoothly. The ascent went smoothly and was broadcast live by SpaceX, NASA Spaceflight and others from different perspectives (outside, inside, fuselage and drone).
About 2 minutes and 13 seconds into flight, one of the Raptor engines shut down and the other two began to gimbal noticeably – designed to test their thrust vector capabilities. The second cut lasted 3 minutes and 15 minutes, and after 3 minutes and 45 minutes the prototype peaked at 10 km. At this point, the ground teams switched him to his collection tank.
At 4:19 am the last Raptor engine stopped and the prototype began its “belly-flop” maneuver. After about a minute and a half of descent, using only the maneuvering surfaces, two of the Raptor engines reignited at 5:45 a.m. and the prototype turned its end around to float to the ground. Perhaps the SN10 prototype proved the third time was the appeal and then managed to bring it in for a soft landing!
The SN10 from below, after completing its “belly-flop” maneuver and restarting its engines. Image Credit: SpaceX
Unfortunately, things didn’t end there. 14 minutes after take-off, the prototype suddenly exploded on the landing pad, apparently as a result of a methane leak. While this indicates that the prototype still has some bugs that need to be fixed before orbital flights can be performed, the test was still a complete success. As with the previous tests, the ascent, descent and maneuver elements of the systems were validated on the SN10 flight.
This time, the spacecraft’s ability to make a soft landing based on multiple systems of the spacecraft was also confirmed. As the company stated in a pre-flight statement:
“A controlled aerodynamic descent with body flaps and vertical landing capability combined with refilling in space is critical to landing Starship on targets throughout the solar system where there are no prepared surfaces or runways and for returning to Earth. This ability will enable a fully reusable transportation system that will carry both crew and cargo on long interplanetary flights and will help humanity return to the moon and travel to Mars and beyond. “
This final launch occurs approximately four weeks after the last one (February 2), which was a little over five weeks after the first (December 23). At this speed, SpaceX achieves a good start-up rate, which is essential for success in space travel. The ability to turn things around quickly, learn from mistakes and build on successes also corresponds to SpaceX’s rapid prototyping and “testing to failure” approach.
The SN10 lands on the landing site shortly before touchdown. Image Credit: SpaceX
As of today, they’re one step closer to Musk’s long-term vision of regular, affordable space travel to orbit, the moon and mars!
Further reading: SpaceX