On Wednesday, May 5, 2021 — 60 years to the day after astronaut Alan Shepard Jr. launched aboard Freedom 7 atop a Mercury-Redstone rocket to become the first American in space — SpaceX hit it out of the park, ushering in the age of practical space travel.
Starship Serial Number 15 (SN-15), 160 feet of gleaming stainless steel rocket, and the first in the new series of orbital prototypes, blasted off from Star Base Boca Chica and majestically soared into the sky, punching through the thick overcast under the power of three redesigned raptor engines.
SN-15 sequentially shut off its engines as it neared its six-mile apogee. Hovering briefly as its last engine shut down, the ship dropped back towards Earth, descending under the active aerodynamic control of its upper- and lower-wing flaps. Flipped to the horizontal (Starship’s signature “belly flop” maneuver), SN-15 was steered by its onboard computer back to Boca Chica. Seconds from landing, all three engines reignited, flipping the ship to back to a vertical position. The engines throttled back, landing legs deployed, and SN-15 gently touched down on its assigned landing pad adjacent to its launch mount with pinpoint accuracy at T + 06:00 minutes.
This was the fifth high-altitude flight test of a Starship prototype, and it was textbook perfect. SpaceX has been working out of that particular textbook for less than two years, writing the first chapter with a tethered flight of its first Starship prototype (Starhopper) on April 3, 2019. In two short years, SpaceX technologies have advanced by leaps and bounds — rising like a phoenix from the often-explosive demise of successive prototypes.
SN-1 imploded during pressure testing, SN-2 successfully tested cryogenic pressurization, SN-3 failed during pressurization, and SN-4 exploded during static fire testing. SN-5 successfully “hopped” untethered, reaching 150 meters. SN-6 duplicated SN-5’s successful hop just a few weeks later. SN-7’s fuel tank was tested to failure.
On December 9, 2020, SN-8 blasted off, soared over six miles into the sky, reoriented to horizontal, flew back to Boca Chica, and exploded when it landed “too hard” on its designated landing platform. SN-9, SN-10, and SN-11 repeated SN-8’s successful flight and return — each ending in a ball of fire.
The whole purpose behind these suborbital prototypes was to validate launch protocols, engine operation, on-board computer programming, controlled descent, the horizontal flip maneuver, and steered return flight. The incremental steps towards perfecting the final vertical descent and safe landing were icing on the cake. SN-12 through SN-14 were scrubbed as no longer necessary — all sub-orbital goals having been met.
SN-15 is the flagship for the new series of improved orbital Starship prototypes, which incorporate a new enhanced avionics suite, updated propellant architecture, and a new Raptor engine design. The new series will eventually incorporate three additional Raptor engines, calibrated for operation in low-Earth orbit.
The gleaming rockets that we’ve watched being put through their paces are actually designed to be the second stage of an orbital system that will launch atop a SpaceX Super Heavy rocket.
Standing almost 400 feet tall, the coupled stages will be the world’s most powerful launch vehicle ever developed, ushering in an era of fully reusable transportation systems designed to carry both crew and cargo to Earth orbit, the Moon, Mars, and beyond.
SN-15 could potentially be refueled and relaunched. SN-16 is waiting in the wings.
The first prototype Super Heavy Starship first-stage, designated Booster Number 1 (BN-1), was built to validate construction techniques and is now being disassembled. BN-2 is now being assembled as an orbit-capable launch vehicle. When fully assembled and secured on its launch pad, BN-2 will undergo pressure testing and static fire tests.
If all goes well, the yet-to-be-built SN-20 is scheduled to be mated to BN-3 and launched into orbit as early as July of this year.