Spacex's Starship Rocket Set for Suicide Mission
Why Spacex's Next Rocket Test Will (Probably) End in Flames
Next week, Spacex’s latest Starship prototype is going to attempt a test flight that CEO Elon Musk says it has only a one in three chance of survival. In all probability, Starship will end up in a fiery grave. While this launch test is crucial to the development of the Starship rocket, its “success” or “failure” is not. Here is what can go wrong and why it may not matter anyway.
What is the Starship Rocket?
The Starship rocket is Spacex’s next generation launch vehicle intended to replace the Falcon 9/Falcon Heavy. Starship will be largest rocket ever built, even larger than the Saturn V rocket that took humans to the Moon. Unlike the Saturn V, however, Starship intends to be fully reusable, with both the first and second stages returning to Earth.
What is this Test About?
The Starship prototype that will be flying next week is the 8th iteration and known as “SN8” or Serial Number 8. SN8 is the upper stage of the full Starship rocket. The upper stage will return from orbit much like the Space Shuttle did, reentering the atmosphere on its side, where the surface area is greatest, with a large heat shield taking the brunt of reentry heat.
Unlike the Space Shuttle, however, Starship does not have proper wings or landing gear. Instead, Starship will land vertically using the same engines that propelled it into the heavens. In order to land vertically, however, the craft must reorient itself from falling on its side to falling bottom first….and this will be no easy feat.
What Could Go Wrong?
To do this, the craft has two pairs of “flaps,” that provide stability during reentry. As the rocket approaches the ground, the rear flaps will need to lift upward to reduce drag, helping ease the bottom of the rocket beneath the front. If these flaps are damaged during reentry or otherwise fail to move, the rocket will be doomed.
The rocket will also need to successfully switch from using its (near empty) main fuel tanks to much smaller “header” tanks. These smaller tanks will have less sloshing of fuel that may cause the engines to suck in a bubble of air as the rocket falls. The switch to the header tanks has to occur as the rocket is falling rapidly at an angle, so one can imagine that unexpected issues could arise.
Finally, the three Raptor engines at the base of the craft will need to light simultaneously on cue, something that has proved problematic in prior ground tests. These engines will also have to gimbal (vector their thrust) as much as 15 degrees to fire their exhaust at an angle to complete the rocket reorientation. They will need to do this carefully such they can propel the rocket into a vertical orientation but not overshoot such that the rocket flips the other direction.
If/When it Explodes….What’s Next?
If SN8 explodes or crashes, as is quite likely to happen, it should not be seen in a negative light. The purpose of this test flight is to identify points of failure in the Starship design and modelling. In a sense, failure is a positive development, because it will help Spacex engineers refine the design on future iterations. SN9, a slightly improved iteration of the Starship, is nearly complete and can be modified to feature adjustments to correct for the issues uncovered by SN8. It make take 2-3 lost Starships before this maneuver is perfected, but once it is perfect, few variables stand in the way to affordable access to space.