The Super Heavy is the lower stage of the most powerful rocket ever built, the Starship.
However, despite the massive size and incredible amount of thrust it produces, the
booster has never been involved in an orbital launch!
But SpaceX, the company designing and testing the Starship, has made
numerous updates and added new features to enable the Super Heavy to finally
launch to orbit as early as June 2022!
What is new on the Super Heavy booster, how powerful is the rocket now, and how is
SpaceX testing the mighty booster?
The Super Heavy section of SpaceX’s Starship is a huge feat of engineering and kudos
must be given to Elon Musk for even daring to attempt to build such a massive
structure!
His courage shows that gone are the days complex and cash-intensive
projects had to be bankrolled and supervised by the government!
Of course, Musk is motivated by his desire to set up people living permanently on Mars,
and he has to find a way to transport both cargo and humans across the vast distance
between Earth and the Red Planet.
However, the Starship will have other uses, including launching satellites to orbit and
spacecraft missions like the James Webb Space Telescope, taking astronauts to the
moon and eventually Mars itself, and rapid transportation of humans and cargo right here
on Earth.
Standing at almost 70 meters, the Super Heavy is almost the height of the complete
profile of SpaceX’s current Falcon 9 rocket.
It has a diameter of 9 meters, allowing it to
support the upper stage, also known as the Ship or simply the Starship.
There is enough space for 3400 tonnes of propellant,
which is a combination of sub-cooled liquid methane and liquid oxygen.
The design says it can produce 7590 tonnes of thrust,
enough for a gross liftoff mass of over 3 million kg!
While the Super Heavy has six retractable legs for landing, SpaceX is exploring a
second option for landing, which is by catching it mid-air with a specialized pair of arms
attached to the launch tower.
That would be the heavy object ever caught in history and
even Musk admits it might not work!
However, the thrill is more than enough reward for
the billionaire entrepreneur!
Yes, we just mentioned landing the Super Heavy because it is entirely reusable,
meaning it can handle multiple launches just like the last airplane you flew in!
SpaceX is even targeting multiple flights in a single
day!
While this introduces lots of challenges in the development of the booster, Musk is looking
forward to the massive cost savings!
The design team is already experienced in designing reusable boosters anyway since
the company has been re-flying boosters from its Falcon 9 and Falcon Heavy rockets.
SpaceX is racing against time to get the Super Heavy ready in time for its first orbital
flight.
This important milestone has seen multiple postponements which were no fault of
the company; which shall see more on that later in this video!
However, SpaceX has taken advantage of the delay to make many
important changes to the Super Heavy.
The biggest one is the decision to use a new prototype for the flight.
Previously, the company had intended to conduct the test flight
with Booster 4, but it has now been replaced by Booster 7.
Booster 4 achieved fame when it was coupled with Ship 20 last
year, giving imposing imagery of the whole Starship system.
SpaceX has also scrapped Ship 20 and is now succeeded by Ship 24.
SpaceX started stress-testing the new booster prototype in the middle of April and is the
first to be capable of supporting the new and upgraded Raptor V2 engines.
Each of these engines can produce up to 230 tons of
thrust during liftoff.
Booster 7 will use up to 33 Raptor engines, increasing its performance significantly.
In fact, even with just 20 of the Raptors, the
Super Heavy remains the most powerful booster ever tested!
This informed why SpaceX took its time to reinforce the testing
area, including lots of custom-designed components.
Booster 7 is the first Super Heavy to reach the test stand with secondary ‘header’
tanks meant to store landing propellant.
The upgrade to the test stand was necessary because of the new design of the Super
Heavy.
SpaceX removed its nine-ram setup and modified the stand to support 13 rams,
confirming its new purpose was to test Super Heavy’s new 13-engine thrust section.
Before Booster 7, all Super Heavy prototypes had a similar nine-engine puck and an
outer ring of 20 engines that would attach directly to the rim of each booster’s cylindrical
body.
Altogether, Super Heavy Booster 7 should be producing about 7600 tons 33 engines
should be able to generate 7600 tons of thrust compared to Super Heavy B4’s 5400
tons.
In fact, in hindsight, it is surprising that SpaceX stuck with the Booster 4 for so
long, given the jump in performance that came with its successor!
The stress test involved filling the booster about a third of the way with almost 1000
tons or 2.2 million pounds of liquid nitrogen or
a combination of liquid oxygen and liquid nitrogen.
Once the rocket was fully chilled, the prototype showed clear signs of added
stress as large sheets of ice that had formed on the side of Booster 7’s skin broke apart
and fell off.
However, going by the part of the booster that showed signs of stress, the
areas close to the base, it seems the stress was caused by pressurizing Super Heavy’s
tanks to the point that they began to appreciably deform or all of the structural test
stand’s hydraulic rams simulating Raptor engines.
However, not everything went well, as SpaceX had to move the prototype from the
orbital launch site for some repairs.
While the company did not update the public on the
issues, a leaked photo showed extensive damage inside Booster 7, confirming that the
Super Heavy’s test campaign had been forced to end prematurely.
You can see the photo right now showing a short portion of Booster 7’s liquid methane
transfer tube that runs through the booster’s new liquid oxygen header tank.
The header tank sits inside Super Heavy’s main liquid
oxygen tank at the aft end of the rocket.
Super Heavy’s liquid methane transfer tube allows methane to safely flow through the
main liquid oxygen tank and fuel up to 33 Raptor engines.
When the booster is at full thrust, the tube would need to supply an insane
20 tons or 45,000 pounds of methane per second!
But the tube does more than just pass methane through the oxygen tank in Booster 7.
SpaceX now makes it switch to a header tank mid-flight, using a set of valves that seals
off the major liquid methane tank when it becomes empty.
This will convert the tube into a giant receptacle of liquid methane for boost-back
and landing burns.
However, it was entirely possible that the damage did not occur during the testing itself.
Likely, an operator accidentally closed or opened the wrong valves while draining the
booster’s transfer tube of liquid oxygen or nitrogen.
As the heavy liquid drained from the tube, a lack of pressure equalization could
have quickly drawn a vacuum and caused the tube to implode.
If that was the case, we can imagine the red face on the said
employee or employees!
Some fans thought that was the end of the road for the Booster 7 but SpaceX has
managed to turn things around for the booster by conducting repairs.
The prototype is now back on the orbital launch mount for more
fixtures and additional tests.
SpaceX first completed some tests to confirm Booster 7 is back to normal and carried
out a pair of full cryogenic proof tests.
Following positive results, SpaceX has now commenced installing the new Raptor V2
on Booster 7.
This became clear as the crew started moving the engines to the
megabay assembly building where the booster was housed.
SpaceX observers have made some interesting observations about how SpaceX plans
to go about Booster 7’s static fire tests, judging by the labels on some of the Raptor
engines spotted around the assembly area.
Two of the three engines spotted bear markings that indicate they are Raptor Boost
engines, or RB, which apply to the engines that will occupy the outer ring of the booster.
This suggests that SpaceX wants to install the full set of 33 Raptors on the booster
before kicking off static fire testing.
Many people expected SpaceX to start with maybe up to three Raptor engines and add
more as tests return positive results.
However, it seems SpaceX will risk something going wrong with all 33 engines by testing
them at the same time!
While risky, it will allow the test to move at a brisk pace, as
other components like heat shields and aerocovers can be rapidly installed.
This means we are in for a much faster test process
for Booster 7 than Booster 4.
Let’s hear what you think of SpaceX’s Super Heavy booster in the comment section
below!