The past week has been pretty eventful for
SpaceX.
On Tuesday, Aug. 27th at 05:00 PM local time
06:00 PM EST, the company conducted its second
free-flight test of the Starship Hopper, which
saw the test vehicle successfully ascend to
150 m (500 ft) above the ground and then land
in a different spot.
This test brings SpaceX one step closer to
orbital tests with their full-scale prototypes
of the Starship.
‘Congrats SpaceX team!’
Elon Musk wrote .
‘One day Starship will land on the rusty
sands of Mars.’
About eight hours later, he then realized
it resembled ‘R2D2’s Dad’ and told the
world about this revelation in a tweet.
But it was what came shortly after this successful
test that has people buzzing right now.
A day after SpaceX's final flight of Starhopper,
company founder Elon Musk dropped a clue about
his super-size plans for the future.
Musk tweeted on Wednesday, 28th August that
he'll present SpaceX's latest thinking about
the Starship system on September 28.
The date marks the 11th anniversary of the
company reaching orbit for the first time
with its Falcon 1 rocket.
Until then, most of what we know about SpaceX
Starship comes from Musk's latest presentation
from September 2018.
At that time, the vehicle was still called
the "Big Falcon Rocket" and was supposed to
be made out of carbon-fiber composites.
SpaceX is now using stainless steel but appears
to be keeping similar dimensions, based on
several renderings posted by Musk, including
SpaceX Starship spaceship on the moon and
Mars surface.
Those dimensions suggest the first operational
version of SpaceX Starship would be a vehicle
about 30 feet (9 meters) wide and 387 feet
(118 meters) tall.
Yet Musk is already dreaming up an even bigger
version of SpaceX Starship.
In this video Engineering Today will discuss
Elon Musk “NEXT GENERATION” craft that
could be 8 Times Bigger than SpaceX Super
Heavy Starship.
Let’s get into details.
SpaceX is currently in the process of assembling
the first full-fidelity prototypes of Starship.
Two prototypes – Mk1 and Mk2 – are simultaneously
being built in Texas and Florida, respectively,
while the beginnings of the first Super Heavy
prototype has visibly begun to take shape
at SpaceX’s Florida campus.
The SpaceX Starship Mk1 and Mk2 are expected
to begin test flights to suborbital altitudes
in the near future.
On Twitter, as Musk was sharing drone footage
of the final Starhopper test, he mused about
how big SpaceX’s next super-heavy launch
system would be.
The statement was made on Wednesday, Aug.
28th at 07:34 PM EST and was issued in response
to a question by one of Musk’s many followers
on Twitter.
Specifically, they wanted to know if Musk
planned on building a larger version at some
point in the future that would more akin to
the SpaceX Starship’s original design.
When asked if future versions measure be 12
m (40 ft) in diameter, which was specified
in the initial design of the SpaceX Starship
– then known as the Interplanetary Transport
System (ITS), or if the engine technology
would be upgraded.
Hinted at in a brief tweet on that day, SpaceX
CEO Elon Musk says that SpaceX’s massive
Starship and Super Heavy launch vehicle could
eventually be followed by a rocket multiple
times larger.
Musk replied “Probably 18m in diameter for
next generation system.”
According to the specifications shared by
Musk during a presentation at SpaceX headquarters
in September of 2018, the Starship element
stands 55 m (180 ft) tall on its own and is
capable of generating 11,500 kN (2,600,000
lbf) of force using its six Raptor engines.
Once complete, SpaceX Starship’s Super Heavy
booster will be the single most powerful rocket
booster ever built, standing at least 70m
(230 ft) tall on its own and capable of producing
as much as 90,000 kN (19,600,000 lbf) of thrust
with 30 250-ton-thrust sea-level-optimized
Raptor engines and 7 200-ton-thrust vacuum-optimized
Raptor engines installed.
Despite its size, orbital-class rocketry in
Earth gravity will almost never fail to benefit
from more thrust; more propellant; more rocket.
In light of this, CEO Elon Musk says that
a theoretical next- next-generation SpaceX
rocket – to potentially follow some years
after SpaceX Starship and Super Heavy – could
be twice the diameter of its predecessors-
the vehicle that is poised to send humans
and cargo to the Moon and to Mars.
Based on Musk’s latest hints, that means
the SpaceX Starship 2.0 could be twice as
large, standing just under 240 m (775 ft)
tall and 18 m (60 ft) wide, literally more
than twice as tall as Saturn V rocket, which
launched the first humans into space, as well
as NASA's forthcoming Space Launch System.
An 18m diameter would also make it the widest
rocket ever built, with Saturn V’s S-IC
first stage measuring 10m wide and the Soviet
Union’s N1 ‘Block A’ first stage measuring
an impressive 17m in diameter at its widest
point.
Simplifying the dimensions of the first-generation
Starship into a cylinder and ignoring its
aerodynamic nosecone gives a finished volume
of about 7.5 million liters.
The same calculation on the next-generation
Starship - assuming its height also doubles-
gives an approximate volume of 60 million
liters.
The area and volume that the diameter implies
leads to some pretty interesting results.
Many will recollect that doubling the diameter
of a circle quadruples its area.
Add in a doubling of height and a theoretical
SpaceX Starship 2.0 would have eight times
the surface area and eight times the propellant
tank volume, requiring roughly eight times
as much thrust and making the vehicle eight
times as heavy as SpaceX Starship 1.0.
A spacecraft of this size would weigh nearly
90 million pounds (40 million kilograms),
and need to over 100 Raptor engines just to
get off the ground.
Potentially occupying the volume says little
about how much payload or people a next-generation
SpaceX Starship could haul into orbit, or
how deep into space such a gigantic spacecraft
could go.
But it's hard not to imagine the answers are
"more, bigger, faster, and farther" since
it could tote that much more fuel and carry
many times more Raptor rocket engines.
Certainly, a nosecone with a diameter as wide
as a basketball court's width is larger than
that of any other planned rocket, and it would
accommodate space telescopes that astronomers
could only dream of right now.
For example, NASA's upcoming James Webb Space
Telescope (JWST) will fold up into a 15-foot-wide
(4.57 meter) fairing of an Ariane 5 rocket
in 2021.
If a next-gen SpaceX Starship is ever realized,
though, it could fit six or more of the $10-billion
space observatories into its fairing at once.
Presumably, that would mean that the next-generation
of SpaceX super heavies would be able to place
payloads up to 1000 tons (2.205 million lbs)
to Low Earth Orbit (LEO), the Moon, and Mars
– provided orbital refueling is an option.
And barring the development of more powerful
engines, roughly 70 Raptors would be needed
SpaceX super heavy to help this rocket take
off!
This would be about twice the payload of the
Sea Dragon.
The Sea Dragon was a 1962 conceptualized design
study for a two-stage sea-launched orbital
super heavy-lift launch vehicle.
The project was led by Robert Truax while
working at Aerojet.
It would have had a payload capacity of 550
tons.
It would have been 150 meters tall and 23
meters in diameter.
Musk's ambition should come as no surprise.
His vision of the future involves humans not
only travelling to Mars but setting up colonies
there - complete with governments, pizza restaurants
and nightclubs.
SpaceX Starship is a key part of this vision,
with the giant rocket supposedly capable of
ferrying up to 100 people at a time to the
Red Planet.
For the time being, SpaceX Starship and Super
Heavy are plenty ambitious on their own, but
it’s unsurprising to hear that SpaceX CEO
Elon Musk already has some thoughts on what
could follow that next-generation launch vehicle
in the new decade.
Granted, this is all speculation at this point.
But one cannot deny that it’s an exciting
prospect.
What’s more, Musk’s allusion to a next-generation
spacecraft that doubles the diameter of the
current SpaceX Starship is in keeping with
his ambitious nature.
As with most things, I guess we’ll just
have to wait and see…
