Hello! Its Scott Manley here! With a very interesting test rig here.
What I have is four solid rocket boosters.
Now, two of them have the landing gear from aircraft attached to them.
One is deployed, and one is not deployed.
And this one has a bunch of random stuff attached to it.
We have ladders, and struts, and pipes, and lights, and radars, and little bits and pieces here.
This is to demonstrate something which you may not know about.
So I'm just going to launch these, and then switch to them.
Now, the thing to notice is that they're all flying at exactly the same speed.
Despite this one having a bunch of stuff on it, it's traveling at the same speed as the unencumbered one.
In fact, the unencumbered one overheats, and explodes.
Also, whether the landing gear is up or down, out, or deployed or not deployed,
these things are accelerating at the same rate.
though what all this has got in common is that these parts are all physics-less, right, there are a number of parts in the game which
Essentially don't count towards mass or drag in the stock game
That's not to say that they don't count towards drag or mass, when you have perhaps
Farram Areospace installed, but these default parts
They don't do anything.
so adding these parts to your ships will not increase the mass, so that, you know
there's a lot of interesting things to do with these letter
lets take a look at those. Well the first thing I'd like to point out is if you
have the standard capsules they all contain mono-propellant as there
there was a moment where they thought they were going to make all the Kerbals
require these but then the changed that
so now we're left with capsules are having a little bit of extra fuel in
them and normally it is isn't used, but if you stick
RCS thrusters on here then of course those RCS thrusters, they are physics-less
right they do not add to the mass they do not add to your ultimate vehicle weight
but once you have deployed the capsule completely once you have
dropped everything else this thing will still have fuel and
enable you to maneuver it in space you can exploit this to get yourself a
little bit extra Delta V and of course in the new version they have
the mono-propellant engines
Now, bizarrely, I would say the mono propellant engines do not have physics
enabled at this time and this might change but at this time the
mono-propellant engines they don't add mass. So this does lead to a very interesting
bit of physics let's see
ok now you may have built something stupid like this in the past and when
you enable infinite fuel you essentially get ridiculous accelerations which is
pretty cool if I right click on this little seismic accelerator I can
actually see how many g's and pulling and I'm accelerating at about 6 or 7 g's but
that's largely because i'm inside the atmosphere and the atmosphere is slowing me down
now as we ascend through the atmosphere and the atmospheric drag is
removed our acceleration increases all up to, almost, there are just over 30 G's
I guess by the looks of things, 31
yeah we top out at about 30 G's because that's essentially constrained by the
thrust to mass ratio of this engine which has a pretty good thrust-to-mass ratio
So I did a video a while back called the moon or express cheats
challenge and I challenged people to figure out the fastest way to get to the
moon and back and put a flag on it and the winning entries were under 10
minutes so the way he did it wasn't with the giant engines it was with the
sepatrons, now the sepatrons when they are, you know, launched initially
their thrust-to-mass ratio is OK but when they are empty their thrust
their thrust-to-mass ratio is something like a hundred and fifty to one so if you had a
spacecraft made of only sepatrons and it was empty sepatrons then you
could get a hundred fifty G's of acceleration out of them
so what you do is more or less them out around
your rocket like this put a few hundred on there and if you did this an infinite
number of times you would get a hundred fifty G's of acceleration
so here we go we're ready to launch and
oh yes of course we have to enable infinite fuel and off we go
once again
so let's see what the g-meter tells me on this says 20 G's but of course we're
still 10 kilometers up we are generating quite a flare here
up to 20 kilometers and yep 100 G's of acceleration but even a hundred G's of
acceleration
well you would still take three days to reach the speed of light or there abouts
though 107 G I could keep adding these things and get up to 150 G or
get very close but you can't exceed them with any other parts until now
ok so the new engine that was added as the O-10 monopropellant engine that is
physics-less so if I add this to the vehicle if I add eight of them you would
imagine that it would add you know eight times name it would add roughly 0.72 tons, right?
turns out it doesn't add anything so if you put these on and then I'm just going
to adjust the rotation to make sure they're firing straight down
that would give you a peak thrust of
well 20 times 8 that would be 160 but you know what
you can add more and more and more and you can keep adding them and then you
can just keep going as long as you can be bothered
obviously landing on these things can be a little dangerous you can also of
course duplicate these it starts to get a little crazy looking there hopefully
this will be relatively these things will be relatively well aligned because
there is no way I'm going to be able to control the rotation of this thing
let's let's try launching and see how well this thing goes
so because the mass of the engines is not included all that's being added is the
thrust so there is no upper limit on the acceleration you can get from this right
previously every time you added an engine you would add the engines mass but
this engine doesn't do that so let's throttle up our engines we've got
infinite fuel enabled and of course we're going to bring up our display .
name 5 GS and
all right away 300 and something she unfortunately we are rotating a little
here
it takes a little bit of work to get one that doesn't rotate but there we go
we're maxing out out of it
590 unfortunately yet this thing will probably spin itself into an early
create that is quite impressive i have to save you look at it go
world spinning around like something crazy of course that thing can actually
get to the speed of lights in a reasonable amount of time if you could
keep it going straight so yeah if you want you can try flying these things to
the moon or you could try doing some other things and so this is what I came
up with a decided to make a space cool
1 10 the mass therefore one tenth of the engines and one-tenth of the chance of
getting them slightly aligned in there
misaligned and therefore having a space probe that spins itself apart so i
thought how long is it gonna take me to get jool and it turns out that before I
get bored of accelerating I got the ETA down to under two hours and this is more
or less me falling towards jool now you'll notice the velocity is actually
decreasing that's probably because it's in surface velocity mode and you know
the rotation of jool is being added and therefore is decreasing and we point is
we're moving about three to four percent of the speed of light
this is not time accelerated this is the real thing that actually greeted me as
they flew towards the planet jool
you just wait for you see I even get it in an encounter with tile for but a second
second but here we go and we bounce off and fly away at about 15 times the speed
of light
I did not expect that at all look this is a zooming out there you have i've
almost back home in but a fraction of a second
it literally shot me back along my initial encounter vector and the
spacecraft was absolutely fine
it was bizarre and cool at the same time I also thought age attempt to set a new
runway speed record
the problem with this tends to be
staying on the runway there was a lot of things exploding and flying off at
strangers velocities and angles and not all of them in one piece
no I did think that maybe I could just fly this vehicle very close to the
surface and get an estimate of the velocity it would achieve have been
sitting actually on the runway and you know we're in the border of the ballpark
of like 1200 meters per second before I finally gave up and decided to ditch
this but that gave me an idea for another activity
you see accelerating in a straight line offers no particular challenges so i
thought why not try flying in a circle specifically how fast can you fly around
the planet kerbin if you use infinite fuel and if you have whatever part
whatever stop parts available
the trick here is I'm traveling at the roughly 15,000 meters up and you see I'm
moving at 12 kilometers per second note that is much faster than orbital
velocity so instead of wanting to get pulled down by gravity instead i'm
having to point my nose down so I dont
fly off into space and as I fly up higher in the atmosphere the drag drops
and my velocity rises
and I need to nose down even more and somewhere in there there is a balance a
balance where you can go
stupidly fast and stay in orbit around kerbin it's really cool to watch the
skies that thing around here it's it's almost like a time acceleration or
something here it unfortunately this is all in the night side you can see some
stuff flying around just wait until data, daylight arises
there we go there's the Sun and oh and getting altitude little quickly here
look at how fast that it going this is ridiculous
and yeah i think at this point I started to really go too high and too fast so I
after very I'm know it
30 km/s look at this thing, this is ridiculous
flying over the the desert like way too fast now point my nose totally down and
I'll just keeping some control here but also picking up speed
this is a lot of this is this is a great challenge so the question is how fast
can you fly around kerbin in this vehicle or any vehicle and I guess the
challenge is
leave from the Space Center arrived back at the Space Center and have the minimum
amount of time on the clock now even the developers to fix the physics
significance flag for these engines
there will still be a bunch of parts that you can use but a word of warning
to you
physics less parts exist any strange kind of gray area in the physics engine
and sometimes they behave in strange ways such as this little rover which
is entirely constructed from physicsless parts and as I start to roll along
you see it's starting to shake a little
it has the old shimmy the Kraken is getting in on the act and we all know
how this ends
(Maniacal Laughing)
so respect these parts and use their powers for awesome
i'm scott manley fly safe