Aug. 4, 2020, 7PM C.S.T., Boca Chica, Texas, U.S.A. — SpaceX Starship SN5 Hop — a milestone on the path to exploration of the Moon, Mars, and Beyond!

## 14 thoughts on “SpaceX Starship SN5 Hop — a milestone on the path to the Moon, Mars, and Beyond!”

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In the engine compartment video between 0:37 and 0:44 you can see yellow flames burning around the power-head above the combustion chamber. Scott Manley commented “It seems that Raptor might have been leaking, I wonder how long this would have worked for?”

I’m not so sure this is a problem. At that point the vehicle was descending through its own exhaust plume, which would entrain some of the exhaust in the open engine compartment. It’s entirely possible unburned methane and oxygen (either from the exhaust or the atmosphere) was burning, ignited by the heat of the combustion chamber. Combustion in a rocket engine is never complete, and there’s the always the possibility of unburned propellants burning around the engines. This is often seen on launches of the Delta 4 heavy, and I believe I’ve also seen similar burning around the centre engine in SpaceX Falcon 9 landing burns.

A leak from the turbomachinery or combustion chamber would have been at very high pressure and resulted in a jet, not the kind of burning seen here. Such leaks usually turn into a big

kaboomin milliseconds. Here is the Space Shuttle Main Engine “blooper reel” showing many such “incidents”.How expensive per mile was this 500 foot hop?

I hope they finish this soon. I would like to send some people to Mars.

It is always amazing to see the control the rocket has to go straight up and basically straight down.

Progress, one hop at a time. I’m rather impressed with SpaceX right now.

Behold the extraordinary efficiency of the engine! Contrast a SpaceX tight jet with clean shock diamonds versus a NASA disordered debris plume.

I prose the NASA Ecocket in which the first stage reacts carbon dioxide and water to give methane and hydrogen. This self-fuels the second stage burning methane and oxygen to carbon dioxide and water. No polluting net emissions, go anywhere. Though it may cost $billions/year and require decades to reduce to practice, it does afford a pure diversity-hire environment with Human Rights management.

(No Irish need apply)

The pace SpaceX is setting is unbelievable. I am in awe of all the people that have worked to achieve this. God Bless the Team SpaceX !

Brilliant engineering, heroic, but seeing Tic Tacs have their way with US Navy F18s plus my own physics work leads me to view all rocket technology as obsolete. There is a much better way.

Yes, but demonstrate a micronewton net thrust in a vacuum without expelled propellant or radiation pressure and the world will beat a path to your door. With cubesats and piggyback launch opportunities, this is something high school classes can afford to build. If the required materials cannot be fabricated with existing technologies (like, for example, 3 nm feature size integrated circuits), then they are speculative technology and not something upon which one can bet.

As soon as I hear the word “thrust” I reach for my “phasor.” 😉

The kind of warp drive we see in the reports from the US Navy pilots Fravor et-al has nothing to do with thrust.

Thrust pushes the vehicle off a zero g-force geodesic. With thrust the vehicle is moving through space. That is not the case with warp drive. It’s a completely different concept. There is zero thrust in warp drive. It’s not propellent less propulsion in the way that James Woodward in his Mach Thruster conceives it. The third law of action-reaction plays no role at all. Tic Tac is controlling its local zero g-force zero thrust geodesic trajectory by controlling the local curvature of space-time with small amounts of energy. Tic Tac does not move through space at all. It is the space that “moves”. In the Alcubierre toy model, space at the nose of Tic Tac contracts, space at the tail of Tic Tac expands and there is relative motion gl0bally between inside Tic Tac and observers outside Tic Tac’s local gravitational field.

In terms of science fiction it’s like Dune where they “fold space”. Even when Tic Tac makes a sharp turn at thousands of apparent mph, there is zero g-force inside Tic Tac. All of this is consistent with Einstein’s General Relativity. The trick is how to do it with small amounts of energy and I with Professor Keith Wanser (Physics Dept Cal State Fullerton) are now confident we have solved that problem not needing any new physics – all in terms of mainstream elementary (conceptually) physics using a loophole in the coupling of energy to gravity that even Wheeler and Thorne missed because they always set G = c = 1 before they start doing calculations.

Hey Sarfatti – the zero emissions/net thrust “engine” was Phong shading (light prsesure).

http://arxiv.org/abs/gr-qc/0205059

… Pioneer anomaly

http://arXiv.org/abs/gr-qc/0307042

… Rationalized Pioneer anomaly

http://arXiv.org/abs/gr-qc/9810085

… Believable rationalized Pioneer anomaly

http://arXiv.org/abs/gr-qc/gr-qc/0310088

… Believable Pioneer anomaly updated

http://www.arxiv.org/abs/gr-qc/0411020

… Pioneer anomaly

http://arXiv.org/abs/physics/0502123

… Commentary on Pioneer anomaly minutia

http://arXiv.org/abs/gr-qc/0506139

http://math.ucr.edu/home/baez/open.questions.html

http://arxiv.org/abs/0710.2656

… 1/3 modeled away

http://arxiv.org/abs/1103.5222

… End of anomaly – Phong shading

http://arxiv.org/abs/1107.2886

… Anomalous slowing is slowing as Pu-238 decay decays.

Physics + diversity = diversity.

PS, the problem is one of condensed matter physics to find the right kind of artificial solid that has the desired electromagnetic susceptibility resonances when pumped by an external electromagnetic field into a non-thermodynamic equilibrium state. This resonance and its associated phase shift between the input electromagnetic pump field and the gravity output it induces via Einstein’s gravity field equation does the low energy trick.

Output gravity tensor field

~ (G/c^4)(Material EM Susceptibility Field) x Stress Energy tensor of EM pump input x cos(phase shift)

For a fixed desired output, as the Susceptibility Field Resonant Peak increases, the amount of Stress-Energy input decreases.

Formally

z = xy with z fixed increase x, decreases y

Additional trick, because of dissipation in the input photon-material electric charge interactions (inelastic scattering) shifting the phase changes sign of the cosine switching back and forth between attractive gravity and repulsive anti-gravity at different locations in the material as required by the warp drive metric models in the literature.

Designing such a material is analogous to getting the right isotopes for the bombs in the Manhattan Project in terms of scale of effort.

Sorry Uncle Al, but I could not understand the relevance of anything you cited. Pioneer Anomaly has nothing to do with anything I am working on. Not in same ball park.

Again, as soon as I hear the word “thrust” I reach for my phasor. Thrust, whether with propellant or not, is completely orthogonal to the metric engineering physics of warp drive Tic Tac Tech. You must divest yourselves from “common sense” of motion through space. In warp drive you do not move through space, you control the curvature of space and time that surrounds you. Tic Tac Tech is for us Time Lords. We are Q. 😉

Some useful references.

arXiv:gr-qc/0009013 [pdf, ps, other]

gr-qc

doi10.1088/0264-9381/11/5/001

The warp drive: hyper-fast travel within general relativity

Authors: Miguel Alcubierre

Abstract: It is shown how, within the framework of general relativity and without the introduction of wormholes, it is possible to modify a spacetime in a way that allows a spaceship to travel with an arbitrarily large speed.

By a purely local expansion of spacetime behind the spaceship and an opposite contraction in front of it, motion faster than the speed of light as seen by observers outside the disturbed region is possible. The resulting distortion is reminiscent of the “warp drive” of science fiction. However, just as it happens with wormholes, exotic matter will be needed in order to generate a distortion of spacetime like the one discussed hereWhen we study special relativity we learn that nothing can travel faster than the speed of light. This fact is still true in general relativity, though in this case one must be somewhat more precise: in general relativity, nothing can travel locally faster than the speed of light.

Since our everyday experience is based on an Euclidean space, it is natural to believe that if nothing can travel locally faster than light then given two places that are separated by a spatial proper distance D, it is impossible to make a round trip between them in a time less than 2D/c (where c is the speed of light), as measured by an observer that remains always at the place of departure. Of course, from our knowledge of special relativity we know that the time measured by the person making the round trip can be made arbitrarily small if his (or her) speed approaches that of light. However, the fact that within the framework of general relativity and without the need to introduce non- trivial topologies (wormholes), one can actually make such a round trip in an arbitrarily short time as measured by an observer that remained at rest will probably come as a surprise to many people.

Here I wish to discuss a simple example that shows how this can be done. The basic idea can be more easily understood if we think for a moment in the inflationary phase of the early Universe, and consider the relative speed of separation of two comoving observers. It is easy to convince oneself that, if we define this relative speed as the rate of change of proper spatial distance over proper time, we will obtain a value that is much larger than the speed of light. This doesn’t mean that our observers will be travelling faster than light: they always move inside their local light-cones. The enormous speed of separation comes from the expansion of spacetime itself.

1

1 This superluminal speed is very often a source of confusion. It is also a very good example of how an intuition based on special relativity can be deceiving when one deals with dynamical spacetime

The previous example shows how one can use an expansion of spacetime to move away from some object at an arbitrarily large speed. In the same way, one can use a contraction of spacetime to approach an object at any speed. This is the basis of the model for hyper-fast space travel that I wish to present here: create a local distortion of spacetime that will produce an expansion behind the spaceship, and an opposite contraction ahead of it. In this way, the spaceship will be pushed away from the Earth and pulled towards a distant star by spacetime itself. One can then invert the process to come back to Earth, taking an arbitrarily small time to complete the round trip. …

This implies not only that the spaceship moves on a timelike curve, but also that its proper time is equal to coordinate time. Since coordinate time is also equal to the proper time of distant observers in the flat region, we conclude that the spaceship suffers no time dilation as it moves. It is also straightforward to prove that the spaceship moves on a geodesic. This means that

even though the coordinate acceleration can be an arbitrary function of time, the proper acceleration along the spaceship’s path will always be zero.physics.pop-ph gr-qc

The Blue Box White Paper

Authors: Benjamin K Tippett, David Tsang

Abstract: This white paper is an explanation of Ben and Dave’s TARDIS time machine, written for laypeople who are interested in time travel, but have no technical knowledge of Einstein’s Theory of General Relativity. The first part of this paper is an introduction to the pertinent ideas from Einstein’s theory of curved spacetime, followed by a review of other popular time machine spacetimes. We begin with an introduction to curvature and lightcones. We then explain the Alcubierre Warp Drive, the Morris-Thorne wormhole, and the Tipler cylinder. We then describe the Traversable Achronal Retrograde Domain in Spacetime (TARDIS), and explain some of its general properties. Our TARDIS is a bubble of spacetime curvature which travels along a closed loop in space and time. A person travelling within the bubble will feel a constant acceleration. A person outside of the TARDIS will see two bubbles: one which is evolving forwards in time, and one which is evolving backwards in time. We then discuss the physical limitations which may prevent us from ever constructing a TARDIS. Finally, we discuss the method through which a TARDIS can be used to travel between arbitrary points in space and time, and the possible dangers involved with exiting a TARDIS from the wrong side. Before we begin, would you like a Jelly Baby?

Submitted 29 October, 2013; originally announced October 2013.

Comments: 17 pages, This is an explanation of a paper at arXiv:1310.7985 – TARDIS is not the zero g warp drive I mean. (Jack) it’s an alternative form of metric engineering.

gr-qc astro-ph.CO astro-ph.HE

doi10.1103/PhysRevD.85.064024

The Alcubierre Warp Drive: On the Matter of Matter

Authors: Brendan McMonigal, Geraint F. Lewis, Philip O’Byrne

Abstract:

The Alcubierre warp drive allows a spaceship to travel at an arbitrarily large global velocity by deforming the spacetime in a bubble around the spaceship. Little is known about the interactions between massive particles and the Alcubierre warp drive, or the effects of an accelerating or decelerating warp bubble. We examine geodesics representative of the paths of null and massive particles with a range of initial velocities from -c to c interacting with an Alcubierre warp bubble travelling at a range of globally subluminal and superluminal velocities on both constant and variable velocity paths. The key results for null particles match what would be expected of massive test particles as they approach +/- c. The increase in energy for massive and null particles is calculated in terms of v_s, the global ship velocity, and v_p, the initial velocity of the particle with respect to the rest frame of the origin/destination of the ship. Particles with positive v_p obtain extremely high energy and velocity and become “time locked” for the duration of their time in the bubble, experiencing very little proper time between entering and eventually leaving the bubble. When interacting with an accelerating bubble, any particles within the bubble at the time receive a velocity boost that increases or decreases the magnitude of their velocity if the particle is moving towards the front or rear of the bubble respectively. If the bubble is decelerating, the opposite effect is observed. Thus Eulerian matter is unaffected by bubble accelerations/decelerations. The magnitude of the velocity boosts scales with the magnitude of the bubble acceleration/deceleration. △ LessSubmitted 25 February, 2012; originally announced February 2012.

gr-qc physics.pop-ph

doi10.1007/s10714-011-1289-0

Detailed study of null and time-like geodesics in the Alcubierre Warp spacetime

Authors: Thomas Müller, Daniel Weiskopf

Abstract:

The Alcubierre warp spacetime yields a fascinating chance for comfortable interstellar travel between arbitrary distant places without the time dilation effect as in special relativistic flights. Even though the warp spacetime needs exotic matter for its construction and is thus far from being physically feasible, it offers a rich playground for studying geodesics in the general theory of relativity. This paper is addressed to graduate students who have finished a first course in general relativity to give them a deeper inside in the calculation of non-affinely parametrized null and time-like geodesics and a straightforward approach to determine the gravitational lensing effect due to curved spacetime by means of the Jacobi equation.Both topics are necessary for a thorough discussion of the visual effects as observed by a traveller inside the warp bubble or a person looking from outside. The visual effects of the traveller can be reproduced with an interactive Java application.△ LessSubmitted 28 July, 2011; originally announced July 2011.

SN6 test nearing. SN7 has a new tank construction and will be destructively tested. Sn5 may be flown again but needs significant repairs. The last begs the question of whether SN6 hop may be delayed to robustify the landing legs.

https://www.popularmechanics.com/space/rockets/a33596956/spacex-starship-prototypes-sn6-sn7-updates/