I have been experiencing wild imaginings of a particular and frequent celestial visitor as it approaches on its inward path towards the Sun and I have been asking the question: will humanity ever be able to visit it?
Its frozen surface, now a cold, inert and desolate block of ice and dust will reawaken after who knows how many previous close Sun encounters, slowly sparking into a spectacular show at perihelion (closest solar approach), observable yet again from around the planet in a display lighting up the sky.
But my task at hand is far more prosaic, how do I exploit my astrodynamical and engineering skills to solve the problem of meeting and staying with Halley’s Comet as it approaches the Sun and then swings away from it again?
By the time this happens, no-doubt I will have kicked the bucket, but as the epitaph of Sir Christopher Wren states: “Si monumentum requiris, circumspice”, however when this rendezvous actually takes place, my magnificient creations and engineering monuments – including my “Optimum Interplanetary Trajectory Software” (OITS) – will probably be perceived as laughably crude.
And the other question is: will humanity still exist at Halley’s next perihelion in 2061? I have to say, the way things are going with Earth’s most brilliant and arrogant species, the likelihood could well be exceedingly low.
Nevertheless I have, using OITS, designed a trajectory to rendezvous with Halley pre-perihelion meaning we can send a probe to check-it-out and monitor the object through the important close solar encounter and beyond.
There is a straight-forward enough low rocket impulse trajectory to Halley exploiting a Jupiter gravity assist (GA) followed by a Uranus GA taking the probe way beneath the orbital plane of all the planets to catch Halley as it rises upwards from an aphelion which is way below the ecliptic plane.
The DeltaV to match Halley’s velocity is about 4 km/s and I dabbled with the idea of using Nuclear Electric Propulsion (NEP) to apply it.
So I, in conjunction with AI, developed some software which solves the extremely challenging low-thrust optimization problem represented by the NEP rendezvous with Halley in as little thrust time as possible. The solution trajectory and relative speed plots are shown below:
I am tackling the challenging problem of rendezvous by a probe of Halley’s comet using Nuclear Electric Propulsion (NEP), and I am assisted by a very powerful and skillfull contributor in the form of AI.
NEP is a low thrust propulsion method with high ‘bang-for-your-buck’ (or specific impulse as we say in rocketry circles), and is about the only forseeable method of applying the necessary velocity change to match velocities with Halley at the huge distances from the Sun that we have in mind.
I laid down the law as to what approach we should use and that would be exploiting Pontryagin’s Maximum Principle (PMP).
PMP has the advantage of giving the THEORETICAL optimal trajectory, and not just a locally optimal solution contingent on the precise thrust vector formulation. Thus the answer we should get would be indisputably optimum.
But the next question would be, what exactly should we optimize? The obvious candidate is to minimize thrust time and therefore fuel mass-loss, but is not appropriate as a first step for reasons of sensitivity of the solution to the thrust cut-off time, every attempt at this approach failed.
But it was I who came up with the key breakthrough which was to try and maximize positive ‘Vz’.
For those who might be a bit confused at this point (as many of you no-doubt are), what the probe needs to do to catch up with Halley is do a gravity assist of Uranus and then swing downwards, way below the ecliptic plane – that means ‘Vz’ is initially negative, right?
The trouble is Halley is actually travelling upwards with a highly positive ‘Vz’ which means that the probe must do a huge U-turn in deep space, to make sure its velocity aligns with that of Halley.
That is a huge challenge but it so happens that when we applied precisely this objective – to maximize positive Vz achieved by the probe – to the PMP, the solutions began to look extremely promising, and this is no-doubt a massive stepping stone by which the overall aim of rendezvousing with Halley with minimum propellant-usage can be enabled.
The reason for this research shall become clear in the near future.
I have a preprint out on the feasibility of the hypothesis that 1998 KY26 is actually the Phobos 1 probe, go here.
I have already conducted extensive research into this possibility. Essentially, apart from physical similarities, the argument can be condensed into two important findings:
(1) Two ΔVs caused by thrust from the Phobos 1 probe’s engines delivered at two critical epochs can completely account for the differences between the nominal Phobos 1 heliocentric orbit and the known 1998 KY26 orbit, and they would be of a total magnitude within the probe’s known propulsive envelope.
(2) Clustering of observations of 1998 KY26 in its orbit, combined with a fixed attitude of 1998 KY26 due to its rapid spin about a principal axis, could explain the observed nongravitational accelerations (NGAs) as caused by sampling bias and would point to a regular shape for 1998 KY26, such as the spinning Phobos 1 probe.
I refer you to my previous two blogs, here and here.
I am pleased to announce I now have further supportive evidence gleaned by analysing the same light curves studied by Santana-Ros et al.
These light curves are distributed across apparitions of 1998 KY26 shortly after discovery in 1998 and again in 2024. They are the same light curves which enabled Santana-Ros et al to accurately determine the rotational time period of 1998 KY26 as (5.3516 ± 0.0001) minutes, which in turn impacted on the interpretation of radar Doppler measurements bringing the best estimate diameter down to (11 ± 2) m.
I decided to analyse these light curves to ascertain whether they could be reproduced by an approximation of the Phobos 1 spacecraft rapidly spinning about its principal axis (see the Figure for a photo of the probe). I was aided in my research by AI (ChatGPT).
Having conducted this research, the partially surprising find was that yes it could, to within a reasonable uncertainty. However, the even MORE surprising discovery was that when parameters pertaining to the physical appearance of Phobos 1 probe were allowed to be optimized by the software in the sense of minimizing the χ2 of the fitted light curves against the measured light curves; on the whole, they tended to converge to the known values of Phobos 1, or at least to within the precision I could establish from the photos of the probe.
The main unknown was the so-called ‘pole’ of the spinning object, in other words the orientation of the axis about which the object is rotating. As a reminder, an axis in 3D space can be completely defined by only two angles – in this case in the inertially-fixed ecliptic J2000 reference frame – here denoted (𝜆, 𝛽). This reference frame was also used by Santana-Ros et al and Farnocchia et al, with the former determining (𝜆, 𝛽) = (36°, -44°). Farnocchia et al then adopted this pole and researched the possibility the shape could be an oblate spheroid with a positive result as far as the fit against astrometric observations was concerned.
My initial investigation was photometric. Thus, I set about performing a coarse raster scan of (𝜆, 𝛽) against the entire sky of possible values, each time optimizing the candidate spacecraft, so that various design-parameters created as close a match as possible to the 8 light curve groups. I then proceeded with a medium resolution scan around the lead candidates, and then finally a fine scan around the remaining solutions. The eventual spacecraft is shown in the Figure below.
If you examine the light curves, provided below, you can see a close similarity between the patterns in the observed brightnesses (the dots) and the fitted (the solid lines).
I then decided upon a different tack and examined the astrometric data of 1998 KY26, with 260 separate observation points altogether. I wanted to ascertain whether I could produce a better fit to these measurements by assuming that there were additional nongravitational forces on this object, caused by flat surfaces (as would be expected of solar panels) being pushed radially by solar radiation pressure (SRP). Since these panels would most likely also be inclined at an angle to the Sun-radius vector, some degree of normal and transverse accelerations might be expected also.
For 1998 KY26, which was found to have an extremely significant normal-to-orbital-plane acceleration by Seligman et al, this normal force was hard to explain by any mechanism other than shedding of gas or dust through the well-known ‘rocket-effect’, though no such outgassing has ever been observed from 1998 KY26. However the investigation by Farnocchia et al showed that these transverse and orbit-normal forces could be effectively reproduced by SRP and Yarkovsky acting on an idealized oblate-spheroid spinning about its principal axis whose pole was determined by Santana-Ros et al through the photometry alluded to above.
When I conducted my investigation assuming SRP on solar panels with fixed inertial orientation, there was a reduction in the root-mean-square (RMS) residual of the fit by 11% compared to the case with no such NGAs modelled. In other words the solar panel assumption was statistically justified. Furthermore the nature of the equations adopted for this solar panel model meant they were still relevant for a pair of panels rotating about their common normal axis, as was assumed in the photometric analysis above. All this, without even modelling the Yarkovsky acceleration, as was required for Farnocchia et al’s oblate-spheroid case.
Anyway, to summarise, all this adds further weight to the notion that 1998 KY26 is Phobos 1. However, yet again, I must remind you that the JAXA spacecraft Hayabusa2# will be heading its way towards the object to rendezvous with it in July 2031. Let’s wait until then before jumping to any rash conclusions.
By the way, you can look at animations of the Phobos 1 probe at two different phase angles elsewhere on my website, here and here.
Yesterday I looked at another ‘Dark Comet’ – 2016 NJ33 to be precise. We have Doppler radar measurements of this object from Arecibo which have allowed Seligman et al to calculate an approximate diameter of 32 m.
As you may know I have a suspicion that many of these inner population ‘Dark Comets’ are defunct spacecraft mission hardware, like upper stages for example. Could this be the case for 2016 NJ33?
It turns out that its orbital inclination is around 6.6 degrees, which immediately makes it a bit of an outlier for human-launched space junk – only Zond 2 really conforms to this.
There is a problem though – 2016 NJ33 was nowhere near Earth when Zond 2 was launched. In fact when you look at the orbit of 2016 NJ33 going back hundreds of years we find ultimately that it had a resonant 2:3 orbit with the Earth (the ratio wasn’t just commensurate – this was definitely a resonant orbit). This would seem to make it very less-likely technogenic (human technology).
So what ON EARTH could it be? Some force must be causing those significantly non-zero Nongravitational Accelerations (NGAs) with NO VISIBLE OUTGASSING, the hallmark of a Dark Comet. I checked for the likelihood of these calculated NGAs being spurious, this turned out to be exceedingly unlikely.
Another strange feature of 2016 NJ33 is the DIRECTION of its NGAs – mainly radially outward from the Sun, but with a 5% tilt out of its orbital plane. The transverse component is negligible.
The whole thing is a mystery, especially as when you look at the MAGNITUDE of its NGA components, they are of a level expected by Solar Radiation Pressure as opposed to Yarkovsky. I dabbled with the notion of a technosignature, but I feel that may be a step too far. So work is on-going.
The problem of what happens to a binary system of stars as it approaches a Super-Massive Black Hole, is one which can be handled, to a certain extent at least, by Newtonian physics.
Hills predicted in 1988 that it was possible for ONE of the pair of stars in the binary to be ejected at high speed from the overall 3-body system, thus creating a ‘Hyper-Velocity Star’ which since have actually been observed. His assumption was that everything was Newtonian.
Thus I decided to download the n-body integration software libraries known as ‘reboundx’ onto my Linux computer and try to reproduce this so-called ‘Hills Mechanism’.
‘reboundx’ has all the functionality of ‘rebound’ but also extra built-in functions for modelling effects due to ‘General Relativity’ should I need them in the future.
The very concise overview of how my software works can be found here:
Having written the software I decided to find out what ChatGPT might think about it and its feedback was exceedingly positive. In fact it immediately saw the power and flexibility of the tool I had created for scientific study, see below.
I have been studying some very unusual celestial bodies, the ‘dark comets’ which are particular sorts of asteroids exhibiting strange inexplicable forces whilst showing absolutely no observable comae or tails as we might see in true comets. These two phenomena are evident signs that outgassing of volatile materials is taking place from the object’s surface, in turn causing a rocket effect, so can we discount this as happening for these dark comets? Absence of osbervational evidence doesn’t necessarily mean absence in reality.
What I’m finding is a convincing pattern emerging, the evidence is accumulating, but let’s put that aside for the moment and talk about the particular dark comet designated ‘1998 KY26’.
The Japanese Aersopace Exploration Agency (JAXA) is sending a mission to this object, the Hayabusa2 spacecraft, arriving in July of 2031 – but what on Earth will it find?
I have found sound and compelling evidence that this so-called ‘dark comet’, hitherto thought to be a natural object and which has several unusual characteristics, may in fact be a defunct Russian Mars probe lost on its way to the red planet way back in 1988.
Let’s discuss what we have from the historical record.
Phobos 1 was launched on 7th July of 1988.
We know that in late August 1988 the Russians uploaded a faulty command to the Phobos 1 probe, on the way to Mars, causing the spacecraft to lose attitude control on 2nd September 1988.
The Russians must then have lost the orbit of the spacecraft, since they requested the European Southern Observatory (ESO) attempt observe the probe based on its last known course. ESO attempted a sighting 20 days after the loss of the probe, but it was not seen at its predicted coordinates leading them to ask ‘had the probe experienced a faulty rocket fire?’
Through my research I discovered that a rocket fire around loss of mission followed by a second much later on, within the thrust envelope of the probe, could just account for the difference in orbits of the two objects – 1998 KY26 and Phobos 1 – opening up the stunning possibility that they could actually be one-and-the-same object.
But there are further pieces of evidence which add weight to this theory. For instance 1998 KY26 is very small at only 11 metres in diameter, just the length of Phobos 1 from one tip of a solar panel to the other.
1998 KY26 is also unusually reflective for an asteroid which agrees with this object being shiny and man-made.
Note also that HUGE fluctuations in apparent magnitude indicate it is spinning and highly elongated. That fits too – the Phobos 1 probe had a high aspect ratio because it was much narrower than its maximum span of 11 metres.
So will the Hayabusa2 spacecraft find the Phobos 1 probe in 2031? We shall have to wait and see.
For those of you interested, the software I used to reconstruct the possible trajectory that allowed Phobos 1 to morph it into 1998 KY26 was written by me in the ‘C’ programming language and exploiting the REBOUND software library.
REBOUND allows integration of the Phobos 1 trajectory forwards in time using numerical integration techniques and assuming the presence of several gravitating bodies, the key ones in this case being the Sun, Earth and Mars of course (for completeness I modelled all the Solar System planets).
Inputs to the software included the DeltaVs themselves – i.e. the directions and magnitudes of the two velocity increments (or ‘impulses’) and the respective times of their delivery. Output from the software was the displacement between 1998 KY26 and the Phobos 1 probe. This ‘displacement’ was NOT simply the positional discrepancy between the two objects, but a highly significant statistical deviation, based on the known uncertainty in the orbit of 1998 KY26, and taking into account position AND velocity (the so-called ‘Mahalanobis Distance’).
A second software package, NOMAD, as well as a CMA-ES python solver (CMA-ES = Covariance Matrix Adaptation – Evolutionary Strategy) were used to find the combination of inputs leading to the minimum output.
Reassuringly, the total velocity impulse from the solution found by NOMAD and CMA-ES, turned out to be 1.9 km/s, which is just within the Delta-V envelope of the Phobos 1 probe. This probe possessed a thrust module for Mars Orbital Insertion with an impressive momentum-change capability.
Although the solution DeltaV total discovered was 1.9km/s, I am still convinced there is a LOWER DeltaV solution out there yet to be found, I am determined to find it when I have the time.
Look below for Tony Dunn’s simulation of the theoretically feasible trajectory followed by Phobos 1 to make it ‘become’ 1998 KY26.
Avi Loeb is talking about the possibility that the first interstellar object to be discovered travelling through our Solar System (1I/’Oumuamua) may actually be alien technology and that my recent discovery that 1998 KY26 may in fact be HUMAN technology (a defunct Russian spacecraft) increases these chances.
Although I wouldn’t quite be so effusive than Avi is, he has a point in this instance. This raises the probability that 1I/’Oumuamua could be technology quite significantly.
1) 1998 KY26 has curious morphology which has been written off by scientists as natural when it clearly isn’t!
2) 1998 KY26 also has considerable Non-Gravitational Accelerations (NGAs) which were before inexplicable but now can be sensibly ascribed to solar radiation pressure. Ring any bells?
I don’t believe, on balance, that ‘Oumuamua is alien tech, but it certainly strengthens the case for a mission to ‘Oumuamua (Project Lyra) quite considerably.
If I was going to exploit my professional relationship with Avi to achieve an aim, then I would try and convince him that we do indeed need a mission to ‘Oumuamua in the form of Project Lyra – which I have researched extensively with my software OITS – and which he rejects outright of course.
Let’s say we eject a spacecraft with a small velocity decrement in the opposite direction to Earth’s own velocity around the Sun, what will happen to it exactly? It will stay around Earth’s heliocentric orbit since its velocity is close to Earth’s, however we shall assume that the spacecraft flies outside of Earth’s theoretical gravitational sphere of Influence (SoI) and also that it is only affected by the Sun’s gravitational field.
Well the first thing to observe is that the body will gradually drift IN ADVANCE of Earth’s orbit around the Sun. That may seem counter-intuitive but look at it this way. By having a lower velocity relative to the Sun than Earth, that means it will reach a perihelion (closest point to the Sun) slightly lower than Earth’s circular orbit and so the time period, TC of the craft will be shorter than the time period of Earth’s orbit, TE (1 year). Since the time-period of the spacecraft’s orbit is shorter, then that means it will gradually get ahead of Earth. The reasoning is that for every 1 period the spacecraft takes, the Earth will be slightly behind it since its period is longer.
So let’s assume that the time period of the spacecraft is indeed lower than that of Earth’s and allow the spacecraft to creep ahead of Earth until it reaches the so-called Sun/Earth L4 point. For the uninitiated, that sits at exactly 60° (π/3 radians) in advance of the Earth along Earth’s orbit around the Sun. How long would that take exactly?
The answer to this turns out to depend on the velocity with which the object leaves the Earth’s SoI, which we shall equate here to the object’s hyperbolic excess speed relative to Earth.
I have done precisely this research and I generated the following two plots.
In these plots, the red-dashed line represents the 2-body problem we are addressing in this blog post, and for information the dark blue solid line indicates the 3-body model, with the Earth included.
When you look at the 2-body model in the first of these plots you can observe some ridges which are even more evident in the second plot. These turn out to be harmonics. They are also present to a lesser extent in the 3-body simulation.
Let’s look at what is happening a little more deeply.
The synodic period between the craft and Earth,TS, is given by the following expression:
If we wish to reach a point at θ in advance of the Earth in time t, then it follows that approximately:
Let us say we wish to reach the S/E L4 point, thus θ=π/3 , and so:
Furthermore we wish elapsed time to be some integer multiple, n, of the craft’s time period TC, whence:
Inserting this into (1) we get:
Now rearranging to get TC , we find:
Thus:
From (3) & (4), this leads to a time required to reach L4 as:
Let us now determine the theoretical hyperbolic excess speed, V∞, needed at Earth to allow a passage to the L4. We know the time-period of the orbit of the spacecraft, TC, how does that translate to, V∞ ?
First we find from Kepler’s third law that, given the ratio TC/TE, then the ratio of semi-major axes, ac/aE , is given by:
The heliocentric velocity, VC , of the spacecraft when it returns to 1 au is described in the following equation from the well-known orbital energy relationship:
The hyperbolic excess needed at Earth is then:
Using equation (8) and with the identity, T =2 π √(a3/μ) , then we can restate equation (10) in terms of time periods as follows:
The L5 Point.
For this we note that the RHS of (1) & (5) must be changed in sign, like so:
We then follow a similar line of reasoning to arrive at:
For various reasons to do with research, I had to recompute the launch ascent trajectory for the New Horizons mission.
New Horizons was a probe sent to Pluto and took various outstanding images and measurements of this very distant dwarf planet.
But it had to be launched into space in the first place, so how did NASA manage that precisely?
Since Pluto is far away, to get there in any reasonable and practical span of time, required a LOT of speed, which translates to a very powerful launch vehicle, which in turn translates to lots of booster stages.
New Horzions was launched on an ATLAS V launch platform as the first stage, equipped with a full 5 solid strap-on boosters.
Once out of the atmosphere it fired a powerful (high specific impulse) liquid cryogenic booster stage known as a ‘Centaur’.
A Centaur has the advantage that its engine can be stopped at some point (for a coast arc) and then restarted later on at a more propitious moment, very handy for interplanetary missions.
In addition the New Horizons mission had a STAR 48B booster to send the probe from an elliptical Sun-bound orbit to a Sun-escape orbit, towards Jupiter in fact, whereupon a gravity assist would be conducted to arrive at Pluto even sooner.
I show attached two plots of the ground track followed by the mission, one generated by my own software – namely LVAS (Launch Vehicle Ascent Software) – and the other representing the actual ground track which I unearthed from the world wide web.
I was using chatGPT, the smarter than smart AI conversation winner – this things knows everything under the Sun, right?
You may skip this detail as it may be completely opaque to you, but I had asked it for the hyperbolic excess of the New Horizons spacecraft mission to Pluto and it came up with an erroneous answer which only someone with a certain level of insider knowledge – like me – could call-out.
So I did!
And lo-and-behold, it dutifully, magnanimously and rather humbly corrected itself, quoting what I knew to be the right figure instead.
Who’d have thought the day would arrive when humans are actually smarter than AI?
I have woken up at some ungodly hour and what of all things should I be obsessing about? You guessed it – that weird celestial body, to use a word employed many times by H. P. Lovecraft himself, the truly eldritch interstellar object known as ‘Oumuamua.
I occasionaly grasp for a mental image of this extrasolar visitor to our abode, but I dare not fill in the unknown aspects of this celestial body to give me a full picture, though my imagination demands it, my scientific integrity simply does NOT allow it.
All we have is its strange set of observed characteristics, one of which being its tumbling motion. That got me to thinking, what exactly sets off a chaotic tumbling state in a body such as ‘Oumuamua? Many scientists believe the likely explanation is that ‘Oumuamua was struck by an object – possibly in its planetary system of origin, indeed many asteroids in our Solar System experience the same phenomenon and with the same explanation.
But why should ‘Oumuamua have left its natal planetary system in the first place? Possibly the collision was a cause of this, but I think that would be unlikely, more likely gravitational resonances or an encounter with a massive planet in its host planetary system was the cause, after all Jupiter is known to have done exactly this to comets in our own system.
But there is a BIG problem here and I shall endeavour to explain the logic below.
What happens when Jupiter ejects a body is that the body’s so-called hyperbolic excess (its speed reached at a great distance, in other words entering into interstellar space) is very small WITH RESPECT TO OUR OWN SOLAR SYSTEM.
Look at it this way, let’s say you throw a ball gently out of a moving train. It is clearly the case that, although the ball’s velocity relative to the train is small, relative to the ground that ball has a velocity which is almost precisely the velocity of the moving train, so anyone observing that ball on the ground would get a good idea of the velocity of the train by measuring the velocity of the ball.
This should also be the case for ‘Oumuamua, by measuring its velocity in interstellar space, we should be able to get an idea of the velocity of its natal system. But therein lies a big mystery.
What we find is that ‘Oumuamua’s velocity in interstellar space was virtually zero – technically it was very close to the Local Standard of Rest (LSR), which is the mean velocity of all the stars in our vicinity as they rotate around our Galaxy’s centre. Going back to our train analogy, that means the train – or planetary system – it came from had almost zero velocity w.r.t. the LSR. What is the likelihood of that happening? My mind now is cast back to my time as a pupil at Stoke Park Comprehensive school where I impressed my chemistry teacher Dr Brooks with the following deduction.
We were studying what is known as the ‘Maxwell Distribution‘, this is what you get when you plot on the horizontal x-axis the speed of the molecules of a particular volume of gas and on the vertical axis the number of molecules in this volume which have this speed.
What one finds is that there is a peak speed, that is there is a MOST likely speed for a molecule and as the possible speeds increase, the number of molecules with these speeds reduce – in fact the graph decays and approaches zero to the right.
But what happens to the left of this peak in the curve – that is as the speed of the molecules decrease to zero?
What we find is that there is a similar decrease on the left side of the peak until the curve actually touches the horizontal axis, AT THE ORIGIN. Another way of looking at this is that the number of molecules with zero speed is actually zero. This is in line with the observation that the only way a gas could have ANY molecules with no speed is at minimum energy or ABSOLUTE ZERO, which is impossible, right?
Now let’s apply this to ‘Oumuamua’s system of origin which, as we have seen, had almost zero speed w.r.t. the LSR, and make the anaolgy of the speed of stars in the galaxy with the speed of molecules in a gas. A zero speed w.r.t the LSR for a star should actually be exceedingly unlikely, in precisely the way it is for molecules in a gas.
It seems the more you think about ‘Oumuamua the stranger – and more eldritch – it gets.
I am back to dark comets (DCs), mysterious bodies showing signs of an anomalous force upon them but which don’t at all exhibit any signs of outgassing of water or carbon dioxide, since they have no coma or tail to indicate that they could actually be comets.
So they are not asteroids NOR comets, what on Earth could they be?
Well I’m pleased to announce I have ‘bagged’ another of these weird objects as NOT being natural at all, but in fact a NASA probe.
This particular object was observed briefly then disappeared altogether, never to be seen by anyone since.
I think I have the answer to this mystery in that the NASA probe in question was probably applying a thrust to change its orbit whilst and soon after it was being observed by astronomers, who incorrectly ascribed to it an anomalous force, but which was in fact deltaV from the probe’s rockets.
Thus since its orbit changed dramatically, any predictions of where this dark comet (actually NASA probe) would be in the future would be entirely erroneous!
I wanted some ‘Bombay Mix’ urgently (next day)! For those of you unfamiliar with this comestible, this is a savoury Indian snack with nuts, crisp vermicelli, sultanas, and the like.
I now sit here scoffing this dangerously addictive, widely-available, over-the-counter product, in the knowledge that in the wrong hands (actually MY hands), this stuff is deadly.
I have just consumed almost half a 200g bag in the space of 2 minutes, and am SO relieved I did not purchase the ‘PHATTAKA’ option from Amazon, since its name gives a clear indicator of its potency level in terms of chilli content.
In fact I am not a hardened addict, and have sufficient self-control (at the moment at least) to avoid the slippery slide to 100% reliance.
The object known as 2024 YR4 has laid down the gauntlet on humanity. ‘See me outside, or take the consequences!’
The consequences however would not be eternal dishonour and ignominy, but a complacent denial of the existential threat posed by Near Earth Asteroids (NEAs) such as this.
True, a few weeks after its discovery in December 2024, 2024 YR4 was determined to have a zero probability of impacting the Earth in December 2032, yet subsequent to this, it was calculated to have a >4% probability of colliding with the Moon.
With further observations recently by the JWST, any collision of the Moon around this timeline can be totally discounted. Thus this finding has been accompanied by much relief since such an impact would have sent huge quantities of debris up into cislunar space, a fair proportion of this debris showering down upon the Moon’s surface and creating a serious hazard for any astronauts or taikonauts on the Moon at the time.
Even worse, had the impact occurred on a particular region of the Moon (which it quite possibly could have done), this debris would have headed rapidly towards the Earth, possibly stimulating the catastrophic ‘Kessler Syndrome’ if the debris had impacted any artificial satellites. The Kessler Syndrome is a cascade effect where when one satellite is struck, more space debris is generated striking other satellites and so on. Needless to say the consequences to humanity would be dire now we are so reliant on satellite technology.
So it seems humanity can now put this dreadful outcome aside and instead we can legitimately ask what we could do about sending a rendezvous mission to arrive at the asteroid, collect a sample and then return it to Earth?
Indeed a flyby mission is high on the 2022 Planetary Decadal Survey list of priorities:
“The highest priority planetary defense demonstration mission…should be a rapid-response, flyby reconnaissance mission targeted to a challenging NEO, representative of the population (∼ 50–100 m in diameter) of objects posing the highest probability of a destructive Earth impact”
Yet alternatively, a sample collection mission, of the kind conducted by OSIRIS-REx would involve an even higher scientific return and is eminently worth considering.
OSIRIS-REx had a launch mass of 2,110 kg, is there anyway such a mass could be inserted by a launch vehicle into an eventual rendezvous mission to perform similar feats of analysis on 2024 YR4 as OSIRIS-REx did on Bennu?
My software, OITS (Optimum Interplanetary Trajectory Software) has found two possible trajectories which would allow a rendezvous mission to be realised with a launch on a SpaceX Falcon Heavy Expendable vehicle.
A friend Justin Wing Chung Hui, lead singer of the Coventry group, the Duck Thieves, is also a software engineer, and on my request has created animations of a trajectory solved by OITS with 2 Deep Space Manoeuvres (DSMs) and another with 2 Earth Gravity Assists.
So should we act on this discovery and send a sample return mission?
That is not for the likes of Justin and me to decide.
‘Oumuamua is inexorably receding from the sun, travelling farther and farther away as time goes by, it is now well beyond the orbit of Neptune, and even beyond the Kuiper Belt.
The opportunity is ebbing away with every tick of the clock.
I, and others of the i4is team, are trying to stimulate interest in a mission to ‘Oumuamua, but however you care to look at the prospect, it throws up loads of difficulties which are, though challenging, not insurmountable.
Q: ‘Oumuamua is travelling at speeds of 26.3km/s, how can we possibly catch it?
A: We can catch up using gravitational assists and slingshots (Oberth Manoeuvres) of the Sun and Jupiter.
Q: ‘Oumuamua was only visible in telescopes for less than three months and because of limited observations we don’t have an accurate fix on where it will be at intercept distances needed by Project Lyra.
A: With the same sort of LORRI telescope used on-board the New Horizons s/c encountering Pluto, we would be able to detect ‘Oumuamua at the expected distances of intercept. Also using more than one probe would help, in fact various mission architectures exist.
Q: The s/c will be travelling in excess of 20km/s w.r.t ‘Oumuamua, will we be able to image anything?
A: The Earth travels at 30km/s w.r.t. sun, does this prevent us from viewing celestial bodies in our own solar system?
The above are just three questions but there are many, many more associated with Project Lyra. Answering them is a matter of science and engineering, and also creativity and imagination. With all humanity aboard, there would be NO STOPPING US, what is it exactly that is holding us back?
A fair few people of my age and older will remember the American actor Doug McClure and his popularity in the UK as the personification of the brave, handsome and daring adventurer into distant lands inhabited by dinosaurs and other strange creatures, in a fairly long list of British action adventure films made largely in the ’70s.
What can I say? I remember them with a great deal of fondness, but I remind you at the time I was a young and impressionable child with a wild imagination and these films were just up my street. Compared to today the special effects were distinctly low-key and primitive, but that left a lot to the imagination and I was always willing to forgive their crudeness and fill in the deficiencies with creations of my own mind. A man in a monster suit, for instance, was never, ever a man in a monster suit but a monster which happened to look like a man in a monster suit.
The film I show you below, I watched at the ABC cinema on Hertford Street, Coventry, with my good friend Ravinder Bains. I’ve mentioned Ravinder before he was well ahead of me in intelligence at this age and he immediately saw through to the tragic ridiculousness of this film and came out of the cinema trying desperately to stop himself laughing – for me – bless him – for I had taken the film so seriously I was rather indignant at his mocking attitude.
My father who had reluctantly taken us and had patiently watched it as well, actually sided with Ravinder on this and of course looking back at this film with the benefit of hindsight; this truly was a pretty crap, risible, attempt at an action-adventure movie.
Let me put people to rights if they have some idea that what I do is unimportant and even irrelevant. Some even make a comparison with art and culture and try to emphasize how art can transcend the material, that these pursuits have inherent worth and validity as they communicate what can’t be in any other way.
That maybe a point, but in my view it seriously misses THE point.
What I like to do is ask the question, ‘what would we do if we discovered an asteroid will collide with Earth and wipe out humanity?’
Knowledge of STEM would be crucial here in designing a spacecraft, a trajectory, a kinetic impactor to throw the asteroid off course at the calculated optimal time and save humanity.
But what good would art be in comparison? An example course-of-action might be to bring different people together and ask individuals to imagine and paint the asteroid impacting the Earth as a kind of cathartic exercise to make us FEEL better.
There is a stark difference, one is actionable and physically useful, the other is socially and psychologically comforting. One saves the Earth, the other lubricates communication.
They each have a place, and we should do our best to realise that – instead that is of succumbing to the ignorance of ridiculous accusations of uselessness.
An article I wrote for Principium, quarterly publication of the ‘Initiative for Interstellar Studies‘, several years ago now, not long after the first interstellar object passing through our Solar System was discovered, namely, 1I/’Oumuamua.
It’s about how I solved the problem of sending a mission to catch 1I/’Oumuamua using my software, ‘Optimum Interplanetary Trajectory Software’ (OITS), which serendipitously I had already developed just before ‘Oumuamua was discovered.
Do give it a read. It is written for a lay-person though admittedly, perhaps, it doesn’t always succeed in that regard.
Here’s a mission to interstellar object 2I/Borisov from which the stills were taken at the end of the article:
A mission to Near Earth Asteroid designated 2024 YR4 which for a while had a relatively high chance of colliding with the Earth.
This probability has dropped to zero but instead the likelihood of impact with the Moon has gone up – it is now ~ 4 %.
Such a collision would cause debris to fly all over the place and any astronauts – or taikonauts for that matter – on the Moon at the time would have to take evasive measures. Furthermore it would hurl debris into cis-lunar space, and might possibly knock out some Earth satellites, leading to onset of the ‘Kessler Syndrome’.
This animation assumes that the asteroid actually misses the Moon with an associated likelihood of ~ 96 %.
So would a sample return mission be feasible for this object?
It turns out yes, assuming 2 Deep Space Manoeuvres (DSMs) on the way and a launch Characteristic Energy (C3) of ~ 81 km2s-2.
This launch C3 would enable the Falcon Heavy Expendable to loft an OSIRIS-REx mass spacecraft to the necessary interplanetary orbit, this being a previous sample return mission to the asteroid ‘Bennu’.
This was all solved and generated by my ‘Optimum Interplanetary Trajectory Software’ (OITS).
I’ve been setting my software, ‘Optimum Interplanetary Trajectory Software’ (OITS) challenging tasks which take ages to solve but are uniquely solvable by my software.
I am looking at Sample Return missions atm, specifically ones which rendezvous with the target, loiter with it, then return home to Earth. The loiter phase includes a lander being dispatched by the spacecraft, picking up a sample from the asteroid’s surface, and returning to the mother craft. The mother craft then leaves the asteroid and heads home.
The key task astrodynamically speaking is how on Earth do we lower the velocity increment needed to match velocity with the asteroid?
The answer to this question is to be in an orbit as close to that of the asteroid’s as possible.
This means one may have to conduct one or more GAs (Gravity Assists) with Earth, for example, to alter the spacecraft’s orbital path to gradually manipulate it so that its orbital elements are as close as possible to that of the target’s.
This is the challenge I have set OITS, and a massive challenge at that. Results so far are inconclusive since it might well just be a matter of waiting long enough for the solution combination to fully converge.
The solutions I’m getting are tantalizingly close to being viable, I so wish and hope that ultimately there is a way!
