Could the soon to be launched Falcon Heavy be aimed at Oumuamua

[colbourne]

With a Falcon Heavy rocket due to be launched and no important mission for it planned (other than car delivery to Mars), would it be possible to grab the opportunity and aim to catch up with , film and gather as much information  on the Oumuamua, inter-stellar asteroid that recently passed Earth.

It is probably just a lump of rock but as its 1:10 shape and high rotation rate make it appear an interesting object, apart from it origin probably being from another star.

There are probably no other rockets planned to be launched soon that could undertake this task.

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

[woods170]

With a Falcon Heavy rocket due to be launched and no important mission for it planned (other than car delivery to Mars), would it be possible to grab the opportunity and aim to catch up with , film and gather as much information  on the Oumuamua, inter-stellar asteroid that recently passed Earth.

It is probably just a lump of rock but as its 1:10 shape and high rotation rate make it appear an interesting object, apart from it origin probably being from another star.

There are probably no other rockets planned to be launched soon that could undertake this task.

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

No chance. Oumuamua is leaving the solar system fast. So fast in fact that FH performance is nowhere near the performance required to catch up with Oumuamua.

And having expensive probes sitting around in storage, possibly for decades or even centuries, doesn't make any sense. For now we can make do with our "eyes in the skies" such as Hubble, Spitzer and other orbiting observatories, as well as many execellent ground-based observatories.

[jebbo]

And having expensive probes sitting around in storage, possibly for decades or even centuries, doesn't make any sense. For now we can make do with our "eyes in the skies" such as Hubble, Spitzer and other orbiting observatories, as well as many execellent ground-based observatories.

When LSST comes online, we should detect about 1 a year. This is derived from how long Pan-STARRS took to find 'Oumuamua so the error bars are large. But exceptionally unlikely to be decades.

Even before LSST, we might start finding more, now we know they really exist and start looking in ernest e.g. staring at the solar apex

So once we have a better idea of frequency and the velocity distribution, a probe isn't such a silly idea. After all, these objects are by far the easiest bulk non-solar material we could study.

--- Tony

[woods170]

And having expensive probes sitting around in storage, possibly for decades or even centuries, doesn't make any sense. For now we can make do with our "eyes in the skies" such as Hubble, Spitzer and other orbiting observatories, as well as many execellent ground-based observatories.

When LSST comes online, we should detect about 1 a year. This is derived from how long Pan-STARRS took to find 'Oumuamua so the error bars are large. But exceptionally unlikely to be decades.

Even before LSST, we might start finding more, now we know they really exist and start looking in ernest e.g. staring at the solar apex

So once we have a better idea of frequency and the velocity distribution, a probe isn't such a silly idea. After all, these objects are by far the easiest bulk non-solar material we could study.

--- Tony

Emphasis mine.

Never underestimate the power of the word "coincidence". Just sayin'...

[jpo234]

With a Falcon Heavy rocket due to be launched and no important mission for it planned (other than car delivery to Mars), would it be possible to grab the opportunity and aim to catch up with , film and gather as much information  on the Oumuamua, inter-stellar asteroid that recently passed Earth.

It is probably just a lump of rock but as its 1:10 shape and high rotation rate make it appear an interesting object, apart from it origin probably being from another star.

There are probably no other rockets planned to be launched soon that could undertake this task.

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

No way. Somebody did the math: https://www.centauri-dreams.org/?p=38728

One potential mission architecture is to make use of SpaceX’s Big Falcon Rocket (BFR) and their in-space refueling technique with a launch date in 2025. To achieve the required hyperbolic excess (at least 30 km/s) a Jupiter flyby combined with a close solar flyby (down to 3 solar radii), nicknamed “solar fryby” is envisioned.

[Req]

I'm sure FH could easily launch a payload and/or kicker stage capable of catching up using either chemical or electric propulsion, and it would be able to deliver a viable and useful scientific payload mass to the vicinity at some point in the future, but no such payload and/or kicker stage currently exist.  They would take time and money to develop, and it's rather likely that said scientific payload would need an RTG, further complicating things.

[speedevil]

When LSST comes online, we should detect about 1 a year. This is derived from how long Pan-STARRS took to find 'Oumuamua so the error bars are large. But exceptionally unlikely to be decades.

Surveys of old images for finding asteroids often have limits on velocity, for practical reasons.
It is in principle possible to reprocess old images and see if similar objects happen to have been seen, and not realised they are the same object, as the surveys were limited to solar system bound orbits to optimise computation.

[jpo234]

I'm sure FH could easily launch a payload and/or kicker stage capable of catching up using either chemical or electric propulsion...

I don't think so. I doubt that even FH could launch enough chemical fuel to reach the required speed and electric propulsion as in SOLAR electric propulsion is not an option, because 'Oumuamua is already too far out.

[Req]

I'm sure FH could easily launch a payload and/or kicker stage capable of catching up using either chemical or electric propulsion...

I don't think so. I doubt that even FH could launch enough chemical fuel to reach the required speed and electric propulsion as in SOLAR electric propulsion is not an option, because 'Oumuamua is already too far out.

I don't doubt that your link is correct in that a BFS (or a Falcon second stage) could not give itself enough dV.  I am not talking about that at all.  A (for example) 50-ton(possibly multiple stage) kicker for a 250kg payload should have no problem.  WRT SEP, you used the word solar, not me, but that being said, there's no reason solar power couldn't be used for some significant period of time if that made any sense.  And there's always the possibilities of assists, potentially many, depending on how long you'd like to wait.

Edit - Having now read the link, it more or less says the same thing that I am saying.

[IRobot]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

[jpo234]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

[Lar]

With a Falcon Heavy rocket due to be launched and no important mission for it planned (other than car delivery to Mars), would it be possible to grab the opportunity and aim to catch up with , film and gather as much information  on the Oumuamua, inter-stellar asteroid that recently passed Earth.

It is probably just a lump of rock but as its 1:10 shape and high rotation rate make it appear an interesting object, apart from it origin probably being from another star.

There are probably no other rockets planned to be launched soon that could undertake this task.

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

I am not sure FH has the delta V for such an undertaking even with a very tiny probe, due to the dry mass of the second stage itself, so the payload would have to include further propulsion.

I don't think we are quite ready to have probes ready that way either. In a decade or two as we move outward and we see a robust interplanetary civlization developing, it will be far easier...

[IRobot]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

Flight spares is very different from a complete spacecraft.

[jpo234]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

Flight spares is very different from a complete spacecraft.

How is a probe different from a satellite (except for the trajectory)?

[Comga]

This is bordering on silly
Even if a probe was ready an interplanetary trajectory requires a precisely timed launch. That is incompatible with this being the first launch of the FH.
In science fiction books the first flights make great missions. In life, not.

Even if FH could launch a probe to this target, it would need nuclear power, an RTG. There are none available, they have never been given to commercial entities, and the Heavy isn’t rated to launch them and couldn’t be for many launches. Only the Atlas V is, to my knowledge. 

Plus the speed required is excessive. New Horizons, the fastest direct launch ever, did not achieve that velocity. And it used the Centaur, with LOX-LH2, which is much better suited for interplanetary velocities.

And the time to launch would have been last year. If all the impossible conditions were met, launching now and catching up in less than a decade would result in a high speed flyby without more propulsion magic.

And it goes on and on.
It’s a cute coincidence, the first interstellar asteroid flying by the first Heavy being assembled. But that’s as close as they get.

[envy887]

This is bordering on silly
Even if a probe was ready an interplanetary trajectory requires a precisely timed launch. That is incompatible with this being the first launch of the FH.
In science fiction books the first flights make great missions. In life, not.

Even if FH could launch a probe to this target, it would need nuclear power, an RTG. There are none available, they have never been given to commercial entities, and the Heavy isn’t rated to launch them and couldn’t be for many launches. Only the Atlas V is, to my knowledge. 

Plus the speed required is excessive. New Horizons, the fastest direct launch ever, did not achieve that velocity. And it used the Centaur, with LOX-LH2, which is much better suited for interplanetary velocities.

And the time to launch would have been last year. If all the impossible conditions were met, launching now and catching up in less than a decade would result in a high speed flyby without more propulsion magic.

And it goes on and on.
It’s a cute coincidence, the first interstellar asteroid flying by the first Heavy being assembled. But that’s as close as they get.

Such a mission would be interstellar, not interplanetary, so there is no launch "window", just a ridiculously high velocity requirement (that gets worse the longer you wait).

[Jim]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

That was the just the structure.  They were gutted and rebuilt.  Also, they were for the same mission. 

[Jim]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

Flight spares is very different from a complete spacecraft.

How is a probe different from a satellite (except for the trajectory)?

GNC, thermal control, attitude control, etc.  Earth satellites take advantage of being in close proximity to earth

[jpo234]

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

That was the just the structure.  They were gutted and rebuilt.  Also, they were for the same mission.

Thanks for the clarification.

The point was, that one can keep space hardware in storage for a long time. GRACE-FO seems not to be the best example, but I think there are others. CASSIOPE comes to mind, which spent years in storage or the donated NRO space telescopes, one of which will become WFIRST. They were probably built a long time before they were donated to NASA.

I think it would be possible to build and store a general purpose imaging probe that can be launched when an unexpected opportunity arises. I wouldn't be surprised if there are in fact a few of them secretly waiting to be used.

However, to get back on topic, this won't help with 'Oumuamua.

[jpo234]

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

Probes are not inert things that can just be used at any time. As an example, even electronic components deteriorate with time, especially capacitors.

Not to mention that this is not Star Trek and probes must be made for a specific mission. As an example, power requirements differ a lot between missions.

We just learned that the soon to be launched GRACE-FO satellites are the flight spares of the original mission from 2002. That means they spent at least 15 years in storage.

Flight spares is very different from a complete spacecraft.

How is a probe different from a satellite (except for the trajectory)?

GNC, thermal control, attitude control, etc.  Earth satellites take advantage of being in close proximity to earth

I knew and understand this. What I meant in this context is: Why would one be able to keep a satellite in storage waiting for a mission and not a deep space probe?

[whitelancer64]

I knew and understand this. What I meant in this context is: Why would one be able to keep a satellite in storage waiting for a mission and not a deep space probe?

You could. You'd just need to refurbish it before it could fly.

[rakaydos]

With a Falcon Heavy rocket due to be launched and no important mission for it planned (other than car delivery to Mars), would it be possible to grab the opportunity and aim to catch up with , film and gather as much information  on the Oumuamua, inter-stellar asteroid that recently passed Earth.

It is probably just a lump of rock but as its 1:10 shape and high rotation rate make it appear an interesting object, apart from it origin probably being from another star.

There are probably no other rockets planned to be launched soon that could undertake this task.

I also feel that we should have probes ready to be launched at short notice , if an event like this occurs again.

No way. Somebody did the math: https://www.centauri-dreams.org/?p=38728

One potential mission architecture is to make use of SpaceX’s Big Falcon Rocket (BFR) and their in-space refueling technique with a launch date in 2025. To achieve the required hyperbolic excess (at least 30 km/s) a Jupiter flyby combined with a close solar flyby (down to 3 solar radii), nicknamed “solar fryby” is envisioned.

Trajectory simulation provided:

[the_other_Doug]

Unfortunately, when you copy in an XKCD comic, you lose the mouseover text.  In this case, that text was something along the lines of "Besides, we're strictly an Orbiter shop, here."

[mikelepage]

Relinking this from earlier in the thread:
https://www.centauri-dreams.org/?p=38728

Combining all those ideas, it sounds to me like the only (remotely) feasible plan would be:
1) to use (refuelled) cargo BFR to launch probe towards Jupiter, for gravity assist (launch window in 2025).
2) perform "solar fry-by" Oberth boost at distance current thermal technologies can handle:
         - calculated that "fry by" at 3 solar radii would give sufficient kick to achieve rendezvous by itself.
         - perhaps "fry by" is possible with current tech at 30 or 300 solar radii (how close can we go safely?).
         - (I'm picturing a Pica-X coated fairing structure that will jettison after solar encounter)
3) Deploy solar sail technology to make up the difference in delta-V.

EDIT: This probe is going to 8.6 solar radii.
https://www.livescience.com/58023-can-spacecraft-fly-to-the-sun.html

[speedevil]

w in 2025).
2) perform "solar fry-by" Oberth boost at distance current thermal technologies can handle:
         - calculated that "fry by" at 3 solar radii would give sufficient kick to achieve rendezvous by itself.
         - perhaps "fry by" is possible with current tech at 30 or 300 solar radii (how close can we go safely?).

In short - no.
To get any meaningful benefit for this mission, it needs to be very, very close to the sun.
The technology in principle isn't very complicated, it's just that you need many layers of vacuum spaced insulation, which works when the top layer is at ~3500C.
This would be something like a tungsten tile outer shield, with one shiny and one treated side, with niobium foil,, backed up with several layers of spaced stainless until  you get to conventional aluminium/high temperature plastic.
This is not going to be easy to develop.

[sanman]

It’s a cute coincidence, the first interstellar asteroid flying by the first Heavy being assembled. But that’s as close as they get.

Maybe the aliens have been watching SpaceX capabilities progress and decided it was time to take a closer look at this planet. 

[mikelepage]

w in 2025).
2) perform "solar fry-by" Oberth boost at distance current thermal technologies can handle:
         - calculated that "fry by" at 3 solar radii would give sufficient kick to achieve rendezvous by itself.
         - perhaps "fry by" is possible with current tech at 30 or 300 solar radii (how close can we go safely?).
3) Deploy solar sail technology to make up the difference in delta-V.*

In short - no.
To get any meaningful benefit for this mission, it needs to be very, very close to the sun.

*Firstly I've added point 3 back into the quote.  Even a "lightsail" style (32m²) solar sail could add a decent dV to a New Horizon's sized probe.

But I guess I'm confused by your answer.  I've always understood the size of the Oberth effect to be proportional to the velocity of the spacecraft when the burn is made (at perihelion in this instance).  In order to get to the "fry-by"  transfer orbit in the first place you've given your spacecraft a Jupiter gravity assist, so the semi-major axis of that transfer orbit has to be about 2.6 AU.  Given this large semi-major axis, how big a difference does a perihelion distance is 0.014 AU (3 solar radii), versus 0.14 AU (30 solar radii), really make? especially when it can make such a difference to the mass/complexity of your shielding apparatus?

[Pete]

But I guess I'm confused by your answer.  I've always understood the size of the Oberth effect to be proportional to the velocity of the spacecraft when the burn is made (at perihelion in this instance).  In order to get to the "fry-by"  transfer orbit in the first place you've given your spacecraft a Jupiter gravity assist, so the semi-major axis of that transfer orbit has to be about 2.6 AU.  Given this large semi-major axis, how big a difference does a perihelion distance is 0.014 AU (3 solar radii), versus 0.14 AU (30 solar radii), really make? especially when it can make such a difference to the mass/complexity of your shielding apparatus?

The difference in velocity at perihelion between those two orbits is very small(*), less than TWO HUNDRED AND FORTY kilometers per second difference.

_{(*) Just in case it is not obvious, at this point the Sarcasm meter is maxed out}

[Asteroza]

Wonder if you could run a solar thermal propulsion rig of sorts during the fryby, using a propellant cooled sunshield as a propellant boiler for a deep solar oberth maneuver?

[mikelepage]

But I guess I'm confused by your answer.  I've always understood the size of the Oberth effect to be proportional to the velocity of the spacecraft when the burn is made (at perihelion in this instance).  In order to get to the "fry-by"  transfer orbit in the first place you've given your spacecraft a Jupiter gravity assist, so the semi-major axis of that transfer orbit has to be about 2.6 AU.  Given this large semi-major axis, how big a difference does a perihelion distance is 0.014 AU (3 solar radii), versus 0.14 AU (30 solar radii), really make? especially when it can make such a difference to the mass/complexity of your shielding apparatus?

The difference in velocity at perihelion between those two orbits is very small(*), less than TWO HUNDRED AND FORTY kilometers per second difference.

_{(*) Just in case it is not obvious, at this point the Sarcasm meter is maxed out}

Okay.  Thanks for showing your working.*
_{(*)Still maxed out}

For anyone else who actually wants to learn something on this forum without being snarked at, the correct formula to use is as follows:

V= (2GM/r - GM/a)^0.5
where:
r is the current altitude of the craft above the sun, and
a is the semi major axis.

So for a=2.6 (coming from Jupiter gravity assist):
where r is 3 solar radii, V=356km/s
where r is 10 solar radii V=194km/s
where r is 30 solar radii, V= 111km/s

[speedevil]

Wonder if you could run a solar thermal propulsion rig of sorts during the fryby, using a propellant cooled sunshield as a propellant boiler for a deep solar oberth maneuver?

In principle, yes.
Liquid hydrogen, pumped through coolant channels might get quite decent ISP.
But, liquid hydrogen is an extreme pain to keep liquid on the way to the sun, it needs to get quite hot indeed, and the heat exchanger is untried technology that needs to be lightweight, large in area, and work at ~2000C and a thousand PSI without leaking.
And you're still 'only' looking at an ISP of ~1000 or so, which you can effectively get with an extra solid stage.

[Pete]

Okay.  Thanks for showing your working.*
_{(*)Still maxed out}

For anyone else who actually wants to learn something on this forum without being snarked at...

It's hard to judge how much detail to include..
One would expect anyone that quotes Oberth effect, to have a very fundamental understanding of orbital dynamics. At least to the extent of knowing that an orbit at 1/10th the height will be a LOT faster.
This is so true that I initially thought the OP was trolling with his comment of "how big a difference does a perihelion distance is 0.014 AU (3 solar radii), versus 0.14 AU (30 solar radii), really make?", as this comment is in the same class as an airplane enthusiast asking "so why is a f14 faster than a Cessna?".
Doubly so as he also states "or 300 solar radii (how close can we go safely?"
Considering the Earth orbits the sun at a mere 260 sol radii, this is a very, very stupid comment to make.


One presupposes that he actually knows the answer and is being sarcastic/trolling in asking that.

In light of this perceived joking mood I found my reply, including the very tongue-in-cheek comment, to be quite appropriate.

[Pete]

Small P.S.
One may ask why they have selected 3 solar radii as the 'fryby' distance, rather than anything closer.
After all, the sun would already extend over a very large part of the sky, total radiative flux would not increase that much as you get closer.

The simple answer is: at the ludicrous speeds one would be moving at that distance, the solar corona might as well be a solid brick wall. As it extends as a significant presence to about 2.6 radii, and is *highly* variable, even 3 radii is taking a big chance of running into something measurable enough to do damage.

And no, I don't think we have the technology to build anything that can survive at 3 solar radii, except as a passive and heavily-shielded package.
Having to put an active probe there, including supplying it with a few dozen km/s of delta-v ability, is way beyond us.
Remember, that it would have minutes to scant hours only to utilize the full benefit of the close flyby. This precludes all of the efficient high-ISP propulsion methods we normally would use, such as ion drives.
The only thing we have that is in the right ballpark would be Orion (bang-bang, not sts), or a solar-thermal as mentioned in a post above.
While both of these are conceptually possible, we are a very,very long way from having working designs for them, in the sort of environment where they would be needed.

[envy887]

But I guess I'm confused by your answer.  I've always understood the size of the Oberth effect to be proportional to the velocity of the spacecraft when the burn is made (at perihelion in this instance).  In order to get to the "fry-by"  transfer orbit in the first place you've given your spacecraft a Jupiter gravity assist, so the semi-major axis of that transfer orbit has to be about 2.6 AU.  Given this large semi-major axis, how big a difference does a perihelion distance is 0.014 AU (3 solar radii), versus 0.14 AU (30 solar radii), really make? especially when it can make such a difference to the mass/complexity of your shielding apparatus?

The difference in velocity at perihelion between those two orbits is very small(*), less than TWO HUNDRED AND FORTY kilometers per second difference.

_{(*) Just in case it is not obvious, at this point the Sarcasm meter is maxed out}

Okay.  Thanks for showing your working.*
_{(*)Still maxed out}

For anyone else who actually wants to learn something on this forum without being snarked at, the correct formula to use is as follows:

V= (2GM/r - GM/a)^0.5
where:
r is the current altitude of the craft above the sun, and
a is the semi major axis.

So for a=2.6 (coming from Jupiter gravity assist):
where r is 3 solar radii, V=356km/s
where r is 10 solar radii V=194km/s
where r is 30 solar radii, V= 111km/s

A larger semi-major axis also increases the fry-by velocity. Using Jupiter to not only change direction but also increase speed, the semi-major axis coming out of the gravity assist could be much larger than 2.6 AU.

[speedevil]

And no, I don't think we have the technology to build anything that can survive at 3 solar radii, except as a passive and heavily-shielded package.
Having to put an active probe there, including supplying it with a few dozen km/s of delta-v ability, is way beyond us.

It doesn't need dozens of km/s (unless you want to rendezvous with the comet).

If we are considering the boost in velocity you get at infinity from a craft falling from infinity, by burning instantaneously at the closest point to the sun, then at three solar radii, with a velocity of 350km/s, a 3.5km/s burn from a solid rocket will get you a factor of ((from wikipedia) , or sqrt(700/3.5) *3.5 = 50km/s excess at infinity.

It's not this good, as this is if you are not trying to modify the trajectory at all, for a jupiter assist this limits you to a very small portion of the sky.
Also, the above calculation is for a parabolic orbit, not a hyperbolic one which a jupiter assist to the sun would get you.

Heat shielding is a really annoying problem, the heat shield on Solar Probe (2005) hit 1900C at 4 solar radii. (solar probe plus is the more recent one going to 8.5 radii that looks like it may launch.

is an image of thermal simulations when hot. Note that's C, not K.
From this study of the now cancelled probe.

The design is 'easy' in principle - you have a cone pointing down towards the sun, which lets it come to a rather lower equilibrium temperature than it might otherwise, as the light is both somewhat reflected by coatings, and only limited exposure to the sun.
Thermal insulators to the back of this shield, which operates at ~400C or so, and radiates the solar gain to space.
And the probe (with the underneath of it very reflective) on non-conductive standoffs within the cone of shadow.

At 3.5 radii, this 'just' gets a little worse.

The design would look something like the above cone, then a stage like the spherical Star 48 solid rocket on top, with a carbon fibre truss out the top to act as a counterweight during thrust.

The mechanical design gets rather harder, as it's got to take several G sideways, with vibration.

There is nothing beyond the laws of physics for even fairly modest solid rockets to do this.
It's just deeply nasty engineering.

[Zed_Noir]

A more relevant question is the Delta-V required to intercept Oumuamua? For a launch in 2020.

[speedevil]

A more relevant question is the Delta-V required to intercept Oumuamua? For a launch in 2020.

Considering direct launch.

From a blog version of the recent paper.

It can be seen that a minimum 𝐶3 exists, which is about 26.5 km/s (703km²/s²). However, this minimum value rapidly increases when the launch date is moved into the future. At the same time, a larger mission duration leads to a decrease of the required 𝐶3 but also implies an encounter with the asteroid at a larger distance from the Sun. A realistic launch date for a probe would be at least 10 years in the future (2027). At that point, the hyperbolic excess velocity is already at 37.4km/s (1400km²/s²) with a mission duration of about 15 years, which makes such an orbital insertion extremely challenging with conventional launches in the absence of a planetary fly-by.

So, at the moment, about 30km/s from LEO.
Falcon heavy launching one of the centre stages, and then being  fully refuelled in LEO,, with a falcon 1 as payload.
(there are issues, which I will neglect)

This may with a following wind get you to 20km/s, and a ton payload, being generous.
That ton payload being three stages of solid rockets might get five kilos to 30km/s - being optimistic.
I am sure you can do a probe that will return some data weighing 5kg and flying by the asteroid at ~10km/s - that this is not precluded by the laws of physics.

But, you're going to need a tiny RTG of some form, and novel optical comms, and you're not going to get much data on a rapid poorly targetted flyby in badly lit conditions.

The above is the sort of thing you can almost justify by handwaving if you avoid looking really hard at any of it.
In reality, you're going to need to put very considerably more thought into this, and it's probably going to either end up as being a large RTG/reactor craft with a big ion engine on the biggest launcher you can find, or something actually preplanned and put in place in advance.

For example, a couple of new horizons type craft hanging around near Jupiter with the ability to use a relatively small kick motor to fall past Jupiter on one side or the other and get quite a large controllable delta-v to have a decent chance of meeting objects like this, combined with a survey network to find them a year before, not a year after apoapsis.

If the question was if we could launch it to intercept the same asteroid if it had its closest appoach next, not last September, the question would be a straightforward yes. (in comparison to the exotic hoops we have to jump through to catch it now)

[Patchouli]

Too bad JIMO was canned as the propulsion technology from it could be used to catch Oumuamua.
I wonder how far did the SAFE-400 get along and could at least the Safe 30 design be brought back into production.

Though another option might be to send a small probe powered by a RTG and use a Caster-30 and a Star-48 as the third and forth stages.

It would already be exiting the solar system very quickly so I'm not sure how much delta V could be added by making use of solar electric propulsion or a solar sail but it might be worth adding.

[Zed_Noir]

A more relevant question is the Delta-V required to intercept Oumuamua? For a launch in 2020.

Considering direct launch.

From a blog version of the recent paper.

It can be seen that a minimum 𝐶3 exists, which is about 26.5 km/s (703km²/s²). However, this minimum value rapidly increases when the launch date is moved into the future. At the same time, a larger mission duration leads to a decrease of the required 𝐶3 but also implies an encounter with the asteroid at a larger distance from the Sun. A realistic launch date for a probe would be at least 10 years in the future (2027). At that point, the hyperbolic excess velocity is already at 37.4km/s (1400km²/s²) with a mission duration of about 15 years, which makes such an orbital insertion extremely challenging with conventional launches in the absence of a planetary fly-by.

So, at the moment, about 30km/s from LEO.
Falcon heavy launching one of the centre stages, and then being  fully refuelled in LEO,, with a falcon 1 as payload.
(there are issues, which I will neglect)

This may with a following wind get you to 20km/s, and a ton payload, being generous.
That ton payload being three stages of solid rockets might get five kilos to 30km/s - being optimistic.
I am sure you can do a probe that will return some data weighing 5kg and flying by the asteroid at ~10km/s - that this is not precluded by the laws of physics.

But, you're going to need a tiny RTG of some form, and novel optical comms, and you're not going to get much data on a rapid poorly targetted flyby in badly lit conditions.

The above is the sort of thing you can almost justify by handwaving if you avoid looking really hard at any of it.
In reality, you're going to need to put very considerably more thought into this, and it's probably going to either end up as being a large RTG/reactor craft with a big ion engine on the biggest launcher you can find, or something actually preplanned and put in place in advance.
<snip>

Just to be clear. The OP's idea of using the Falcon Heavy demo test flight to intercept Oumuamua seem not feasible.

However as an alternate flight architecture to the one outline by @speedevil.

Put a single engine Centaur on top a complete Falcon Heavy stack enclosed in a RUAG PLF. Launch the Falcon Heavy in the fully expendable mode. Use the Centaur as the Earth Departure stage for a probe similar in mass to the New Horizon spacecraft. Assuming a gravity assist at Jupiter. The probe itself will have a MMRTG power source charging batteries for high power radio transmissions, since the MMRTG only output about 100W electrical power.

Would the probe have enough Delta-V to intercept Oumuamua?

[ThereIWas3]

Gravity assistance from Jupiter is useful if you want to accelerate in the plane of the planets.  I am not sure it is useful in this case where IIRC Oumuamua's path is inclined at 60°.

[AncientU]

Gravity assistance from Jupiter is useful if you want to accelerate in the plane of the planets.  I am not sure it is useful in this case where IIRC Oumuamua's path is inclined at 60°.

I believe that gravity assist is the best way to change the plane of your trajectory, which you'll need if you are going for any gravity assist maneuvers.

[mikelepage]

It's hard to judge how much detail to include..
One would expect anyone that quotes Oberth effect, to have a very fundamental understanding of orbital dynamics. At least to the extent of knowing that an orbit at 1/10th the height will be a LOT faster.

Yeah, I should explain that my misunderstanding was less conceptual and more about just not being very strong on the math of ellipses.  Of course I understand that a circular orbit at 1/10th the height (i.e. 1/10th the semi-major axis) would be a lot faster,  but I had intuitively thought that for two elliptical orbits with the same semi major axis, a difference in perihelion height of less than 5% of the semi-major axis distance, would not make that big a difference.  It didn't help that the online ellipse segment area calculator I used to check my thinking was actually calculating the area from the centre of the ellipse, not the focal point.  Lesson learned.  Sometimes you just gotta learn the math.

Gravity assistance from Jupiter is useful if you want to accelerate in the plane of the planets.  I am not sure it is useful in this case where IIRC Oumuamua's path is inclined at 60°.

I believe that gravity assist is the best way to change the plane of your trajectory, which you'll need if you are going for any gravity assist maneuvers.

Problem with Jupiter is that it's only in position for out-of-ecliptic plane-change maneuvers once every 12 years (and I think we can assume the path of any interstellar interloper is almost definitely out of the ecliptic).  The faster we can get a probe on it's way, the slower it needs to go, and the farther/cooler it's "fryby" perihelion burn can be.  Would be interesting to keep a probe out at EML1/the DSG that was almost fully built and ready to go, maybe with some kind of "plug-in" RTG technology, that meant you could send it on it's way to Jupiter within a few months of finding a target.  Having that kind of capability would make it much less likely that you miss the next 12-yearly Jupiter plane-change window.

[envy887]

Doesn't Jupiter cross every plane intersecting the sun every 6 years?

[Pete]

...  Sometimes you just gotta learn the math.

Or play enough KSP to get an intuitive feel for what is likely.
That game may not teach one the math or the numbers applicable to the Sol-Earth solar system, but it sure does ingrain an intuitive feel for orbital dynamics, despite its abbreviated sim of the physics.

In my case i did actually not know the exact formula for the speed, but i knew that with the aphelion being hundreds of times as far as the perihelion, i could just work with the escape velocity at perihelion altitude. The error would be  well under 1%
And I got escape velocity by the simple expedient of taking orbital velocity times sqrt(2)

At the sort of speed and gravity environment we were discussing, an exact answer would require a brief discussion with relativity, but the answer would still be correct to several decimals.

[mikelepage]

Or play enough KSP to get an intuitive feel for what is likely.

Hmmm, well I have been to the Mun and back several times, but not yet successfully performed a direct entry from Munar return.  Always had to perform a burn at periapsis to kill off the excess energy.  So I knew it was faster compared to low orbit, but can't say I noticed much of a difference in velocity between periapsis heights on my various returns.  Also haven't yet tried to perform an Oberth maneuver to go anywhere else... been busy saving stranded Kerbals 

Doesn't Jupiter cross every plane intersecting the sun every 6 years?

Technically yes, but pretty sure this Jupiter-assist, Solar-Oberth fryby maneuver is only good for trajectories in that plane, which are on Jupiter's side of the solar system.  It's impossible to go after out-of-plane objects on the far side of the sun from Jupiter.

[Jdeshetler]

To get a better sense how fast Oumuamuaa go, how long will it take to reach the same distance from the Sun as Voyager 1 (launched in 1977) which is now 141 AU (2.11×1010 km), approximately 13 billion miles (21 billion km)?

[Pete]

To get a better sense how fast Oumuamuaa go, how long will it take to reach the same distance from the Sun as Voyager 1 (launched in 1977) which is now 141 AU (2.11×1010 km), approximately 13 billion miles (21 billion km)?

Well, Voyager has a V_infinity of roughly 17km/s
Oumuemuaa has a V_infinity of about 26.3 km/s
Voyager is ahead by 2.11e10 km
.
So it should take mr.longname some 2268817204 seconds, or 71.9 years to pass Voyager1's then distance.
Or, it will take roughly 25.4 years to get as far out as Voyager1 is at this date.

The problem is not that we cannot possibly overtake and (flyby) intercept it, the problem is doing so within your lifetime, and while the investigating probe has a realistic chance of beaming answers back.

Also, the speed difference at flyby is of some concern.
If your investigating probe is 20km/s faster than the target, you will only get *at most* 100 seconds of observation from less than 1000km distance, and under one second at a closer distance than 10km, should you wish to attempt that.

[MaxTeranous]

In short, plan for the next one, don't try chasing the last one!

[speedevil]

Gravity assistance from Jupiter is useful if you want to accelerate in the plane of the planets.  I am not sure it is useful in this case where IIRC Oumuamua's path is inclined at 60°.

I was assuming something like a two stage vehicle hanging out in a distant orbit from jupiter, or trojan,  a ~1km/s or so boost to get it headed towards Jupiter, falls inwards from 'infinity' getting ~55km/s or so at perigee, burn then a couple of km/s at perigee, combined with getting to pick which side of jupiter you fall on gets you ~10km/s in a large slice of possible directions, as well as the possibility of just burning in other directions with your 3km/s.

[rakaydos]

Gravity assistance from Jupiter is useful if you want to accelerate in the plane of the planets.  I am not sure it is useful in this case where IIRC Oumuamua's path is inclined at 60°.

I was assuming something like a two stage vehicle hanging out in a distant orbit from jupiter, or trojan,  a ~1km/s or so boost to get it headed towards Jupiter, falls inwards from 'infinity' getting ~55km/s or so at perigee, burn then a couple of km/s at perigee, combined with getting to pick which side of jupiter you fall on gets you ~10km/s in a large slice of possible directions, as well as the possibility of just burning in other directions with your 3km/s.

If I were designing it, have a "launch safe" inactive reactor sitting on the probe. As the primary RTG winds down on the long wait ad long trip, the reactor is activated to provide transmission power to report findings back, and possibly even slow down for intercept.