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Project Lyra: Sending a Spacecraft to 1I/’Oumuamua (formerly A/2017 U1), the Interstellar Asteroid

Now that we have determined that the object now known as 1I/’Oumuamua is indeed interstellar in origin, is there any way we could launch a mission to study it? The study below, written by key players in the Initiative for Interstellar Studies (i4is), examines the possibilities. Andreas Hein is Executive as well as Technical Director of i4is, while Nikolas Perakis, a graduate student at the Technical University of Munich, serves as Deputy Technical director. Kelvin Long is president and co-founder of i4is; Adam Crowl, a familiar figure to Centauri Dreams readers, is active in its technical programs. Physicist and radio astronomer Marshall Eubanks is the founder of Asteroid Initiatives; systems engineer Robert Kennedy is president of i4is-US and general chair of the Asilomar Microcomputer Workshop. Propulsion scientist Richard Osborne serves as i4is Director of Technology & Strategic Foresight. Their plan for 1I/’Oumuamua follows. For a more in-depth look, view the paper just released on arXiv at https://arxiv.org/abs/1711.03155.

by Andreas M. Hein, Nikolas Perakis, Kelvin Long, Adam Crowl, Robert G. Kennedy III, Marshall Eubanks and Richard Osborne

A mysterious visitor from our galaxy has entered our solar system. On October 19th 2017, the University of Hawaii’s Pan-STARRS 1 telescope on Haleakala discovered a fast-moving object near the Earth, initially named A/2017 U1, but now designated as 1I/’Oumuamua [1]. This object was found to be not bound to the solar system, with a velocity at infinity of ~26 km/s and an incoming radiant (direction of motion) near the solar apex in the constellation Lyra [2]. Due to the non-observation of a tail in the proximity of the Sun, the object does not seem to be a comet but an asteroid. More recent observations from the Palomar Observatory indicate that the object is reddish, similar to Kuiper belt objects [3]. This is a sign of space weathering. Its orbital features have been analyzed by [2,4].

When will such an object visit us again? In 10 years, 100 years, 1000? We do not know. This could be the only opportunity in a lifetime, or even in a 100 lifetimes to observe an interstellar visitor close by. As 1I/‘Oumuamua is the nearest macroscopic sample of interstellar material, likely with an isotopic signature distinct from any other object in our solar system, the scientific returns from sampling the object are hard to overstate. Detailed study of interstellar materials at interstellar distances are likely decades away, even if Breakthrough Initiatives’ Project Starshot, for example, is vigorously pursued. Hence, an interesting question is if there is a way to exploit this unique opportunity by sending a spacecraft to 1I/’Oumuamua to make observations at close range.

To answer these questions, the Initiative for Interstellar Studies, i4is, has announced Project Lyra on the 30th of October. The goal of the project is to assess the feasibility of a mission to 1I/’Oumuamua using current and near-term technology and to propose mission concepts for achieving a fly-by or rendezvous. The challenge is formidable: 1I/’Oumuamua has a hyperbolic excess velocity of 26 km/s, which translates to a velocity of 5.5 AU/year. It will be beyond Saturn’s orbit within two years. This is much faster than any object humanity has ever launched into space. Compare this to Voyager 1, the fastest object humanity has ever built, which has a hyperbolic excess velocity of 16.6 km/s. As 1I/’Oumuamua is already on its way of leaving our solar system, any spacecraft launched in the future needs to chase it. However, besides the scientific interest of getting data back from the object, the challenge to reach the object could stretch the current technological envelope of space exploration. Hence, Project Lyra is not only interesting from a scientific point of view but also in terms of the technological challenge it presents.

Figure 1: Logo for the i4is initiative Project Lyra

After days of intense work, we are now able to present some preliminary results for reaching the object within a timeframe of a few decades.

Trajectory analysis

Given the hyperbolic excess velocity and its inclination with respect to the solar system ecliptic, the first question to answer is the required velocity increment (DeltaV) to reach the object, a key parameter for designing the propulsion system. Obviously, a slower spacecraft will reach the object later than a faster spacecraft, leading to a trade-off between trip duration and required DeltaV. Furthermore, the earlier the spacecraft is launched, the shorter the trip duration as the object’s distance increases with time. However, a launch date within the next 5 years is likely to be unrealistic, and even 10 years could be challenging, in case new technologies need to be developed. Hence, a third basic trade-off is between launch date and trip time / characteristic energy C3. The characteristic energy is the square of the hyperbolic excess velocity, which can be understood as is the velocity at infinity with respect to the Sun. Nikolaos Perakis (i4is) has captured these trade-offs in Figure 2. The figure plots the characteristic energy for the launch with respect to mission duration and launch date. An impulsive propulsion system with a sufficiently short thrust duration is assumed. No planetary or solar fly-by is assumed, only a direct launch towards the object. The deformations of the velocity curves is due to the Earth’s orbit around the Sun, which results in a more or less favorable position for a launch towards the object. 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.

Figure 2: Characteristic energy C3 with respect to mission duration and launch date.

Apart from the hyperbolic excess velocity at launch, the excess velocity relative to the asteroid at encounter (𝑣∞,2) has to be taken into account since it defines the type of mission that is achievable. A high excess velocity with respect to the asteroid reduces the flight duration but also reduces the time available for the measurements close to the interstellar object. On the other hand, a low value for 𝑣∞,2 could even enable orbital insertion around the asteroid with an impulsive or low thrust maneuver to decelerate the probe. The excess velocity at arrival is plotted in Figure 3 as a function of the launch date and the flight duration. It can be seen that a minimum excess velocity of about 26.75 km/s implies a launch in 2018 and a flight duration of over 20 years. Such value for excess velocity does not prohibit an orbital insertion around ‘Oumuamua. However, this minimum value rapidly increases for later launch dates. A realistic launch date for a probe would be between 5 to 10 years in the future (2023 to 2027). At that point, the required hyperbolic excess velocity for the mission is between 33 to 76 km/s, for mission durations between 30 to 5 years. These values highly exceed the current chemical and electric propulsion system capabilities for deceleration and orbital insertion, and hence a fly-by would be more reasonable.

Figure 3: Hyperbolic excess velocities with respect to mission duration and launch date

Figure 4 shows the approximate distance at which the spacecraft passes the object. For a realistic launch date of 2027 or later, the spacecraft flies past the object at a distance between 100 and 200 AU, which is similar to the distance to the Voyager probes today. At such a distance, obviously power and communication becomes an issue and nuclear power sources such as RTGs are required.

Figure 4: Launch date versus mission duration. Color code indicates the distance at which the spacecraft passes the object

Figure 5 shows a sample trajectory with a launch date in 2025. The orbit of Earth can be seen as a tiny ellipse around the Sun (indicated as a black circle) at the bottom right of the figure. The trajectories of the comet and the spacecraft are almost straight lines.

Figure 5: Sample spacecraft trajectory for a launch in 2025 and an encounter with 1I/‘Oumuamua in 2055

Another thought by Robert Kennedy (i4is) is to not necessarily chase 1I/‘Oumuamua but to prepare for the next interstellar object to enter our solar system by developing the means to quickly launch a spacecraft towards such an object.

Two scenarios are analysed: First a mission with short duration of only a year, leading to an encounter only 5.8 AU from the sun. However the required hyperbolic excess velocity the current launcher capabilities at approximately 20 km/s. Finally, due to the angle of the encounter, a high velocity relative to the asteroid would be expected, amounting to 13.6 km/s, shown in Figure 6.

Figure 6: Trajectory for a launch in 2017 and an encounter in 2018

A mission on the same launch date but with a duration of 20 years is shown in Figure 7. At encounter, the relative velocity of the spacecraft with respect to the object is relatively low (about 600m/s for this specific case), which would be an opportunity for a deceleration maneuver.

Figure 7: Trajectory for a launch in 2017 and an encounter in 2037

To summarize, the difficulty of reaching 1I/‘Oumuamua is a function of when to launch, the hyperbolic excess velocity, and the mission duration. Future mission designers would need to find appropriate trade-offs between these parameters. For a realistic launch date in 5 to 10 years, the hyperbolic excess velocity is of the order of 33 up to 76 km/s with an encounter at a distance far beyond Pluto (50-200AU).

Concepts and technologies

As shown previously, chasing 1I/‘Oumuamua with a realistic launch date (next 5-10 years), is a formidable challenge for current space systems. Adam Crowl (i4is) and Marshall Eubanks (Asteroid Initiatives LLC) have pondered a single launch architecture. Nominally a single launch architecture, via the Space Launch System (SLS) for example, would simplify mission design. However other launch providers project promising capabilities in the next few years. 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. This maneuver is also known under “Oberth Maneuver” [5]. The architecture is based on the Keck Institute for Space Studies (KISS) [6] and the Jet Propulsion Laboratory (JPL) [7] interstellar precursor mission studies. Using the BFR however eliminates the need for multi-planet flybys to build up momentum for a Jupiter trajectory. Instead via direct launch from a Highly Eccentric Earth Orbit (HEEO) the probe, plus various kick-stages, is given a C3 of 100 km²/s² into an 18 month trajectory to Jupiter for a gravity assist into the solar fryby. A multi-layer thermal shield protects the spacecraft, which is boosted by a high-thrust solid rocket stage at perihelion. The KISS Interstellar Medium study computed that a hyperbolic excess velocity of 70 km/s was possible via this technique, a value which achieves an intercept at about 85 AU in 2039 for a 2025 launch. More modest figures can still fulfill the mission, such as 40 km/s with an intercept at 155 AU in 2051. With the high approach speed a hyper-velocity impactor to produce a gas ‘puff’ to sample with a mass spectrometer could be the serious option to get in-situ data.

The above architecture emphasizes urgency, rather than advanced techniques. Kelvin Long (i4is) has thought about using more advanced technologies, for example solar sails, laser sails, and laser electric propulsion could open up further possibilities to flyby or rendezvous with 1I/‘Oumuamua. In the following, first order analyses for solar and laser sail missions are given.

For the solar sail mission, Kelvin assumed a launch from Earth orbit, given a time to launch of 3 to 4 years. The velocity requirement is ~55 km/s, suggesting a lightness number for the mission of 0.15, and a characteristic acceleration of 0.009 m/s2. This requires a sail loading of 1 g/m², advanced materials with light payloads might achieve 0.1 g/m². Given this, for different spacecraft masses assuming a sail loading of σ = 1 g/m² sail design leads to the values shown in Table 1 for a circular and square-shaped sail.

Table 1: Solar sail parameters with respect to spacecraft mass

Spacecraft mass [kg] Sail area [m²] Circular radius [m] Square size [m]

























The most appropriate and practical design would assume a launch in 4 years and a 1 kg spacecraft mass and lower.

Laser-pushed sail-based missions, based on Breakthrough Initiatives’ Project Starshot technology [8–10], would use a 2.74 MW laser beam, with a total velocity increment of 55 km/s, launched in 3.5 years (2021), accelerating at 1g for 3,000s, the probe size would be about 1 gram. It would reach 1I/‘Oumuamua in about 7 years. With a 27.4 MW laser then a 10 gram probe could be used. Higher spacecraft masses could be achieved by using different mission architectures, lower acceleration rates, and longer mission durations. However, with such a laser beaming infrastructure in place, hundreds or even thousands of probes could be sent, as illustrated in Figure 8. Such a swarm-based or distributed architecture would allow for gathering data over a larger search volume without the limitations of a single monolithic spacecraft.

Figure 8: Laser sail swarm (Image credit: Adrian Mann)

Another concept proposed by Streeman and Peck [11] is to send ChipSats into the magnetosphere of Jupiter, then using the Lorentz force to accelerating them to very high velocities of about 3,000 km/s [11–13]. However, controlling the direction of these probes might not be trivial.

An important implication is that once an operational Project Starshot beaming infrastructure has been established, even at a small scale, missions to interstellar objects flying through the solar system could be launched within short notice and could justify their development. The main benefit of such an architecture would be the short response time to extraordinary opportunities. The investment would be justified by the option value of such an infrastructure.

Regarding deceleration at the object, obviously existing propulsion systems could be used, e.g. electric propulsion, though limited by the low specific power of RTGs as a power source. With an intercept distance beyond the Heliosphere, into the pristine Interstellar Medium (ISM) more advanced technologies such as magnetic sails [14,15], electric sails [16], and the more recent magnetoshell braking system [17] are worth investigating. The Technological Readiness of these more advanced technologies is currently low, dependent on breakthroughs in superconducting materials manufacture, but they would multiply the scientific return by orders of magnitude.

The small size of the object and its low albedo will make it difficult to observe it once it has entered deep space again. This means the navigation problem of getting a sufficiently accurate fix on 1I/‘Oumuamua to get close enough to the object to send back useful data is considerable. Due to the positional uncertainty of such a difficult-to-track object, a distributed, swarm-based mission design that is able to span a large area, should be investigated.


The discovery of the first interstellar object entering our solar system is an exciting event and could be the chance of a lifetime or several lifetimes. In order to assess the feasibility of reaching this object, i4is has recently initiated Project Lyra. In this article, we identified key challenges of reaching 1I/‘Oumuamua and ballpark figures for the mission duration and hyperbolic excess velocity with respect to the launch date. In any case, a mission to the object will stretch the boundary of what is technologically possible today. A mission using conventional chemical propulsion system would be feasible using a Jupiter flyby to gravity-assist into a close encounter with the Sun. Given the right materials, solar sail technology or laser sails could be used.

An important result of our analysis is that the value of a laser beaming infrastructure from the Breakthrough Initiatives’ Project Starshot would be the flexibility to react quickly to future unexpected events, such as sending a swarm of probes to the next object like 1I/‘Oumuamua. With such an infrastructure in place today, intercept missions could have reached 1I/‘Oumuamua within a year.

Future work within Project Lyra will focus on analyzing the different mission concepts and technology options in more detail and to downselect 2-3 promising concepts for further development.


[1] The International Astronomical Union – Minor Planet Center, MPEC 2017-V17 : New Designation Scheme for Interstellar Objects, Minor Planet Electronic Circular. (2017). https://www.minorplanetcenter.net/mpec/K17/K17V17.html (accessed November 7, 2017).

[2] E. Mamajek, Kinematics of the Interstellar Vagabond A/2017 U1, (2017). http://arxiv.org/abs/1710.11364 (accessed November 5, 2017).

[3] J. Masiero, Palomar Optical Spectrum of Hyperbolic Near-Earth Object A/2017 U1, (2017). http://arxiv.org/abs/1710.09977 (accessed November 5, 2017).

[4] C. de la F. Marcos, R. de la F. Marcos, Pole, Pericenter, and Nodes of the Interstellar Minor Body A/2017 U1, (2017). doi:10.3847/2515-5172/aa96b4.

[5] R. Adams, G. Richardson, Using the Two-Burn Escape Maneuver for Fast Transfers in the Solar System and Beyond, in: 46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, American Institute of Aeronautics and Astronautics, Reston, Virigina, 2010. doi:10.2514/6.2010-6595.

[6] L. Friedman, D. Garber, Science and Technology Steps Into the Interstellar Medium, 2014.

[7] L. Alkalai, N. Arora, S. Turyshev, M. Shao, S. Weinstein-Weiss, A Vision for Planetary and Exoplanet Science: Exploration of the Interstellar Medium: The Space between Stars, in: 68th International Astronautical Congress (IAC 2017), 2017.

[8] P. Lubin, A Roadmap to Interstellar Flight, Journal of the British Interplanetary Society. 69 (2016).

[9] A.M. Hein, K.F. Long, D. Fries, N. Perakis, A. Genovese, S. Zeidler, M. Langer, R. Osborne, R. Swinney, J. Davies, B. Cress, M. Casson, A. Mann, R. Armstrong, The Andromeda Study: A Femto-Spacecraft Mission to Alpha Centauri, (2017). http://arxiv.org/abs/1708.03556 (accessed November 5, 2017).

[10] A.M. Hein, K.F. Long, G. Matloff, R. Swinney, R. Osborne, A. Mann, M. Ciupa, Project Dragonfly: Small, Sail-Based Spacecraft for Interstellar Missions, Submitted to JBIS. (2016).

[11] B. Streetman, M. Peck, Gravity-assist maneuvers augmented by the Lorentz force, Journal of Guidance, Control, and Dynamics. (2009).

[12] M. Peck, Lorentz-actuated orbits: electrodynamic propulsion without a tether, NASA Institute for Advanced Concepts, Phase I Final Report. (2006). http://www.niac.usra.edu/files/studies/abstracts/1385Peck.pdf (accessed April 18, 2016).

[13] J. Atchison, B. Streetman, M. Peck, Prospects for Lorentz Augmentation in Jovian Captures, in: AIAA Guidance, Navigation, and Control Conference and Exhibit, American Institute of Aeronautics and Astronautics, Reston, Virigina, 2006. doi:10.2514/6.2006-6596.

[14] D. ANDREWS, R. ZUBRIN, Magnetic sails and interstellar travel, British Interplanetary Society, Journal. (1990). http://www.lunarsail.com/LightSail/msit.pdf (accessed April 16, 2016).

[15] N. Perakis, A.M. Hein, Combining Magnetic and Electric Sails for Interstellar Deceleration, Acta Astronautica. 128 (2016) 13–20.

[16] P. Janhunen, Electric sail for spacecraft propulsion, Journal of Propulsion and Power. (2004). http://arc.aiaa.org/doi/abs/10.2514/1.8580 (accessed August 14, 2016).

[17] A. Shimazu, D. Kirtley, D. Barnes, J. Slough, Cygnus Code Simulation of Magnetoshell Aerocapture and Entry System, Bulletin of the American Physical Society. (2017).

Comments on this entry are closed.

  • Jean Schneider November 10, 2017, 11:52

    Note that if, according to some predictions, LSST will detect about one such object per year
    after 2020, Lyra will have better targets by that time.

    • Michael Fidler November 10, 2017, 19:59

      Wasn’t there a wide field space telescope planned that was going to look for asteroids near the sun? If it would of been funded we might catch an interstellar object coming in around the Sun early enough to send a spacecraft head-on to it. There would be no need for a high speed spacecraft to catch up with it and an impactor from the spacecraft could send material from the interstellar object up high to be sampled by the flyby of the main spacecraft. Sounds like it would be a lot cheaper and easier to do and we would have an early warning system for objects on collision course with Earth from the direction of the Sun!

  • andy November 10, 2017, 13:36

    The initial character in the name should be an ʻokina (as also used in the name of the Haumean satellite Hiʻiaka), not an apostrophe/quotation mark. In Unicode this is U+02BB, the right single quotation mark U+2019 is definitely wrong.

  • Alex Tolley November 10, 2017, 14:32

    Lyra – from “When World’s Collide”?

    Did marshall not want his name on the author list?

    The analysis is very interesting. However, the Rx for achieving the goal of

    the scientific returns from sampling the object are hard to overstate.

    seem lost in the various proposals for intercept.

    A 1 kg sail probe is not going to be able to make any sample analysis. Nor are the sail swarms. High power, laser propelled sails are nowhere near ready for prime time, which seems to rule out their use in the needed time frame.

    A larger probe, in the 1 MT class is going to be needed and it will need to be launch soonest with the necessary delta v. At a minimum, a probe with a mass spectrometer could do a sample on a flyby of a projectile was shot into the asteroid and the probe sampled the gas and dust ejecta. Better still would be to add more instruments to do as much analysis as possible during the flyby. Sample return seems unlikely, even with sail technology, so that is the best we can hope for. Planning on the current vapourware status of the BFR being available is dubious, although even the SLS is increasingly looking unlikely to ever be available.
    Even if a suitable probe was available off-the-shelf, getting a launch date might still prove non-trivial, although SpaceX might be the best bet over the next few years with the proven F9. Whether it can carry the needed propulsion systems necessary to achieve the required velocity would need to be looked at.

    Lastly, who is going to develop this project? Is it going to need private funding and support? I cannot imagine NASA or ESA being able to manage such a program in the needed time frame even if either agreed that this should be a priority mission.

    • Paul Gilster November 10, 2017, 15:13

      Glad you caught that, Alex. I’ve added Marshall’s name to the list.

    • Mark Zambelli November 11, 2017, 5:42

      You’re correct to point out how difficult the “doing science” would be with such small sails / probes and I asked myself the same question. One of the better solutions may be to use something akin to the Mars rover ‘Curiosity’s’ ‘ChemCam’ instrument during a (slow as possible) flyby… it might be easy enough to shrink that instrument further to fall within the few kg (mission total) range for such an attempt.

    • David Herne November 11, 2017, 11:10

      The object in ‘When Worlds Collide’ was Zyra.

      • Alex Tolley November 12, 2017, 19:08

        I blame my failing memory for that mistake!

  • Ioannis Kokkinidis November 10, 2017, 14:47

    This is a very interesting study which will certainly be dusted off again when the next interstellar object gets discovered. I have been following the Parker Solar Probe from the time it was the SP+ and the serious trouble it has been having in developing material capable to withstand a flyby at 8 solar radii. Engineering a mission to withstand even more heat at 3 solar radii and the cold of interstellar space is likely to be quite challenging, to say the least. The SpaceX BFR is nowhere near launch readiness so I have been wondering: say that we limit ourselves to the SLS, what is the velocity we can launch a New Horizons weight probe on a direct ascent to Jupiter, and would such a hypothetical probe receive sufficient velocity from gravity assist to catch up to 1U/Oumuamua ?

  • Robin Datta November 10, 2017, 18:57

    How about spacecraft parked at LaGrange points of Earth and other planets / moons performing some observational duties / missions while mostly in hibernation, but ready at a moment’s notice to spring into action to intercept any object, whether from within the Solar system or without?

    And while contemplating setting up such a system, maybe we could use some of the current versions of the Department of Defence’s combat lasers to ablate bits of asteroids for spectroscopic study.

  • Kolyo November 11, 2017, 6:36

    Hey Ioannis,

    You made a great point here. The study is fantastic in terms of ideas, but the feasibility of some of them at next 5-10 years is very doubtful. I think a focus on a well tested architecture like New Horizon is the best bet we can catch this object. The sooner the launch the better. Also very close to Sun passage is also challenging. I didn’t see any calculations for only Jupiter gravity assistance, Is it possible at all? Best chances if it is not possible is to make this fryby maneuver but at bigger distance from the Sun and slow final Interstellar velocity for a possible catch near 200 AU. Seems entering into orbit around the object won’t be possible unless the lunch date is very soon or a very robust ion engine is build to enable deceleration of 5-7 km/s. I think the biggest challenge and possibly the final dead of this project which I don’t want to see will be the lack of very precise trajectory. In case we launch at 26-36 km/s interstellar velocity to something we can’t see and the position error is building with the square of time, there’s no way to catch this thing at a sufficiently close distance. I think we need imediate response from Hubble and VLT teams for additional astrometric observations will it is still possible. If we have a good orbit and multinational efforts with Space X lunch vehicle in place and a direct rebuilding of New Horizon from NASA we may launch in 2-4 years which will make the mission possible otherwise we must be prepared for the next such randevou in 10-100 or 1000 years. I am still optimistic that the rate we can catch such object will be in order of 1 in 10 years, but the calculations some groups did shows that this is way too optimistic.

    • Charlie November 11, 2017, 15:16

      You made a quite interesting comment regarding the fact that astrometric observations would give a more precise trajectory, but you think that a not very precise trajectory can be accomplished in this mission; I tend to disagree with you since I believe that with the use of radar, you can track the object quite well, and determine its position and velocity to a much higher degree than you might think. If such a mission would be realized it might be a good idea to have an radar system on board the craft that would allow the craft to zero in on the targeted asteroid. Just a thought here.

      • Marshall Eubanks November 13, 2017, 0:35

        Radar is always subject to the 1/R^4 decay of power with distance; there was no chance to observe this object with even the terrestrial Goldstone radar (Arecibo is still down).

        Fortunately it looks like there will be both Hubble and Spitzer time allocated to observing 1I, which should improve the astrometry by a factor of 100, crucial to targeting a mission to it (as for an intercept at 50 – 100 AU any probe will be navigating blind until it gets a few million km away).


      • Ioannis Kokkinidis November 13, 2017, 3:17

        Radar consumes too much energy. The energy needed to get a reflection increases with the fourth power of the distance. There is good reason why even Arecibo has not done much radar studies beyond 20 lunar diameters.

  • djlactin November 11, 2017, 9:30

    1I/‘Oumuamua was really big and by passing close to the sun, obvious. I predict that open eyes will spot them regularly, although not on such a convenient trajectory.

  • Kolyo November 11, 2017, 14:06

    Object with 100-500 m diameter can be spotted with conventional high-tech telescopes prepared for wide field surveys like PANSTARRS only up to 22 magnitude and this magnitude for such small size objects mean they can be spotted only up to 20-30 million km from Earth. This make our probe space very limited. If such an objects pass close to Jupiter for example we will never spot them unless the most gigantic telescopes on Earth look at this spot which won’t happen. I see that LSST will improve our capabilities with an order of magnitude at least compared to PANSTARRS but I still think that we won’t see such objects very often. Maybe one in few decades?

  • Randy Chung November 11, 2017, 14:43

    I am very impressed by the amount of work done by i4is’s experts, and how quickly it was done. I can’t think of another volunteer organization that could do this level of analysis and trade study, and doing it in less than a month is remarkable and commendable.

    • Andreas Hein November 11, 2017, 17:03

      Dear Randy,
      Thank you very much for your kind words! The team will be very happy to hear that. We really appreciate it! Best wishes with your start-up! The work I have seen so far was very impressive.

  • Charlie November 11, 2017, 15:06

    To say that this entire prospect is fanciful is probably putting it putting it into the category of perhaps the greatest understatement that is ever been suggested.
    Does everyone here themselves talking? You’re suggesting programs that take on average just 10 years or more just to plan, much less implement into a concrete reality.
    You are anticipating that you can build the spacecraft, either provide it with thermal insulation that will allow a flyby of the sun and at the same time have sufficient amount of propulsive energy to perhaps perform a rendezvous with this object?
    Computationally the entire problem is easily planned out and able to be mapped out, but computations don’t produce actual spacecraft to be designed, built, integrated with the launch vehicle, assemble, that the launch facility and placed on the pad. This would only be in the realm of a realistic proposal if Earth was being threatened by a rogue celestial body and might possibly be able to be diverted by a push from a nuclear device, or perhaps a nudge the vice solar radiation, or some combination thereof to prevent impact with our home planet. But nobody, nobody is going to do this because the fact that you’re interested in seeing what a asteroid looks like from deep interstellar space no matter how scientifically interesting it can possibly be. That being said, it should be noted that this may be possibly our only chance to accomplish this, but I’m very, very skeptical that there would be any ‘political Delta V’ that could be applied to this project that would cause the government to say yes, let’s do this because the scientists want to get a sample of an interstellar body.
    Don’t forget that the economy is far from being in any kind of stable condition and again, the question comes down to who’s going to pay for this and what will necessarily have to be sacrificed to allow this to be implemented and greenlighted. Perhaps this should be planning for the next body that comes from deep space and simply write this off as to too little foresight and failure to plan ahead.

    • DJ Kaplan November 21, 2017, 14:32

      Charlie, it’s pretty clear that this is a mental exercise. The object will be “gone baby gone” by the time humans figure out what to do about it.

    • ajay December 11, 2017, 9:56

      “To say that this entire prospect is fanciful is probably putting it putting it into the category of perhaps the greatest understatement that is ever been suggested.”

      It says “Imagining and Planning Interstellar Exploration” in big letters right at the top of this web page. If you dislike people talking about fanciful space projects, you may be in the wrong place.

      • J. Jason Wentworth December 14, 2017, 10:21

        I concur, and in that same spirit, Oumuamua might be an ideal place to use penetrator probes. Being small and lightweight, yet tough, they could gather surface and subsurface data, take images (the Mars 96 mission’s penetrators [which unfortunately never reached Mars] had imagers as well as instruments), and serve as tracking beacons for the larger “mother” spacecraft, which would enable Oumuamua’s exact “rotation situation” and internal mass distribution to be determined. If necessary, they–and/or the mother spacecraft–could also carry floodlights, strobe lights, or pseudo-white (combined red/blue/green) lasers (and scanning mirrors) to illuminate Oumuamua’s surface for photography.

  • Brett Bellmore November 12, 2017, 12:00

    I wonder if it wouldn’t be possible to power a VASIMR drive with a microwave beam, skipping all power conversion equipment? Might get substantial performance improvements doing that.

  • Curious November 13, 2017, 1:01

    If you realy want to think about this in a serious way I suggest they consider real launch vehicle technology instead of vaporware. (That way you can focus on the probe which will be challenging enough) Run the analysis with something like a Delta IV Heavy as the main launch vehicle with some solid motored 3rd stage. For example look at what the Parker Solar Probe will use https://en.wikipedia.org/wiki/Parker_Solar_Probe

    • Tim Kyger November 13, 2017, 16:40

      Or, for that matter, making more than one launch. A Falcon 9, say, puts the propulsion for the probe into LEO; a second launch of the probe takes it into LEO. Dock the two; light the fire; off ya go.

  • CharlyUY November 13, 2017, 12:18

    Astronomers talk about an “asteroid”, they discarded a cometary like body due to the lack of coma in very stacked pictures at VLT, we have never found asteroid like objets beyond Neptune, TNOs are usually icy bodies, even the spectum captured at Hale telescope does not match exactly the characteristical red like spectrum of the TNOs studied so far, this object is not so red, if our solar system does not show probes of sending rocky asteroids outside towards other stars, how we consider an asteroid from other solar system could scape toward us? so if icy should have shown cometary activity, but nothing found, so rocky, but asteroids at least in our solar system are inner objects, also is the fact to pass so close to the sun without falling into the sun for an erratic object in the milky way, I see too much things with low probability happening toghether for this object, all orbit calculations I suppose were based on an inert object, that is, an object with no possibility to apply any force by itself to modify its trajectory, but if this wouldn’t be the case, orbit calculations could yield to a useless backwards path, not real, just suppose if our Voyager space probes could have the technology to take decision to change their trayectory according the object found in order to avoid collision, an observer in other system with same or lower capabilities than us, could not find a natural matching orbit, unfortunately we didn’t know where the object was in the sky exactly 10 months earlier i.e., astronomers should research stored sky surveys of the past months to try to find the object in the caclulated trayectory for that moment in time. We also hope to see more data from top equipment (HST, ALMA, VLT, etc) in the next weeks, what about radio surveys for this object ?? I have found nothing

  • ljk November 14, 2017, 10:55

    How about this idea as a potential probe for Oumuamua…


    An Impacting Descent Probe for Europa and the other Galilean Moons of Jupiter

  • Michael November 15, 2017, 12:53

    If we had a powerful laser system we could accelerate a light sail probe to high velocity and stop it into an orbit around the asteroid. We would use two sails one which will have the probe attached and second which will be used as the reflecting brake, a powerful laser should still be effective way out. Starshot has so many uses even before going to full power if it is built in modules.

  • Kolyo November 15, 2017, 15:51

    With HST observations planned for later this month and next month we may have much improved orbit and potentially be able to catch it even if the mission started in few years. However there will be significant technical challenges which however seems solvable with current technology only.

  • DJ Kaplan November 21, 2017, 14:27

    Revisiting this to examine one comment:
    “1I/’Oumuamua has a hyperbolic excess velocity of 26 km/s, which translates to a velocity of 5.5 AU/year. It will be beyond Saturn’s orbit within two years. This is much faster than any object humanity has ever launched into space.”

    Now what exactly could have imparted more velocity to this object than anything humans have ever built?

  • Dirac November 26, 2017, 17:10

    Why not resurrect project Orion to have an intercept with this object as it is technically and economically feasible with current technology?

  • GoneToPlaid November 30, 2017, 1:25

    Oumuamua probably has been stripped “clean” after hundreds of thousands or millions of years of flying through the interstellar medium.

    No wonder Oumuamua has an extreme cylindrical shape with a width to length ratio of 1:10 (similar to lunar craters which have a height to width ratio of 1:10 or shallower), a low albedo, and no detectable coma which suggests that what Oumuamua is mostly rock and metals.

    It is assumed that within each star’s heliopause, the solar system within the star’s heliopause has been mostly swept clean. Yet beyond, and into the interstellar medium, is anybody’s guess. The interstellar medium may be much dirtier, and that wouldn’t be particularly surprising. In other words, I am suggesting that Oumuamua originally could have been much larger and much more spheroidal when Oumuamua was ejected from its solar system long ago. If true, then Oumuamua is the derilict remnant of an asteroid which was ejected from its solar system long ago.

    Our star (the Sun) and our solar system are thought to have been born at approximately the same time (over 4 billion years ago) as other nearby stars and solar systems. Thus the chance to examine Oumuamua theoretically could be off scale high in terms of scientific knowledge about not only the history of our own solar system, but also about the solar system from which Oumuamua originates. Oumuamua probably originated from a relatively nearby solar system. Just a guess, but probably not more than 500 light years away, which is very close in terms of the overall size of our Milky Way galaxy. A billion years divided by Oumuamua’s inbound velocity might be a rough maximum bound estimate of potentially how far Oumuamua came from.

    It is hypothesized that such objects pass through our solar system roughly once a year. Yet that hypothesis did not come with any constraints as to the size of such objects like Oumuamua. I suggest that Oumuamua is an off scale high aberration at the high end of the size of such interstellar objects. Thus, an interstellar asteroid the size of Oumuamua, which has managed to survive aeons of erosion by the interstellar medium, may indeed be quite rare.

    I don’t think that one BFR isn’t enough. Two BFR launches would allow combining a booster stage with a science payload consisting of an impactor and some serious science instrumentation. Both stages would merge after launch, and then boost towards Oumuamua.

    Three or four BFR launches perhaps potentially could add a sample return package in addition to the above. All the BFR has to do is work as designed. Without this, there is no point in proceeding with further development of the other aspects of such a mission to Oumuamua. In other words, shoot some money down the drain to get working BFRs, while at the same time designing and performing the initial developments of the BFR payloads. If the BFR design fails, then kill the rest. If the BFR is successful, then the remainder of the entire project has an achievable goal.

    I do not like the idea of betting on unproven technologies such as solar sails which are boosted by lasers. Instead, I propose that if the BFR works, then the rest should be based on proven technologies. In other words, two timelines. One timeline is proving the launch system, and the other timeline is the rapid development of the payloads which are based on proven technologies. The timelines will have to be concurrent, just as how NASA developed the Saturn V along one timeline, and at the same time NASA developed the Saturn V payloads which consisted of the Command and Service Modules, the Lunar Modules, the Lunar Rovers, the Lunar Spacesuits; and the Apollo Metric and Panorama Camera which were carried by the Saturns to the moon.


    “We came in peace for all mankind.” This is what is written on the plaque which is attached to the Apollo 11 Lunar Module’s descent stage which rests on the moon. Apollo would not have been successful if the astronauts themselves had not been given carte blanche to force the hardware manufacturers to make design changes in order to fix flaws which they independently observed.

    If mankind wants to succeed in examining Oumuamua, then all mankind must participate in order to accomplish this task, since the time to do so is short. The initial design phases for the payloads must be open for review by engineers around the globe, and not just to aerospace engineers. Why? Because both scientists and aerospace engineers, although quite brilliant, tend to wear blinders as a result of their intense focus on their specific diciplines. Blinders can prevent one from seeing the potentially obvious, such as running high voltage lines with thin insulation adjacent to low voltage lines which are attached to systems which were never, in any of the wildest dreams by the low voltage system engineers, expected to ever encounter high voltages. Yet an electrical short between two completely separate high and low voltage systems is exactly what brought down an airliner.

    Zero complacency. The only way to achieve this is to have a lot of “outside eyes” from both the same and different engineering diciplines looking at all initial individual system designs and at all system integration designs. Why? To remove all blinders which are related to intense specific diciplines.

    Zero complacency. In order to achieve the above, systems and aggregates of systems have to be be both macro managed and micro mangaged in order to find flaws which are independently and potentially found by either experts within a given engineering dicipline, or which are found by experts in other engineering disiclines. This can be accomplished by bottom-top reviews and alerts which must also quickly revert to top-bottom alerts and revisions, in order to quickly keep everyone on the same page, such that the process can reiterate.


    At some point, and relatively quickly if mankind is going to investigate Oumuamua, the major science system parameters will have to be relativly quickly carved in stone. Otherwise things will get out of control and most likely result in delay after delay. The Apollo Lunar Module development slowly spiraled out of control since Lockheed persisted in repeatedly proposing design modifications to the design of the Lunar Module. NASA had no choice but to “lay down the hammer” by stating that the latest current Lunar Module design from Lockheet “is it” and that there would no further major design changes, and that there would only be tweaks to this overall design.


    There is no point in trying to pursue the above if initial studies do not indicate, in the best of scenarios, that the launch of an Oumuamua discovery mission can not be theoretically completed within five years. Initial studies are just that — initial studies.


    This is the maximum time frame for the launch of an Oumuamua mission. Given that time frames invetibly slip, I figure that an very optimistic five year mission time frame for launch could slip to as much as eight years. A plot of accummulating time frame slippage should be, come hell or high water, the sole and non-political factor in terms of whether or not to proceed further.

  • Benjamin R Stockton November 30, 2017, 13:43

    Given the object is heading out towards interstellar space, where we have long been aspiring to go, and if we can hope to hit the object with an explosive to obtain spectragraphic data, could we also stick a tracking device on there?

    As I don’t have to build it, I am free to speculate that such a device would be nuclear powered, would “sleep” most of the time except for annually scheduled transmissions, would expect to run for 100 years or so, and would be built to have a “deployment mode” that would have several missions:
    1. upon detecting proximity to a solar system during one of its “wake up” periods, execute processes make itself obvious as the object approaches the local sun by:
    1.a. power up a local transmitter system intended to stir up interest from any capable civilization in the area;
    1.b. deploy a balloon, sail or other visible element to be easily found by anyone looking for it locally
    1.c. transmit an easily decipherable “Rosetta Stone” code base in hopes of facilitating eventual communications if there were a capable civilization in the area.
    2. separate a component to attempt to stay in some orbit around the local star, providing at least a beacon or better yet telemetry sent back to Earth
    3. if it nears its own demise without having detected a star in proximity, execute all of the above anyway so that the object is permanently marked with evidence, then explode the separate component to provide a hopefully detectable event for our descendants.

  • Robert Clark December 2, 2017, 21:25

    I was surprised in the study by Hein, et.al. that they didn’t consider the possibility of using ion drive. Ion drive has already been used by NASA for space probes to reach high velocity.

    Oumuamua was moving at a speed of about 25 km/s. The Dawn mission to Ceres could manage 10 km/s via ion drive. And the Atlas V and in-space stages used for the launch of New Horizons were able to give the spacecraft a speed of about 12 km/s. So using this architecture of chemical propulsion to leave Earth at an initial high speed then using ion drive analogous to that used on Dawn, we could already get 22 km/s. Tweaking both the chemical stages and ion drives should be able to gives us the 25 km/s needed to catch Oumuamua.

    Bob Clark