PROJECT GAMMA: SENDING A PROBE TO LOW LUNAR ORBIT

To send a probe from earth to escape its strong gravity, travel the approximate 380,000km to the Moon and then be caught by its relatively weak gravity to continually orbit it in Low Lunar Orbit (LLO) – for just NZ $20,000,000 – we will have to not only scour numerous past theories, ideas, concepts and tested inventions since the Apollo era (and pick out the best of the best) but also be inventive ourselves. No doubt, we will employ the best astrophysicists and engineers we can find in this part of the world to do just that and can come up with what they believe is the best technology and methods for the job.

The above mentioned shoestring budget of NZ $20,000,000 was not just pulled out of the air but taken as a challenge after examining a similar example from the past. This is the landmark case of the Lunar Prospector of the late 1990s, which was sent by America to the Moon for just US $65,000,000 at the time. Such a figure would roughly be in the order of about US $150,000,000 today when adjusted for inflation. When examining the breakdown of this US $65,000,000 budget, it appeared that most of it was for developing the space vehicle and launching it, as opposed to on-board systems or anything else. Therefore, we believe that by utilising the previously mentioned initiatives to develop our own technologically advanced system (made locally) and launching it from an international airport (instead of a major overseas space facility) or other locally available facility, is what will enable us to achieve this ultimate goal. In fact, by the time we reach this stage in the program, we are likely to have some accumulated funds from the payoffs of previous projects. Thus, prizes of money (of less than NZ $20,000,000) can be awarded to whoever can successfully conduct this project for us in exchange for the full rights to their achievements. This strategy could be used for future projects as well.

As described earlier, when heading towards a planetary body in space, if you approach it too slowly you will fall into it, too fast and you will overshoot it but at just the right speed you will enter the low orbit of its gravitational field and perpetually circle it. As one gets closer to the Moon the earth’s gravity becomes weaker and that of the Moon becomes stronger (and vice versa). In fact, there are certain positions between earth and the Moon where the gravity of both are so finely balanced that they pull against each other equally so an object can comfortably stop and sit right there. These positions are called LaGrange points.

On our part, we would recommend also utilising the following concepts to further aid with the project’s development and payoffs:

  • Have the probe fitted with high quality cameras (perhaps with powerful telescopes fitted inside) that can be used to relay top notch photos and footage back to earth for both publicity and commercialisation.
  • Have the probe fitted with instruments from other firms who wish to use them for their own lunar research in exchange for funding. In general, we should always be welcoming of other firms and happy to work with them as opposed to against or in competition with them. Some firms may even provide us with much needed parts at no charge (such as on-board computers, cameras, solar panels and antennae) simply to promote their own brands and products. NZ firms currently involved in space, which may make excellent allies, include the Kiwi Space Foundation and Rocket Lab.
  • If possible, use highly advanced computer models for testing instead of individual launches and 3D printing for producing parts and hardware instead of conventional construction.

    • THE ROUTE TO THE MOON

    The diagram to the left shows the traditional approach (called the Hohmann Transfer Orbit) used in sending a probe from earth to the Moon. It involves a probe first taking off and entering space and then ascending to Low Earth Orbit (LEO), as shown in the blue circle around the earth. From there it fires its rockets and pushes away with a speed of about 11km/s (kilometres per second) to escape earth’s gravity and then travels across the black arrow, further and further away from earth, until it reaches the Moon, whose orbit is shown by the large orange arrow and circle. At the Moon, it fires its rockets again to slow down enough to be caught in LLO.

    In place of using the above approach, we propose that we employ a unique method, as pictured to the right, which was developed by Edward Belbruno and used to help a Japanese space probe, Hiten, successfully reach the Moon back in the early 1990s. This involves the probe slowly escaping earth by continuing to orbit it, getting further away with each successive orbit (labelled as the Earth spiral), and then firing its rockets to escape earth to gently coast along (without any more of its own propulsion) towards the Moon. Once there, it fires its rockets again to slowly get caught in its gravity and gradually orbit it, getting closer with each successive orbit (labelled as the Lunar spiral).

    This method is less risky and cheaper than the Hohmann approach because it does not require as much fuel to slow it down when arriving at the Moon. However, since it travels to the Moon much slower and spends time orbiting both the earth and Moon on the way, it takes a bit longer: approximately two years! Of course, the shortest possible journey is desired when humans are aboard but when it is only machinery and robotics we can afford to take a little longer.

    Since the route described above requires much less power, the probe could potentially be solar powered. On that note, there is even the possibility of using ‘solar sails’ that fold out from inside the probe to reflect vast amounts of sunlight away from it and, in turn, push it towards the Moon.

    Lastly, another interesting route that bears consideration is the one used to take the famous Indian probe, Chandrayaan 1, to the Moon in 2008, which immediately made the beautiful nation a spacefaring one. As pictured to the left, the probe simply kept orbiting earth ecliptically, gradually getting further away from it with each successive orbit, until it eventually reached the Moon at a distance of about 380,000km.

    Astrophysicists have been quoted as saying, “the hardest part is leaving earth”. This is certainly true as one can easily see from the size of rockets that are launched from the ground to what is left of them once they enter space. To cut costs with the initial launch, we would suggest using a large hydrogen balloon attached to the top of the probe to first lift it as high as possible into the earth’s atmosphere and then give it fuel (being the actual hydrogen gas inside the balloon) to burn as propellant until it reached space. The hydrogen bag would then detach and fall back to earth, burning up in its atmosphere. Another method is to use a single advanced, reusable booster rocket to send the probe high into the sky and to the edge of space to continue on its own while the booster rocket (with no fuel left in it) detaches and parachutes back to earth where it will be collected for reuse.