This summer, NASA delivered to JAXA a sample of asteroid Bennu collected by the OSIRIS-REx mission as part of the sample exchange between the NASA OSIRIS-REx and JAXA Hayabusa2 mission teams. In 2021, JAXA had delivered sample to NASA from asteroid Ryugu that had been collected by Hayabusa2.
Asteroid exploration is one aspect of the ongoing collaboration between the US and Japan that extends forward to JAXA's Martian Moons eXploration (MMX) mission, and the NASA-led international Artemis program for human exploration on the Moon. For MMX, NASA has contributed one of the remote sensing instruments, MEGANE, and one of the two samplers for collecting material from the surface of Phobos, the P-SMP. Part of JAXA's contribution to the Artemis program will be the development of a pressurized rover in collaboration with Toyota to carry out crewed exploration on the lunar surface.
On July 18, shortly before the delivery of the Bennu asteroid sample, the Associate Administrator of NASA's Science Mission Directorate, Dr Nicola Fox, visited Japan. JAXA ISAS Deputy Director General Fujimoto Masaki met with Dr Fox to discuss current and future projects between the two space agencies.
―― The top three topics that we'd really like to discuss is the sample exchange between the Hayabusa2 and OSIRIS-REx missions, our collaboration with the MMX mission, and also Artemis! Shall we begin with the sample exchange?
Nicola Fox: We're really looking forward to the sample exchange. Old asteroids are really great places to go for the search for life. We're very excited about the samples that came back from OSIRIS-REx last September, as well as Hayabusa2's sample that returned to Earth in 2020. The OSIRIS-REx return capsule landed in the Utah desert with a beautiful, soft landing and then we opened that capsule. We're very proud of the sample we got back from the asteroid Bennu. The overall sample was huge - much larger than we were hoping.
We are excited about the successful completion of our sample exchange with Japan at the end of August. Sharing the samples from OSIRIS-REx and Hayabusa2 missions allow us to do some really great collaborative work with JAXA. Although the samples are probably going to be very similar because the asteroids have a fairly similar path and similar age, I think it's a really great example of how the United States and Japan are working together to maximize the science we can do, especially since they are very different types of asteroids and we have different ways of looking at the samples at the same time. When we can actually do comparative work between Bennu and Ryugu, we not only get a lot more out of having the different types of samples, but also different types of scientists looking at them which always maximizes the results that we can get. It very much fits in with our open-source science model of sharing all of our information with the world and getting more scientists the ability to study them. I bet we'll find some really exciting things. We thank JAXA for the great partnership with these two missions.
―― Asteroid Bennu and Ryugu are different kinds of sample, but both have features that are not found within the meteorite collection.
Nicola Fox: What is so exciting is that we are actually getting pristine samples. They are just like they were when the Solar System was forming. And, both asteroids are very old. So, it lets us look at what the Solar System was like in these very early stages. I think it's interesting finding the differences in asteroids that you couldn't do unless you brought the samples back. And you can do that in really fine detail. We are excited about the [successful] sample exchange with Japan. When I was at NASA's Johnson Space Center earlier this year, I got to see the Hayabusa2 samples, the OSIRIS-REx samples, and some of the Moon samples as well.
―― Did they look similar to your eyes?
Nicola Fox: Well, to my eye, they looked like tiny specks. So yes, they looked very similar to me.
But I'm sure under a mass spectrometer they're very different.
―― Something that's happening here in Japan is a rising interest from the general public not only in Japanese missions, but in the international missions that is being driven by these partnerships. So you first might be interested in Hayabusa2 itself, but then you see the collaboration between Hayabusa2 and OSIRIS-REx, and the joint press events.
Nicola Fox: I think also celebrating not only the sample exchange, but also the very large role that JAXA had in the full OSIRIS-REx mission is important. I will note that once the samples dropped down from the sky, then the OSIRIS-REx spacecraft itself got renamed to OSIRIS-APEX because it is now the Apophis Explorer. At NASA, we also like to take advantage of opportunities to use our missions to observe other aspects in our Solar System on their way toward their final destination. OSIRIS-APEX just had a pretty close fly-by of the Sun, not Parker Solar Probe close, but still a lot closer than what it was designed for. We're very happy that it survived, especially since that fly-by was at about half an Astronomical Unit from the Sun and collected a lot of great data for us to view the Sun from a new vantage point that will help us better understand our neighborhood star. OSIRIS-APEX is now putting itself into an orbit and will then go up and rendezvous with the asteroid Apophis. Apophis will fly by the Earth in February of 2029. After it has done its closest approach to our planet, OSIRIS-APEX will fly past Apophis. We are working together with JAXA and ESA, to look at sending up a mission that will rendezvous with OSIRIS-APEX right before it flies past Apophis. We can actually look at how that close fly by with Earth changes what we see with the asteroid. We do all of this as part of our international efforts to search for signs of life in our Solar System and beyond. We are coming to find that these asteroids help our search because they contain the ingredients and building blocks needed to sustain life.
―― What is your view on our collaboration for JAXA's MMX mission to the Martian moons, Phobos and Deimos?
Nicola Fox: MMX is another great opportunity. Providing an instrument for the mission allows us to make the measurements that we really want to make in an area that we wouldn't have access to without the MMX mission. Now, we can do all those measurements from the MEGANE instrument, and we are able to observe changes around the Martian moons. We also benefit from MMX's sample collection. It's just a continuation demonstration of how we do so much more when we work together.
―― A paper written by one of our junior colleagues proposed that the remote observations with MEGANE (the NASA contributed instrument onboard MMX) may be able to reveal the formation origin of the Martian moon, Phobos. This paper was a quantitative analysis of the operations required to reach that conclusion, led by a young scientist performing mission orientated work to guide the operation for a collaborative mission. These are new opportunities coming from the collaboration. Also, if MEGANE can help determine the origin of the moon, we can prepare much better for the analysis once the sample is back on Earth.
Nicola Fox: It is true that the remote sensing observations will be critical in laying the groundwork for interpreting the samples here on Earth. You can draw some initial conclusions but of course it will be fascinating to see if these conclusions are still correct when we have the samples to analyze. The other benefit to the samples is that we can take them from below the surface and try to get down to samples indicative of the conditions during the evolution of our Solar System. Those samples will be so important.
―― We also have a sampler from the US as well onboard MMX, which we really appreciate.
Nicola Fox: The P-SMP sampler, along with MEGANE, yes. And I understand they're both here in Japan, ready to go.
―― It's really nice that we will have two samplers, as we really want to ensure that we can collect a material from Phobos. We're now getting ready for launch in FY 2026!
Let's move on to the last question: our collaboration in Artemis. This collaboration has been driven by science, and I think that it is hard to exaggerate how important it is to have science as the driver for the collaboration. Would you agree?
Nicola Fox: The Artemis program and Moon to Mars, objective science have been the key pillars. The three pillars are inspiration, national posture and science. But really it is the science that drives everything. We explore because we want to know more about the world around us. We want to always discover more, and that's science. The knowledge that we pursue to something you didn't know before is science.
With the launch of the Artemis rocket back at the end of 2022, it ushered in a new way for us to be able to do science again. Having science baked into the Artemis program from the beginning is so crucial. We are looking at how much science we can include in every single mission as we move forward. Even in Artemis I, Biological and Physical Sciences had a payload inside the Orion capsule, so we were able to take yeast, fungi and seeds all the way out into microgravity - the same radiation environment that our astronauts will have to survive in.
We have science experiments that we would like to fly with Artemis II. With Artemis II, we will send a crew up in the Orion capsule, so they will orbit the Moon. We're looking forward to putting some science instruments on Artemis II, things like testing the saliva of the astronauts to see how their body, their immune system, may change. It's a great opportunity to look at the effect of radiation on our astronauts while they are in space.
For Artemis III, when we go down to the lunar surface, we have a geology team currently working with the astronauts, talking about what they're going to find and what they what we want them to look for.
The south pole of the Moon is where we're really interested in going. That is because we believe that there's water, which was actually discovered by the Clementine Mission.
We have the tools that we've selected for the astronauts to take down to the lunar surface with them, then our instruments and science will be left there.
Science is baked into every one of the Artemis missions, but also through the commercial lunar payload services program that we have to get more science to the lunar surface as quickly as possible. And we have JAXA participation in some of those instruments going on CLPS [Commercial Lunar Payload Services]. I think we have JAXA participation in the Artemis III surface instruments too. So again, really good collaboration. And everything always driven by the science that we want to do.
―― We have now set up a biweekly meeting between NASA and JAXA members. Originally, this was to discuss the science of the pressurized rover for the Artemis program. But during these conversations, I realized that this would be for Artemis VII, and we are now working together for Artemis III. So I reformed that meeting to talk about Artemis science, starting from Artemis III and marching towards Artemis VII. Everything that will be done during Artemis III and Artemis IV will shape the Artemis setting better.
Nicola Fox: The Lunar pressurized rover is JAXA's biggest contribution to the Artemis program. I think the pressurized rover is such an exciting concept, the idea that you are in a kind of "shirt sleeve" environment. You can actually look at all of those samples and have somebody choose the perfect ones to bring back the very best.
―― We were sad to learn about cancellation of VIPER (NASA lunar rover that planned for exploration of the south pole region of the Moon). Of course, these difficult choices are the conclusion of carefully considered procedures. Is there a chance that other missions can cover a few of the VIPER mission goals?
Nicola Fox: Obviously, it was a very difficult decision. We are no longer able to continue with our VIPER rover because of the growing cost in a very constrained budget environment. When it became clear that we could not launch the mission in 2024, we had to make the tough decision to cancel the project, as we were faced with delays of many years which would add considerable cost on top of the already inflated budget. This would have threatened many other CLPS missions, both in delays or even cancelations of future CLPS missions. VIPER, while it's a wonderful mission, and it would have done great science, could only operate for about a two and half months. The reason is that it needs sunlight to power the rover, generated by the huge solar panels on its side. We would have to launch around November to be able to get to the south pole of the Moon, when there's still enough sunlight there to keep the rover powered. Around the end of February there's no longer enough sunlight to generate power, so the rover won't function anymore. It was a short duration mission with a large cost. And what we'd actually want to do is take the instruments and the technology that's on VIPER and put it on other CLPS Landers. Our goal is to have a regular cadence of our commercial landers going to the Moon. We do have great science coming up on CLPS. We have Lunar Trailblazer that will launch soon with the second Intuitive Machines lander. This will be a slightly larger version of the IM1 which landed on the Moon in Feb 2024. Lunar Trailblazer will orbit the Moon and do all kinds of great science by mapping areas that could have water and volatiles. We have Firefly Aerospace's Blue Ghost lander that will be launching later this year, and that actually has a drill on the leg of the lander. When that lands, the drill will deploy and go into the regolith. It also has a really nice experiment that's going to look at the plume interaction. There's great science on all of it.
We want to make sure that we maximize the science we can do with a diverse data set and a full program. We feel that we can do really great science by keeping the vibrance in the CLPS portfolio and allowing us to keep the pace of getting science to the Moon.