Deep-Space Exploration by CubeSats Set to Begin
NASA – Lunar IceCube to Take on Big Mission From Small Package
“In what scientists say signals a paradigm shift in interplanetary science, NASA has selected a shoebox-size mission to search for water ice and other resources from above the surface of the moon.”
Marc’s note: CubeSats for deep-space exploration is an exciting new aspect of space exploration. It opens space exploration to more participants at a much lower cost. Combined with an eventual lower cost in launch through reusability, this could lead to a proliferation of new missions.
I can see this as a good test for cubesats in general, but the science for this mission has already been done by LRO.
The full story goes into some detail about that. This is very different from LRO, in the sense that a megapixel detector is huge by the standards of planetary IR mapping spectrometers and the instrument is specifically focused on water bands in the near IR. I got the impression that this is the difference between detecting water somewhere in the polar regions, and being able to say, “you probably want to dig 2.5 km north-northwest of Shackleton crater’s central peak.” CubeSats tend to be good at this sort of thing: One, very specific, focused observation.
I was excited to read about this, as it’s led by university collaboration etc until i got to this part:
“But before the Lunar IceCube can begin its science operations, it will
have to get to the moon first. The satellites selected for EM-1 will be
installed inside the adapter, which connects Orion to the upper stage of
NASA’s newest rocket — the SLS, a 32-story launch vehicle designed to
ferry humans and gear around the moon and beyond..
Busek’s RF Ion BIT-3 thruster, along with a carefully designed
trajectory modeled by Goddard’s state-of-the-art trajectory-design
software, will get IceCube to its destination in about three months, “
Wait, what ? SLS is going to launch a piggybacked cubesat that will take three months to get there ? Hello, is this mister Ugotabe Kidding calling ?
Which part of that makes you incredulous?
That’s a really cool trajectory problem. Another piggyback cubesat is proposing solar sailing from the same separation point. Great fun.
I’m fairly sure the CubeSat will get to the moon in under three months. But it won’t stop. The EM-1 trajectory goes past the moon at too high a velocity for that. The three months is what it takes for low-thrust, electric propulsion to slow the CubeSat down and get into lunar orbit.
You can always go to NASA’s “Cutting Edge” Summer 2015 issue and look at the low thrust transfer trajectory image on page 3.
We certainly need more and better information about the ice, etc, available on the Moon. Let’s not commit to a crewed landing until we are clear about the costs, and what it is going to buy us towards the project of long-tern human space settlement.
But using SLS seems strange. Surely making it a secondary payload on some launch to GSO would make more sense? (There are lots more frequent opportunities — who knows when SLS will actually launch?)
The ion drive seems good.
This way, even if Orion is running behind schedule, SLS will still have a payload to launch.
EtOH I wonder if SLS will launch if the only payload is a couple of CubeSats! If we spend a launch on them, we would have to wait a long time before we could stack another SLS for launch. More likely, SLS would wait for months (or years?) for MPCV/Orion.
JPL is sending a cubesat to Mars in March 2016 along with Insight mission.
http://www.jpl.nasa.gov/cub…
Methink cubesat in BLEO have a high possibility being toasted by a stray cosmic ray. We shall see.
I read somewhere that during a human trip to Mars, EVERY cell in an astronaut’s body will be struck by a high energy cosmic ray.
oh come ON, Yale! You are the guy always prodding for a link to back up assertions, So where did you hear that? doesn’t really pass the smell test…
Well, the integrated flux of galactic cosmic rays is roughly 1/sqcm/s. Spectrum has a max around 100 MeV, then tails off as a power law at higher energies, line E to the -2.7 power, roughly. So that would be 1 hit in every (1/5000th cm X 1/5000th cm) square, in a 9 month trip (continuing after arrival, but for planetary shielding, as there is no magnetic shielding). I think human cells are typically ~10 um in size, so that suggests several hits
But I think cells are pretty good at repairing DNA, and the DNA is a much smaller target than the cell. This flux is actually roughly the same (in particles/cmsq/s) as on the surface of earth, only the ENERGY flux is much higher, due to the high energy of the particles. And it’s more complex than just counting hits.
High energy protons are the main component of CRs, and the ionization damage they cause decreases with energy, and so I think the real problem is when HE CRs hit an atomic nucleus and cause a shower of (still high energy…, etc) particles. A slow alpha particle is a disaster, I think it can kill a cell, but a fast proton probably not, I believe.
But cells mostly are replaced, and DNA mostly repaired. So low fluxes don’t kill you, because the repair processes are fast enough to keep up. But they may cause cancer years later when a critical bit of DNA is blown up.
I’m not certain about any of this quantitatively, but I’m fairly sure it is about right. Cells will probably be hit, but not mortally wounded. Unfortunately the HE CRs are very difficult to shield against. The accumulation of DNA damage is one of the two big issues in space medicine going to Mars (the other being 0g). But neither is a show stopper (I hope.)
CLICK ON IMAGE TO MAKE IT ANIMATE!
https://timedotcom.files.wo…
It is a view from 1 million miles sunward of a full Moon crossing a full Earth. That is the FAR side of the Moon!
DSCOVR (Goresat)
Notice how dark the Moon is compared to the Earth. The soil on the Moon is as dark as charcoal and reflects very little light. The reason the Moon looks so bright to us in our night sky is that it we see light bounced off a body 2000 miles across in an image the size of a pea held at arms length.
But it is a new moon, as seen from Earth, of course. Note the Sea of Moscow on the far side.