NASA's Going to Europa; Are We Building a Lunar Orbiting Habitat?; JWST and TRAPPIST-1

NASA’s Mission to Europa has finished the first phase of its design and science review; NASA and the international partners are quietly completing design of possible Moon-orbiting space station; and a look at what JWST will teach us about the exopla

Published by Tony Darnell on 10th Mar, 2017

Hello Space Fans and welcome to another edition of Space Fan News. This week, an update on NASA’s Mission to Europa which has finished the first phase of its design and science review and now also has a name; also, NASA and the international partners are quietly completing design of possible Moon-orbiting space station; and a short look ahead at what the upcoming James Webb Space Telescope will teach us about the newly discovered exoplanets in the TRAPPIST-1 system.

First up, it looks like NASA is finally going to Jupiter’s moon, Europa. Like many of you, this is a mission I’ve been waiting a loooong time for, and it looks like it’s actually going to happen!

I know, right?

So far, NASA has plans to build and launch an orbiter that will be launched in the 2020’s and just this week was given the official mission name, ‘Europa Clipper’, and the next phase will include an actual landing mission!

The Europa Clipper mission plan calls for a spacecraft to be launched to Jupiter in the 2020s, arriving in the distant planet’s orbit after a journey of several years. The spacecraft would orbit the giant planet about every two weeks, providing many opportunities for close flybys of Europa. The mission plan includes 45 flybys, during which the spacecraft would image the moon's icy surface at high resolution and investigate its composition and the structure of its interior and icy shell.

The orbiter will carry nine instruments including an ice penetrating radar which will determine the thickness of the moon’s icy shell and search for subsurface lakes similar to those beneath Antarctica. The mission also will carry a magnetometer to measure the strength and direction of the moon’s magnetic field, which will allow scientists to determine the depth and salinity of its ocean.

A thermal instrument will scour Europa’s frozen surface in search of recent eruptions of warmer water, while additional instruments will search for evidence of water and tiny particles in the moon’s extremely thin atmosphere.

So that’s all going to happen in the 2020, but wait that’s not all.

As you may know back in early 2016, congress directed NASA to begin looking into a mission to the Jovian moon Europa and NASA’s Planetary Science Division began what’s called a pre-Phase A study that would assess the science value and engineering design that would, after all was said and done, include an actual Europa lander in addition to Europa Clipper.

NASA routinely conducts such studies -- they call them Science Definition Team (SDT) reports -- and they do these long before the beginning of any mission to gain an understanding of the challenges, the feasibility and science value of the potential mission. In June 2016, NASA convened a 21-member team of scientists for the SDT. Since then, that team has deliberated to define a workable and worthy set of science objectives and measurements for the mission concept, and they submitted a report to NASA last Feb. 7.

Their report listed three science goals for the lander mission. The primary goal is to search for evidence of life on Europa. OK, that was a good pick - I approve. The other goals are to assess the habitability of Europa by directly analyzing material from the surface, and to characterize the surface and subsurface to support future robotic exploration of Europa and its ocean. (Future robotic missions - yay!)

Most Scientists agree that the evidence is very strong that Europa, which is slightly smaller than Earth’s moon, has a global saltwater ocean beneath its icy crust. This ocean has at least twice as much water as Earth’s oceans - and we have quite a bit.

While recent discoveries have shown that many bodies in the solar system either have subsurface oceans now, or may have in the past, Europa is one of only two places where the ocean is understood to be in contact with a rocky seafloor (the other being Saturn's moon Enceladus). This rare circumstance makes Europa one of the highest priority targets in the search for present-day life beyond Earth.

Not since the days of the Viking lander has a NASA Science Definition Team been tasked to design a search for life, and an associated life-detection strategy. The report makes recommendations on the number and type of science instruments that would be required to confirm if signs of life are present in samples collected from the icy moon's surface.

The report also describes some of the theoretical instruments that could be expected to perform measurements in support of these goals. This happened during JWST planning when they had to invent instruments that didn’t exist yet to achieve the science goals of the mission. But don’t worry, NASA’s been there before.

The team also worked closely with engineers to design a system capable of landing on a surface about which very little is known, obviously they’ll learn more when Europa Clipper gets there. Given that Europa has no real atmosphere that would help them land, the team developed a concept that could deliver its science payload to the icy surface without the benefit of technologies like a heat shield or parachutes.

No seven minutes of terror here.

Next, while we’re on the subject of NASA, a space fan pointed me to this story. Apparently NASA and other ISS Partners are looking into the possibility of a lunar orbiting space station.

According to the post on the Planetary Society’s Website, last month, experts from five space agencies held a behind-the-scenes meeting in Tsukuba, Japan, the home of the Japan Aerospace Exploration Agency (JAXA). In the following few months, the designs for the largest international undertaking in human spaceflight since the ISS will be reviewed by space agencies. Engineers might also begin constructing the first full-scale prototype of the near-lunar habitat here on Earth to assess the ability of proposed modules to support the crew.

This space station would be built in what is called a cis-lunar orbit which is a fancy word for the space near the moon. This orbit is important though because the ISS partners decided to build and assemble the station in something called a Near-Rectilinear Halo Orbit, or NRHO.

This giant, egg-shaped orbit extends 70,000 kilometers from the Moon at its farthest point and comes as close as 1,500 kilometers at the nearest. An this would enable the station to save propellant for orbital corrections and avoids the blocking of sunlight by the Moon from reaching the station’s solar panels, while always keeping the spacecraft within a line of sight to ground controllers on Earth.

Each orbit around the moon would take about a week and they are still designing the station itself. The primary servicing vehicle would be NASA’s Orion spacecraft that is currently being built and tested and will be the space agency’s next human crew spaceship. They key delivery vehicle to get the major components assemble will be delivered by the Space Launch System and it isn’t clear yet who might provide cargo missions, that could go to other companies like SpaceX.

According to the Planetary Society, assembly of the station is currently proposed to begin with the third flight of Orion around 2023. The first logistics flight for the cis-lunar outpost might be required between 2024 and 2025.

It feels so good to be talking about NASA and the moon again.

Finally, with the recent discovery of the seven Earth-sized planets in the habitable zone of the Red Dwarf TRAPPIST-1, exoplanet researchers are chomping at the bit to get Hubble’s successor, the James Webb Space Telescope launched.

The biggest question they want answered is, do any of these planets have an atmosphere? Remember, so far all we know is that they are rocky, about the size of the Earth, and that there are seven of them. That’s it.

For life to have much of a chance of being there, those planets or at least one of them, needs to have an atmosphere and JWST was designed to answer exactly this kind of question. It has on board an instrument called NIRSpec, a spectrometer with microshutters that can block out the overwhelming light from the star so it can directly measure the planet passing in front.

By looking at the light that goes through any atmosphere the exoplanet may have, NIRSpec will be able to make out what it’s made of, and other characteristics, like density and thickness.

TRAPPIST-1 is the first system bright enough, and small enough, to make it possible for JWST to look at each of these planets’ atmospheres and you can be sure this system will be high priority for those on the time allocation committee tasked with telling JWST where to point.

I’ll keep you posted.

Well, that is it for this week Space Fans. I want to alert you to a special SFN live event I’m holding next Tuesday, March 14 on both YouTube and the SFN Facebook Page. I’ll be live streaming at 4pm ET and I want to talk with you about some ideas I have about the future of SFN, I hope you can make it live to let me know what you think, but if you can’t, you can always leave comments after the fact and I’ll be sure to read them and respond to you.

I want to thank all SFN Patreon Patrons for your kind and generous support, you are making a difference. Thanks to all of you for watching and as always, Keep Looking Up!


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