Sample Return Technology

How does one go about the extraordinarily difficult task of returning a sample from another world back to Earth? Honey Bee Robotics is testing technology to do just that – the Planet Vac.

Credits: NASA Photo / Lauren Hughes

From NASA/Honey Bee Robotics/Masten Space Systems:

Just a sample will do.

Honeybee Robotics in Pasadena, California, flight tested its pneumatic sampler collection system, PlanetVac, on Masten Space Systems’ Xodiac rocket on May 24, launching from Mojave, California, and landing to collect a sample of more than 320 grams of top soil from the surface of the desert floor.

“The opportunity to test a technology on Earth before it is destined for another planet allows researchers and mission planners to have confidence that once the technology arrives to its space destination it will work,” said Ryan Dibley, NASA Flight Opportunities program campaign manager. Flight Opportunities program funded the test flight.

PlanetVac is a surface soil collection system for a sample return mission. The configuration tested would replace a foot pad of a planetary lander spacecraft. The goal is to bring back a sample of surface soil from a celestial body.

“Bringing something back from another planet, celestial body, is the Holy Grail of planetary science,” said Justin Spring, senior project engineer for Honeybee Robotics. “It allows you to have something from another world, here, so Earth instruments can analyze it. We’re still analyzing what we collected from the moon years ago!”

The pneumatic sampler foot pad starts operation after the lander touches down on a surface. Compressed gas is injected into the foot pad enclosure, lofting the soil into a cyclone separator for collection.

“What it does is kind of like your vacuum,” said Spring. “It creates an area of high pressure in the front and uses an area of low pressure in the back to suck up the sample. The best thing about PlanetVac is how simple it is. Aside from a single actuator to trigger the gas flow, the system is entirely pneumatic, which reduces complexity and risk.”

“There are other ways to collect samples,” he adds. “The Mars Curiosity rover uses a drill. The Mars Phoenix lander had a scoop. But to keep it simple when all you need is surface dirt then using this pneumatic system can bring the sample back.”

“The Flight Opportunities program allowed us to take the PlanetVac idea and actually strap it on to Masten’s rocket putting it in a situation more realistic to what it might encounter in a space mission,” said Spring. “This reduces the risk since we now know it can survive both landing and heating loads as well as the rocket environment and still collect the sample and retain it to come back.”

Through the Flight Opportunities program, the Space Technology Mission Directorate (STMD) selects promising technologies from industry, academia and government for testing on commercial launch vehicles and enables public-private partnerships for the agency. The program is funded by STMD and managed at NASA’s Armstrong Flight Research Center in Edwards, California.

STMD is responsible for developing the crosscutting, pioneering, new technologies and capabilities needed by the agency to achieve its current and future missions.

CubeSat Plasma Thruster

Nice, it was only a matter of time.

ESA: This micro-pulsed plasma thruster has been designed for propulsion of miniature CubeSats; its first firing is seen here. The thruster works by pulsing a lightning-like electric arc between two electrodes. This vaporizes the thruster propellant into charged plasma, which is then accelerated in the electromagnetic field set up between the electrodes.

Developed for ESA by Mars Space Ltd and Clyde Space of the UK with Southampton University, this 2 Watt, 42 Newton-second impulse plasma thruster has been qualified for space, with more than a million firing pulses demonstrated during testing.

It has been designed for a range of uses, including drag compensation in low orbits, orbit maintenance, formation flying and small orbit transfers. The thruster could also serve as a CubeSat deorbiting device, gradually reducing orbital altitude until atmospheric re-entry is achieved.

About the size of a DVD reader, the thruster weighs just 280 grams including its propellant load and drive electronics.

Stellar Bubble

ESA: This turbulent celestial palette of purple and yellow shows a bubble of gas named NGC 3199, blown by a star known as WR18 (Wolf-Rayet 18).

Wolf-Rayet stars are massive, powerful, and energetic stars that are just about reaching the end of their lives. They flood their surroundings with thick, intense, fast-moving winds that push and sweep at the material found there, carving out weird and wonderful shapes as they do so. These winds can create strong shockwaves when they collide with the comparatively cool interstellar medium, causing them to heat up anything in their vicinity. This process can heat material to such high temperatures that it is capable of emitting X-rays, a type of radiation emitted only by highly energetic phenomena in the Universe.

This is what has happened in the case of NGC 3199. Although this kind of scenario has been seen before, it is still relatively rare; only three other Wolf-Rayet bubbles have been seen to emit X-rays (NGC 2359, NGC 6888, and S308). WR18 is thought to be a star with especially powerful winds; once it has run out of material to fuel these substantial winds it will explode violently as a supernova, creating a final breath-taking blast as it ends its stellar life.

This image was taken by the European Photon Imaging Camera (EPIC) on ESA’s XMM-Newton X-ray space observatory, and marks different patches of gas in different colours. The incredibly hot, diffuse, X-ray-emitting gas within the Wolf-Rayet bubble is shown in blue, while a bright arc that is visible in the optical part of the spectrum is traced out in shades of yellow-green (oxygen emission) and red (sulphur emission).

This blue and yellow-green component forms an optical nebula – a glowing cloud of dust and ionised gases – that stretches out towards the western end of the X-ray bubble (in this image, North is to the upper left). This lopsided arc caused astronomers to previously identify WR18 as a so-called runaway star moving far faster than expected in relation to its surroundings, but more recent studies have shown that the observed X-ray emission does not support this idea. Instead, the shape of NGC 3199 is thought to be due to variations in the chemistry of the bubble’s surroundings, and the initial configuration of the interstellar medium around WR18.

Image: SA/XMM-Newton; J. Toalá; D.Goldman


Martian Dust Storm

The planet Mars is becoming shrouded in dust. I mentioned the other day the rover Curiosity seemed to be in pretty good shape as far as dust coverage goes or at least did not have as much dust coverage as I thought it would.

The situation for Curiosity may change as a dust storm becomes prevalent both in storm density and duration. The rover Opportunity (indicated with the blue dot in the center of the image) seems to be obscured now and power levels could be impacted, we’ll have to wait and see.

Typically the southern summer warms the environment and the dust and sends the particles high into the mostly carbon dioxide atmosphere. As the particles rise in the atmosphere they in turn create more wind and so on, a feedback loop. Exactly how this works is not known – yet. It could be the dust particles absorb enough heat from the Sun to remain boyent or it could be the seasonal variation of methane plays a part; or it could be something completely different and unrelated. Time will tell.

The current storm was detected on 01 June 2018 and is still going on and could continue for weeks or months. That seems like a long time but on Mars it happens, maybe not often, but it a well observed phenomenon. The image shown was taken on 06 June 2018 courtesy of Malin Space Science Systems. The map was produced by the Mars Color Imager (MARCI) camera on NASA’s Mars Reconnaissance Orbiter spacecraft, which Malin Space Science Systems produced and operates.

A Triple System Close to Home

Yes, it’s Alpha Centauri system. A new study yields a surprising result.

The short version from NASA:

A new study involving long-term monitoring of Alpha Centauri by NASA’s Chandra X-ray Observatory indicates that any planets orbiting the two brightest stars are likely not being pummeled by large amounts of X-ray radiation from their host stars. This is important for the viability of life in the nearest star system outside the Solar System. Chandra data from May 2nd, 2017 are seen in the pull-out, which is shown in context of a visible-light image taken from the ground of the Alpha Centauri system and its surroundings.

Alpha Centauri is a triple star system located just over four light years, or about 25 trillion miles, from Earth. While this is a large distance in terrestrial terms, it is three times closer than the next nearest Sun-like star.

The stars in the Alpha Centauri system include a pair called “A” and “B,” (AB for short) which orbit relatively close to each other. Alpha Cen A is a near twin of our Sun in almost every way, including age, while Alpha Cen B is somewhat smaller and dimmer but still quite similar to the Sun. The third member, Alpha Cen C (also known as Proxima), is a much smaller red dwarf star that travels around the AB pair in a much larger orbit that takes it more than 10 thousand times farther from the AB pair than the Earth-Sun distance. Proxima currently holds the title of the nearest star to Earth, although AB is a very close second.

The Chandra data reveal that the prospects for life in terms of current X-ray bombardment are actually better around Alpha Cen A than for the Sun, and Alpha Cen B fares only slightly worse. Proxima, on the other hand, is a type of active red dwarf star known to frequently send out dangerous flares of X-ray radiation, and is likely hostile to life. Planets in the habitable zone around Proxima receive an average dose of X-rays about 500 times larger than the Earth, and 50,000 times larger during a big flare.

Tom Ayres of the University of Colorado at Boulder presented these results at the 232rd meeting of the American Astronomical Society meeting in Denver, Colorado, and some of these results were published in January 2018 in the Research Notes of the American Astronomical Society. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

Image credit: Optical: Zdenek Bardon; X-ray: NASA/CXC/Univ. of Colorado/T. Ayres et al

Drilling on Mars

Curiosity is back to drilling (see earlier video).

Here’s a nice image from Curiosity thanks to: NASA/JPL-Caltech/MSSS. Not as much dust build up as I expected.

Here’s the original caption:
The drill bit of NASA’s Curiosity Mars rover over one of the sample inlets on the rover’s deck. The inlets lead to Curiosity’s onboard laboratories. This image was taken on Sol 2068 by the rover’s Mast Camera (Mastcam).

Malin Space Science Systems, San Diego, built and operates the Mastcam. NASA’s Jet Propulsion Laboratory, a division of the Caltech in Pasadena, California, manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington. JPL designed and built the project’s Curiosity rover.

Juno Solves a Mystery

The Juno has helped solve the mystery of Jupiter’s lightning. PLUS, NASA has announced the Juno mission has been re-planned adding 41 months in orbit. That change will enable the spacecraft to collect more data, the orbits are 53 days instead of the planned 14 so collecting the necessary data takes longer.

So great news there and now about the lightning (artist concept above from NASA/JPL-Caltech/SwRI/JunoCam(:

NASA: Ever since NASA’s Voyager 1 spacecraft flew past Jupiter in March, 1979, scientists have wondered about the origin of Jupiter’s lightning. That encounter confirmed the existence of Jovian lightning, which had been theorized for centuries. But when the venerable explorer hurtled by, the data showed that the lightning-associated radio signals didn’t match the details of the radio signals produced by lightning here at Earth.

In a new paper published in Nature today, scientists from NASA’s Juno mission describe the ways in which lightning on Jupiter is actually analogous to Earth’s lightning. Although, in some ways, the two types of lightning are polar opposites.

“No matter what planet you’re on, lightning bolts act like radio transmitters — sending out radio waves when they flash across a sky,” said Shannon Brown of NASA’s Jet Propulsion Laboratory in Pasadena, California, a Juno scientist and lead author of the paper. “But until Juno, all the lightning signals recorded by spacecraft [Voyagers 1 and 2, Galileo, Cassini] were limited to either visual detections or from the kilohertz range of the radio spectrum, despite a search for signals in the megahertz range. Many theories were offered up to explain it, but no one theory could ever get traction as the answer.”

Enter Juno, which has been orbiting Jupiter since July 4, 2016. Among its suite of highly sensitive instruments is the Microwave Radiometer Instrument (MWR), which records emissions from the gas giant across a wide spectrum of frequencies.

“In the data from our first eight flybys, Juno’s MWR detected 377 lightning discharges,” said Brown. “They were recorded in the megahertz as well as gigahertz range, which is what you can find with terrestrial lightning emissions. We think the reason we are the only ones who can see it is because Juno is flying closer to the lighting than ever before, and we are searching at a radio frequency that passes easily through Jupiter’s ionosphere.”

While the revelation showed how Jupiter lightning is similar to Earth’s, the new paper also notes that where these lightning bolts flash on each planet is actually quite different.

“Jupiter lightning distribution is inside out relative to Earth,” said Brown. “There is a lot of activity near Jupiter’s poles but none near the equator. You can ask anybody who lives in the tropics — this doesn’t hold true for our planet.”

Why do lightning bolts congregate near the equator on Earth and near the poles on Jupiter? Follow the heat.

Earth’s derives the vast majority of its heat externally from solar radiation, courtesy of our Sun. Because our equator bears the brunt of this sunshine, warm moist air rises (through convection) more freely there, which fuels towering thunderstorms that produce lightning.

Jupiter’s orbit is five times farther from the Sun than Earth’s orbit, which means that the giant planet receives 25 times less sunlight than Earth. But even though Jupiter’s atmosphere derives the majority of its heat from within the planet itself, this doesn’t render the Sun’s rays irrelevant. They do provide some warmth, heating up Jupiter’s equator more than the poles — just as they heat up Earth. Scientists believe that this heating at Jupiter’s equator is just enough to create stability in the upper atmosphere, inhibiting the rise of warm air from within. The poles, which do not have this upper-level warmth and therefore no atmospheric stability, allow warm gases from Jupiter’s interior to rise, driving convection and therefore creating the ingredients for lightning.

“These findings could help to improve our understanding of the composition, circulation and energy flows on Jupiter,” said Brown. But another question looms. “Even though we see lightning near both poles, why is it mostly recorded at Jupiter’s north pole?”

In a second Juno lightning paper published today in Nature Astronomy, Ivana Kolmašová of the Czech Academy of Sciences, Prague, and colleagues, present the largest database of lightning-generated low-frequency radio emissions around Jupiter (whistlers) to date. The data set of more than 1,600 signals, collected by Juno’s Waves instrument, is almost 10 times the number recorded by Voyager 1. Juno detected peak rates of four lightning strikes per second (similar to the rates observed in thunderstorms on Earth) which is six times higher than the peak values detected by Voyager 1.

“These discoveries could only happen with Juno,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute, San Antonio. “Our unique orbit allows our spacecraft to fly closer to Jupiter than any other spacecraft in history, so the signal strength of what the planet is radiating out is a thousand times stronger. Also, our microwave and plasma wave instruments are state-of-the-art, allowing us to pick out even weak lightning signals from the cacophony of radio emissions from Jupiter. “

NASA’s Juno spacecraft will make its 13th science flyby over Jupiter’s mysterious cloud tops on July 16.