In this SETI Institute blog, Mars expert Pascal Lee talks about a Mission to Phobos and Deimos: Exploring the Moons of Mars :
After five decades of spacecraft exploration of the Solar System, the origin of two moons of Mars, Phobos and Deimos, remains a perplexing mystery. Are they a) captured asteroids, b) remnants of Mars’s formation, or c) reaccreted impact ejecta from Mars?
These small bodies lie at the crossroads of a wide range of outstanding issues in solar system research, and elucidating their origin tests our understanding of planet formation and solar system evolution, including the question of how water and organics became available on Earth. Meanwhile, Phobos and Deimos are emerging as key stepping stones in the future human exploration of Mars.
Dr. Lee’s talk will cover the history of our efforts to understand Phobos and Deimos, and new prospects in their exploration.
SPHERE — the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument — has been installed on ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile and has achieved first light. This powerful new facility for finding and studying exoplanets uses multiple advanced techniques in combination. It offers dramatically better performance than existing instruments and has produced impressive views of dust discs around nearby stars and other targets during the very first days of observations. SPHERE was developed and built by a consortium of many European institutes, led by the Institut de Planétologie et d’Astrophysique de Grenoble, France, working in partnership with ESO. It is expected to revolutionise the detailed study of exoplanets and circumstellar discs.
This infrared image shows the dust ring around the nearby star
HR 4796A in the southern constellation of Centaurus. It was oneof the first produced by the SPHERE instrument soon after it was
installed on ESO’s Very Large Telescope in May 2014. It shows
not only the ring itself with great clarity, but also reveals the
power of SPHERE to reduce the glare from the very bright star
— the key to finding and studying exoplanets in future
SPHERE passed its acceptance tests in Europe in December 2013 and was then shipped to Paranal. The delicate reassembly was completed in May 2014 and the instrument is now mounted on VLT Unit Telescope 3. SPHERE is the latest of the second generation of instruments for the VLT (the first three were X-shooter, KMOS and MUSE).
SPHERE combines several advanced techniques to give the highest contrast ever reached for direct planetary imaging — far beyond what could be achieved with NACO, which took the first ever direct image of an exoplanet. To reach its impressive performance SPHERE required early development of novel technologies, in particular in the area of adaptive optics, special detectors and coronagraph components.
“SPHERE is a very complex instrument. Thanks to the hard work of the many people who were involved in its design, construction and installation it has already exceeded our expectations. Wonderful!” says Jean-Luc Beuzit, of the Institut de Planétologie et d’Astrophysique de Grenoble, France and Principal Investigator of SPHERE.
SPHERE’s main goal is to find and characterise giant exoplanets orbiting nearby stars by direct imaging [1]. This is an extremely challenging task as such planets are both very close to their parent stars in the sky and also very much fainter. In a normal image, even in the best conditions, the light from the star totally swamps the weak glow from the planet. The whole design of SPHERE is therefore focused on reaching the highest contrast possible in a tiny patch of sky around the dazzling star.
The first of three novel techniques exploited by SPHERE is extreme adaptive optics to correct for the effects of the Earth’s atmosphere so that images are sharper and the contrast of the exoplanet increased. Secondly, a coronagraph is used to block out the light from the star and increase the contrast still further. Finally, a technique called differential imaging is applied that exploits differences between planetary and stellar light in terms of its colour or polarisation — and these subtle differences can also be exploited to reveal a currently invisible exoplanet (ann13069, eso0503) [2].
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These sequences show the SPHERE exoplanet imaging instrument
during installation on the VLT. The second section shows an
engineer working on the complex optics and electronics of the
SPHERE instrument, shortly before it was installed and
achieved successful first light in May 2014.
SPHERE was designed and built by the following institutes: Institut de Planétologie et d’Astrophysique de Grenoble; Max-Planck-Institut für Astronomie in Heidelberg; Laboratoire d’Astrophysique de Marseille; Laboratoire d’Etudes Spatiales et d’Instrumentation en Astrophysique de l’Observatoire de Paris; Laboratoire Lagrange in Nice; ONERA; Observatoire de Genève; Italian National Institute for Astrophysics coordinated by the Osservatorio Astronomico di Padova; Institute for Astronomy, ETH Zurich; Astronomical Institute of the University of Amsterdam; Netherlands Research School for Astronomy (NOVA-ASTRON) and ESO.
During the first light observations several test targets were observed using the many different modes of SPHERE. These include one of the best images so far of the ring of dust around the nearby star HR 4796A. It not only shows the ring with exceptional clarity but also illustrates how well SPHERE can suppress the glare of the bright star at the centre of the picture.
Following further extensive tests and science verification observations SPHERE will be made available to the astronomical community later in 2014.
“This is just the beginning. SPHERE is a uniquely powerful tool and will doubtless reveal many exciting surprises in the years to come,” concludes Jean-Luc Beuzit.
NASA’s flying saucer-shaped test vehicle is ready to take to the skies from the U.S. Navy’s Pacific Missile Range Facility in Kauai, Hawaii, for its first engineering shakeout flight.
The first launch opportunity for the test vehicle is June 3, when the launch window opens at 8:30 a.m. HST. The test will be carried live on NASA TV and streamed on the Web. The Low Density Supersonic Decelerator (LDSD) will gather data about landing heavy payloads on Mars and other planetary surfaces.
“The agency is moving forward and getting ready for Mars as part of NASA’s Evolvable Mars campaign,” said Michael Gazarik, associate administrator for Space Technology at NASA Headquarters in Washington. “We fly, we learn, we fly again. We have two more vehicles in the works for next year.”
As NASA plans increasingly ambitious robotic missions to Mars, laying the groundwork for even more complex human science expeditions to come, accommodating extended stays for explorers on the Martian surface will require larger and heavier spacecraft.
The objective of the LDSD project is to see if the cutting-edge, rocket-powered test vehicle operates as it was designed — in near-space at high Mach numbers.
“After years of imagination, engineering and hard work, we soon will get to see our Keiki o ka honua, our ‘boy from Earth,’ show us its stuff,” said Mark Adler, project manager for the Low Density Supersonic Decelerator at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “The success of this experimental test flight will be measured by the success of the test vehicle to launch and fly its flight profile as advertised. If our flying saucer hits its speed and altitude targets, it will be a great day.”
The way NASA’s saucer climbs to test altitude is almost as distinctive as the test vehicle itself.
“We use a helium balloon — that, when fully inflated, would fit snugly into Pasadena’s Rose Bowl — to lift our vehicle to 120,000 feet,” said Adler. “From there we drop it for about one and a half seconds. After that, it’s all about going higher and faster — and then it’s about putting on the brakes.”
A fraction of a second after dropping from the balloon, and a few feet below it, four small rocket motors will fire to spin up and gyroscopically stabilize the saucer. A half second later, a Star 48B long-nozzle, solid-fueled rocket engine will kick in with 17,500 pounds of thrust, sending the test vehicle to the edge of the stratosphere.
“Our goal is to get to an altitude and velocity which simulates the kind of environment one of our vehicles would encounter when it would fly in the Martian atmosphere,” said Ian Clark, principal investigator of the LDSD project at JPL. “We top out at about 180,000 feet and Mach 4. Then, as we slow down to Mach 3.8, we deploy the first of two new atmospheric braking systems.”
The project management team decided also to fly the two supersonic decelerator technologies that will be thoroughly tested during two LDSD flight tests next year.
If this year’s test vehicle flies as expected, the LDSD team may get a treasure-trove of data on how the 6-meter supersonic inflatable aerodynamic decelerator (SIAD-R) and the supersonic parachute operate a full year ahead of schedule.
The SIAD-R, essentially an inflatable doughnut that increases the vehicle’s size and, as a result, its drag, is deployed at about Mach 3.8. It will quickly slow the vehicle to Mach 2.5 where the parachute, the largest supersonic parachute ever flown, first hits the supersonic flow. About 45 minutes later, the saucer is expected to make a controlled landing onto the Pacific Ocean off Hawaii.
NASA TV will carry live images and commentary of LDSD engineering test. The test vehicle itself carries several onboard cameras. It is expected that video of selected portions of the test, including the rocket-powered ascent, will be downlinked during the commentary. Websites streaming live video of the test include:www.nasa.gov/nasatv
NASA’s Space Technology Mission Directorate in Washington funds the LDSD mission, a cooperative effort led by JPL. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages LDSD within the Technology Demonstration Mission Program Office. NASA’s Wallops Flight Facility in Virginia is coordinating support with the Pacific Missile Range Facility and providing the balloon systems for the LDSD test.
Update: Here is a NASA press conference about the test:
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