ESA is in a Race Against Time to Fix ExoMars' Parachutes

Getting a probe safely to the surface of Mars is not easy: Numerous landing attempts have crashed. Sufficiently slowing a lander in the thin air requires plenty of sophisticated kit, including designer heat shields, powerful retrorockets, and, sometimes, giant airbags. But the European-Russian ExoMars mission is struggling with a bit of technology that hails from the 18th century: parachutes. High-altitude tests earlier this year revealed that ExoMars's chutes were tearing as they were pulled from their bags. The European Space Agency has turned to NASA colleagues for help, and this week, a joint team begins tests to see whether redesigned bags and chutes now work, and if not, why. It could be their last chance to fix the problem and preserve a launch scheduled for July 2020—or face another 2 years of delay.

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China to Launch Lunar Sample Return Mission in Late 2020

China is aiming to launch its complex Chang’e-5 lunar sample return mission in late 2020, following launch vehicle-related delays.

The ambitious mission is now scheduled to launch atop the fifth Long March 5 heavy-lift rocket. The mission will launch from the Wenchang Satellite Launch Center situated on Hainan island.

Chang’e-5 will attempt to collect and return around two kilograms of lunar samples from a site close to Mons Rümker, a volcanic formation situated in the Oceanus Procellarum region of western edge of the near side of the moon.

The mission will involve the first robotic lunar orbit rendezvous. After the lander collects samples, an ascent vehicle will liftoff and dock with an orbiter module above the moon. A return capsule will then perform a ‘skip reentry’ following separation from the orbiter close to Earth. The return capsule will deliver the samples to the same site as where the country’s Shenzhou crewed missions land.

The complexity of the mission is considered by observers to be related future crewed lunar landing ambitions. The last lunar sample return, the Soviet Union’s 1976 Luna 24 mission, utilised a much simpler direct return approach.

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NASA IG has Concerns About the Europa Missions

Despite early-stage robust funding, NASA is facing serious management and schedule challenges in its ambitious Europa Clipper program that will send an orbiter and lander to Jupiter’s ice covered moon beginning in 2023.

“Specifically, NASA’s aggressive development schedule, a stringent conflict of interest process during instrument selection, and an insufficient evaluation of cost and schedule estimates has increased project integration challenges and led the Agency to accept instrument cost proposals subsequently found to be far too optimistic,” the audit found.

“Moreover, Clipper has had to compete with at least four other major JPL-managed projects for critical personnel resources, causing concern that the project may not have a sufficient workforce with the required skills at critical periods in its development cycle,” the report said.

The audit also noted that the Europa program’s biggest backer, John Culberson, no longer chairs the House appropriations subcommittee. The Republican Congressman from Texas was defeated in his reelection bid last year.

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China Remains on Course for 2020 Launch of Mars Missions

China remains on schedule to ready its first independent mission to Mars in time for a short launch window in mid-2020, according to a leading space official.

“Mars 2020 mission spacecraft is undergoing integration,” Wang Chi, director of the National Space Science Center (NSSC) in Beijing, told SpaceNews in a rare update on the mission.

Ambitiously, the mission consists of both an orbiter and a rover, with a total of 13 science payloads. The NSSC will be involved in integration of the instruments with the spacecraft.

The orbiter will be equipped with a high-resolution camera comparable to HiRise on board NASA’s Mars Reconnaissance Orbiter, a medium-resolution camera, subsurface radar, minearology spectrometer, neutral and energetic particle analyzers and a magnetometer.

The 240-kilogram solar-powered rover, nearly twice the mass of China’s Yutu lunar rovers, will carry a ground-penetrating radar, multispectral camera, a Laser Induced Breakdown Spectroscopy instrument and payloads for detecting the climate and magnetic environment.

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India Preparing for March 2018 Chandrayaan-2 Lunar Mission

The launch of the next Moon mission could be just four months away. India plans to return to the Moon in a big way with the ambitious Chandrayaan-2, which includes an orbiter, lander, and a small rover. If it all succeeds, it will be India's first soft landing on another world, and only the second such landing since the end of the Apollo and Luna era. For India, landing success would be "a stepping stone for future exploration missions to other planets," according to Indian Space Research Organisation Satellite Centre (ISAC) director M. Annadurai.

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NASA's Juno Probe is now Orbiting Jupiter

NASA’s Juno spacecraft, on a mission to study Jupiter’s interior and its magnetic field, successfully entered orbit around the planet late July 4 after completing a critical maneuver.

Juno fired its main engine as planned at 11:18 p.m. Eastern time July 4, slowing down the spacecraft as it made a close approach to Jupiter. The engine shut down 35 minutes later, within one second of its planned duration, placing the spacecraft into a 53-day orbit around the planet.

“We have the tone for burn cutoff on delta-v,” mission control at NASA’s Jet Propulsion Laboratory announced to cheers as they received telemetry from the spacecraft that the engine had shut down at the end of its burn. “Welcome to Jupiter.”

“NASA did it again,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute, at a press conference shortly after orbit insertion. “Now the fun begins with science.”

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Lander rocket exhaust effects on Europa regolith nitrogen assays

Lander rocket exhaust effects on Europa regolith nitrogen assays

Author:

Lorenz

Abstract:

Soft-landings on large worlds such as Europa or our Moon require near-surface retropropulsion, which leads to impingement of the rocket plume on the surface. Surface modification by such plumes was documented on Apollo and Surveyor, and on Mars by Viking, Curiosity and especially Phoenix. The low temperatures of the Europan regolith may lead to efficient trapping of ammonia, a principal component of the exhaust from monopropellant hydrazine thrusters. Deposited ammonia may react with any trace organics, and may overwhelm the chemical and isotopic signatures of any endogenous nitrogen compounds, which are likely rare on Europa. An empirical correlation of the photometrically-altered regions (‘blast zones’) around prior lunar and Mars landings is made, indicating A=0.02T1.5, where A is the area in m2 and W is the lander weight (thus, ~thrust) at landing in N: this suggests surface alteration will occur out to a distance of ~9 m from a 200 kg lander on Europa.

Is the Chinese Shijian-10 an X-37b or Dragon Equivalent?

Following in the steps of the Shijian-8 mission in 2006, China has launched the Shijian-10 recoverable satellite. The launch of Shijian-10 took place at 17:38 UTC on Tuesday using a Long March-2D launch vehicle from the 603 Launch Pad at the Jiuquan Satellite Launch Center’s LC43.

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ExoMars Spotted on its way to Mars

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1/3 Model of China's 2020 Mars Mission

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Okay, India.  You beat the Chinese to Mars (and the Russians going back for that matter...and the Japanese), time to get there again before the Chinese.

NASA Weighing two Discovery Mission Awards

NASA might end up funding two of the five mission concepts just selected for further study in the latest Discovery-class planetary science mission competition, a senior agency official said.

“We are not committing to selecting two, but we are stating that we may choose either one or two,” David Schurr, NASA’s deputy director for Planetary Science, wrote in an Oct. 1 email.

NASA winnowed a field of 27 competitors down to five Sept. 30, evenly splitting $15 million in one-year study money among two Venus concepts and three asteroid concepts in the long-awaited first down-select for the agency’s 13th small robotic solar-system mission competition. Final selection, of either one mission or two, is expected in September 2016, NASA said in a press release.

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Touchdown on Venus!

Touchdown on Venus: Analytic wind Models and a Heuristic Approach to Estimating Landing Dispersions

Author:

Lorenz

Abstract:

The ‘landing ellipse’ or region of uncertainty within which an unguided probe to Venus may be expected to land is calculated. The region can be usefully seen as the convolution of three different factors: an initial circular delivery uncertainty which is smeared at a grazing entry angle onto the planetary sphere, an along-track uncertainty due to atmospheric density and vehicle aerodynamic variations during hypersonic entry, and a descent dispersion due to uncertain and/or variable zonal and meridional winds. This decomposition allows the various contributions to be instructively exposed and conveniently traded-off, without conducting explicit entry and descent dynamics simulations. It is seen that for descent durations and delivery errors typical of past Venus missions, the zonal wind contribution (determined with an analytic fit to Pioneer Venus tracking data) generally dominates, causing a ~200 km E-W (99%) dispersion, with meridional dispersions being about 4 times smaller. However, when entry angles become shallower than about 8 degrees, the along-track dispersions may dominate, with the resulting ellipse becoming longer or wider depending on the entry azimuth. The analytic wind descriptions presented here may be applied to scientific problems, such as the dispersal of volcanic plumes or impact ejecta.

UK Beagle II Mars Probe Found Landed, but Only Partially Deployed

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Chinese Spacecraft Service Module Enters Lunar Orbit

A Chinese spacecraft service module has entered orbit around the moon, months after being used in the country's landmark test flight that sent a prototype sample-return capsule on a flight around the moon and returned it to Earth.

The service module from China's circumlunar test flight arrived in orbit around the moon this week, according to Chinese state media reports. The spacecraft is currently flying in an eight-hour orbit that carries it within 125 miles (200 kilometers) of the lunar surface at its closest point, and out to a range of 3,293 miles (5,300 km) at its highest point.

According to chief engineer Zhou Jianlian of the Beijing Aerospace Control Center the module will make its second and third braking in the early hours of today (Jan. 12) and tomorrow, Beijing time. Doing so will enable the module to enter a 127-minute orbit around the moon, Zhou said.

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NASA's Maven Finds Hints of Martian Atmospheric Loss due to Solar Wind

Early discoveries by NASA's newest Mars orbiter are starting to reveal key features about the loss of the planet's atmosphere to space over time.

The findings are among the first returns from NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission, which entered its science phase on Nov. 16. The observations reveal a new process by which the solar wind can penetrate deep into a planetary atmosphere. They include the first comprehensive measurements of the composition of Mars' upper atmosphere and electrically charged ionosphere. The results also offer an unprecedented view of ions as they gain the energy that will lead to their to escape from the atmosphere.

"We are beginning to see the links in a chain that begins with solar-driven processes acting on gas in the upper atmosphere and leads to atmospheric loss," said Bruce Jakosky, MAVEN principal investigator with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. "Over the course of the full mission, we'll be able to fill in this picture and really understand the processes by which the atmosphere changed over time."

On each orbit around Mars, MAVEN dips into the ionosphere - the layer of ions and electrons extending from about 75 to 300 miles above the surface. This layer serves as a kind of shield around the planet, deflecting the solar wind, an intense stream of hot, high-energy particles from the sun.

Scientists have long thought that measurements of the solar wind could be made only before these particles hit the invisible boundary of the ionosphere. MAVEN's Solar Wind Ion Analyzer, however, has discovered a stream of solar-wind particles that are not deflected but penetrate deep into Mars' upper atmosphere and ionosphere.

Interactions in the upper atmosphere appear to transform this stream of ions into a neutral form that can penetrate to surprisingly low altitudes. Deep in the ionosphere, the stream emerges, almost Houdini-like, in ion form again. The reappearance of these ions, which retain characteristics of the pristine solar wind, provides a new way to track the properties of the solar wind and may make it easier to link drivers of atmospheric loss directly to activity in the upper atmosphere and ionosphere.

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China Details Space Exploration Plans

China hopes to put a rover on Mars around 2020, complete a manned space station around 2022 and test a heavy carrier rocket around 2030, a top space scientist revealed Sunday.

Lei Fanpei, chairman of the China Aerospace Science and Technology Corporation (CASC), the main contractor for the space program, revealed the details in an interview with Xinhua after the launch of CBERS-4, a satellite jointly developed with Brazil, from the Taiyuan base, by a Long March-4B rocket.

It was the 200th flight of the Long March variants since April 1970 when a Long March-1 carried China's first satellite, Dongfanghong-1, into space.

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NASA/APL's Europa Clipper Mission Moves Ahead, Selects Solar Panels Over RTGs

Designers of a proposed NASA mission to study the icy and potentially habitable Jupiter moon of Europa have decided to use solar panels rather than a nuclear power source for the spacecraft, while keeping spacecraft’s launch options open.

In an Oct. 3 presentation at the 65th International Astronautical Congress here, Europa Clipper deputy project manager Thomas Magner of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said that using large solar panels for the mission was both technically viable and less expensive than a radioisotope thermoelectric generator (RTG).

“For the last two years, we did extensive risk reduction work looking at whether solar is feasible,” Magner said. “We found that solar works fine, so our final decision about two months ago was to go to solar.”

Those tests included subjecting solar cells to a range of temperatures and radiation conditions the spacecraft would experience during the mission. Engineers also examined whether the large solar panels, with an area of 50 square meters, would cause jitter that would adversely affect the spacecraft’s scientific instruments.

Europa Clipper would not be the first solar-powered Jupiter mission: NASA’s Juno spacecraft, launched in 2011 and scheduled to go into orbit around Jupiter in July 2016, also uses solar panels. Magner said they tested solar cells used for Juno, exposing them to a wider range of temperatures to reflect the different trajectory that Europa Clipper would take to reach Jupiter.

A solar-powered Europa Clipper would be less expensive than one that used an RTG, Magner said, although he did not quantify the difference in costs. It would eliminate the need for an environmental impact statement that is required for nuclear-powered spacecraft and launch approval from the director of the Office of Science and Technology Policy. It would also free up constrained supplies of plutonium-238, the isotope used in RTGs, for other potential missions.

Magner said after his presentation that using solar power would increase the spacecraft’s mass in order to accommodate the panels and structures, although it remained well within current design margins. A few other tweaks would be needed to the spacecraft’s design to incorporate the solar panels, he said.

While NASA has not yet decided to develop Europa Clipper or any other mission to Europa, Magner said the project passed a NASA-sponsored mission concept review in September “with flying colors” and predicted the agency would move ahead with it.

“We expect later this year for NASA to select us as the mission they want to go forward with to Europa, and we’ll get a new start early next year,” he said.

If NASA does choose to proceed with Europa Clipper, it will defer a choice of launch vehicle for several years. One mission design could use an existing rocket, such as the workhorse Atlas 5. In that scenario, Europa Clipper would launch in mid-2022 and, after a series of gravity assist flybys of Venus and Earth, would arrive at Jupiter in early 2030.

An alternative approach would use NASA’s still-in-development Space Launch System heavy-lift rocket to send Europa Clipper on a direct trajectory to Jupiter. A mid-2022 launch would allow the spacecraft to reach Jupiter in fewer than three years, without the need of any flybys.

Launching on SLS, Magner said, would reduce the costs of operating Europa Clipper given the much shorter travel time to Jupiter, and also simplify the thermal design since the spacecraft would not have to perform a Venus flyby in order to reach Jupiter. However, it was unclear how much more Europa Clipper would have to pay for an SLS launch.

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Comprehensive Model of Enceladus' Geysers

HOW THE GEYSERS, TIDAL STRESSES, AND THERMAL EMISSION ACROSS THE SOUTH POLAR TERRAIN OF ENCELADUS ARE RELATED

Authors:

Porco et al

Abstract:

We present the first comprehensive examination of the geysering, tidal stresses, and anomalous thermal emission across the south pole of Enceladus and discuss the implications for the moon's thermal history and interior structure. A 6.5 yr survey of the moon's south polar terrain (SPT) by the Cassini imaging experiment has located ~100 jets or geysers erupting from four prominent fractures crossing the region. Comparing these results with predictions of diurnally varying tidal stresses and with Cassini low resolution thermal maps shows that all three phenomena are spatially correlated. The coincidence of individual jets with very small (~10 m) hot spots detected in high resolution Cassini VIMS data strongly suggests that the heat accompanying the geysers is not produced by shearing in the upper brittle layer but rather is transported, in the form of latent heat, from a sub-ice-shell sea of liquid water, with vapor condensing on the near-surface walls of the fractures. Normal stresses modulate the geysering activity, as shown in the accompanying paper; we demonstrate here they are capable of opening water-filled cracks all the way down to the sea. If Enceladus' eccentricity and heat production are in steady state today, the currently erupting material and anomalous heat must have been produced in an earlier epoch. If regional tidal heating is occurring today, it may be responsible for some of the erupting water and heat. Future Cassini observations may settle the question.

Enceladus' Geysers are Caused by Tidal Forces

TIDALLY MODULATED ERUPTIONS ON ENCELADUS: CASSINI ISS OBSERVATIONS AND MODELS

Authors:

Nimmo et al

Abstract:

We use images acquired by the Cassini Imaging Science Subsystem (ISS) to investigate the temporal variation of the brightness and height of the south polar plume of Enceladus. The plume's brightness peaks around the moon's apoapse, but with no systematic variation in scale height with either plume brightness or Enceladus' orbital position. We compare our results, both alone and supplemented with Cassini near-infrared observations, with predictions obtained from models in which tidal stresses are the principal control of the eruptive behavior. There are three main ways of explaining the observations: (1) the activity is controlled by right-lateral strike slip motion; (2) the activity is driven by eccentricity tides with an apparent time delay of about 5 hr; (3) the activity is driven by eccentricity tides plus a 1:1 physical libration with an amplitude of about 0fdg8 (3.5 km). The second hypothesis might imply either a delayed eruptive response, or a dissipative, viscoelastic interior. The third hypothesis requires a libration amplitude an order of magnitude larger than predicted for a solid Enceladus. While we cannot currently exclude any of these hypotheses, the third, which is plausible for an Enceladus with a subsurface ocean, is testable by using repeat imaging of the moon's surface. A dissipative interior suggests that a regional background heat source should be detectable. The lack of a systematic variation in plume scale height, despite the large variations in plume brightness, is plausibly the result of supersonic flow; the details of the eruption process are yet to be understood.

Exolance Mission to Look for Life on Mars

To find life on Mars, some scientists believe you might want to look underground for microbes that may be hiding from the harsh radiation that bathes the red planet’s surface. Various NASA rovers have scraped away a few inches at a time, but the real paydirt may lie a meter or two below the surface.

New concepts for Mars-probing rovers would use Martian wind to move around the planet. James Williams gets a look at two of the designs.

NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (Cornell University), and M. Wolff (Space Science Institute, Boulder)

That’s too deep for existing instruments, so a team of space enthusiasts has launched a more ambitious idea: dropping arrow-like probes from the Martian atmosphere to pierce the soil like bunker-busting bug catchers.

The “ExoLance” project aims to drop ground-penetrating devices, each of which would carry a small chemical sampling test to find signs of life.

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