Space Sunday: hearing Mars, looking at Bennu and roving the Moon

One of InSight’s 2.2 metre (7-ft) wide solar panels was imaged by the lander’s Instrument Deployment Camera fixed to the elbow of its robotic arm. Credit: NASA/JPL

It’s always a remarkable time when a new mission arrives on or around another planet in our solar system, so forgive me if I once again kick-off a Space Sunday with NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander, which touched down on Mars just 10 days ago.

Over the course of the last several days, NASA has been putting the lander’s 1.8 metre (6 ft) long robot arm through its paces in readiness for operations to commence. The arm has multiple functions to perform, the most important of which is to place two major science experiments on the surface of Mars. The arm is also home to one of the two camera systems on the Lander.

InSight’s deck partially imaged be the IDC on the lander’s robot arm. Credit: NASA/JPL; annotations: Inara Pey

Very similar to the Navcam systems used by both Opportunity and Curiosity, the camera is called the Instrument Deployment Camera (IDC). It is mounted above the arm’s “elbow” and has a 45-degree field of view. As well as offering a first-hand view of everything the robot arm is doing, IDC can provide colour, panoramic views of the terrain surrounding the landing site.

The arm hasn’t as yet been fully deployed, but in being put through its paces, it has allowed the IDC to obtain some tantalising views of both the lander and its surroundings.

Left: a view of the ground scoop on the robot arm, again seen with the grapple stowed. Note this image was captured with the protective dust cover still in place over the camera lens. Right: a view of InSight’s deck. The copper-coloured hexagonal object is the protective cover for the seismometer, and the grey dome behind it is the wind and thermal shield which will be placed over the seismometer after its deployed. The black cylinder on the left is the heat probe, which will drill up to 5 metres into the Martian surface. Image: NASA/JPL

Some powering-up of science systems has also occurred, notably Auxiliary Payload Sensor Systems (APSS) suite. The air pressure sensors immediately started recording changes in air pressure across the lander’s deck indicative of a wind passing over InSight at around 5 to 7 metres a second (10-15mph). However, the biggest surprise can from the seismometer designed to listen to the interior of Mars.

As this was tested, it started recording a low-frequency vibration in time with the wind recordings from APSS. These proved to be the wind blowing over the twin 2.2-metre circular solar panels, moving their segments slightly, causing the vibrations, which created a sound at the very edge of human hearing. NASA later issued recordings of the sounds, some of which were adjusted in frequency to allow humans to more naturally “hear” the Martian wind.

The InSight lander acts like a giant ear. The solar panels on the lander’s sides respond to pressure fluctuations of the wind. It’s like InSight is cupping its ears and hearing the Mars wind beating on it.

– Tom Pike, InSight science team member, Imperial College London

Once on the surface of Mars and beneath its protective dome, the seismometer will no longer be able to hear the wind – but it will hear the sound of whatever might be happening deep within Mars. So this is likely to be the first of many remarkable results from this mission.

To Touch an Asteroid

NASA’s OSIRIS-REx (standing for Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer), launched in September 2016, has arrived at its science destination, the near-Earth asteroid Bennu, after a journey of two billion kilometres.  It will soon start a detailed survey of the asteroid that will last around  year.

Bennu as seen by OSIRIS-REx. Credit: NASA

Bennu, which is approximately 492 m (1,614 ft) in diameter, is classified as a near-Earth object (NEO), meaning it occupies an orbit around the Sun that periodically crosses the orbit of Earth. Current orbital predictions suggest it might collide with Earth towards the end of the 22nd Century.

To this end, OSIRIS-REx will analyse the thermal absorption and emissions of the asteroid and how they affect its orbit. This data should help scientists to more accurately calculate where and when Bennu’s orbit will intersect Earth’s, and thus determine the likelihood of any collision. It could also be used to better predict the orbits of other near-Earth asteroids.

Bennu is primarily comprised of carbonaceous material, a key element in organic molecules necessary for life, as well as being representative of matter from before the formation of Earth. Organic molecules, such as amino acids, have previously been found in meteorite and comet samples, indicating that some ingredients necessary for life can be naturally synthesized in outer space. So, by gaining samples of Bennu for analysis, we could answer many questions on how life may have arisen in our solar system – and OSIRIS-REx will attempt to do just that.

Towards the end of the primary mission, OSIRIS-REx will be instructed to slowly close on a pre-selected location on the asteroid, allowing a “touch and go” sampling arm make contact with the surface for around 5 seconds. During that moment, a burst of nitrogen gas will be fired, hopefully dislodging dust and rock fragments, which can be caught by the sampling mechanism. Up to three such sample “hops” will be made in the hope that OSIRIS-REx will gather between 60 and 2000 grams (2–70 ounces) of material. Then, as its departure window opens in March 2021, OSIRIS-REx will attempt a 30-month voyage back to Earth to deliver the samples for study here.

China Goes To The Lunar Far side

China launched its long-awaited lander and rover mission to the far side of the Moon on Saturday, December 8th local time. The Chang’e-4 lunar probe mission, named after the moon goddess in Chinese mythology, launched on a Long March 3B rocket from the south-western Xichang launch centre at 02:23 local (1823 GMT, Friday, December 7th).

The mission is daring one; unlike the relatively flat side of the Moon that is tidally locked to always face Earth, the lunar far side (often mistakenly called the “dark side”, even though it receives almost as much sunlight as the face turned towards Earth) is a rugged, mountainous place never before directly visited by a vehicle from Earth.

Moment of lift-off. A long March 3B rocket launches China’s Chang’e 4 lunar probe from the Xichang Satellite Launch Centre on December 8th, 2018 (local time). Credit: Jiang Hongjing / Xinhua / Zuma

Unlike other recent Chinese mission,s Chang’e-4 launched in relative secrecy; it was only after the vehicle had performed its trans-lunar injection (TLI) manoeuvre and was en-route to the Moon that the China Aerospace Science and Technology Corporation (CASC), officially announced it was on its way.

The flight  to the Moon will take five days, but Chang’e 4 will not land until the start of January 2019, after the sun has risen over the planned landing site within the Von Kármán crater in late December. To facilitate communications with Earth – there is obviously no direct line between the Moon’s far side and Earth – Chang’e 4 will use the Queqiao relay satellite launched in May 2018 to a halo orbit at the Earth-Moon L2 point, 65,000-85,000 km beyond the Moon. From that point, the satellite can “see” both the far side of the Moon and Earth, allowing it to act as a communications relay.

How Chang’e 4 will communicate with Earth. Credit: The Planetary Society

The landing site is situated in the South Pole-Aitken Basin (SPA), a 2,500-km wide, 12-km deep ancient impact crater of intense scientific interest which could contain exposed material from the moon’s upper mantle. Investigation of the composition of areas of the SPA could reveal clues to the history of the moon and development of the wider solar system. The 4-tonne lander / rover combination carries cameras and science payloads to analyse the lunar surface geology  in the area. and to monitor subsurface, solar wind interactions. It will also carry out low-frequency radio observations in the unique radio-quiet environment on the far side of the Moon.

In addition to the instruments to probe the lander and rover’s environment, Chang’e 4 carries a mini biosphere experiment designed by 28 Chinese universities, containing potato and Arabidopsis seeds and silkworm eggs, is also a part of the mission to test respiration and photosynthesis in the low-gravity and high-radiation environment on the lunar surface.

I’ll have more on this mission in the new year.

SpaceX: two Launches, three flights, one landing

On Monday, December 3rd, SpaceX launched 64 satellites into orbit atop a single Falcon 9 booster, one of the largest multiple launches undertaken. The flight lifted-off from Space Launch Complex 4E at Vandenberg Air Force Base in California, and was of particular note not only because of its payload, but because it marked the third launch and recovery of the same Falcon 9 first stage in just 6 months.

The stage, officially called B1046, had previously flown on May 11th, 2018, lifting Bangabandhu-1, the first Bangladeshi geostationary communications and broadcasting satellite to space from Pad 39A at Kennedy Space Centre. On August 7th, 2018, the stage was again used in the launch of the Indonesian telecommunications satellite Merah Putih, launched  from Space Launch Complex 40 at Cape Canaveral Air Force Station. On both of these missions and that of December 3rd, B1046 successfully landed at sea on one of the company’s Autonomous Drone Landing Ships.

The mission carried to orbit 15 micro-satellites and 49 CubeSats belonging to 34 different clients including public, private and university sources from 17 different countries including South Korea, France and Kazakhstan. Two of the CubSats carried unusual cargoes. One bore the ashes of Robert Henry Lawrence Jr., the first African-American astronaut selected for a national space programme, who was killed in 1967 while training a junior pilot. The second carried Orbital Reflector, by artist Trevor Paglen, an inflatable sculpture designed to inflate and orbit the earth for several weeks before disintegrating upon re-entry into Earth’s atmosphere.

The mission marked 32nd successful landing of a Falcon 9 first stage, meaning almost half the Falcon 9 first stages flown have been successfully recovered. An attempt was made to recover a payload fairing using the fast capture ship Mr Steven. The attempt was unsuccessful, the fairing splashing down instead. But it remained afloat, allowing Mr Steven to recover it.

Two days later, on December 5th, SpaceX launched another Falcon 9, this time from Space Launch Complex 40 at Cape Canaveral Air Force Station and carrying a Dragon resupply vehicle loaded with supplies – including Christmas goodies – destined for the International Space Station. The Dragon capsule was making its second trip to the ISS, while the launch was the first for the Falcon first stage.

It had been hoped the latter would make a dry touchdown at Canaveral Air Force Station. Unfortunately, a failure with one of the “grid fins” that deploy from the base of the stage to hold it steady during descent caused a loss of control, and the stage splashed down just off the Florida coast. However, it remained afloat, allowing an at-sea recovery to be made.

Left: the Dragon capsule “parked” just off of the International Space Station, December 8th, 2018. Right: moment of capture – the ISS robot arm takes hold of the Dragon capsule ready to dock it with the station. Credit: NASA

As well as the Christmas goodies for the crew, this 16th ISS resupply mission flown by SpaceX carried 2,573 kg of science equipment and supplies aloft. As is usual for such mission, the Dragon took two days to “catch up” with the ISS, with the rendezvous and docking – which uses its robot arm to grapple the Dragon and manoeuvre it to a vacant docking port – completed successfully on Saturday, December 8th, after an issue with NASA communications networks delayed it by a few hours.

The flight marked the 20th successful launch for the Falcon 9 system in a single year, setting a new record for SpaceX.

Soyuz Resumes Flights

Less than two months after the aborted launch of Soyuz MS-10 (read here for more), Roscosmos resumed crewed flights to the ISS with the successful launch of Soyuz MS-11 on December 3rd, 2018. Aboard the spacecraft were Russian cosmonaut Oleg Kononenko, American astronaut Anne McClain and Canadian astronaut David Saint-Jacques. All three will stay on the station for six and a half months, briefly overlapping with the current ISS crew of Serena Auñón-Chancellor, Alexander Gerst and Sergey Prokopyev.

Soyuz MS-11 lifts off from the Baikonur Cosmodrome, December 3rd, 2018. Credit: NASA TV

An investigation led by Roscosmos, with NASA as an observer, concluded that one of the four side boosters on the Soyuz MS-10 vehicle had been incorrectly attached to the rocket core, causing it impact the core on separation. While the rocket was destroyed, the two crew on board safely escaped via the rocket’s launch abort system. Since that incident there have been four successful uncrewed Soyuz launches, giving Roscosmos high confidence MS-11 would be safe. Following successful orbital insertion, the Soyuz successfully rendezvoused and docked with the ISS six hours after launch.

With both Soyuz MS-11 and the Dragon resupply mission docked, the ISS currently has a fully complement of six vehicles docked with it. The remaining four being: the Soyuz MS-09 that will return Auñón-Chancellor, Gerst and Prokopyev to Earth, two Russian Soyuz Progress resupply vehicles, and an American Cygnus resupply vehicle.

A graphic showing the location of all six vehicles docked at the ISS on December 8th, 2018. Credit: NASA