Sunday, October 16th, 2016, marked the first in two important dates during the month for the European Space Agency. It was at 14:42 UT that the Schiaparelli Entry, Descent and Landing Demonstrator Module (EDM) separated from its parent orbiter, the Mars Trace Gas Orbiter (TGO) as the two entered the final three days of their approach to Mars.
TGO / Schiaparelli form the first part of the European Space Agency’s ExoMars mission, which represents an ambitious expansion of European studies of Mars by placing TGO in orbit around Mars where it will study the atmosphere, then following it in 2020 with a rover mission, for which Schiaparelli is a pre-cursor.
It’s been a mission a long time in the making – in the case of the still-to-fly rover mission, more than a decade has already passed since its inception, was a certain amount of the delay due to NASA. Originally, both TGO and rover were to launch aboard Russian vehicles, but a 2009 agreement with the US space agency resulted in a comprehensive re-design of both missions, which were to fly aboard / as part of US vehicles / missions (the TGO science was to have flown on NASA’s Mars Science Orbiter (MSO) mission, for example). However, NASA unilaterally cancelled the agreement at the start of 2012 due to cost overruns with the James Webb Space Telescope, forcing a further complete redesign of both TGO and rover vehicle.
October 16th was an important milestone for the mission, as it saw TGO release the Schiaparelli demonstrator in what was a textbook operation, watched via telemetry at mission control, with a nine-and-a-half-minute time delay separating events from receipt of data. It was a single line of that data that indicated separation had been successful.
Schiaparelli will not proceed ahead of TGO, their paths slowly diverging, until Wednesday, October 19th, when TGO will enter its preliminary orbit around Mars. Over the course of the next year, that orbit will be further and further refined until the vehicle is correctly positioned to commence its 5-year primary mission. For this, TGO will perform detailed, remote observations of the Martian atmosphere, searching for evidence of gases which may be possible biological importance, such as methane and its degradation products. At the same time, TGO will continue to image Mars, and act as a communications for both Schiaparelli and for the 2020 rover vehicle.
At the same time as TGO enters that preliminary orbit, Schiaparelli will commence a much more hazardous journey to the surface of Mars. This will commence with the 2.4 metre (8ft) diameter EDM slamming into the Martian atmosphere at 21,000 km/h (13,000 mph; 5.8 km/s / 3.6 mi/s), where it will use a heat shield and atmospheric friction to rapidly decelerate.
Once through the upper reaches of the Martian atmosphere, the EDM will jettison the heat shield and deploy a parachute system from its protective aeroshell. This will carry it down to an altitude of several dozen metres above the surface, before the lander drops clear of the aeroshell. Rocket motors on the lander will then fire, slowly bringing it to around 2 metres (6.6ft) above the ground, where they’ll shut down, allowing Schiaparelli to drop to the surface, the impact cushioned by a crushable structure designed to deform and absorb the final touchdown impact. The entry, descent and landing should take around 6 minutes.
Throughout the descent, Schiaparelli will record a number of atmospheric parameters and lander performance, with a camera system recording its descent. Once on the surface, it will measure the wind speed and direction, humidity, pressure and surface temperature, and determine the transparency of the atmosphere. It will also make the first measurements of electrical fields at the planet’s surface.
The EDM will only operate for a short time on the surface of Mars – between 2 and 8 sols (Martian days) is the estimate. Its small size, coupled with the limited amount of space within it, means it is not equipped with solar arrays to re-charge its battery systems. However, the core aim of the mission is to better characterise the Martian atmosphere and test critical descent and landing systems needed for future missions, rather than carrying out long-term surface studies.
The planned landing point for Schiaparelli is Meridiani Planum, the region NASA’s Opportunity rover has been exploring since 2004. The EDM will be arriving during the dust storm season, which will provide a unique chance to characterize a dust-loaded atmosphere during entry and descent, and to conduct surface measurements associated with a dust-rich environment.
I’ll have more on TGO and Schiaparelli in my next Space Sunday update.
The Glaciers and Frozen Sea of Mars
As noted above, ESA’s Mars Express has been observing Mars for almost 12 years. During that time it has found some remarkable evidence of the planet’s past history. Most recently, it has been studying the chaotic terrain between the Red Planet’s southern highlands and the northern lowlands. This boundary is one of the oldest and most prominent features on Mars, marking a height difference of several kilometres – and it is where evidence for Mars’ glacial past has been found.
Colles Nili, seen above (“colles” coming from the Latin for “hill”), is the erosional remnants of a former plateau. It exhibits many of the classic signs of repeated glaciation: soundly rounded hills, rounded valleys with smooth, layered deposits gently sloping away from the sides of the hills, with a fine series of ridges and troughs covering the channels between them.
Analysis of the region indicates it has ice buried beneath it, with the landforms likely shaped by the passage of glaciers across it a multiple occasions within the last 100 million years. As the ice sheet retreated, so it was gradually covered by erosional debris and dust.
A high-resolution image of Colles Nili from a slightly different perspective reveals the rounded hills, together with the faint ridges and troughs, many of which cut through impact craters, suggesting the passage of glaciers over several hundred million years. Credit: ESA / DLR / FU Berlin
This s not the only evidence Mars Express has found for water ice once being present on Mars. In 2005, the orbiter examined the equatorial region of Elysium Planitia, where a massive frozen sea was discovered, estimated to be 800 km (500 mi) by 900 km (560 mi) in size, with the ice extending to a depth of 45m(148 ft).
The evidence for the sea initially came from images showing the flat plain is covered with irregular block-like shapes strongly resembling rafts of fragmented sea ice seen off the costs of Antarctica. They’ve long since been covered by dust and other material, with the water which formed them thought to have originally been an outflow from the Cerberus Fossae fissures about 2 to 10 million years ago. The region, which also has elevated traces of methane gas, is slated for investigation by NASA’s InSight mission in 2018.
China Readies for Space Lab Crew Launch
Following the successful launch of its second orbital laboratory, Tiangong-2 (“Heavenly Palace 2”), from their Jiuquan Satellite Launch Centre, the Chinese are now ready to launch the first crew to the facility aboard their Shenzhou-11 vehicle.
Taikonauts Jing Haipeng and Chen Dong, are due to lift-off from the Jiuquan Satellite Launch Centre at 06:30 local time, on Monday, October 17th (23:30 UT, October 16th). Their launch vehicle will be the veritable Long March 2F booster, and lift-off will mark the start of a 33-day mission, of which 30 days will be spent aboard the orbiting laboratory – twice as long as either of the missions flown to China’s first orbital output, Tiangong-1.
“This mission is characterised by its longer duration and more tests,” Chen Dong, the junior astronaut on the mission, told reporters in a televised news conference. “We will focus on improving our ability to handle emergencies in orbit, medical first aid, mutual rescue capabilities and space experiments.”
Mission commander Jing Haipeng, willing making his third trip into orbit with this mission – he previously commanded the first crewed mission to Tiangong-1 – and will celebrate his 50th birthday aboard Tiangong-2. Both he and Chen Dong are officers serving in the People’s Liberation Army Air Force.
Tiangong-2 is equipped with a diverse range of science experiments and equipment, much of which will be used by the crew. There are fourteen experiments focused on cutting-edge technologies such as space materials science and space life science. Included in the equipment aboard the laboratory is a gamma-ray detector, and a space-Earth quantum key distribution and laser communications experiment to be used in conjunction with the Mozi Quantum Science Satellite, and the world’s first-ever in-space cold atomic fountain clock. Tiangong-2 also has its own robot arm the crew are expected to test, and Shenzhou-11 is also carrying a number of experiments up to the orbital facility which have been designed by Hong Kong school children.
A New Member of the Solar System – Maybe
While much of recent space news has been on the subject of exoplanets, a team of students at the University of Michigan has discovered a new dwarf planet in our own solar system, as reported by the IAU Minor Planet Centre.
Officially designated as 2014 UZ224, this body is located about 14 billion km (90 astronomical units, or 8.5 billion miles) from the Sun, and takes around 1,100 Earth years to complete a single orbit around our star. It is not only the latest member of the our Solar family, it is also the second-farthest body from our Sun with a stable orbit. It lies within the Kuiper Belt, and is the latest such small body to be discovered in the last 15 years, alongside the likes of Makemake, Sedna, and Eris. It is also, at approximately 530 km (330 mi) across, the smallest.
To put this in perspective, Charon, Pluto’s largest moon (/ “twin”) is some 1,200 km (750 mi) in diameter, and reaches a maximum distance of about 4.5 billion miles (7.3 billion km) from the Sun, taking 248 Earth years to complete a single orbit.
The new world was discovered by students examining images from the Dark Energy Camera (DECam), part of the Dark Energy Survey. “Dark energy” is the name scientists give to the mechanism powering the expansion of the universe, and DECam is designed to observe the movement of galaxies and supernovae (exploding stars) as they move away from the Earth in an attempt to reveal what dark energy actually is and / or where it comes from.
However, since even solar objects very far from the Sun still show motion against the cosmic backdrop, they can show up when comparing images of the same part of space taken by DECam several month apart. Which is how 2014 UZ224 was discovered, although it took students two years of careful image comparisons to confirm its existence: hence the “2014” in its designation.
Whether or not 2014 UZ224 officially makes the grade is still to be determined by the International Astronomical Union. Right now, the smallest “official” dwarf planet is Ceres, lying within the asteroid belt, which has a diameter of 950 km (550 mi) – close two twice 2014 UZ224’s estimated size. However, the new discovery ticks several of the boxes required to consider it a dwarf planet: it orbits the Sun and is not a satellite of another body; and it has not cleared the neighbourhood around its orbit. It’s size suggests it will likely have a round shape, the fourth requirement for it to be considered a “planet”.
Antares Readies for Launch; SpaceX Readies Dragon for Re-use; Blue Origin readies for Crewed Flights
On October 16th, 2016, those living on the US east coast could witness the late evening launch of Orbital ATK’s updated Antares booster carrying an automated Cygnus resupply vehicle up to the ISS. The launch will take place from NASA’s Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility, Virginia, and is scheduled for 20:03 EDT (00:03 UT on October 17th) which should be visible from a large part of NE USA.
The launch will mark the return to flight status for Antares, complete with new Russian-built RD-181 rocket motors, following the catastrophic loss of both launcher and Cygnus resupply vehicle in 2014. Since then, Orbital ATK has been working to update Antares while continuing with Cygnus launches to the ISS atop Atlas launch vehicles supplied by United Launch Alliance.
Early October also saw the International Symposium for Personal and Commercial Spaceflight (ISPCS) take place, at which SpaceX and Blue Origin made significant announcements.
SpaceX indicated that from 2017, it will start re-using its existing Dragon cargo capsules to deliver supplies to the International Space Station (ISS). The move is intended to allow the company to free-up production facilities to focus on the Dragon V2 crewed version of the capsule.
Dragon V1 has always been intended to be reusable, but the contract with NASA stipulated that initial flights must use a new capsule for each launch. SpaceX has now been able to demonstrate to NASA that the vehicles recovered from the first batch of missions are fit to be re-used, and the contract has been adjusted accordingly. As a result, the first Dragon capsule to re-fly is slated for a February 2017 launch.
Also at ISPCS, and following a very successful test of the New Shephard launch abort system, Blue Origin have announced they plan to start crewed test flights of the system.
The abort system test took place on October 5th, when a New Shephard capsule was lifted to an altitude 4,893 metres (16,053 ft) by its propulsion module, before rocket engines on the capsule fired to blast it clear of the booster.
As I reported just after the test, the aim was to show that the New Shepard crew capsule could escape from the propulsion module and land safely, should a malfunction occur in the booster following launch. While the capsule initially accelerated at a punishing 10G, Blue Origin are confident a crew would not suffer lasting ill effects from the acceleration, and the capsule’s parachute system would safely deliver them back to Earth. As a result, the company is now looking to move towards crewed test flights in 2017, with the aim of commencing fare-paying sub-orbital flights for passengers in 2018.