China is readying for the next phases of its space ambitions.
In July, the country is due to launch its first mission to Mars. Officially referred to as the Mars Global Remote Sensing Orbiter and Small Rover mission, it comprises an orbiter, a lander vehicle and a small rover, with the orbiter and rover between them carrying the majority of the mission’s 18 scientific instruments.
The priorities for the mission include finding evidence of current or previous microbial life, and evaluating the planet’s surface and environment. In addition, solo and joint explorations of Mars, the orbiter and rover will produce maps of the Martian surface topography, and obtain data on soil characteristics, material composition, water ice, atmospheric composition, ionosphere field intensity, and other scientific data.
On April 24th, the Chinese announced the lander vehicle is to be called Tianwen, or “Quest for Heavenly Truth.” It will use a landing system comprising a parachute, retrorockets, and an airbag to achieve a soft landing. The rover will be solar powered, as with China’s Yutu family of lunar rovers.
The name represents the Chinese people’s relentless pursuit of truth, the country’s cultural inheritance of its understanding of nature and universe, as well as the unending explorations in science and technology.
– China’s National Space Administration (CNSA) statement
The Chinese tend to be fairly close-lipped about their space missions (among many other things), but from what has been announced, the mission is being built along similar lines to both NASA surface missions like InSight and MSL, and Europe’s ExoMars orbiter / lander missions. Following its arrival in Mars orbit in February 2021, the combined orbiter / lander will remain there for an unspecified period while the intended landing site is confirmed.
Once on the surface, the 200 gram 6-wheeled rover is expected to operate for at least 3 months, with a selection of its science systems comprising Ground-Penetrating Radar (GPR), to image about 100 m below the Martian surface, a magnetic field detector, a Mars meteorological instrument and multiple camera instruments. The rover is expected to be given its own name in due course.
At the same time, China rolled out a Long March 5B launcher in preparation for a mission to prove space station launch capabilities and to test a new spacecraft for deep space human space flight. It is expected to lift-off on, or around, May 5th 2020, carrying the first of China’s new generation of crew-capable vehicles designed to supersede the Soyuz-derived Shenzhou craft.
The new craft resembles an Apollo command and service module (CSM) combination, comprising a conical capsule vehicle protected by an atmospheric entry heat shield, and a cylindrical service module that provides the primary source of power and propulsion when operating in space. For the first flight, it will carry around 10 tonnes of fuel, intended to allow the vehicle to offer a similar mass to the core stage of the upcoming Chinese space station. The fuel will also allow the vehicle to reach a high orbit and and achieve a fast re-entry velocity.
This latter is important as the the new vehicle is intended for deep space crewed missions, including acting as the carrier for crews engaged in future missions to the Moon. Such missions will – like America’s Orion coming back from the Moon – return to Earth as a higher velocity than an orbital craft. As such, the first flight of this new Chinese vehicle will be somewhat similar in nature to the Orion’s first uncrewed flight in 2018.
To achieve its full envelope of uses, the new crew vehicle comes in two variants: a capsule and small service module which together weigh 14 tonnes, to be used in local orbital flights, and a version with a larger service module, giving a mass of 20 tonnes for the combined craft. This will likely be used for missions into deeper space. Either craft be able to carry up to six astronauts, or three astronauts and 500 kg of cargo to low Earth orbit.
Overall, the May launch of the vehicle has a lot hinging on it. A successful flight will clear the way for the two-month-long launch campaign required for the Mars Global Remote Sensing Orbiter and Small Rover mission mentioned above, using a Long March 5. In will also be see as opening the way for the Long March 5B vehicle to undergo a series of launches ahead of placing the 20-tonne Tianhe module, intended to be the core element of China’s new space station, due in early 2021. Weighing 20 tonnes, the module’s launch will mark the first in about a dozen that will be needed to complete the station between 2021 and 2022 /23.
When is an Exoplanet Not and Exoplanet?
As I’ve frequently remarked in these pages, we’ve so far confirmed the presence of over 4,000 exoplanets orbiting other stars. The number is such that it’s easy to think that detecting these worlds is just a matter of observing and waiting for that regular tell-tale dipping of brightness in a starts luminosity as seen from our orbiting telescopes, and which has been the more common means of detecting the worlds around other stars.
However, finding and confirming the presence of exoplanets is a complicated process, one that can be ripe with false positives. An example of this is Fomalhaut b, which has been puzzling astronomers since it was first observed in 2004. Orbiting the A-type main-sequence star Fomalhaut, some 25 light-years from Earth in the constellation of Piscis Austrinus, the planet was first observed by the Hubble Space Telescope, marking as the first to be detected in visible wavelengths (that is. the Direct Imaging Method).
Continue reading “Space Sunday: China’s missions and a disappearing “planet””
Inara Pey: Living in a Modemworld 