A resuscitation service for old satellites
What if we repair the satellites in orbit, instead of abandoning them as soon as they fail and launching new ones instead? This common sense idea finally becomes possible, thanks to Northrop Grumman’s successful experience. The American aerospace company has sent a “Mission Expansion Vehicle” (MEV-1) into space, charged, as its name suggests, with extending the mission of another satellite already in orbit. The rescue machine is the Intelsat IS-901 communications satellite. Its fuel tanks are nearly empty, preventing it from maneuvering, and it was decommissioned in December 2019 while waiting for a helping hand.
It was this Tuesday, at 8.15 a.m. Paris time, that the space ambulance intervened. Northrop Grumman’s MEV very slowly joined the Intelsat satellite at an altitude of 36,000 kilometers (90 times higher than the international space station) and docked there without problem. Thanks to his own propulsion system, he will push his patient into a new orbit allowing him to work for another five years. Intelsat 901 is expected to return in March.
Photo taken by the MEV-1 satellite, showing the Intelsat 901 at a distance of 80 meters, before stowage. In the background, the Earth. (Photo Northrop Grumman. SpaceLogistics)
“This service life extension is just the first step”, Northrop Grumman Announcement. The goal is to develop a whole “fleet” vehicles that “Not only will the mission of the satellites be extended, but they will provide other services such as tilting, vessel inspections”, and even robotic repair and assembly services for satellites in orbit.
The nucleus of Mars on the scales
While the Insight undercarriage listen earthquakes in mars and tries (painstakingly) toinsert a thermal probe in its soil, two researchers from Japan are interested in the internal composition of the red planet. Thanks to the study of Martian rocks and “Measurements of satellites in orbit”, they were able to estimate that the border between its core and its mantle is around 1,800 kilometers deep.
Inner structure of Mars. (Image Takashi Yoshizaki, 2020)
The small nucleus of Mars therefore represents “Only one sixth of its total mass, where the Earth’s core represents one third of its mass”, explains Takashi Yoshizaki. Insight’s seismometer will be able to directly verify this new model of Martian composition by analyzing the propagation of seismic waves.
Lunar stones
On the Moon, the Chinese rutter Yutu-2 continues to sniff the rocks, since more than a year. A few days ago, he discovered unusual stones. Apparently lighter than the regolith (rock dust) on which they rest, they are very little eroded for rocks faced with regular drops of micrometeorites and large changes in temperature between day and night. That means they are still young. Finally, young people on the Moon scale … “Between ten and one hundred million years”, valued American researcher Dan Moriarty, but it could just as easily be “One or two billion years”, for a Moon that has blown 4.5 billion candles.
Photo published in February 2020 of the Von Kármán crater, with its clear and young rocks, taken by the rover Yutu-2. (Photo CNSA. CLEP)
It depends on where these stones come from, which are enthroned in the Von Kármán crater. They should be inspected more closely to determine their age. If they have “The appearance of heterogeneous fragments welded together”, it’s a breach regolith agglomerated by the heat of a meteorite impact. If, on the contrary, the rocks are more homogeneous, they can come from deeper into the lunar crust, and be brought up to the surface during an impact.
Images from above: Martian selfie and making-of
In his latest selfie, the Curiosity rover is all dusty but seems in good shape. The vehicle captured this image, as usual, using the “Mahli” camera (Mars Hand Lens Imager) installed at the end of its articulated arm.
Sol 2687 MaHLI panoramic, on the floor of the next step of the mission: that Greenheugh pediment.https://t.co/7rroD6ajRX pic.twitter.com/FpLZ50IYWk
– Damia Bouic (@db_prods) February 28, 2020
With another of its seventeen cameras, Curiosity photographed his arm and the selfie being made, shot by shot. We can see how “The arm moves around the optical center of Mahli”, note Damia Bouic, passionate about astronomy who has reconstructed the mosaic of the Martian landscape.
How this selfie was made? Answer here, with the navcam animation from when this mosaic was taken. See how the arm moves around the optical center of the MaHLI. pic.twitter.com/yIoxwVf0Nw
– Damia Bouic (@db_prods) February 29, 2020
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