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They used to call it RoboBee—a flying machine half the size of a paperclip that could flap its pair of wings 120 times a second. It was always tethered to a power source, limiting its freedom. Now, though, RoboBee becomes RoboBee X-Wing, as Harvard researchers have added solar cells and an extra pair of wings, freeing the robot to blast off to a galaxy far, far away. Or at least partway across the room, as it can sustain flight for only half a second, and only indoors.

But hey, baby steps. The teeniest of quadrotors measure a few inches across and weigh a third of an ounce. RoboBee X-Wing is about the same size as those untethered fliers, but weighs a hundredth of an ounce, which earns it the distinction of being the lightest aerial vehicle to manage sustained untethered flight. One day that could make it ideal for navigating tight, sensitive spaces in a galaxy very, very near.

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Physicists have discovered a novel kind of nanotube that generates current in the presence of light. Devices such as optical sensors and infrared imaging chips are likely applications, which could be useful in fields such as automated transport and astronomy. In future, if the effect can be magnified and the technology scaled up, it could lead to high-efficiency solar power devices.

If SpaceX gets a fully reusable Super Heavy Starship flying to orbit in 2020 and then has 100 fully reusable flights by 2023 then the cost of space will drop by 100 times. This will start fulfilling the plans for lunar bases, lunar mining, and space-based solar power.

If each Super Heavy Starship costs $300 million and has $1 million in operating and maintenance cost per flight then the per flight cost is $4 million. Super Heavy Starship is supposed to launch about 100 tons to orbit.

Assuming that 800 Starlink satellites are launched by April 2020, then SpaceX will start doubling its revenue from $2–3 billion to $5–6 billion in 2020 and ten billion in 2021. This will mean that SpaceX will be able to afford to build dozens of Super Heavy Starships.

Popeye would be proud.


Popeye uses spinach to power his muscles. Now, scientists are looking to spinach as a power source for making electricity.

A solar cell converts sunlight into electricity. Most of these, today, are made of a material called silicon. The new device instead uses proteins from spinach and from a bacterium called Rhodobacter sphaeroides.

To make the solar cell, a team of biologists and chemists at the Massachusetts Institute of Technology in Cambridge extracted certain light-sensitive proteins from the spinach and the bacteria. They placed about 2 billion of these proteins on a piece of glass. They made the proteins stick by embedding them in a special framework that looks and acts like a cell membrane.

We can do this by shrinking the size and mass of the spacecraft, allowing many to be launched together.

Sprite

The Sprite is a tiny (3.5 by 3.5 centimeter) single-board spacecraft. It has a microcontroller, radio, and solar cells and is capable of carrying single-chip sensors, such as thermometers, magnetometers, gyroscopes, and accelerometers. To lower costs, Sprites are designed to be deployed hundreds at a time in low Earth orbit and to simultaneously communicate with a ground station receiver.

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In solar cells, the cheap, easy to make materials called perovskites are adept at turning photons into electricity. Now, perovskites are turning the tables, converting electrons into light with an efficiency on par with that of the commercial organic light-emitting diodes (LEDs) found in cellphones and flat screen TVs. And in a glimpse of how they might one day be harnessed, researchers reported last week in Science Advances that they’ve used a 3D printer to pattern perovskites for use in full-color displays.

“It’s a fantastic result, and quite inspirational,” says Richard Friend, a physicist at the University of Cambridge in the United Kingdom whose team created the first perovskite LED in 2014. The result raises hopes that the computer screens and giant displays of the future will consist of these cheap crystalline substances, made from common ingredients. Friend cautions, however, that the new perovskite displays aren’t yet commercially viable.

The materials in current semiconductor LEDs, including the organic versions, require processing at high temperatures in vacuum chambers to ensure the resulting semiconductors are pristine. By contrast, perovskites can be prepared simply by mixing their chemical components in solution at room temperature. Only a brief heat treatment is needed to crystallize them. And even though the perovskite crystals end up with imperfections, these defects typically don’t destroy the materials’ ability to emit light.

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