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Open Access
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Article
| Open AccessAccommodating unobservability to control flight attitude with optic flow
Attitude can be extracted from optic flow when combined with a motion model that relates attitude to acceleration direction, which leads to stable flight attitude control with slight oscillations due to unobservable conditions.
- Guido C. H. E. de Croon
- , Julien J. G. Dupeyroux
- & Franck Ruffier
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Article |
Aerial additive manufacturing with multiple autonomous robots
An additive manufacturing method using a team of autonomous aerial robots allows for scalable and adaptable three-dimensional printing, and is used to deposit building materials during flight.
- Ketao Zhang
- , Pisak Chermprayong
- & Mirko Kovac
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Article
| Open AccessOptimization of avian perching manoeuvres
To perch safely, large birds minimize the distance flown after stalling when swooping up from a dive to a perch, but not the time or energy required.
- Marco KleinHeerenbrink
- , Lydia A. France
- & Graham K. Taylor
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Article
| Open AccessBirds can transition between stable and unstable states via wing morphing
Analysis of inertial characteristics across 22 bird species shows that evolution has selected for avian manoeuvrability using both stable and unstable flight dynamics.
- C. Harvey
- , V. B. Baliga
- & D. J. Inman
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Perspective |
The challenges and opportunities of battery-powered flight
The economic, technical, environmental and safety requirements of battery-powered aircraft are considered, and promising technologies and future prospects for battery innovation are discussed.
- Venkatasubramanian Viswanathan
- , Alan H. Epstein
- & Michael Winter
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Article
| Open AccessIn-orbit demonstration of an iodine electric propulsion system
The successful in-orbit operation of an electric space propulsion system based on iodine, rather than the more expensive and difficult-to-store xenon, is demonstrated.
- Dmytro Rafalskyi
- , Javier Martínez Martínez
- & Ane Aanesland
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Article |
Three-dimensional electronic microfliers inspired by wind-dispersed seeds
With a design inspired by wind-dispersed seeds, a series of three-dimensional passive fliers at the macro-, meso- and microscale are realized that can bear active electronic payloads.
- Bong Hoon Kim
- , Kan Li
- & John A. Rogers
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Article |
Autonomous navigation of stratospheric balloons using reinforcement learning
Data augmentation and a self-correcting design are used to develop a reinforcement-learning algorithm for the autonomous navigation of Loon superpressure balloons in challenging stratospheric weather conditions.
- Marc G. Bellemare
- , Salvatore Candido
- & Ziyu Wang
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Letter |
Untethered flight of an insect-sized flapping-wing microscale aerial vehicle
Sustained flight of an insect-sized flapping-wing aerial vehicle weighing just 259 milligrams that does not need to fly tethered to an off-board power supply is demonstrated.
- Noah T. Jafferis
- , E. Farrell Helbling
- & Robert J. Wood
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Letter |
Flight of an aeroplane with solid-state propulsion
A solid-state propulsion system can sustain powered flight, as demonstrated by an electroaerodynamically propelled heavier-than-air aeroplane.
- Haofeng Xu
- , Yiou He
- & Steven R. H. Barrett
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Letter |
Glider soaring via reinforcement learning in the field
A reinforcement learning approach allows a suitably equipped glider to navigate thermal plumes autonomously in an open field.
- Gautam Reddy
- , Jerome Wong-Ng
- & Massimo Vergassola
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Letter |
Measurement of Jupiter’s asymmetric gravity field
Precise Doppler tracking of the Juno spacecraft in its polar orbit around Jupiter is used to determine the planet’s gravity harmonics, showing north–south asymmetry caused by atmospheric and interior flows.
- L. Iess
- , W. M. Folkner
- & S. J. Bolton
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Letter |
Smart wing rotation and trailing-edge vortices enable high frequency mosquito flight
In addition to generating lift by leading-edge vortices (as used by most insects), mosquitoes also employ trailing-edge vortices and a lift mechanism from wing rotation, which enables them to stay airborne despite having a seemingly unlikely airframe.
- Richard J. Bomphrey
- , Toshiyuki Nakata
- & Simon M. Walker
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Letter |
Mechanical metamaterials at the theoretical limit of isotropic elastic stiffness
Finite-element models are used to identify a material geometry that achieves the theoretical bounds on isotropic elastic stiffness—a combination closed-cell cubic and octet foam.
- J. B. Berger
- , H. N. G. Wadley
- & R. M. McMeeking
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News |
False dawn for Japan's Venus mission
Akatsuki probe will have to survive for six more years to get a second chance of orbit.
- David Cyranoski
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News |
Space tourism to accelerate climate change
Scientists predict that soot from commercial space flight will change global temperatures.
- Adam Mann
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News |
Space capsule probed for asteroid dust
Hayabusa holds lessons for future sample-return missions.
- David Cyranoski
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News |
Origami that folds itself
Programmable sheet puckers up spontaneously into an aeroplane or a boat.
- Philip Ball