XNAV Steer Your Way By X-Ray Pulsar
XNAV - or X-ray Navigation - could be the GPS of the solar system (or even the galaxy). X-ray astronomers have mapped a substantial number of x-ray pulsars whose pulsed emissions are as regular as atomic clocks. Several papers will be presented at the IEE/ION PLANS 2008 conference describing how this idea could be applied for spacecraft navigation.
An X-ray pulsar is a magnetized neutron star in a binary star system with a normal companion star. The strength of the magnetic field of a neutron star is a trillion times as large as the Earth's magnetic field strength measured on the Earth's surface.
(X-ray pulsarx-ray pulsar)
Material from the companion star is taken in by the neutron companion, directed into the magnetic poles. This gas falls into the neutron star at speeds of up to half the speed of light; the resulting hotspots generate temperatures of more than a million degrees. As the neutron star rotates, these polar hotspots produce regular pulses of x-ray radiation like lighthouses.
These sources are highly reliable, and are fixed in position. Phase measurements of these sources can be used to establish the location of a spacecraft.
Several different improvements to the use of X-ray Navigation have been proposed. In Noise Analysis for X-ray Navigation Systems, it is suggested that the performance of an XNAV system beyond the orbit of Jupiter could be accurately predicted.
In Online Time Delay Estimation of Pulsar Signals for Relative Navigation using Adaptive Filters it is suggested that the positions of two spacecraft could be determined if both are locked to a known pulsar which emits a waveform that reaches them with a differential time delay that is proportional to the distance between the spacecrafts. The spacecrafts' relative inertial position could be determined by observing appropriately distributed pulsar sources.
Astronomers have thought long thought about pulsars, which were discovered in 1967, as some kind of interstellar beacon. The incredible regularity - and rapidity - of the signal pulsation seemed (at that time) to have no natural explanation.
However, science fiction writers thought about it at least fifteen years earlier. And what's more, suggested that it might be possible to create beacons. In his 1952 story Troubled Star, George O. Smith wrote about space beacons which were created to ease galactic space travel:
"We use the three-day variable to denote the galactic travel lanes. Very effective. We use the longer variable types for other things - dangerous places like cloud-drifts, or a dead sun that might be as deadly to a spacecraft as a shoal is to a seagoing vessel. It's all very logical."
"...you're going to make a variable star out of Sol, just for this?"
Scyth Radnor shook his head. "Please do not think us hard... You're not going to insist that your animal comforts are more important than the functioning of a galaxy-wide civilization?"
(Read more about space beacons)
From IEE/ION PLANS 2008 via
Scroll down for more stories in the same category. (Story submitted 5/8/2008)
Follow this kind of news @Technovelgy.
| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
you like to contribute a story tip?
Get the URL of the story, and the related sf author, and add
Comment/Join discussion ( 1 )
Related News Stories -
NASA's LADEE Enters Lunar Orbit
'... dust normally on the surface picks up and keeps a charge.' - Hal Clement, 1956.
Nuclear Interceptors Designed For Planetary Protection
See NASA's concept for a nuclear interceptor.
SpaceX Grasshopper Divert Video
Isn't this the way that rocket ships were meant to land?
Ultrasonic Noise Betrays ISS Leaks
Gentlemen, Be Seated!
Technovelgy (that's tech-novel-gee!)
is devoted to the creative science inventions and ideas of sf authors. Look for
the Invention Category that interests
you, the Glossary, the Invention
Timeline, or see what's New.
Army's New Bird-Like Surveillance UAV
'The prototype blue-bellied, gray-backed tracer-bird with the wide-angle eye...'
Honda's Tumblebug - The UNI-CUB beta
'A tumblebug does not give a man dignity...'
NASA's LADEE Enters Lunar Orbit
'... dust normally on the surface picks up and keeps a charge.'
3D Printing An Entire Car
"... Almost as good as the original it was printed from."
Aldebaran Robot Talks Like C3PO - Almost
'See Vee Threepio - Vee for versatility - at your service...'
Google's Skin Tattoo Lie Detector
'Three and a half centimetres in diameter, permanently fixed in the centre of his forehead.'
inFORM Dynamic Shape Output Device
Like that pushpin device you remember, but supercharged.
Owlet Vitals, The Future Of Baby Monitoring
'In every diaper there is a fine copper wire...'
Robert Heinlein, Your Personal Electric Helicopter Will Be Ready In 2016
"They were half way home when a single flyer, hopping free in a copter harness, approached the little parade."
WildCat Runs Faster Than You, Untethered
'...moving with such drifting ease that it was like a single solid cloud of black-grey smoke blown at him in silence.' Almost.
HiBot's ACM-R5H Robot Video Shows Graceful Terminator-Style Swimming
'No! No! Aaaaaaarrrrrrgh!'
tDCS Jumpstarts Your Future
'We invented a scanner that can change the labyrinthine neural connections of the brain by tiny electronic impulses...'.
RealView Interactive Live Medical Holography
Surgeons can see an organ in its entirety in a live image.
Britney Spears And Lynn Minmay - Weapons Of Choice
An attack can take many forms.
Aireal Haptics Inching Towards Holodeck Experience
How to feel something that isn't there?
Starchase Pursuit Management ala Star Wars
Yes, but does it follow evil doers through hyperspace?
More SF in the News Stories
More Beyond Technovelgy science news stories