Starchip Mission to Alpha Centauri

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Jim Leff
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Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 2:58 pm

The Starchip story (sending camera-wielding nano space ships to Alpha Centauri via laser acceleration to 1/4 the speed of light) is in lots of news reports this week, but the coverage from The Economist offers richer technological detail than others.

The report mentions that at 80,000 km/sec, the spacecrafts will be one third of the way to Mars' orbit in ten minutes. So I tried to use my meager math skills to compute the time it'd take to pass Voyager's position, 20M km distant. 20,000,000 divided by 80,000 is 254, but 254 seconds makes no sense, as it requires hours to communicate with Voyager at the full speed of light. What am I doing wrong?

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Re: Starchip Mission to Alpha Centauri

Post by neufer » Wed Apr 13, 2016 3:01 pm

Jim Leff wrote:
The Starchip story (sending camera-wielding nano space ships to Alpha Centauri via laser acceleration to 1/4 the speed of light) is in lots of news reports this week, but the coverage from The Economist offers richer technological detail than others.

The report mentions that at 80,000 km/sec, the spacecrafts will be one third of the way to Mars' orbit in ten minutes. So I tried to use my meager math skills to compute the time it'd take to pass Voyager's position, 20M km distant. 20,000,000 divided by 80,000 is 254, but 254 seconds makes no sense, as it requires hours to communicate with Voyager at the full speed of light. What am I doing wrong?
Voyager's position, 20 BILLION km distant :?:
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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 3:07 pm

Thanks, Neufer. So three days to reach Voyager's position. Pretty incredible!

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Re: Starchip Mission to Alpha Centauri

Post by neufer » Wed Apr 13, 2016 3:18 pm

Jim Leff wrote:
Thanks, Neufer. So three days to reach Voyager's position. Pretty incredible!
It would probably take at least a month of diminishing acceleration to reach peak speed.
https://en.wikipedia.org/wiki/Starwisp wrote:
<<Starwisp is a hypothetical unmanned interstellar probe design proposed by Robert L. Forward. It is propelled by a microwave sail, similar to a solar sail in concept, but powered by microwaves from a man-made source. Although the diffraction limit severely constrains the range of the transmitting antenna, the probe is designed to have an extremely high acceleration of 24 m/s2, so that it can reach a significant fraction of the speed of light within a very short distance, before passing out of range. The antenna uses a microwave lens 560 km in diameter, would transmit 56 GW of power (from 56 nuclear reactors, 37 Mojave Wind Farms or 13,000 square kilometers of solar panels), and would accelerate the probe to 10% of the speed of light.

A major problem this design would face would be the radiation encountered en route. Traveling at 20% of light speed, ordinary interstellar hydrogen would become a significant radiation hazard, and the Starwisp would be without shielding and likely without active self-repair capability. Another problem would be keeping the acceleration of the Starwisp uniform enough across its sail area so that its delicate wires would not tear or be twisted out of shape. Distorting the shape of the Starwisp even slightly could result in a runaway catastrophe, since one portion of the Starwisp would be reflecting microwaves in a different direction than the other portion and be thrust even farther out of shape. Such delicate and finely-balanced control may prove impossible to realize.

The possibility of using a dusty plasma sail in which a dusty substance that is maintained as a plasma within space is responsible for the reflection of electromagnetic radiation could circumvent problems associated with radiation damage to the medium responsible for the transfer of radiation pressure (the dusty plasma sail might not be as easy to damage as a thin film or the like). Dusty plasma sails can also adapt their three-dimensional structure in real time to ensure reflection perpendicular to any incident light/microwave beam.>>
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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 3:37 pm

No. The 100GW laser array will fire for only ten minutes. It'd be impractical to direct millions of lasers at targets this small, fast, and distant for much longer.

Note that this isn't Starwisp, it's a newly-announced program, Starshot. It's so new that the Wikiepdia article is still under-developed, but, again, the Economist report has greater detail.

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Re: Starchip Mission to Alpha Centauri

Post by neufer » Wed Apr 13, 2016 3:52 pm

Jim Leff wrote:
No. The 100GW laser array will fire for only ten minutes. It'd be impractical to direct millions of lasers at targets this small, fast, and distant for much longer.
[list]Ye Gods :!: [/list]
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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 4:02 pm

Indeed!

I love how the EASY part is to manufacture thousands of spacecrafts, each with the weight of a paper clip and carrying a computer, a camera, a laser communication system, and a plutonium engine.

I'm done complaining about my non-ownership of a jetpack. Between this and the craft beer boon, I've decided I like the future.

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Re: Starchip Mission to Alpha Centauri

Post by neufer » Wed Apr 13, 2016 4:24 pm

Jim Leff wrote:
I love how the EASY part is to manufacture thousands of spacecrafts, each with the weight of a paper clip and carrying a computer, a camera, a laser communication system, and a plutonium engine.
  • I know just whom to send to Alpha Centauri:
https://en.wikipedia.org/wiki/Office_Assistant wrote: <<The Office Assistant was an intelligent user interface for Microsoft Office that assisted users by way of an interactive animated character, which interfaced with the Office help content. The default assistant in the English Windows version was named Clippit (though Clippy is a common nickname). The character was designed by Kevan J. Atteberry. The feature drew a strongly negative response from many users. Microsoft turned off the feature by default in Office XP, acknowledging its unpopularity in an ad campaign spoofing Clippy. The feature was removed altogether in Office 2007 and Office 2008 for Mac, as it drew criticism from customers and even Microsoft employees. The default assistant Clippy has been heavily mocked in popular culture, being parodied, appearing in memes, and even being made fun of by Microsoft themselves from 2001 onwards.
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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 4:25 pm

Good idea, but I worry that the eyeballs and brows might put him just over-weight.

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Re: Starchip Mission to Alpha Centauri

Post by rstevenson » Wed Apr 13, 2016 4:54 pm

I must be the only one in the world who liked Clippy. I've never used a Help system before or since that was as inhumanly helpful while being fun at the same time. I cynically observed at the time that it made perfect sense for Microstuff to get rid of the only good thing it ever invented.

Rob

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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 5:32 pm

I'm a big Jar Jar Binks fan.....

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Re: Starchip Mission to Alpha Centauri

Post by bystander » Wed Apr 13, 2016 6:37 pm

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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NASA Begins Testing of Revolutionary E-Sail Technology

Post by bystander » Wed Apr 13, 2016 6:49 pm

And now for something completely different ...

NASA Begins Testing of Revolutionary E-Sail Technology
NASA | Marshall Space Flight Center | HERTS | 2016 Apr 11
Click to play embedded YouTube video.

Testing has started at NASA’s Marshall Space Flight Center in Huntsville, Alabama, on a concept for a potentially revolutionary propulsion system that could send spacecraft to the edge of our solar system, the heliopause, faster than ever before.

The test results will provide modeling data for the Heliopause Electrostatic Rapid Transit System (HERTS). The proposed HERTS E-Sail concept, a propellant-less propulsion system, would harness solar wind to travel into interstellar space.

“The sun releases protons and electrons into the solar wind at very high speeds -- 400 to 750 kilometers per second,” said Bruce Wiegmann an engineer in Marshall’s Advanced Concepts Office and the principal investigator for the HERTS E-Sail. “The E-Sail would use these protons to propel the spacecraft.”

Extending outward from the center of the spacecraft, 10 to 20 electrically charged, bare aluminum wires would produce a large, circular E-Sail that would electrostatically repel the fast moving protons of the solar wind. The momentum exchange produced as the protons are repelled by the positively charged wires would create the spacecraft’s thrust. Each tether is extremely thin, only 1 millimeter -- the width of a standard paperclip -- and very long, nearly 12 and a half miles -- almost 219 football fields. As the spacecraft slowly rotates at one revolution per hour, centrifugal forces will stretch the tethers into position. ...
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

Jim Leff
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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Wed Apr 13, 2016 7:25 pm


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Re: Starchip Mission to Alpha Centauri

Post by geckzilla » Wed Apr 13, 2016 9:18 pm

rstevenson wrote:I must be the only one in the world who liked Clippy. I've never used a Help system before or since that was as inhumanly helpful while being fun at the same time. I cynically observed at the time that it made perfect sense for Microstuff to get rid of the only good thing it ever invented.
I liked Clippy, just not the "help" it offered. Clippy was cute like a puppy that chewed through a slipper every day.
Just call me "geck" because "zilla" is like a last name.

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Re: Starchip Mission to Alpha Centauri

Post by Jim Leff » Thu Apr 14, 2016 12:29 am

There's apparently a great detailed view of this on the April 9th episode of the podcast, Skeptics Guide to the Universe.

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Re: Starchip Mission to Alpha Centauri

Post by neufer » Thu Apr 14, 2016 3:13 am

Click to play embedded YouTube video.
Not coincidentally...the laser array makes one hell of an anti-satellite weapon :!:
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Breakthrough Starshot Launches World's Smallest Spacecraft

Post by bystander » Tue Aug 01, 2017 3:04 pm

Breakthrough Starshot Launches World's Smallest Spacecraft
Rubinstein Communications | 2017 Jul 26

Breakthrough Starshot, a multi-faceted program to develop and launch practical interstellar space missions, successfully flew its first spacecraft -- the smallest ever launched.

On June 23, a number of prototype “Sprites” -- the world’s smallest fully functional space probes, built on a single circuit board -- achieved low Earth orbit, piggybacking on OHB System AG’s ‘Max Valier’ and ‘Venta’ satellites. The 3.5-by-3.5-centimeter chips weigh just four grams but contain solar panels, computers, sensors, and radios. These vehicles are the next step of a revolution in spacecraft miniaturization that can contribute to the development of centimeter- and gram-scale “StarChips” envisioned by the Breakthrough Starshot project.

The Sprite is the brainchild of Breakthrough Starshot’s Zac Manchester, whose 2011 Kickstarter campaign, “KickSat,” raised the first funds to develop the concept. The Sprites were constructed by researchers at Cornell University and transported into space as secondary payloads by the Max Valier and Venta satellites, the latter built by the Bremen-based OHB System AG, whose generous assistance made the mission possible.

The Sprites remain attached to the satellites. Communications received from the mission show the Sprite system performing as designed. The spacecraft are in radio communication with ground stations in California and New York, as well as with amateur radio enthusiasts around the world. This mission is designed to test how well the Sprites’ electronics perform in orbit, and demonstrates their novel radio communication architecture. ...
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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