Stephen Hawking's Interstellar Spaceship Proposal (And More!)

Stephen Hawking and a Russian Billionaire Want to
Build an Interstellar Starship:

"In a joint announcement at the One World Observatory in New York
City today, Milner and Stephen Hawking unveiled Breakthrough
Starshot, a $100 million research and engineering program seeking to
lay the foundations for an eventual interstellar voyage. The first step
of the program involves building light-propelled "nanocrafts" that can
travel at relativistic speeds--up to 20 percent the speed of light. At
such high velocities, the robotic spacecraft would pass Pluto in three
days and reach our nearest neighboring star system, Alpha Centauri,
just over 20 years after launch."

See:

http://gizmodo.com/a-russian-billion...ild-1770467186


=============================


NASA funds Direct Drive Fusion Propulsion:

"The Direct Fusion Drive (DFD) concept provides game-changing
propulsion and power capabilities that would revolutionize interplanetary
travel. DFD is based on the Princeton Field-Reversed Configuration
(PFRC) fusion reactor under development at the Princeton Plasma
Physics Laboratory."

See:

http://nextbigfuture.com/2016/04/nas...ve-fusion.html


=============================


NASA testing electric solar sail for near term
propulsion 3-7 times faster than Pluto Express:

"Testing has started at NASA's Marshall Space Flight Center in
Huntsville, Alabama, on revolutionary propulsion system called the
electric sail. Relatively conservative designs could send spacecraft at
100-200 km/second by utilizing solar wind traveling at 400 to 750
kilometers per second.

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."

See:

http://nextbigfuture.com/2016/04/nas...-sail-for.html


=============================


I wonder which (if any) of these ideas will ever actually fly?

wrote:
See:

http://gizmodo.com/a-russian-billion...ild-1770467186

Indeed, the hurdles range from how to create the laser array
capable of accelerating a small payload off Earth to how to
transmit data back to us over interstellar distances. These will
be huge accomplishments, with reverberations throughout many
fields of science and technology.

I was wondering how they were going to get comms back from such a
small package. I guess the answer is they haven't exactly figured
that out yet.

rick jones
--
the road to hell is paved with business decisions...
these opinions are mine, all mine; HPE might not want them anyway...
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...

On Thursday, April 14, 2016 at 11:31:39 AM UTC+12, Rick Jones wrote:
wrote:
See:

http://gizmodo.com/a-russian-billion...ild-1770467186

Indeed, the hurdles range from how to create the laser array
capable of accelerating a small payload off Earth to how to
transmit data back to us over interstellar distances. These will
be huge accomplishments, with reverberations throughout many
fields of science and technology.

I was wondering how they were going to get comms back from such a
small package. I guess the answer is they haven't exactly figured
that out yet.

rick jones
--
the road to hell is paved with business decisions...
these opinions are mine, all mine; HPE might not want them anyway...
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...

This was all worked out by my friend Bob Forward back in the 1980s, in his Starwisp proposal.

http://www.centauri-dreams.org/?p=3816

http://www.niac.usra.edu/files/studi...rt/4Landis.pdf

This was updated by one of Bob's students, Young Bae just recently.

http://ykbcorp.com/downloads/Bae_pho...irculation.pdf

A solar power satellite that uses a solar pumped laser to deliver billions of watts to Earth, can be adapted to send probes to nearby stars using these approaches.

William Mook wrote:
This was all worked out by my friend Bob Forward back in the 1980s,
in his Starwisp proposal.

http://www.centauri-dreams.org/?p=3816

That had only a passing reference to communications.

http://www.niac.usra.edu/files/studi...rt/4Landis.pdf

My read of the link above was admittedly cursory, but it did not seem
to address the matter of communications, just propulsion.

This was updated by one of Bob's students, Young Bae just recently.

http://ykbcorp.com/downloads/Bae_pho...irculation.pdf

Again, a cursory read, but it seems to discuss propulsion and not
communications.

rick jones
--
It is not a question of half full or empty - the glass has a leak.
The real question is "Can it be patched?"
these opinions are mine, all mine; HPE might not want them anyway...
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...

In article , says...

wrote:
See:

http://gizmodo.com/a-russian-billion...ild-1770467186

Indeed, the hurdles range from how to create the laser array
capable of accelerating a small payload off Earth to how to
transmit data back to us over interstellar distances. These will
be huge accomplishments, with reverberations throughout many
fields of science and technology.

I was wondering how they were going to get comms back from such a
small package. I guess the answer is they haven't exactly figured
that out yet.

No kidding. It's hard enough getting a signal from probes like Pioneer
10 and Voyagers 1 and 2 which are "only" a few light hours away. Probes
that are light *years* away would be much more difficult.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

In article , says...

William Mook wrote:
This was all worked out by my friend Bob Forward back in the 1980s,
in his Starwisp proposal.

http://www.centauri-dreams.org/?p=3816

That had only a passing reference to communications.

http://www.niac.usra.edu/files/studi...rt/4Landis.pdf

My read of the link above was admittedly cursory, but it did not seem
to address the matter of communications, just propulsion.

There was a very brief mention of using the laser light collected by the
sail to communicate with earth. This, presumably, is the reason for the
65 GW earth based laser. This still presents some huge problems that
would need to be solved like pointing, minimizing beam spread, how to
modulate the beam for communications, and etc.

This was updated by one of Bob's students, Young Bae just recently.

http://ykbcorp.com/downloads/Bae_pho...irculation.pdf

Again, a cursory read, but it seems to discuss propulsion and not
communications.

Yes, communications does seem to be an afterthought in these proposals.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

"Jeff Findley" wrote in message
...

In article , says...

wrote:
See:

http://gizmodo.com/a-russian-billion...ild-1770467186

Indeed, the hurdles range from how to create the laser array
capable of accelerating a small payload off Earth to how to
transmit data back to us over interstellar distances. These will
be huge accomplishments, with reverberations throughout many
fields of science and technology.

I was wondering how they were going to get comms back from such a
small package. I guess the answer is they haven't exactly figured
that out yet.

No kidding. It's hard enough getting a signal from probes like Pioneer
10 and Voyagers 1 and 2 which are "only" a few light hours away. Probes
that are light *years* away would be much more difficult.

One possibility is if you're sending multiple probes (and honestly, once
you've built the laser, the probes are cheap) you just do it as a relay.

Probe 1 transmits to Probe 2 that retransmits back to Probe 3, etc.

But yeah, my first thought was that getting there is only part of the issue.
Getting the data back is a much bigger issue.


Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

On Friday, April 15, 2016 at 12:31:44 PM UTC+12, Rick Jones wrote:
William Mook wrote:
This was all worked out by my friend Bob Forward back in the 1980s,
in his Starwisp proposal.

http://www.centauri-dreams.org/?p=3816

That had only a passing reference to communications.

http://www.niac.usra.edu/files/studi...rt/4Landis.pdf

My read of the link above was admittedly cursory, but it did not seem
to address the matter of communications, just propulsion.

This was updated by one of Bob's students, Young Bae just recently.

http://ykbcorp.com/downloads/Bae_pho...irculation.pdf

Again, a cursory read, but it seems to discuss propulsion and not
communications.

rick jones
--
It is not a question of half full or empty - the glass has a leak.
The real question is "Can it be patched?"
these opinions are mine, all mine; HPE might not want them anyway...
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...

Bob Forward was a friend of mine. He planned on equipping each element to be able to measure precisely their position relative to their nearer neighbours, and have them all operate in a swarm to create an extended phased array communications system as well as sensory system. Multiple cameras whose point spread function is known, and position relative to other cameras, can do a lot of interesting things.

http://www.centauri-dreams.org/?p=33409
http://interstellar-flight.ru/design...e/starwisp.pdf
http://breakthroughinitiatives.org/Research/3

Young Bae, a student of Forward, perfected the laser light sail by creating the photonic laser thruster, for which he will be forever known. One of the applications Bae has published when he was working for the AFRL was to provide precise positioning between small probes using PLT efficiently to measure and push probes relative to one another, to create an extended array for both sensing and communications.

http://govcomm.harris.com/solutions/...yantennas.aspx
www.dtic.mil/get-tr-doc/pdf?AD=ADA530515

On Friday, April 15, 2016 at 2:58:08 PM UTC+12, Jeff Findley wrote:
In article , says...

William Mook wrote:
This was all worked out by my friend Bob Forward back in the 1980s,
in his Starwisp proposal.

http://www.centauri-dreams.org/?p=3816

That had only a passing reference to communications.

http://www.niac.usra.edu/files/studi...rt/4Landis.pdf

My read of the link above was admittedly cursory, but it did not seem
to address the matter of communications, just propulsion.

There was a very brief mention of using the laser light collected by the
sail to communicate with earth. This, presumably, is the reason for the
65 GW earth based laser. This still presents some huge problems that
would need to be solved like pointing, minimizing beam spread, how to
modulate the beam for communications, and etc.

This was updated by one of Bob's students, Young Bae just recently.

http://ykbcorp.com/downloads/Bae_pho...irculation.pdf

Again, a cursory read, but it seems to discuss propulsion and not
communications.

Yes, communications does seem to be an afterthought in these proposals.

Starwisp used the array to sense the star system as it flew through and communicate the data back to the beaming antenna. A 1 km diameter spacecraft with 100 billion points of intersection massed 20 grams and was powered by a 10 GW microwave power system that operated at 3 cm. This was a typical power satellite design from the 1980s. This was a power source that beamed energy through a 50,000 ton fresnel microwave transmitter that was 50,000 km in diameter to efficient form a beam on the 1 km diameter starwisp.

http://interstellar-flight.ru/design...e/starwisp.pdf

Sending an inflatable optical probe from Earth to Jupiter, to use gravity assist to enter a highly elliptical orbit above the solar poles, which at perihelion is circularised using solar sail technology, is the first step in creating a highly efficient solar powered system.

A solar pumped laser at 1/50th AU, operating at 3.42 MW per square meter, is 2500x solar intensity, which is outlined in my solar energy patent, and routinely achieved in the 1990s in my shop.

http://www.google.com/patents/US20050051205

US 7081584

An emitter operating at 250 nm wavelength over a distance of 800 AU can form a spot efficiently that's 5 km in diameter using an objective that's 5 km in diameter.

http://scitation.aip.org/content/aip...0.1063/1.93625
http://news.mit.edu/2013/chips-that-...eer-light-0109
http://www.deepspace.ucsb.edu/wp-con...aper_R05.p df

A 5 km diameter sphere that's 1 micron thick made of structured silicene occupies 78.54 cubic meters of space and efficiently folds into a 5,320 mm diameter sphere that weighs 94.25 tonnes. Placed into LEO polar orbit, in constant sunlight, with a 100 tonne launcher, it inflates to 5 km diameter using solar power.

It collectes 26.86 billion watts on orbit around Earth, and ejects material from its surface at 120 km/sec. . It absorbs light energy efficintly from the sun across the range of visible colours, and fires up an array ion engines that eject 3.73 kg/sec of propellant producing 45.65 tonnes force of thrust, accelerating the satellite at 0.58 gees.

It takes 6.24 km/sec from LEO to enter a transfer orbit from Earth to Jupiter. It takes 18.28 minutes to boost from LEO to Jupiter transfer, and 3.98 tonnes. It takes 2.736 years to fly from Earth to Jupiter, and from there it is tossed into an orbit with a perihelion of 0.025 AU. This takes another 2.118 years.

At perihelion this sphere produces 67.15 terawatts of power and can form a beam with a spot size 9.1 meters in diameter at 1 AU distance! At 800 AU energy can be efficiently beamed to another 5 km sphere of similar design, and the energy transmitted into any direction.

The surface absorbs the full spectrum of sunlight, and powers an array of UV lasers operating at the 250 nm wavelength, can efficiently send energy to a similar sphere sent to 800 AU distance, equipped to efficiently absorb and generate 250 nm wavelength energy.

Once the first satellite is in place, another second satellite of similar construction is orbited and opens to receive 67.15 TW of power. The energy is exchanged between satellites, to create photonic thrust between them. The plane of the orbit of the first satellite is perpendicular to the direction of transmission. This causes the reaction to offset the orbital plane from the center of the Sun, creating a powerful restoring force at the 0.025 AU distance. Meanwhile, the second satellite is accelerated again a 0.581 gee, but this time with photons only! After 53 days its travelling at 8.7% light speed. It now absorbs energy and ejects protons and electrons at 3.4 light speed. 8.60 tonnes of hydrogen is ejected in this way, to slow the sphere to zero velocity at 800 AU from Sol, after 106 days of travel.

We are now in a position to beam energy from near the solar surface to 800 AU, and have that beam reformed and beamed AROUND the Sun, so that the gravity of the Sun focuses the laser energy on objects receding along the line connecting the center of the second satellite the center of the Sun, and the center of a third object, the spacecraft leaving Earth. and the center of a target star. Energy an be efficiently send and received using this technique across the galaxy.

http://www.newyorker.com/tech/elemen...mile-telescope
http://www.centauri-dreams.org/?p=785

A third sphere enters Earth orbit, and receives energy from the Sun orbiting satellite directly. This is accelerated at 0.58 gees from Earth to 800 AU, along a line opposite the second satellite. Energy is then beamed from the first satellite to the second satellite, and then to the third satellite by gravity lens focusing, to continue acceleration, until 35% light speed is attained, in about 10 months about 1/4 light year out from Sol. The third satellite then coasts until it reaches 1/4 light year of the target star.. Energy is then beamed from Sol, to the third satellite via the second satellite through gravity lensing. Communications is continuous. The satellite uses hydrogen ejected at 75% light speed energised by the beam, to slow down. The satellite then uses local star power to navigate within the star system, sending information back to Sol.

The gravity lensing technique is very powerful. It should be able to form a spot only 1 km across at Sag A* at the center of the Milky Way galaxy. It should also be able to form images of that resolution as well. So, we should be able to learn a lot about Sag A* in the process, and figure out how to communicate through Sag A* ergosphere, and have signals emerge before they arrive. and use this Penning process to eiminate the time lag in long distance communication.

This is certainly something to explore. Success along these lines will permit us to send avatars to distant stars and interact with them live,

https://www.youtube.com/watch?v=rVlhMGQgDkY

So, we send a signal to Sag A* and it arrives there 30,000 years in the future. However, because we know a lot about the physics of Sag A* we have our signal hit the right spot at the right time, so that it emerges 60,000 years in the past, and is moving in the right direction to come back to us, and our device. So, that signals we send arrive the moment they are sent on Earth. Signals sent from the device are similarly picked up at the right place and time, so that they too arrive at Earth instantly.

Success permits communications through time, which has many applications here.

https://www.youtube.com/watch?v=GHC8z6ULs18
https://www.youtube.com/watch?v=tgUbWkiWNCo
http://www.phys.uconn.edu/~mallett/main/papers.htm

The weak interaction that Mallett predicts, would be astronomically stronger within Sag A* ergosphere, and should make instantaneous communications across the galaxy possible along the lines described.


Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

On Friday, April 15, 2016 at 2:51:47 PM UTC+12, Jeff Findley wrote:
In article , says...

wrote:
See:

http://gizmodo.com/a-russian-billion...ild-1770467186

Indeed, the hurdles range from how to create the laser array
capable of accelerating a small payload off Earth to how to
transmit data back to us over interstellar distances. These will
be huge accomplishments, with reverberations throughout many
fields of science and technology.

I was wondering how they were going to get comms back from such a
small package. I guess the answer is they haven't exactly figured
that out yet.

No kidding. It's hard enough getting a signal from probes like Pioneer
10 and Voyagers 1 and 2 which are "only" a few light hours away. Probes
that are light *years* away would be much more difficult.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

In college I worked with Paul Horowitz and John Kraus and developed the first digital signal processor using the Cooley Tukey theorem of FFT decomposition. The USN and USAF were interested in this for a variety of reasons, but I was interested in SETI.

The Arecibo radio telescope has the ability to communicate with its twin anywhere in the Milky Way. The Very Large Array in Socorro NM is capable of detecting leakage from radio usage anywhere in the Perseus Arm, and can communicate with a twin of itself anywhere in the Galactic Cluster we inhabit. (if we knew when and where to point the array). The VLA is not used for SETI however, a product of the Golden Fleece Award back in the 1980s.

https://www.youtube.com/watch?v=u9WHs49nlHk
http://frank.harvard.edu/~howard/pap...arter_ARAA.pdf
http://seti.harvard.edu/grad/dpdf/thesislt.pdf