# B Pale Red Dot Mission

1. Jul 11, 2016

### Clever Penguin

Mission objective: Send a spacecraft to the Alpha Centauri star system and collect data
People behind the mission: Mark Zuckerberg, Stephen Hawking, Martin Rees, Pete Worden, Avi Loeb, Freeman Dyson, Lou Friedman, Saul Perlmutter, Philip Lubin, Santa Barabara.
Estimated mission launch: 2030s
Mission details:
1. A mothership will launch into high-Earth orbitbefore releasing many (potentially thousands) of probes, one by one.
2. Each probe contains a StarChip which has cameras, sensors, navigation and communication computers, a power supply, and photon thrusters. All this on a chip the size of a postage stamp, and surrounded by a one metre2 sail, and a combined mass of just a few grams.
3. In a dry location at high altitude will be a large array of 1 million 1 kW lasers, giving a combined power of 1 GW.
4. The momentum of the laser photons on the sail pushes the StarChip away from Earth. The high power and low mass means that after 10 minutes the StarChips will be accelerated to 20% of the speed of light.
5. The StarChips will reach Proxima Centauri in 21 years, and Alpha Centauri in 22 years.
Estimated time of arrival at Proxima Centauri: 2050s
Speed of probe: 0.2c
Other: This project has been awarded $100 million by the Breakthrough Foundation, which will cover the beginning of the research and development process. The entire project is expected to cost several billion dollars Source: Astronomy Now Magazine, July 2016 edition Thought this was worth sharing, and created this thread as a place for discussion of the project. 2. Jul 11, 2016 ### .Scott So this camera will snap photos on its 0.20c flyby of whatever it finds. Then it will transmit this information back to Earth where we hope to be able to detect and receive this signal. This project certainly has its share of technology hurdles. 3. Jul 11, 2016 ### mfb ### Staff: Mentor The idea got announced a while ago. I doubt it will get funded. It is an interesting project that would advance our knowledge in various areas on Earth, but the main science mission is not really interesting - even if we get an image of a planet or of the star, it won't have a high resolution. Think about the images Hubble made of Pluto, but now replace Hubble by a downsized phone camera, and let the camera fly 10 times the Pluto diameter per second with questionable attitude control and no way to steer once the probe left Earth. I guess the main purpose would be the PR effect - increase funding for spaceflight in general, motivate people to learn about science and so on. 4. Jul 12, 2016 ### Clever Penguin Mark Zuckerberg could (probably) fund it all on his own And the laser array. There will have to be a nuclear power station nearby to power them, they say. 5. Jul 12, 2016 ### mfb ### Staff: Mentor If the cost estimate is realistic. 6. Jul 12, 2016 ### Clever Penguin 'Several billion' 7. Jul 12, 2016 ### mfb ### Staff: Mentor Yes. How realistic is that? No one knows. In addition, so far I haven't seen anyone privately funding a science mission with billions (or even a single billion) of dollars. There are multiple persons who could fund a second JWST, or even take a good share of the ITER costs. No one does. 8. Jul 12, 2016 ### Clever Penguin Indeed. Also, I made a mistake in the OP. The combined power of the lasers is 100 GW, not 1 GW. 9. Jul 12, 2016 ### BvU What's a reasonable estimate for the efficiency of a laser in ten years from now ? 10. Jul 12, 2016 ### mfb ### Staff: Mentor CO2 lasers can reach efficiencies of up to ~30% today. I would not expect huge improvements there, and the absolute physical limit is not that far away. 11. Jul 12, 2016 ### BvU So for a thousand Schips I get 100 TW / 0.3 x 600 sec = 200 PJ, the annual US electricity consumption. One nuclear power plant ? Oops, that was only the government. But at 7 c/kWh for industrial use, the electricity bill would be 2e17 / (3.6e6 * 0.07) = 8e12 (dollar I suppose). Mark Z needs rich friends ... 12. Jul 12, 2016 ### mfb ### Staff: Mentor 4 billion dollars electricity cost. You have to multiply by 0.07, not divide by it. 13. Jul 12, 2016 ### Gigel I think it's 1 laser for all ships. 14. Jul 12, 2016 ### Clever Penguin The StarChips are released one by one, and all 1 million lasers are aimed at the sail 15. Jul 12, 2016 ### BvU 1 or 1e6 makes no difference for the energy calculation. Oops , apparently energy is cheap enough; no wonder the US capita use so much 4G$ is peanuts for Mark or Bill

I try to avoid billion and trillion because US doesn't understand those numbers. In the civilized world billion is tera and trillion is zetta.
(apparently

16. Jul 12, 2016

### Gigel

That laser can have some serious applications. E.g. it can be used to move away incoming asteroids. If the 100 GW would be focused on a (100 m)^2 surface on an asteroid, it would heat its surface to some 3000 K and it could vaporize some 11 tons of water / second, which would give at that temperature a force on the asteroid of about 26 MN or higher. It would be enough to change the asteroid's speed by 1 km/s in about a day for 100 m diameter objects or in about 2 years for a 1 km diameter object.

But other applications can be found; say propelling some large craft to Pluto or mining the Moon by vaporizing its surface material. Or deep layer spectroscopy in giant planets' atmospheres.

17. Jul 12, 2016

### BvU

And for the army it's a much cleaner device than all those nuclear bombs !

18. Jul 12, 2016

### Gigel

Just use the 10^n or 1en notations. Or k, M, G and so on. There are at least 2 kinds of billions. For me, the billion is 1G or 10^9.

19. Jul 12, 2016

### Clever Penguin

Yes, billion is 109, and trillion is 1012

20. Jul 12, 2016

### BvU

Yes, I thought T and Z would be less than clear.
This short scale misconception anything to do with Napoleon failing to civilise the English ? These UK guys managed to make it official in ... 1974
Seems like a recognizable tendency to act against own interest