Need some help. If anyone is curious to follow the idea of launching a boulder of the surface of Phobos in order to impact Mars and release 10^18 joules. Phobos is at an altitude of 6000 km. At that orbital height, it is moving at around 2141 m/s. How do you calculate the velocity of a body that will be d-orbited from that height to surface impact?
It would be easier to redirect a near Mars asteroid of the equivalent size.
Quote from: Stan-1967 on 04/11/2016 03:08 pmNeed some help. If anyone is curious to follow the idea of launching a boulder of the surface of Phobos in order to impact Mars and release 10^18 joules. Phobos is at an altitude of 6000 km. At that orbital height, it is moving at around 2141 m/s. How do you calculate the velocity of a body that will be d-orbited from that height to surface impact?Calculating a Hohmann transfer orbit from Phobos to Mars surface is one starting point. If I did the math right the required dv is about 0.6km/s.
Heat & WaterHow to heat the proposed hab and greenhouse domes to room temperature? Trying a rough calc:Assumptions: Domes are circular, 300 m diameter.Dome external surface temperature is 5 C (water).Heat exchanger transfers treated water at 50 C from Lake Matthew bed, with heating required 18 hr / sol.Head is 200 m.There is negligible heat loss through bedrock in the micro-environment.Dome U value is 1 W / m2K.Rough result:Water flux is ~1 liter / second. Pump power requirement is ~0.6 kW, or ~0.8 hp.Does that look about right?And would anyone want to estimate the heating power requirement, without terraformation?
Heat & Water
Building a 1 GWe nuke plant on Mars is arguably further out of our technical grasp than diverting a very small asteroid.
Then heat transfer to the air inside the dome from water fountain in lake from the deep water . Water that is cooled by the air is now on the surface of the lake?
...A 1GWe nuclear reactor...
The methods are non-nuclear and shown to be safe.
Quote from: Stan-1967 on 04/11/2016 07:30 pmBuilding a 1 GWe nuke plant on Mars is arguably further out of our technical grasp than diverting a very small asteroid. What makes you think that? Nuclear reactors can be very compact and small. They can even be their own way to get there (NERVA), The bigger issue with nuclear plants in space is the political resistance to them.
Asteroid hitting Mars?How much dust would be put in the atmosphere of Mars from such an impact.?Building more colonies, how would any preexisting colony handle a new asteroid impact ( quake ) on Mars?
Quote from: Elmar Moelzer on 04/11/2016 07:50 pmQuote from: Stan-1967 on 04/11/2016 07:30 pmBuilding a 1 GWe nuke plant on Mars is arguably further out of our technical grasp than diverting a very small asteroid. What makes you think that? Nuclear reactors can be very compact and small. They can even be their own way to get there (NERVA), The bigger issue with nuclear plants in space is the political resistance to them.A 1 gigawatt nuclear reactor core Weighs hundreds of tons and requires huge amounts of cooling.
Quote from: Stan-1967 on 04/11/2016 10:36 pmQuote from: Elmar Moelzer on 04/11/2016 07:50 pmQuote from: Stan-1967 on 04/11/2016 07:30 pmBuilding a 1 GWe nuke plant on Mars is arguably further out of our technical grasp than diverting a very small asteroid. What makes you think that? Nuclear reactors can be very compact and small. They can even be their own way to get there (NERVA), The bigger issue with nuclear plants in space is the political resistance to them.A 1 gigawatt nuclear reactor core Weighs hundreds of tons and requires huge amounts of cooling.1. Since we want to heat a lake, we have the cooling right there. We are not going to build a carnot cycle. We are just interested in the thermal output.2. The reactor core can be in the rage of 10 tons, or so. The rest is shielding, mostly. Timberwind showed that you can build high power reactors with a relatively small weight footprint.
Quote from: Stan-1967 on 04/11/2016 10:36 pmQuote from: Elmar Moelzer on 04/11/2016 07:50 pmQuote from: Stan-1967 on 04/11/2016 07:30 pmBuilding a 1 GWe nuke plant on Mars is arguably further out of our technical grasp than diverting a very small asteroid. What makes you think that? Nuclear reactors can be very compact and small. They can even be their own way to get there (NERVA), The bigger issue with nuclear plants in space is the political resistance to them.A 1 gigawatt nuclear reactor core Weighs hundreds of tons and requires huge amounts of cooling.NERVA is a nuclear reactor core, output multiple GW and had a mass of just a few tons. Almost a gigawatt per ton for some designs. And we actually tested NERVA, so it's not like this overall idea is ridiculous. You could land a 10-20ton Gigawatt reactor on Mars on a typical human-rated lander design.