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View Full Version : Is a mission to a (very) hot O type of star dangerous or not?



Denis12
2006-Apr-05, 02:20 PM
It is impossible i know but if it (is) possible ,is a mission to for example (Mintaka) in the belt of Orion a dangerous thing or just not ,it is a blue (very) hot type O star. Is it safe to get close to a very hot O type of star? What are you thinking about this? Thanks.

mantiss
2006-Apr-05, 06:01 PM
It's highly unsafe, plus by the time you actually get there, you will likely only have a stellar cadaver to observe unless you use something blazingly fast *s*

Denis12
2006-Apr-05, 09:39 PM
And by the time we (can) spacetravel to the stars it is maybe possible to put very strong heatshields around a (unmanned) spacecraft the we send to Mintaka or other very hot O type of stars ,but if a spacecraft survive the trip then it is possible to get its way back to the Earth ,after it has observed and discovered ,and photographed the type O star. But i think youre right that it is very dangerous and unsafe to get to such a star ,because a manned mission looks like impossible ,the only chance in the far far far future is sending a (un)manned spacecraft to Mintaka in the belt of Orion ,and it needs mega good protection against the enormous heat of such a star. And it is difficult to get it in a close orbit around it. Maybe a distant orbit looks like a good and safer alternative. What are you thinking about this future mission? And how can we develop a spacecraft that can get close to a O type of star? And how quick can we get there?:question:

antoniseb
2006-Apr-05, 10:21 PM
how can we develop a spacecraft that can get close to a O type of star? And how quick can we get there?

If we try to launch it in the next twenty years, it will take hundreds of thousands of years to get there (and cost trillions to launch). On the other hand if we wait a few thousand years before trying to design the mission, perhaps we can get there a lot faster, and use unimagined technologies for the heat protection.

Eckelston
2006-Apr-06, 01:06 AM
If we try to launch it in the next twenty years, it will take hundreds of thousands of years to get there (and cost trillions to launch). On the other hand if we wait a few thousand years before trying to design the mission, perhaps we can get there a lot faster, and use unimagined technologies for the heat protection.

A few thousand years? I'll be old by then.

VenusROVER
2006-Apr-06, 01:10 AM
ya really antoniseb i dont wanna to be dead by the time we reach another solar system or for that matter pluto

antoniseb
2006-Apr-06, 01:14 AM
i dont wanna to be dead by the time we reach another solar system or for that matter pluto

As before, I'd recommend that we put money into life-extension technology so you can live to be thousands of years old. If you want to see us get to other stars, I think that's your only hope.

VenusROVER
2006-Apr-06, 02:02 AM
why not faster then light travel

VenusROVER
2006-Apr-06, 02:03 AM
a probe will reach proxima centuri by 2050 i'd say

Omicron Persei 8
2006-Apr-06, 02:04 AM
why not faster then light travel

There is no known way of doing that. Not now, not in the foreseeable future.

VenusROVER
2006-Apr-06, 02:05 AM
Jeese you guys really dont care that u won't see other planets until your long dead. Its almost like you want it that way.

Omicron Persei 8
2006-Apr-06, 02:14 AM
Jeese you guys really dont care that u won't see other planets until your long dead. Its almost like you want it that way.

What are we suppose to do? Snap our fingers and expect magical technologies to fall from the sky? Not only are we limited in money for these missions but also the scientific theories that we use to make them happen. We can't just build a spacecraft using physics that don't exist to us.

VenusROVER
2006-Apr-06, 02:15 AM
Who knows it could happen!

Omicron Persei 8
2006-Apr-06, 02:21 AM
Who knows it could happen!

Well I could say the same thing about me meeting my future self, but it doesn't mean its true. Sure I'd love to see other planets, other stars. It's just that in life there needs to be a balance between imagination and realism. There is nothing wrong with having a good imagination. But some things are just plain impractical from a financial and technical standpoint. Sure, at some point in our future existence routine interstellar travel may come to fruition but I just don't see it happening in the near future.

Denis12
2006-Apr-06, 02:37 AM
Whan the unmanned spacecraft has launched and start its trip to the (very) hot blue O type of star Mintaka ,is it necessary to start its voyage with many flyby,s around the Sun or Jupiter to get more and more speed? I think that is needed because only then it can reach a high speed. What is your opinion?

Denis12
2006-Apr-06, 01:25 PM
Can we talk about my (last) reply? Friendly thanks.

Denis12
2006-Apr-06, 09:41 PM
Com on give reactions please ,i asked this because the tread sinks away and there are no new reactions. Lets (restart) the dead tread. Thank you.:(

Cl1mh4224rd
2006-Apr-07, 12:38 AM
Whan the unmanned spacecraft has launched and start its trip to the (very) hot blue O type of star Mintaka ,is it necessary to start its voyage with many flyby,s around the Sun or Jupiter to get more and more speed? I think that is needed because only then it can reach a high speed. What is your opinion?
I'm no expert (not even close), but it'd probably be helpful. It would add a significant amount of time to the trip (although, relatively speaking, probably not that significant), though...

Van Rijn
2006-Apr-07, 01:26 AM
Whan the unmanned spacecraft has launched and start its trip to the (very) hot blue O type of star Mintaka ,is it necessary to start its voyage with many flyby,s around the Sun or Jupiter to get more and more speed? I think that is needed because only then it can reach a high speed. What is your opinion?

Mintaka is 915 light years away. Assuming we managed to get a spacecraft up to 70,000 mph (an excellent result for a gravity assist) we could expect it to take a bit under 9 million years to get there.

Fram
2006-Apr-07, 08:05 AM
I suppose there is a maximum speed we can reach by using sling shots in our solar system? I mean, if your speed is sufficiently high, you don't get a slingshot but just zip past (with only a very slight course correction). Does anyone know what the theoretical max is a probe could get (an approximation will do just fine ;-) )

mantiss
2006-Apr-07, 08:14 PM
I suppose there is a maximum speed we can reach by using sling shots in our solar system? I mean, if your speed is sufficiently high, you don't get a slingshot but just zip past (with only a very slight course correction). Does anyone know what the theoretical max is a probe could get (an approximation will do just fine ;-) )

Including a slingshot using the Sun? Or just planets?

I find that the lack of a suitably close black hole for sling-shotting to be detrimental :p:p:p

Saluki
2006-Apr-07, 09:17 PM
Including a slingshot using the Sun? Or just planets?

I find that the lack of a suitably close black hole for sling-shotting to be detrimental :p:p:p

I don't think you could get a gravitational assist from the sun. The assist we get from planets comes from a transfer of angular momentum. Since the planets (and the probes) are orbiting the Sun, the Sun has no angular momentum to give from the perspective of the probe.

lpetrich
2006-Apr-09, 03:37 AM
A problem with going near an OB star is its very high surface temperature. This means that it will have much smaller angular size for the same apparent luminosity. Consider a typica one, Zeta Ophiuchi (http://en.wikipedia.org/wiki/Zeta_Ophiuchi), one of the closest of them (460 lyr; 140 pc). Its spectral type is O9, surface temperature is 32500 K, its luminosity 68000 times the Sun's, and its radius 8 times the Sun's.

To be at a distance where its apparent luminosity is the Sun's from Earth, one would have to be 260 AU from it. And it would have an angular diameter of only 1' -- it would be a brilliant bluish dot.

Furthermore, much of the luminosity will be in the ultraviolet; from Wien's Law, the peak emission will be at 100 nm instead of the Sun's 500 nm. That can cause trouble for plastics and other organic materials. Including skin and eyes, likely making it dangerous to be illuminated by the light of such a star if at a Sun-at-Earth brightness, at least without filtering out that UV.

I remember calculating this in another thread when I considered observing X-ray binaries -- their X-ray luminosity is enough to make it dangerous to approach close enough to resolve any details.

-

And as to the star still existing when one gets there, that could certainly be a problem. A typical OB star lasts only a few million years, and to get to Zeta Ophiuchi in a million years requires traveling at 140 km/s -- much faster than is feasible with chemical rockets. One would need a nuclear reactor, but a nuclear-powered spacecraft can potentially go as fast as 10,000 km/s, using an available-energy fraction of 0.001 * (total mass)*c^2.

So one could visit Zeta Ophiuchi and other close OB stars, like Rigel, but not many others.

Van Rijn
2006-Apr-09, 04:20 AM
I don't think you could get a gravitational assist from the sun. The assist we get from planets comes from a transfer of angular momentum. Since the planets (and the probes) are orbiting the Sun, the Sun has no angular momentum to give from the perspective of the probe.

You can use a powered gravitational assist. That is: Fire your rockets at closest approach to the sun. You gain from the reaction mass that you took with you deep into the gravity well, but aren't taking out.

The closer you get, the better you do, but there is that hot sun to deal with. Also, it only helps you so much. In this case, you might be able to shave a few million years off the flight. You might get there in five million years, or even a bit less.