The thread for space cadets!

[hobbsyoyo]

There is some really cool footage of the launch today if anyone wants to link to it. I won't be able to until later tonight at the earliest. Seeing the droneship grow as Stage 1 descended was awesome.

 

[hobbsyoyo]

On the broader goals of a company aligning with a business opportunity -

To put it one way, Boeing could make Cessna sized aircraft for personal use but (afaik) don't. One of the reasons they don't is that it just isn't a strategic interest for them.

 

[Synobun]

My god, Hobbs, edit these posts together.

 

[uppi]

Thanks for the explanation.

Looks like I was not the only one who had this "put 100 CubeSats on one rocket" idea:
http://timesofindia.indiatimes.com/...n-one-go-in-february/articleshow/56332988.cms

Isro will launch a record 103 satellites in one go using its workhorse PSLV-C37 in the first week of February

Admittedly, that rocket is a bit bigger than a Falcon 1.

 

[Berzerker]

what prevents us from flying into space and back with a plane?

I need to change what I said about one of those theories I mentioned, the 'evaporate' theory suggests the process required tidal locking very early on - the near side was baked by Earth's heat and escaping volatiles were deposited on the far side. This would explain the differences in crustal thickness and elevation.

The theory also suggests the maria formed because the near side crust had already been thinned, so impacting asteroids during the LHB had less rock to go through before finding and releasing magma whereas the thicker crust on the far side provided more protection.

 

[uppi]

what prevents us from flying into space and back with a plane?

Short answer: Planes need air to fly and there is none in space.

Longer answer: You can build a rocket-powered plane that flies like a plane in the atmosphere and like a rocket in space.
For example: https://en.wikipedia.org/wiki/SpaceShipOne
However, this means that you have to spend fuel to carry all the plane parts (wings, control surfaces, maybe air-breathing motors) up into space, where they'll be useless. In the end, I don't know whether this could be more efficient than just building a rocket without the plane parts.

 

[Gigaz]

The longer and perhaps more accurate answer is that orbital velocity, the speed which a satellite must achieve to not fall back to Earth, is very fast. Faster than what a modern jet can achieve, and at the upper theoretical limits of scramjet engines. If you could make a plane fast enough, you could just steer upwards and leave Earth, or you could reach the orbit with a very small rocket attached to the plane.

 

[Berzerker]

thx guys, would a plane have to enter into orbit and leave the atmosphere to be at risk of burning up returning?

Seems we should be able to leave and enter the atmosphere

 

[hobbsyoyo]

The thermal load of a reentering space plane is much higher than that of a quasi-ballistic capsule though the heat flux ( rate) is lower at any given time. So your thermal protection system for a plane needs to withstand lower temps for a much longer time, basically.

SS1 is an oddball due to low speed/altitude and it's feathered re-entry system. I'll try and write more late just been super duper busy.

 

[Cutlass]

 

[Samson]

I came across this paper (?) on the Breakthrough Starshot project. 20 years travel for 2 hours of measurements! I like the idea of cheap and numerous. It also struck me how SMALL interstellar distances are. It takes 7.5 years of the 20 to get throught the ort cloud.

 

[r16]

so , is it an Xenforo thing that ı no longer get alerts that there have been posts in threads ı have previously posted ? Say , lack of participation , say for a month , means no alerts are necessary ? 'Cause ı might have a good rant out of it .

 

[Gigaz]

Politico reports that the Trump administration plans a shift for NASA away from Mars and towards Moon landings and promotion of space commercialization. Doesn't happen often these days, but I approve.

 

[Michkov]

so , is it an Xenforo thing that ı no longer get alerts that there have been posts in threads ı have previously posted ? Say , lack of participation , say for a month , means no alerts are necessary ? 'Cause ı might have a good rant out of it .

Under the forum tab there is a "Watched Threads" subtab. This should should show you the threads you posted in. You can sort it to last post.

Also in the reply to thread is a tickbox for email notifications at the bottom.

 

[ori]

you might want to look into site feedback for a rant - the short version ist that xenforo will allert you once to any new post in a subscribed thread and then only after you read the thread again - the alert though gets dismissed automagically if you do not read it for a set amount of time (a month apparently) so that it is quite possible to have new posts without getting new alerts. Changing that behavior seems to necessitate third party add-ons which is a pain. Xenforo is all sorts of things but not actually well documented or terribly responsive to design criticism .

 

[hobbsyoyo]

Spoiler :

https://thespacecadetblog.com/2017/02/12/sandys-beach/

Not the post I wanted to write but the one I needed to.

 

[Cutlass]

Nice writeup.

 

[r16]

thanks for the xenforo thing and apologies for the interruption .

 

[hobbsyoyo]

Politico reports that the Trump administration plans a shift for NASA away from Mars and towards Moon landings and promotion of space commercialization. Doesn't happen often these days, but I approve.

Possibly spoke to soon on this. As the threat of change to NASA and its programs has grown a lot of congress members, academics and industry professionals have lined up to sing the praises of the SLS. We don't have a ton of inside information about what Trump and his team are planning but if it involves cancelling the SLS, we can expect southern Republicans to fight it tooth and nail. If SLS and Orion stay, there won't be a whole lot left in the budget to increase commercialization at least until the designs are fully mature and into normal production. Even then, their low production rate will drive very high unit costs that will continue to put strain on NASA's budget.

Also, JPL just presented their new Europa orbiter preliminary design to the public and it has been mandated by Congress to fly on the SLS. This basically guarantees at least 2 SLS launches (the other is an unmanned Cislunar loop around in the moon in 2018-2019) over the next decade though the gap between launches (mid 2020's for Europa at best) will further drive up costs to keep the SLS in production.

 

[warpus]

I came across this paper (?) on the Breakthrough Starshot project.

What if this thing hits a micrometeor or some speck of dust along the way, or something like that? Seems like it doesn't have any sort of protective shield. I understand that in between solar systems the odds of hitting something are low.. but they aren't 0. And when you're exiting our solar system and its gravitational well, there is a lot more stuff that you can hit along the way.. same thing when you are approaching the other solar system.