Topic: Space Questions for Jonny?

[BlackNMild2k1]

We still never found out what exactly a "Space Elevator" is and why we don't have one already.

Also what everyday inventions we use today that we have NASA to thank for.
especially the stuff that really seems un-space related in anyway whatsoever.

[UncleBob]

Not to step on Jonny's toes... but for your Space Elevator research, check out this video:

[S-U-P-E-R]

I'm out of questions. I already know everything about space. My dad invented space. I've already been to the moon like, five times.

I guess, uh, what are some far-reaching effects of disasters, such as with Challenger and Columbia, that aren't readily apparent to gas station Joes that don't work in aerospace?

[S-U-P-E-R]

Oh oh oh. Do you think the reds may have attempted to put a man in space before Yuri Gagarin and never made it public when it didn't turn out so well? Or is that a little too tinfoil hat? Know any cool history along the Russian side of things?

[Fatty The Hutt]

what everyday inventions we use today that we have NASA to thank for.
especially the stuff that really seems un-space related in anyway whatsoever.

Tang

[NWR_insanolord]

Unless we find a way to make money by sending people to Mars, we've got a much better chance of getting there on the government's dime than through private industry.

I think a private company could make a small fortune sending people to Mars.  I can think of a few people in this thread we could send.  I could start a Kickstarter.

Mars as the new Australia. I like that idea a lot.

[ShyGuy]

Jonny ain't never been to space. James Bond went to space in Moonraker, let's start a thread asking him questions.

[Jonnyboy117]

There may already be enough questions for the next edition, but Scott suggested I bump the thread in case anyone wants to get one in for consideration. We'll probably record soon after the telethon.

[Ceric]

There may already be enough questions for the next edition, but Scott suggested I bump the thread in case anyone wants to get one in for consideration. We'll probably record soon after the telethon.

I was hoping you were going to refute Shyguy.

[Jonnyboy117]

Sorry it's been so long, but we are getting close to recording the next Space Q&A. I'll work with Scott to pull more questions out of this thread, but feel free to add more. There have been many recent space events that would be good topics!

Also, I put an old rocket science quiz online for people to try in advance -- I'm hoping to walk through some of these True/False statements with Scott on the show. I gave these questions to Aerospace sophomores a few years ago, and they are designed to generate discussion for people with little or no knowledge of rocketry.

https://t.co/zlN3b5CZea

[azeke]

Can i try to answer here?

The common form of Newton’s 2nd Law, F = m*a, does NOT apply (except instantaneously) to a rocket while it is being fired.

If it's being fired then a force is applied to it and law affects it.

Because of inertia and lack of friction, you can fire a rocket in space once and maintain that acceleration indefinitely after the propellant is all used up.

Inertia keeps constant speed, not constant acceleration.

The efficiency of a cold gas rocket can be increased by heating up the propellant (i.e. hot gas rocket).

No idea, not big on chemistry, but since no answer is given less points then incorrect one (pretty smart ranking there) and because every question in this sheet seems to be a trick question, i'm gonna go with no.

Space shuttle launches are environmentally safe because the combustion of liquid H 2 and O2 produces only water.

I thought they still used kerosene as a rocket fuel? And even beside fuel itself, there are user carrier rocket parts and even satellite parts if launch was unsuccessful. I kinda should know, i live here. Also weren't there something that each launch pierces ozone layer or something and resulting hole stays for a while? So no.

Since electric rockets can be powered by solar cells, they can operate (“burn”) indefinitely as long as they stay in the sunlight.

What's electric rockets? I don't think that exists.

Voyager 1 and 2 are still flying out of our solar system because their nuclear rocket engines are still burning.

Don't remember clearly, but going with sheets overall tone, i'm going with no.

Exotic rockets like solar sails and orbital tethers have higher theoretical efficiency than any current technology.

Solar wind sails -- what a cool tech! They don't consume any energy and give enough impulse to traverse ship in the system. Too bad it takes centuries to go anywhere. Theoretically -- probably yes cause apart from energy to manage sail you don't spend any energy at all.

Rocket staging, which involves dumping hardware in flight when it is no longer needed, is an effective means for reducing overall rocket mass and cost.

What does "effective" stands for here? It works. Something with carrier plane and returnable space shuttle that is used in commercial space flights is probably more effective but not very scalable if we want more than a small pod with one person on board... Going with yes, it's effective for now.

In modern times, the most common use of rockets is for space travel.

Fireworks are rockets too. So are tomahawks in jetfighters and whatnot.
Even if we limit to space only, most or the space launches don't carry passengers, it's mostly satellites and then equipment for ICS.

[S-U-P-E-R]

Tell us all about the Hayabusa probe! I had some Japanese pals tell me about it and how it was a pretty awesome success, and for some reason I hadn't heard of it before then.

[oohhboy]

Lets roll.

-The common form of Newton’s 2nd Law, F = m*a, does NOT apply (except instantaneously) to a rocket while it is being fired.

False. As long as any force is acting on it F=ma applies and that includes gravity when it is sitting on the launch pad.

-Because of inertia and lack of friction, you can fire a rocket in space once and maintain that acceleration indefinitely after the propellant is all used up.

False. The lack of any external force acting on the rocket like friction and air resistance is what allows it to keep it's velocity not acceleration. Inertia is the minimum amount of energy required to move an object.

-The efficiency of a cold gas rocket can be increased by heating up the propellant (i.e. hot gas rocket).

True. By heating up the propellent, the exhaust will have more energy than when it was cold therefore produce more force upon exit.

-Space shuttle launches are environmentally safe because the combustion of liquid H 2 and O2 produces only water.

False. While the shuttle itself burns a Hydrogen Oxygen mixture, the solid boosters burn Aluminum.

-Since electric rockets can be powered by solar cells, they can operate (“burn”) indefinitely as long as they stay in the sunlight.

False. Such rockets still require some mass to act as propellent. While very mass efficient, it cannot burn indefinitely.

-Voyager 1 and 2 are still flying out of our solar system because their nuclear rocket engines are still burning.

False. Because there is not external force slowing them down or changing their course back into the system, they continue to "coast" along out of the system. The nuclear batteries power the electronics.

-Exotic rockets like solar sails and orbital tethers have higher theoretical efficiency than any current technology.

False. Solar sails and orbital tethers aren't rockets therefore that measure of efficiency doesn't apply

-Rocket staging, which involves dumping hardware in flight when it is no longer needed, is an effective means for reducing overall rocket mass and cost.

True. A single stage rocket if feasible would have extremely poor rocket mass to payload ratio.

-In modern times, the most common use of rockets is for space travel.

False. Fireworks.

WTF is with this quiz. It's more of an English exam than one about physics.

[Jonnyboy117]

Rocket scientists have to use English, too! Actually, I think you see the lawyer-ized wording more because you understand the concepts so well... But you didn't get all of them right, and some of your explanations are wrong even if got for the answer right. ;-)

[oohhboy]

I figured I wouldn't get them all. I was pulling knowledge from 10+ years ago half asleep from a long day. Still not bad. The rocket staging explanation is pretty rubbish since it doesn't actually remotely touch on the physics of staging and why we do it beyond monetary costs. Looking at it now with a night sleep, it's embarssing how many times I use the wrong term. The Exotic rocket question still gets a laugh out of me "They aren't rockets damn it!". But efficiency does apply in the sense that getting mass up an orbital teather to orbit requires a lot less energy/resources than a rocket and a solar sail has 100% efficiency since it expends no energy once deployed to aquire thrust.

[pokepal148]

i demand a rant on all of the conspiracy theories about the space program

[oohhboy]

You want Buzz Aldrin to punch you?

[azeke]

i demand a rant on all of the conspiracy theories about the space program

Space program is all faked, and all footage is made in Bollywood, because the earth is flat.

[oohhboy]

Finally caught up with the podcast. Nice to know I am not that far behind. 9/10 isn't half bad although I would have scored a little lower (8/10) had I been forced to give long form answers. I really should have caught that first question, but the problem would have been that I couldn't come up with a long form answer. I don't think I have ever done a T/F quiz since maybe primary school. Long form answers is always the norm.

I can't believe you liked the new Star Trek movie. It insults my intelligence and the Trekie in me.

[pokepal148]

no seriously what is your response to those things

[BranDonk Kong]

Question - who kicks more ass: Commander Chris Hadfield or Cobra Commander?

[NE_austin]

This thread is dead. Maybe I best use some other form of transmitting my questions about space. Or maybe not! Here are my questions about space:

1) Kerbal Space Program. Have you looked into it? Thoughts on how "accurate" it is vs. how "fun" it is? Do you think it's a good way to learn about rocket/orbital mechanics? If you've not touched KSP, you can skip this question.

2) Could you talk about what you actually do at your job?

3) Your thoughts on the Saturn V vs. things like the shuttle's SRBs/main tank, SpaceX's Falcon 9, etc etc. Do you think it remains the most elegant and efficient solution for space travel, given its simplicity? Should we model future rockets after it, or move towards reusable rockets/something else?

Feel free to answer all of these, none of these, or some of these. Thanks to the two of you!

[Ceric]

Jonny has answers to those spread out among his massive audio library but it be nice to have those condensed.  I do have a question.

By my understanding you particular specialty is Habitats and Life Support.  You've mentioned being inspired by the BioDome teams.  In light of the recent flooding and wildfires, Could you and how would you build a self sustaining environment that could weather those types of events going on outside of it?

I know this is probably almost the exact opposite of what you are thinking about with space and other planets, no liquid on most other planets and space; no burnable matter on most other planets and in space.  I still think it be interesting.