Launching an object into OUTER space

[mrxyz]

I've been wondering something.

My question is, if someone wanted to launch an object into space - how feasible will it be from a physical perspective, what the challenges of this will be and whether it can be done on a reasonable budget.

Note that when I say into space I mean space, not just the troposphere which can be done with a helium filled balloon. I mean to have it escape the Earth's pull such that it can venture towards another celestial body or into a particular direction.

The object in this case would be extremely small compared to the rockets launched by NASA. Maximum weight for the object to be sent would be about 5kg or less - that will make up the technological equipment, to do the 'monitoring' and transmit back the results.

As unfeasible as this sounds to me I just wanted to ask because I am hoping that maybe it's not impossible even if someone doesn't have a huge budget like one of these space companies.

 

[Drakkith]

It is not possible unless you have, at minimum, several hundred thousand dollars to buy a hollow tube and the fuel to fill it. Let's not get into complicated things like nozzles, navigation systems, etc.

 

[phinds]

It is not possible unless you have, at minimum, several hundred thousand dollars to buy a hollow tube and the fuel to fill it. Let's not get into complicated things like nozzles, navigation systems, etc.

But Ralph Kramden launched Alice to the moon for a lot less that that

 

[Drakkith]

But Ralph Kramden launched Alice to the moon for a lot less that that

I don't that was ever verified!

 

[russ_watters]

It is not possible unless you have, at minimum, several hundred thousand dollars to buy a hollow tube and the fuel to fill it. Let's not get into complicated things like nozzles, navigation systems, etc.

There's no way it could be done for "several hundred thousand dollars". Several hundred million maybe.

We have an archetype to follow: Elon Musk. He spent $300 million to develop the Falcon 9 and I don't think it meets the OP's requirement of escaping Earth.

 

[mrxyz]

The technological aspect wouldn't be a problem. My engineering background is good enough (as good as a college student can have). I can comfortably build robotics capable of encompassing a navigation system, transmitting data, detecting temperature or distance from objects, detaching parts as necessary and a lot more which is why I emphasized the 'physical' side of this in the first post.

My understanding of this on the physics side however is that which can be gained from watching documentaries so quite limited. I'm willing to learn but it's better to know about the feasibility before putting hours of research into understanding the relevant equations to then find out it's something that's impossible without a huge budget.

So let me rephrase my question, if a helium balloon can go up to 20KM above sea level (the troposphere), why can't the rocket be lifted to this height by the balloon and then launched from there in turn saving a large amount of petrol. After the rocket is launched from this height - it has to travel the lesser 80KM until it is in what is considered outer space. Can someone explain why this is so difficult that it requires that much money to do.

Perhaps I'm thinking of it wrong but my only point of reference is a car traveling 80KM which definitely doesn't require that much fuel.

 

[Ryan_m_b]

A few quick points: reaching 100km altitude and getting into orbit (I.e staying in space) are two different things. Also a car isn't propelling itself through the air to reach escape velocity but is instead rolling on land.

 

[mrxyz]

There's no way it could be done for "several hundred thousand dollars". Several hundred million maybe.

We have an archetype to follow: Elon Musk. He spent $300 million to develop the Falcon 9 and I don't think it meets the OP's requirement of escaping Earth.

Hmm. Just looked into this.

Falcon 9's aim is to deliver payloads to the ISS which is 370KM above sea-level. It is in orbit around Earth, much higher than the point where outer space is said to begin at 100km. It is also designed to be able to send humans to Mars later in the coming decades so it seems like this is the type of rocket I need a mini version of. To put it into perspective the Falcon 9 is built to support a payload of 13,150 kilograms as compared to the tiny 5kg (possibly slightly more) I'm aiming to send.

 

[mrxyz]

A few quick points: reaching 100km altitude and getting into orbit (I.e staying in space) are two different things. Also a car isn't propelling itself through the air to reach escape velocity but is instead rolling on land.

Planes then.

 

[Bandersnatch]

Take a look at Tsiolkovsky's rocket equation and plug in all the numbers to get a feel for the lower limit of what you might need in terms of propellant mass and exhaust velocity.

 

[Vanadium 50]

The technological aspect wouldn't be a problem. My engineering background is good enough (as good as a college student can have).

By writing this, you have proved that your engineering background isn't good enough, and furthermore, you don't even understand the challenges involved.

The first - and I believe still only - amateur rocket launch into outer space was in 2004, and went 116km above the ground - 100 km is considered the boundary of space. It was 20 feet tall, weighed 700 pounds, and took a team of about 30 - many of whom had day jobs in aerospace - to build it.

 

[Astronuc]

Hmm. Just looked into this.

Falcon 9's aim is to deliver payloads to the ISS which is 370KM above sea-level. It is in orbit around Earth, much higher than the point where outer space is said to begin at 100km. It is also designed to be able to send humans to Mars later in the coming decades so it seems like this is the type of rocket I need a mini version of. To put it into perspective the Falcon 9 is built to support a payload of 13,150 kilograms as compared to the tiny 5kg (possibly slightly more) I'm aiming to send.

Two things to consider are altitude and velocity. Getting something to orbit at about the altitude of ISS requires accelerating to ~17,080 mph or 27 500 km/h. No small feat.

Not only does one need the launch vehicle, but one needs the infrastructure to support the launch.

 

[mrxyz]

By writing this, you have proved that your engineering background isn't good enough, and furthermore, you don't even understand the challenges involved.

Is that a revelation to you?

I mentioned in my original post that I don't understand the challenges involved hence asking. It's a pretty simple concept actually, when you don't understand something you ask. The other side of it is when you don't know the answer, don't try to ridicule the asker.

 

[mrxyz]

Two things to consider are altitude and velocity. Getting something to orbit at about the altitude of ISS requires accelerating to ~17,080 mph or 27 500 km/h. No small feat.

Woah I didn't know this. The fastest traveling plane can only travel at half that speed. So to make a rocket pointing straight up - that would require a huge amount of fuel.

This is a good article I've found that I'm currently reading...
http://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html

The rocket propellant also needs to comprise a huge percentage of the actual rocket itself. I think the size of the rocket will increase greatly when factors such as the fuel are added. That 5kg will increase exponentially.

 

[Ryan_m_b]

Planes then.

Planes and rockets are very different, which is why we don't fly to space. Planes take in air, mix in fuel and blast the result out the back for propulsion. The atmosphere is too thin to do this at higher altitudes necessitating much more fuel for the rocket.

 

[phinds]

The rocket propellant also needs to comprise a huge percentage of the actual rocket itself. I think the size of the rocket will increase greatly when factors such as the fuel are added. That 5kg will increase exponentially.

NOW you are beginning to understand the challenges. You still have not begun to address the infrastructure and the cost.

 

[Ryan_m_b]

You might be interested in this article written for laymen about what it would take to launch to the border of space using amateur model rockets. The numbers aren't good
http://what-if.xkcd.com/24/

 

[mrxyz]

That number definitely doesn't offer confidence. lol

 

[Drakkith]

That number definitely doesn't offer confidence. lol

Nope. As I said in post 2, just to buy a hollow tube and fill it with enough fuel would be at least several hundred thousand dollars. And that probably is waaaay underestimating it, and it wouldn't be that simple anyways. Things like engines, electronics, fuel pumps, fuel tanks for separate fuel, launching infrastructure, and a thousand other things would cost several peoples arms and legs. Maybe Phinds will let you use his.

 

[Astronuc]

Woah I didn't know this. The fastest traveling plane can only travel at half that speed. So to make a rocket pointing straight up - that would require a huge amount of fuel.

This is a good article I've found that I'm currently reading...
http://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html

The rocket propellant also needs to comprise a huge percentage of the actual rocket itself. I think the size of the rocket will increase greatly when factors such as the fuel are added. That 5kg will increase exponentially.

Yes. The solid rocket boosters (SRBs) on the space shuttle are attached to the external tank (ET), and their sole mission is to lift the tank (with liquid hydrogen/oxygen) and themselves along with the space shuttle.

A rocket must lift its payload, the payload support structure, as well as the rocket body and propellants.

The propulsion system needs propellant and the energy to heat the propellant. Assuming one has a lot of thrust, it takes a several (~7.5) minutes to get to orbit, so one needs enough propellant to last a several minutes. Liquid propellants (LH/LOX) require turbo-pumps, a power head and combustion chamber. Then there is the cryogenic storage system on the ground and on the launch vehicle. The launch vehicle require guidance and control systems. One should look at scaling Titan or Delta rockets.

It's not a project for one person.

 

[russ_watters]

Falcon 9's aim is to deliver payloads to the ISS which is 370KM above sea-level. It is in orbit around Earth, much higher than the point where outer space is said to begin at 100km.

You said in the OP that you wanted to escape Earth's pull. That's much higher and much faster than the Falcon 9's capabilities. I'm not sure though if you really understand what that means, given the contradictions and different requirements you've given, plus the implication that you don't seem to understand the need for both altitude and speed.

It is also designed to be able to send humans to Mars later in the coming decades so it seems like this is the type of rocket I need a mini version of. To put it into perspective the Falcon 9 is built to support a payload of 13,150 kilograms as compared to the tiny 5kg (possibly slightly more) I'm aiming to send.

Perhaps another 13,000 kg of fuel would enable an escape trajectory, but I tend to doubt it.

Perhaps I'm thinking of it wrong but my only point of reference is a car traveling 80KM which definitely doesn't require that much fuel.

A car only has to overcome friction. It gains neither kinetic nor potential energy during the trip.

Is that a revelation to you?

I mentioned in my original post that I don't understand the challenges involved hence asking. It's a pretty simple concept actually, when you don't understand something you ask. The other side of it is when you don't know the answer, don't try to ridicule the asker.

It isn't ridicule, it is a reality check. You can't post an impossible goal and then say you have the technical knowledge to do it and not expect to get handed a blunt reality check. There's a reason people say "as hard as rocket science". It really is about the most difficult pursuit humans have ever undertaken.

And look at it from the other way around: by coming here and telling a bunch of scientists and engineers that you can do it, you are insulting us.

Now you're even contradicting yourself about your technical knowledge. You may notice this thread is in General Discussion, not in our Aerospace Engineering forum. It is in general discussion because it is not a serious thread.

 

[Drakkith]

Now you know why there is interest in alternative launch methods. Things like orbital lifts, accelerator launchers, etc. Too bad we don't have the technology to build them yet.

I have a related question. Is it more efficient to accelerate a vehicle to a high speed using something like a ground based accelerator and then have the vehicle maintain this speed through the atmosphere? I noticed that in the comic linked earlier the rocket was designed NOT to accelerate to a high speed very early on because of wind resistance. I assume this is a complicated question that depends on the design of the vehicle, the speed, and a number of other issues of course.

 

[mrxyz]

@russ_waters

1. I recently joined the forum so forgive me for not knowing which is the 'serious' place to post a thread.

2. I understand and admitted it was a very ambitious goal, impossible is a word I don't like to use unless it's completely beyond the realms of possibility. But it's extremely ambitious.

3. I stand by the statement that I have the technical knowledge to do the robotics side of it. And if you want to make a statement indefinitely claiming that I don't then you better bring some proof or don't make such statements at all. Maybe both of you didn't understand what I meant by technical, I meant the technological side of it I.E I know of how the payload/mini- spacecraft will operate itself in space, take measurements and transmit them. However, admittedly, I absolutely don't have the know-how for putting it into space in the first place hence the thread.

 

[mrxyz]

http://myblog.rsynnott.com/2010/03/rocket-fuel-not-as-expensive-as-youd.html
http://en.wikipedia.org/wiki/Multistage_rocket

These offer some hope.

The thing with these large aerospace companies is that they have a huge workforce of scientists with very healthy salaries working on it. That combined with the labour cost of building such a huge object. Most of the costs of launching these aircrafts don't factor these costs out.

$16 per kg definitely sounds more feasible.

 

[Astronuc]

http://myblog.rsynnott.com/2010/03/rocket-fuel-not-as-expensive-as-youd.html
http://en.wikipedia.org/wiki/Multistage_rocket

These offer some hope.

The thing with these large aerospace companies is that they have a huge workforce of scientists with very healthy salaries working on it. That combined with the labour cost of building such a huge object. Most of the costs of launching these aircrafts don't factor these costs out.

$16 per kg definitely sounds more feasible.

kg of what? Perhaps $16,000 per kg is more like it.

The cost of the launch vehicle will be quite expensive. Bear in mind, one must construct the chassis and the propellant storage system. Solid rocket motors use a high strength steel, and the components and joints/welds must meet strict requirements. Similarly for cryongenic systems.

For the payload, if one plans on communications and telemetry, then one need rad resistant microcircuitry/chips. Is one planning to have solar cells for onboard power?

 

[mrxyz]

Yes, solar panels. For the type of data gathering I aim to do, it will use need extremely little electrical energy. Possibly that used to charge a mobile phone.

Let's keep this hypothetical. I have two more questions.

1. In space if someone pushes an object, on Earth friction causes objects to stop but since there is no friction in space will the object continue towards that direction eternally at the same speed unless there's a planetary body pulling on it? Doesn't this mean we just have to aim at an object in space where we know the route to that object won't be in a strong pull from any large objects and give it a 'little push'. Since there is nothing to stop it surely it will get there without requiring additional energy expenditure, right?

2. How far does an object need to be from Earth for Earth's gravity to have an almost 0 effect on it (I understand it can never actually be 0) but a position where if you put the object and give it a nudge - Earth's gravity won't be able to pull it back down.

 

[Astronuc]

Now you know why there is interest in alternative launch methods. Things like orbital lifts, accelerator launchers, etc. Too bad we don't have the technology to build them yet.

I have a related question. Is it more efficient to accelerate a vehicle to a high speed using something like a ground based accelerator and then have the vehicle maintain this speed through the atmosphere? I noticed that in the comic linked earlier the rocket was designed NOT to accelerate to a high speed very early on because of wind resistance. I assume this is a complicated question that depends on the design of the vehicle, the speed, and a number of other issues of course.

Yes, and yes. There have been various ideas such as a ballistic launch with a gun, e.g., Gerald Bull's HARP and a later development, SHARP (http://en.wikipedia.org/wiki/Super_High_Altitude_Research_Project), as well as various railgun/maglev concepts.

Aerodynamic heating is indeed a problem. Note that the SR-71 (top speed ~M3.5) and X-15 (~ M6.72, (4,520 mph, 7,274 km/h)) got pretty hot at their comparatively low speeds at their altitudes. For the highest speed flights, the X-15 used an ablative layer.

For hypersonic aircraft, there has been some thought of using the hydrogen propellant to cool the leading edges, but that can be impractical for a large volume/area.

The space shuttle actually has to throttle back to avoid traveling too fast at lower altitude, not from the standpoint of heating, but from the mechanical limits on the structure.


One possibility would be to use a scaled down version of the Pegasus rocket -
http://en.wikipedia.org/wiki/Pegasus_(rocket )

 

[mrxyz]

That is extremely interesting. So one could, if one was very rich of course, select a route and 'fire' the spacecraft towards it. If the route is selected carefully enough the object in its millions of years of travel make its way past thousands of stars. Possibly to be intercepted by an alien race. If NASA hasn't done this already they definitely should and pass some Earthly messages with it.

 

[Astronuc]

Yes, solar panels. For the type of data gathering I aim to do, it will use need extremely little electrical energy. Possibly that used to charge a mobile phone.

Let's keep this hypothetical. I have two more questions.

1. In space if someone pushes an object, on Earth friction causes objects to stop but since there is no friction in space will the object continue towards that direction eternally at the same speed unless there's a planetary body pulling on it? Doesn't this mean we just have to aim at an object in space where we know the route to that object won't be in a strong pull from any large objects and give it a 'little push'. Since there is nothing to stop it surely it will get there without requiring additional energy expenditure, right?

Yes - gravity assist is used for interplanetary missions.

http://www2.jpl.nasa.gov/basics/grav/primer.php

http://saturn.jpl.nasa.gov/mission/gravityassistsflybys/

http://www.esa.int/Our_Activities/Space_Science/Let_gravity_assist_you

Locally, one could use the moon.

2. How far does an object need to be from Earth for Earth's gravity to have an almost 0 effect on it (I understand it can never actually be 0) but a position where if you put the object and give it a nudge - Earth's gravity won't be able to pull it back down.

Just use g(r) = GM/r², where M is mass of earth, and determine what is an acceptable g(r).

Beyond earth, there is the sun's gravity.

 

[Astronuc]

That is extremely interesting. So one could, if one was very rich of course, select a route and 'fire' the spacecraft towards it. If the route is selected carefully enough the object in its millions of years of travel make its way past thousands of stars. Possibly to be intercepted by an alien race. If NASA hasn't done this already they definitely should and pass some Earthly messages with it.

That is essentially what NASA did with the two Voyager spacecraft .

http://voyager.jpl.nasa.gov/
http://www.nasa.gov/mission_pages/voyager/index.html

http://www.jpl.nasa.gov/news/news.php?release=2012-381

http://en.wikipedia.org/wiki/Voyager_program

 

[mrxyz]

About Earth's Escape Velocity; the place I have the problem is when I jump, I'm clearly not traveling at 11.2km/s and yet I'm escaping the Earth's gravity - although very slowly and for an extremely short time.

When a rocket is 20km above ground the escape velocity should be less since it's farther from Earth. So why does the rocket need to be traveling 11.2km/s.

On another note, that speed is so fast that I'm doubting my understanding of maths and measurements. Does 11.2km/s really mean 11.2 kilometres a second. That is unbelievably fast, especially in a direct upward direction!

 

[phinds]

About Earth's Escape Velocity; the place I have the problem is when I jump, I'm clearly not traveling at 11.2km/s and yet I'm escaping the Earth's gravity - although very slowly and for an extremely short time.

No, you most emphatically are NOT escaping Earth's gravity. Like much of the rest of your discussion, this just points to your ignorance of the fundamentals. I do not say this to be rude, but if you want to swim in the deep end of the pool you need to know how to do more than just splash around and make noise.

When a rocket is 20km above ground the escape velocity should be less since it's farther from Earth. So why does the rocket need to be traveling 11.2km/s.

Look up the radius of the Earth and figure out what % your have changed your height when you add 20km. Again, you are simply missing the basics.

On another note, that speed is so fast that I'm doubting my understanding of maths and measurements. Does 11.2km/s really mean 11.2 kilometres a second. That is unbelievably fast, especially in a direct upward direction!

yes

 

[Bandersnatch]

About Earth's Escape Velocity; the place I have the problem is when I jump, I'm clearly not traveling at 11.2km/s and yet I'm escaping the Earth's gravity - although very slowly and for an extremely short time.

When a rocket is 20km above ground the escape velocity should be less since it's farther from Earth. So why does the rocket need to be traveling 11.2km/s.

On another note, that speed is so fast that I'm doubting my understanding of maths and measurements. Does 11.2km/s really mean 11.2 kilometres a second. That is unbelievably fast, especially in a direct upward direction!

Escape velocity is the V₀ of an object at ground level. With this initial velocity and no other acceleration but gravity, it'll reach infinity and stop there. You certainly can't do that with jumping.

Km/s is right.
Compare Earth's orbital speed around the Sun(30km/s) or Solar system's orbital speed around the galactic centre(~250km/s). These are the kinds of velocities you encounter in outer space.

 

[mrxyz]

Escape velocity is the V₀ of an object at ground level. With this initial velocity and no other acceleration but gravity, it'll reach infinity and stop there. You certainly can't do that with jumping.

Km/s is right.
Compare Earth's orbital speed around the Sun(30km/s) or Solar system's orbital speed around the galactic centre(~250km/s). These are the kinds of velocities you encounter in outer space.

That was helpful, thanks :)

 

[micromass]

This thread has been sufficiently answered. It has gone severely off-topic, so this is locked.