All Questions

12
votes
1answer
5k views

If we can make an Alcubierre drive, how fast can it move a ship?

Assuming we ever manage to solve the energy generation problem (and whatever other problems may face it) and build a functioning Alcubierre drive, how "fast" would we be able to travel? That is, from ...
9
votes
3answers
297 views

What causes the costs of operating an existing planetary mission?

I read on the Planetery Society blog that it costs USD 25 million this year to maintain the Opportunity rover on Mars and the LRO Lunar orbiter. I would like to see a break down of those budgets. I ...
5
votes
1answer
441 views

Moving object in space

I am a learner in this field. I have a doubt after watching movie "Gravity". In that movie, an explosion occurs in a spacecraft and the particles of that vehicle move so faster than a bullet, (as ...
4
votes
0answers
122 views

What is the impact of micro-G environment and magnetic field in LEO on blood flow and brain function?

How are sleeping and cognition in microgravity, with rapid changes in magnetic field, different from the normal human life on Earth?
7
votes
2answers
475 views

Does building a vessel to work in vacuum also make it watertight?

Does building a vessel such that it can maintain a breathable atmosphere in a vacuum (like all our manned space vessels) also makes this vessel watertight? If not, why?
3
votes
1answer
259 views

When was the first commercial delivery to an orbiting space station?

What was the first commercial space vehicle, that is not the property of a government entity; to make a delivery of goods to a community (one or more) in Earth orbit that was at the time occupied by ...
4
votes
2answers
1k views

What are the MDM's on the ISS, and how many different kinds are there?

In the prelude for SpaceX CRS-3 mission, the failure of a Multiplexer-Demultiplexer (MDM) on the International Space Station (ISS) seems to be a real concern for launching. In the pre-launch press ...
6
votes
2answers
2k views

How long might the Curiosity Mars rover last, and what would be the most likely cause to end its mission capability? [closed]

Given the life expectancies of all its components (mechanical, electrical, electronic, etc.), how long could the Curiosity rover reasonably be expected to continue performing useful science in an ...
8
votes
1answer
752 views

Why do we differentiate between astronauts and cosmonauts?

And how tenable is this distinction now that a third space agency carries out manned flights (China), and others are poised to follow? I can think of no other profession/job title where this ...
13
votes
3answers
11k views

What propulsion methods does the ISS use for station-keeping?

The International Space Station is constantly losing orbital energy due to atmospheric drag. How does station-keeping work for the ISS? What sort of propulsion system is used to keep it in the desired ...
3
votes
1answer
80 views

What parameters should be monitored during spacewalks?

When an astronaut goes to outer space, what can you measure? I'm thinking about the person's safety, so this is what I got so far: Oxygen level Heart beat Suit pressure Blood pressure Solar radiation ...
4
votes
1answer
190 views

Will the EFT-1 mission for Orion carry an escape tower?

December 2014 is the scheduled date for the Exploration Flight Test-1 (EFT-1) mission of the Orion space capsule. It will be launched on a Delta IV Heavy rocket as a surrogate for the unavailable SLS ...
8
votes
4answers
2k views

Oberth effect for Earth vehicles

I don't understand this and must ask a probably very stoopid question here: The Oberth effect says that a rocket is much more efficient when (and in the orbital direction of) a payload when it ...
9
votes
2answers
4k views

What software is often used to plan, launch, and track orbits?

Various questions have been asked on this StackExchange about free versions of software that can do various things, such as simulations or tracking. Many of the answers point to free software ...
1
vote
3answers
608 views

What would your altitude be after you had achieved escape velocity from the moon?

I have been trying to work out how much ΔV would be required to deorbit a spacecraft after it had achieved escape velocity from the moon but I don't know how to work out what the radius of the orbit ...
11
votes
4answers
14k views

Calculate Satellite Coordinates From TLE Data

I know it is not that hard for those familiar with the equations for it, but I am having trouble with the math. In order to fully understand the orbit elements of TLEs I read this which I found very ...
6
votes
0answers
2k views

Is there any open source software that can compute GPS ground coverage? I need a free alternative to AGI's System Tool Kit (STK)

Does any open source software exist that can compute GPS ground coverage in real time? At work I used STK which would do the job perfectly, but I'm at school now so I only have the free version. For ...
15
votes
2answers
3k views

If Saturn or Jupiter were in Earth's orbit, would any of their moons be habitable for humans?

The majority of exoplanets found so far are comparable in size to Jupiter or Saturn. Which, as we know, are problematic for human habitation. But their moons have a lot of potential. Some of these ...
4
votes
3answers
706 views

Does the Earth have any Trojan asteroids?

Are there any known Trojan objects residing in the Sun-Earth L4 (SEL4) and L5 (SEL5) Lagrange points, also named "Greek" and "Trojan" groups, respectively?
7
votes
1answer
962 views

Are there useful materials which can only be manufactured in microgravity?

Are there any known materials which could only (or a lot easier) be manufactured in microgravity and which would have properties which would make them useful for industrial applications back on earth? ...
10
votes
1answer
202 views

Does NASA have a plan to search for the life in Europa?

Europa is one of the most interesting moons in our solar system. It seems possible that some kind of living beings are able to live beneath its frozen surface. Question. Does NASA (or any other ...
31
votes
6answers
6k views

Why is there a “coasting” phase in some space launches?

During the PSLV (India's Polar Satellite Launch Vehicle) C24 launch on 4 April 2014, once stage 3 (PS3) had burned out, it wasn't immediately jettisoned, but instead there was a coasting phase for ...
12
votes
1answer
1k views

Can you print 3D with iron in space?

A couple of recent questions; How is the unwanted cold welding prevented in space? & Would unpainted iron or steel rust in space? indicate that some pure metals like iron that have been forged in ...
5
votes
2answers
1k views

How exactly does the inclination and direction (specifically retrograde) of orbit affect the velocity I need to attain orbit?

this is my first question here; and a lot of what I've learnt so far has been pretty much self taught so I thought I best hear from professionals. :) First let me set the scene as to what I am trying ...
9
votes
1answer
640 views

Are any tools available for realtime visual tracking of live launches?

Being a fan of http://www.spaceflightnow.com and it's launch schedule page, I thought it would be great if it were possible for "launch enthusiast" to track live launch trajectories using Google Earth,...
12
votes
3answers
1k views

Sending trash into space

What would be the positive and negative affects of using other planets and/or space itself for storing trash - instead of wasting place for that on Earth? Also, what are the possible obstacles of ...
27
votes
1answer
20k views

How is the unwanted cold welding prevented in space?

Metallic surfaces touching in the vacuum can stick to each other and fuse. This is known as the "cold welding" and it seems to be a possible issue in space if it happens where it should not. It was ...
5
votes
1answer
600 views

Is the MARPOST (Mars Piloted Orbital Station) mission still in the works?

The Russian MARPOST plan in its simplest form, to me, sounds like a great idea: Establish a manned orbital presence around Mars before deploying humans to the surface. The Wikipedia article says that ...
7
votes
5answers
609 views

Would a smaller re-entry vehicle better handle very high re-entry speeds?

"Inspiration Mars" has the idea to use a free return trajectory for a crew of two rounding Mars. While attractive in some ways, this free return trajectory has the disadvantage of ending up with a ...
11
votes
1answer
1k views

Would a satellite in retrograde orbit have a different speed than it would in prograde?

I understand that more power is required to launch a satellite into retrograde orbit, but once it's up there how much does the orbit differ from the more usual West to East? Would you still use $v\...
13
votes
3answers
7k views

Would unpainted iron or steel rust in space?

Iron and steel are made primarily of the same substance and they tend to rust. I believe other materials like non-ferrous metal are generally preferred for their lighter weight and strength, in most ...
19
votes
3answers
4k views

Could 3D printing be used to achieve perfect grain geometry of solid and hybrid rocket motors?

Solid cores, either for solid-fueled of hybrid rocket motors, use various propellant grain geometries to achieve thrust curve needed. For example, some of these could look like:    &...
9
votes
2answers
1k views

Have SRBs or SSMEs ever launched without a space shuttle?

It seems to me that the April 12, 1981 launch of Columbia (STS-1) was the manned spaceflight with the most untested hardware of any manned space launch. Even the Vostok and Mercury launch systems had ...
13
votes
7answers
3k views

Orbital mechanics: trying to understand counterintuitive behavior (braking to overtake)

If one spacecraft wants to overtake another (e.g. for a rendezvous), it has to (counterintuitively) brake, go into a lower orbit and use the higher angular velocity of that orbit/shorter orbital ...
8
votes
1answer
284 views

Does a persons weight effect their potential selection to be an astronaut?

Every extra bit of weight cost extra to send to orbit. Presumably it also impacts the possible payload. Assuming a generally healthy build, and otherwise physically able and fit person. In ...
10
votes
1answer
1k views

Mars Orbit Upon Intercept

I'm running a numerical simulation that calculates an interplanetary trajectory from Earth to Mars, and I'm trying to get a spacecraft into an orbit about Mars upon intercept, but am having a little ...
10
votes
1answer
8k views

What happens if an astronaut is hit by a tiny micrometeorite?

A micrometeorite (including space debris in LEO) hitting the metal wall of the ISS would likely cause a shower of secondary high speed fragments. But there are other "softer" materials proposed which ...
11
votes
2answers
4k views

What is the planned date for the Falcon Heavy Demo launch from Vandenberg AFB?

According to Wikipedia and SpaceX, this demo flight is scheduled for 2014. A group of us from San Diego want to come and watch the launch from a distance. Is there any scheduled date for the launch? ...
11
votes
2answers
2k views

What significance did Pioneer 10 & 11 have?

The images taken by Pioneer 10 and 11 were of much lower quality than those of later planetary probes. I wonder if this is representative also for their other instruments. For example, they don't seem ...
15
votes
2answers
6k views

What is a launch vehicle resting on prior to launch?

While a launch vehicle is being fueled on the launch pad, what is holding it up? Surely not all that weight is being held up by the engine nozzles. What parts of the launch vehicle are supporting its ...
20
votes
1answer
4k views

Why is a stick required to operate Soyuz's computer?

In this screenshot from the recent Soyuz TMA-12M launch, a crewmember is seen using a stick to enter commands into the computer: Is this stick standard, taken on all Soyuz flights? Also, why aren't ...
10
votes
4answers
3k views

How does a thin metal rocket engine not get crushed by the weight of the flying rocket?

It looks like a liquid fuel rocket engine is made of rather thin metal. Here's photo of RD-107 from Wikipedia Nothing personal, but it looks like it's made of several shiny thin metal cans (connected ...
11
votes
4answers
3k views

Is Cape Canaveral the ideal launch location in the US?

Is there any reason why we can't launch from other primary locations other than Cape Canaveral? I know we have begun launching some rockets from Virginia, but is the Space Coast really the ideal ...
15
votes
3answers
4k views

Petrol as rocket fuel

Why are petrol and diesel not used as rocket fuel like kerosene ? Which properties make them unfit for use in rocket fuel ?
7
votes
2answers
2k views

How can I predict what an object's orbital state vectors will be in the future?

I have a position and velocity vector for an orbiting object and can calculate the orbital elements. From a simple two-body situation, how can I predict where in the orbit the object will be at some ...
17
votes
2answers
2k views

What factors determine whether a spacecraft/probe/satellite uses gyroscopes or propellant thrusters to rotate?

Say I'm designing a probe or satellite. To control its attitude, I can add some gyros, or I can put thrusters on each corner, or I can add both and pick one in flight according to the situation. How ...
27
votes
7answers
63k views

Does the space shuttle fly straight “up” when leaving Earth?

I was watching space shuttle launch recently, and at 2:53 you can see the space shuttle from an angle, even though it's high above the earth and you should see only the bottom. Does the space shuttle ...
11
votes
3answers
15k views

Does ISS follow Earth's rotation?

Is ISS orbiting with or against the rotation of Earth? Is it important in any aspect for the space station?
2
votes
1answer
548 views

How could Mercury be used as a gravity sling to the outer planets?

Mercury's orbital speed is 48 km/s or about 10 AU/year. Wouldn't probes accelerate towards the Sun if we give them a little push from LEO, and only 0.6-1.6 AU from here take a big gravity assist from ...
9
votes
1answer
272 views

What is the diameter of magnetopause 1.5 millions kilometers behind the Earth?

Earth has strong magnetic field, which changes concentration of charged particles from Sun near the planet. There is rather safe torus near the Earth (LEO non-polar orbits), and also there is long ...

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