All Questions
18,905
questions
24
votes
1
answer
2k
views
What's the path of something dropped from a space elevator
What sort of paths would payloads follow after being released from a space elevator such as the one described in Clarke's Fountains of Paradise?
- 15.8k
17
votes
1
answer
2k
views
Has anyone had sex in space?
Has anyone admitted to having sex in space?
What policies/protocols are there in place for this kind of activity?
- 451
13
votes
3
answers
4k
views
How far downrange would a reusable Falcon 9 first stage land (without fly-back)?
Let's imagine a rocket like the Falcon 9 recovers its first stage via a soft landing, but doesn't attempt a return to the launchpad. For the sake of argument, let's imagine that there are no ...
- 16.3k
53
votes
2
answers
20k
views
Why is gold used in space technology to protect from heat radiation?
AFAIK, NASA and others are using mainly gold to protect surfaces from heat radiation.
But, as we can see with our own eyes, chrome or silver had probably a much better albedo, because they are white, ...
- 3,288
11
votes
1
answer
1k
views
What's the name of this maneuver for unlimited delta-v?
Let's say you have magical unlimited delta-v, but very low thrust-to-weight ratio. You could travel by accelerating constantly for half the trip, then braking for the other half, until your arrival.
...
- 285
14
votes
3
answers
2k
views
Is there an upper limit for the internal size of space stations?
I was reading about the various TransHab proposals (at http://www.astronautix.com/craft/traodule.htm, among others), and I started to think about pushing the idea to its limits. Assuming you had a ...
- 3,227
6
votes
3
answers
907
views
What algorithms are used to correct the flight-path?
As a launch vehicle begins to veer slightly off course during a launch, what sort of algorithms are used to determine how far off the vehicle's trajectory is pointing from the intended trajectory and ...
- 5,928
8
votes
3
answers
3k
views
Is there a simple relation between delta-v and travel time?
For example, if it takes a delta-v of 4 km/s to fly from LEO to Mars in 8 months, according to one mission plan, would it take half the time, 4 months, if the delta-v was doubled to 8 km/s? Is there ...
- 27k
21
votes
5
answers
6k
views
Can Voyager still use its thrusters to avoid hazards?
Voyager 2 started its journey some 37 years back so all of the gases must have been exhausted, but it's still moving at a speed of 15km/s. I can say that this might be due to no opposing force to slow ...
- 2,128
8
votes
1
answer
196
views
Could the Philae comet lander "hop"?
"Lander" is maybe not a good job description for the Rosetta sub probe Philae. I understand that there is no practically useful gravity there. Philae will try to hook itself onto the comet surface in ...
- 27k
7
votes
3
answers
261
views
Can a launch-provider determine from the flight-profile whether the payload will be in the wrong orbit?
The British Broadcasting Corporation writes to say
The European Space Agency (Esa) says the latest two satellites for Europe's version of the American GPS satellite navigation system have not gone ...
- 13.6k
15
votes
1
answer
966
views
How did Goddard's rocket reach 41 feet altitude in under 2.5 seconds?
I'm working on a simple rocket flight simulation program, and am trying to reproduce aspects of Goddard's first successful rocket flight. My sources put the empty weight at 5.75-6lbs, loaded weight 10....
- 169k
8
votes
2
answers
492
views
Will Roscosmos et.al attempt to revive nuclear-engine space technology violate the OST?
This article dated. 2013 writes to say
After a multi-decade hiatus, both NASA and the Russian Federal Space Agency (which developed many of its own NTRs during the Cold War but never physically ...
- 13.6k
6
votes
2
answers
5k
views
Why do Estes model rockets recommend a smaller engine (B class) for first launches, but support bigger engines later?
While building model rockets with my son, I figured I would ask a question that had been bothering me for a while. When you look at the packaging of the Estes rockets, regardless of complexity level (...
- 79.6k
7
votes
1
answer
784
views
What conventional reference frame is used for interplanetary telemetry and navigation?
Specifically a location in the celestial sphere that is fixed, most likely a star, which creates a set of still coordinates with respect to the Sun. There are many ways to do this, but I am interested ...
- 5,928
11
votes
1
answer
3k
views
Have liquid cooling systems been tested for reentry surfaces?
A tough exterior of heat-dissipating material is generally used for reentry modules. I am wondering if there have been any attempts or experiments at using liquid cooling systems as thermal protection ...
- 5,928
9
votes
1
answer
2k
views
Why did we take dinosaur bones into space?
For the past few days, since I found out about this, I've been trying to figure out what was the reasoning behind taking dinosaur bones into space. Everywhere I looked I couldn't find any explanation ...
- 197
8
votes
2
answers
347
views
Will kicked-up "dust" be a problem for Rosetta and lander Philae?
I see that escape velocity on 67P/Churyumov–Gerasimenko is 0.64 m/s. (Contrast Earth's 11,186 m/s.) With such light gravity I imagine any material kicked up would take hours to land, or orbit ...
- 892
13
votes
3
answers
2k
views
Space Elevator Between Doubly-Tidally Locked Bodies
Space elevators may be a reality only in the future, but I know we have the basic principles down pat. Something has been bugging me, though. If we had the proper materials, we could build such an ...
- 3,227
4
votes
1
answer
845
views
What would be the delta-v of rendezvousing with temporarily captured asteroids in Sun-Earth L-points?
It is believed that at any point in time, a handful of small asteroids (TCO's) are temporarily orbiting the Sun-Earth Lagrange points 1 & 2. They are random samples from the Asteroid Belt and ...
- 27k
18
votes
3
answers
3k
views
What missions could be done with Orion on Falcon Heavy?
Orion is being developed in tandem with the SLS. But Falcon Heavy is scheduled to fly earlier, early 2015, and be cheaper. So I wonder what kind of missions Orion could do with FH. Could it for ...
- 27k
27
votes
3
answers
4k
views
Why does the Soyuz Rocket system fire the third stage while stage two is still attached?
Also, I believe that the second stage continues to burn for quite some time even after seperation of stage 3.
- 271
10
votes
1
answer
687
views
Numbers for Falcon 9 booster MECO scenarios?
I hoping to look at learn more about Main Engine Cut Off (MECO) for various scenarios.
5 quantities I want are:
1) Booster mass at lift off.
2) Booster mass at MECO
3) Booster velocity at MECO (...
- 15.8k
20
votes
1
answer
726
views
Extending Use of ISS Beyond End of Mission
Given that the ISS will eventually come to the end of its mission (currently extended to 2020 (source)), would it be possible to re-purpose it for non-human space flight?
To clarify: does the ...
- 849
9
votes
5
answers
1k
views
Have launch system propellants evolved since RP1/LH2?
So I was chasing something else when this page popped into my field
I'm quite sure the page isn't exhaustive. What little content is there on the page though seems to indicate the below listed ...
- 13.6k
5
votes
2
answers
2k
views
How do we measure the atmospheres of Solar system planets?
How much is it possible to measure from Earth and how accurately without sending probes to the planets? I am curious about how atmospheric boundary (altitude), atmospheric pressure, scale height were ...
- 153
5
votes
1
answer
522
views
Why is SpaceX testing Pad Abort at LC-40 (CCAFS) but Max-Q abort at Vandenberg?
Per SpaceNews article SpaceX has set November 2014 for a Pad Abort test from LC-40 in Florida, and January 2015 for a Max-Q abort test from Vandenberg Airforce Base in California.
They have only done ...
- 79.6k
32
votes
6
answers
6k
views
If we build a space elevator from Earth surface to GEO, could I step off it at GEO and remain in GEO?
Ignore for a moment the question of whether building such a space elevator is practical. Let's also ignore the minute delta-v involved in "stepping off" something in orbit.
If we were to build a ...
- 7,310
5
votes
2
answers
3k
views
How could a trip to Mars benefit from a "Distant (Lunar) Retrograde Orbit" DRO?
This guest blog text by Martin Elvis mentions a kind of orbit which I've never heard of before. How does the orbital mechanics work so that a DRO could benefit an interplanetary mission?
... ...
- 27k
6
votes
1
answer
572
views
What has been done and what remains to be done to land humans on Mars? [closed]
I get the impression that NASA has done alot to make a crewed landing on Mars possible. Not as a focused mission like Apollo, but piece by piece in spite of the lack of dedicated and lasting political ...
- 27k
2
votes
0
answers
99
views
Besides mechanical failure, what other systems have failed/deteriorated on Yutu?
Yutu was ferried to Luna by way of Chang`e in December 2013
The Wikipedia article on the mission writes to say the mission duration for the lander, and rover were as follows.
Lander: 1 Year
Rover: 3 ...
- 13.6k
13
votes
4
answers
3k
views
Realistic space battle, how it could looke like? No hollywood version or videogames like [closed]
I am about to program space exploration simulation game in the future, but I need to consider many factors. I would like to be as much realistic as possible, but keeping the game playable as well and ...
- 331
17
votes
2
answers
3k
views
Why have so few countries developed satellite launching vehicles of their own?
With the example of SpaceX and Orbital Sciences building brand new launchers in a small number of years, it seems that the time has come technologically where it is not quite as much 'rocket science' ...
- 323
4
votes
1
answer
2k
views
how to calculate the brightness of a passing satellite?
I'm looking for a formula can be used to calculate the magnitude of a passing satellite (e.g. the ISS) based on it's TLE
- 259
6
votes
3
answers
3k
views
Space travel: Is there an speed limit lower than speed of light?
Propulsion exhaust speed is lower than speed of light, I think and if it is so, than how could spaceship go faster that exhaust speed? Right? So exhaust speed is a maximum speed for spaceship? (If ...
- 331
8
votes
1
answer
437
views
Rosetta's lander, Philae will "anchor" itself on Comet 67P. What level of control can we have over this?
Rosetta's lander, Philae is scheduled to land on Comet 67P in November 2014. This will involve use of "harpoon" to anchor itself to make sure Philae remains attached to the surface despite weak ...
- 199
10
votes
1
answer
365
views
How accurately do they know where Rosetta is, and how do they know?
Title says it all really: how accurately do they know where the Rosetta space vehicle is at any given time, and how do they know that?
- 310
9
votes
1
answer
517
views
Is Rosetta really "in orbit around" 67P, or just conveniently co-located?
The pictures of Rosettas orbit show it doing some straight legs past 67P for the next while.-
Does this mean that at the current distance, the force of 67P's gravity is not really significant, and ...
- 310
14
votes
4
answers
2k
views
Do humans need less calories and water in microgravity?
Astronauts in microgravity don't use their legs much. This has negative health effects in the long run. But I wonder if it doesn't have the good side of lowering human need for food and water and thus ...
- 27k
0
votes
1
answer
312
views
Why doesn't 67P get a name?
Now that it is a really special comet, and every one is talking about it, why doesn't it get a name, instead of just a number?
- 310
4
votes
1
answer
694
views
Considerations for Taking Photos from CubeSat in LEO
When taking photos in space with consumer grade cameras modules, what factors need to be taken into account? For example, is auto-focus needed? Will the photos end up washed out because of the ...
- 849
34
votes
4
answers
4k
views
Is this really Rosetta's orbit around 67P?
From this link I fount the following representation of Rosetta's orbit relative to 67P:
A video from ESA depicts a similar orbit.
My questions are:
is that really the relative orbit?
If yes:
why ...
- 980
11
votes
1
answer
1k
views
Function of the RL10 Oxygen Turbopump's Splined Shaft End
The oxygen turbopump in the RL10 upper stage engine has been openly discussed by NASA for some decades now, in publications like SP-8107. On page 8 of this document is a drawing of this turbopump. The ...
- 8,394
12
votes
2
answers
1k
views
Hypothesized parameters of reactionless drives
If we assume that the claims for the EmDrive, Woodward effect and/or quantum vacuum plasma thruster are born out (notice I did NOT mention the Dean Drive), what would be the upper limit of potential ...
- 17.5k
1
vote
0
answers
102
views
Is our technology advanced enough to start asteroid mining? [duplicate]
Here is a comparison of nearby asteroids with their worth in US Dollars. Does our technology have the capability to reach any of these asteroids and bring back enough of the materials to be considered ...
15
votes
3
answers
4k
views
Why is it preferable for SpaceX to land their booster vertically rather than fly it down with wings?
SpaceX lands their booster rocket vertically, this seems complicated. The space shuttle landed with wings which seems more simple. Why is it preferable for the rocket to land vertically as opposed to ...
- 253
17
votes
2
answers
2k
views
Why is the "impossible" space drive impossible?
So apparently NASA just built an impossible propulsion device:
Sawyer's engine is extremely light and simple. It provides a thrust by "bouncing microwaves around in a closed container." The ...
user12
18
votes
3
answers
10k
views
How do you 'make oxygen' on Mars?
This morning's BBC News says that a 2020 rover mission to Mars will "make oxygen". There is a brief line indication that it will extract it from atmospheric CO₂, but no other details.
What process ...
- 27.1k
1
vote
1
answer
172
views
Paperback Books in Space?
Would it be possible (not necessarily plausible) for an astronaut to bring a paperback novel along on a mission and accidentally leave it in space somehow?
Would an astronaut even be allowed to bring ...
- 33
14
votes
4
answers
2k
views
What are the consequences of NASA validating this "impossible" space drive?
A British inventor invented an engine that can provide thrust in outer space without a propellant. This engine has been tested by a Chinese team, and more recently by NASA:
The engine itself is The ...
- 1,185