Questions tagged [launch]

Questions regarding the takeoff or the liftoff phase of the flight of a rocket and the set of activities required for preparation of the launch vehicle leading to it.

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7
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1answer
476 views

Would a frog on the side of a rocket be enough to steer it substantially offcourse?

Recently, someone posted this picture in The Pod Bay, our chatroom: It shows a frog being blown off of the launch of LADEE, a lunar probe. It got me thinking: Would a frog, successfully holding on ...
4
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1answer
274 views

Launch from the top of high places [duplicate]

Would launching space ships at the top of high places (like buildings or mountains) would have significant effect? What would be the height where launching would be less energy-/fuel-consuming than ...
3
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1answer
1k views

What advantage or disadvantage when the craft moves through the axis of rotation?

Spacecraft typically launch close to the equator along Earth's rotation. This contributes some velocity to the craft. In addition Earth's gravity is weakest along the equator (bar mountainous regions)....
6
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2answers
916 views

Can a “free launch” from a space elevator really be free?

The question Benefit of sling shot effect with a space elevator implies that you can get free $\Delta V$ from a space elevator launch. As highlighted in this answer on SciFi quoting Sheffield book "...
9
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3answers
692 views

What are the deal-breakers with a preheated Hydrogen gas tank orbital rocket?

Consider this thought process: In selecting the propellant for a reaction engine, lower atomic mass is better because equipment is largely temperature limited, and lighter gas will get higher ...
16
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1answer
841 views

What should I consider in choosing what launch to see live?

I've never been to see a rocket launch. I'd like a checklist of what to consider in choosing where to go, what type of launch to pick, and what to allow for in terms of missed launch dates or other ...
9
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2answers
17k views

What is the success rate of NASA launches?

What is the success rate of NASA launches since it was founded in 1958? I'd appreciate a decade by decade statistic. By successful I mean a successful launch into space and release of payload (if any)....
28
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1answer
1k views

For a 3 booster rocket, why do they start with igniting the starboard booster, followed by the center and port?

In today's launch of the Delta IV heavy, it was stated that the starboard booster rocket would be ignited first, followed by the port and centre boosters. I would have thought this would give some ...
38
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2answers
65k views

What is the vapour/smoke that comes from a rocket before launch?

While a rocket is waiting on the platform during the final countdown, it often seems to have clouds of steam or something similar escaping from it. Is this normal, and what are these clouds?
45
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11answers
38k views

Could it be possible to launch a rocket from a balloon?

There are several (commercial) organisations looking into alternative means to launch space-bound rockets. One commonly proposed method is to use a large airplane as the launch platform. This method ...
17
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2answers
565 views

Can solid fuel leak?

Recently the ISRO GSLV launch was called off on account of a fuel leak. Other launches too have, on occasion, been called off for similar reasons. Fuel used to launch a craft to orbit may be solid, ...
9
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1answer
2k views

During launch, how is the launch vehicle tracked?

Obviously a launch vehicle needs to be tracked quite precisely during launch, but how is this accomplished? Is it all done from the ground, or do launch vehicles normally fly with GPS receivers? Is ...
19
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2answers
8k views

How does a single rocket place multiple satellites into orbit?

Nowadays, many rockets transport more than one satellite in orbit. But how does a single rocket place multiple satellites into their orbits? Do all rockets which place multiple satellites into orbit ...
11
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3answers
506 views

Have all spacecraft on record been launched from land?

Water is a little buoyant which may be part of the reason a lot of commerce happens on the waves. How much of a difference in terms of fuel would it make if the craft were launched from a water-body?...
52
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2answers
44k views

What is the purpose of the jets of water often under rocket engines during launch?

I have watched several STS launches, and noticed that there were always huge jets of water that would begin right before the rocket engines lit. They were right under the rocket, mounted to the pad. ...
9
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3answers
1k views

How do vehicles get smoothly to a circular low Earth orbit?

Playing Kerbal Space Program, I wonder why they do several burns to get into orbit. Why can't a vehicle get smoothly to it, just pointing slightly off its course? I saw a Soyuz launch at night from ...
16
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4answers
5k views

Could a ship take off from Earth using ion thrusters?

If you had enough ion thrusters, could you take off from Earth's surface into low Earth orbit? If not, why not?
6
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3answers
254 views

Are payload and impulse the sole criteria to decide the engine?

There do not appear to be a definite number of stages to launch a craft. Amongst others entries under the 'launch', 'spacecraft-development' tags mention as many as 4 stages. Engines and fuel vary too....
31
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3answers
16k views

Why are hydrogen-fluorine fuels not used for rockets more frequently?

Many rockets use hydrogen- and oxygen-based propellants as fuel. Why are hydrogen-fluorine fuels not used? It has a specific impulse of 390 seconds, higher than hydrogen-oxygen combustion (360 ...
15
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2answers
2k views

Do all rockets get fueled during the countdown?

Does rocket propellant (solid or liquid) get added to the rocket during the final preparation of the launch (count down) in all cases? If so, why is it filled at the final instant?
15
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1answer
2k views

Why are satellites and other payloads always placed at the top of rockets?

In all rockets that launch satellites to orbit, the satellite is always placed at the top. Why are payloads always placed at the top of rockets?
13
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1answer
410 views

Primary payload influence on hitchhiking CubeSat integration and testing?

Integration is the process of assembling or otherwise combining the separate subsystems into your final overall system. Testing involves making sure your components, subsystems, and overall system ...
13
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1answer
321 views

Do long term missions receive insurance coverage?

Wikipedia speaks of satellite insurance. This is restricted as follows: It covers three risks: relaunching the satellite if the launch operation fails; replacing the satellite if it is destroyed,...
8
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1answer
1k views

Gravity drag Delta-v calculation for launches to orbit

It would appear that gravity drag has a exact formulation for an instantaneous moment in a rocket launch. I'm tempted to think that some calculus could get you an exact number for Delta-v of an ...
9
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1answer
802 views

How does the launch of a Polar Satellite differ from that of an East-West orbiter?

A polar satellite orbits a planet over it's poles. An East/West orbiter (I couldn't find the term for such satellites) may orbit anywhere from LEO up as high as GEO. How does the launch process (...
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2answers
2k views

What kind of launch escape system (LES) does Dream Chaser have?

What kind of launch escape system will be aboard Dream Chaser?
39
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4answers
14k views

Why didn't the Space Shuttle have a launch escape system?

Since the very beginning of space exploration, rockets had some sort of Launch Escape System (LES). From this Wikipedia article, we know that Mercury and Apollo had an escape tower, while Vostok and ...
12
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3answers
4k views

Are all rocket launch sites surrounded by water bodies?

Are all rocket launch sites surrounded by water bodies (such as sea)? If so, what is the purpose of having a rocket launch site near a water body?
107
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4answers
17k views

What is the purpose of having a countdown during a rocket launch?

Every rocket launch has a countdown. But what purpose does it serve?
7
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1answer
413 views

Does the delta v requirement of a rocket to place a satellite in orbit depend on the position of other planets?

Does the necessary delta v given to a satellite (earth orbiting) by the rocket during its launch depend on the positions of other planets? Please justify your answer.
5
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0answers
119 views

How much cheaper would a high level launch be from a sea level launch? [duplicate]

What is the difference in delta-V required for a launch from the highest natural point on Earth (about 8,800 m or 29,000 ft) as opposed to a sea level launch? Assuming a completely ground based ...
19
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2answers
443 views

Does the Perseid peak affect mission launches?

Tonight (Aug 12 2013) is the annual peak of the Perseid meteor shower. Since meteors are chunks of rock flying through the atmosphere at crazy high speeds, I'm wondering if there are any ...
15
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3answers
1k views

Horizontal space launch

Space ships are always launched vertically. Its reason is pretty obvious: vertical launch has the lowest distance between the desired height and surface. However, would horizantal launch be worth to ...
5
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1answer
90 views

Would fuel depots allow lighter fuel tanks for post LEO use?

In addition to the benefits of smaller and more frequent launches (and perhaps other benefits), could fuel depots also provide a modest benefit in reducing the mass of fuel tanks for vehicles leaving ...
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0answers
77 views

When is Fēngyún-3C planned to launch? [closed]

When is Fēngyún-3C planned to launch? The CEOS/ESA EO Handbook states July 2013, but this was last updated October 2012, and I don't think it's actually been launched. WMO-sat.info says >= 2013, but ...
16
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11answers
15k views

Highest number of satellites launched on a single rocket

What is the highest number of satellites that have been launched on a single rocket? What were the number of stages used in that launch? (It may be from the past or a future mission)
19
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3answers
17k views

How much of an advantage do equator-proximal launch sites provide?

Comparing ESA's Kourou (5° off) with NASA's Cape Canaveral (28°) and JAXA's Tanegashima (30°) launch sites, how advantageous is proximity to the equator? Considering the fact that the ESA and all of ...
9
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1answer
2k views

Speed-mass graph of starting rocket?

Could someone provide a graph of speed vs mass of a typical spacecraft - say, Soyuz or Dragon, as it rises towards LEO? If not graph, then a single fixed point of mass at speed of 2 km/s will do. ...
23
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2answers
4k views

Why do pressure fed engines have combustion instabilities?

Reading about the Sea Dragon idea, I came upon this argument against it, which sounds compelling, but relies on more detailed knowledge than I have: Those are to be pressure-fed to avoid "...
25
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1answer
4k views

Do all launches include self-destruct mechanisms?

Do all launches involve self-destruct mechanisms? How do they usually work? Is it just the boosters that are required to self-destruct? In the case of the space shuttle, how about the external tank? ...
7
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3answers
475 views

What is the basic idea of the Truax “Space Truck”?

Robert Truax is said to have advocated a "space truck". From the NYT: He did calculations showing that complexity, not size, drove costs. Hence, his proposed “space truck,” two football fields ...
13
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4answers
1k views

Day versus night launches

Most launches that I've seen have occurred during the day. But I've also seen a couple of missions that have been launched at night. Are there any specific advantages or disadvantages to a day launch ...
9
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3answers
4k views

What was the first attempt in history for space exploration?

Before the space race or modern technology of 20th century, what was the earliest point in history that space exploration was attempted? If available, I'd love to read the documentation.
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4answers
7k views

Can gunpowder get you to the moon?

In 'From the Earth to the Moon' (1873) by Jules Verne, A huge cannon is used to send a spaceship to the moon. A lively discussion in chapter IX leads to using 400,000 pounds of fulminating cotton to ...
34
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3answers
14k views

Effect of atmospheric drag on rocket launches and benefits of high altitude launch sites

What is the approximate influence of atmospheric drag on the cost of rocket launches? Is it beneficial to have launch sites located at higher altitudes? Cape Canaveral is at sea level, but I've ...
30
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5answers
5k views

Do any launches bypass LEO?

If sending a payload to GEO (geosynchronous orbit) or any other high orbit, you could start off launching to LEO (low Earth orbit), and then use a Hohmann transfer to raise the height of the orbit. I ...
25
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4answers
8k views

Is there any advantage in launching spacecraft from a high latitude, or why was Plesetsk built so far north?

For launching satellites or other spacecraft, there is a significant advantage in being close to the equator: angular momentum helps in gaining initial speed and one can launch into any inclination. ...
11
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3answers
4k views

How much fuel would one need to launch a 1kg object from 100,000 feet?

Back in the old days of the cold war the US and Russia were trying to develop a Nuclear powered aircraft. Problems with radiation shielding and "safety" held them back. Let's say that they got this ...
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3answers
1k views

The Russians recently tested a new launch trajectory that goes to the space station in about six hours. What allowed for the difference?

According to this article, Russia recently tested a new launch trajectory that shaved over 45 hours off their normal flight time. What allowed for this difference? Doesn't it seem like the shortest ...
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0answers
83 views

What are the barriers to partial nonrocket spacelaunch? [closed]

What technological and financial barriers prevent proposals for partial nonrocket spacelaunch such as magnetic levitation trains from becoming a reality? These systems, if created, could ...