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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16
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5answers
24k views

Can magnets be used to launch spacecraft?

I assume there is some reason we don't use magnets to launch off Earth. Are they not strong enough? Isn't magnetic force technically stronger than gravity?? Would either of these work: A tube tunnel ...
6
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1answer
637 views

Which launch vehicles are considered SSTO?

Are there any operating SSTO (single stage to orbit) vehicles? Are there others being tested such as Reaction Engine's Skylon?
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3answers
1k views

What is the most widely used first-stage rocket engine in operation today?

I'm trying to do some research on this but very much struggling to work it all out. I'm looking for a cutaway diagram of said rocket engine (ideally one used on a first-stage), but I can't for the ...
7
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1answer
719 views

How will the SRBs used by the SLS differ from those used by the Shuttle?

The Space Launch System, which recently secured funding from Congress, uses many features that were developed from the Shuttle program, including the first-stage engines and boosters, and it's overall ...
11
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1answer
611 views

How do they get up-close views of far away spacecraft after launch?

I was watching the most recent Antares rocket launch. While I was watching it, I saw extreme close up video when it was even T+5 or T+7 minutes, when it was very far away from Earth. This was not the ...
8
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1answer
551 views

How do you handle variations in launches with a solid second stage?

Watching the Antares launch for Orb-1 mission of Cygnus, I was thinking about the booster. First stage is built in Ukraine by the company that makes the Zenit. They use the NK-33 engine, (Called an ...
10
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2answers
3k views

What is “downrange distance”?

On the SpaceX mission I hear periodic "Downrange distance: N kilometers" for various values of N (initially 1, then 3, then 383, 920, 1500...). What is the meaning of this value?
29
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4answers
9k views

Why not travel to Mars in 2 months?

Just to clarify... I've made some research and generally know what the case is, didn't mean to make the question sound stupid... :) I know there is a thing called Hohmann transfer orbit, named after ...
6
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2answers
229 views

Has there ever been done research on mechanical assisted landing and takeoff?

With this I mean using elastic energy to land and possibly reuse this energy at takeoff. So that the "spring" will remain in the compressed state between landing an takeoff by locking it in to place. ...
70
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10answers
52k views

Why is SpaceX considering Methane as fuel for their next engine, the Raptor?

Currently, SpaceX has developed the Merlin 1 family (1B (Falcon 1), 1C (Falcon 9 v1.0), 1D (Falcon 9 v1.1/F9-R/Falcon Heavy), vacuum versions and sealevel versions) which are LOX/RP1 based. (75-...
8
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1answer
144 views

Were there any extra objects in the latest Falcon 9 launch?

The previous launch of the Falcon 9 included a number of mysterious objects. Has there been any indication that the recent SES launch produced similar objects?
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5answers
1k views

Is there any non-rocket spacelaunch concept within reach of current material science and technology?

Suppose for a moment that cost would be no issue (and noone brought pruning shears) - could we build any of the non-rocket spacelaunch systems from earth listed here or elsewhere? Which one is the ...
10
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1answer
576 views

How are fuel leaks discovered on a rocket?

Most are aware of the fact that the launch of GSLV has been aborted due to a fuel leakage, but how was the cryogenic fuel leak discovered? I'm not interested in this case only, but in general. What ...
9
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1answer
3k views

What is a flame trench?

This answer to a question states that: .... construction left a large pit, now filled with water, that will be used for the Ariane 6 flame trench. What is a flame trench, and what is its ...
13
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2answers
1k views

Which currently operational orbital launch vehicle achieves highest system-specific impulse?

I'm primarily looking for comparison of currently operational orbital launch vehicles by system-specific impulse, or Issp, and to get a fair impression of achievable rocket propellant performance and ...
16
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1answer
2k views

Why aren't SpaceX controllers allowed to abort during the final 10 seconds?

During yesterday's aborted SpaceX launch, someone was giving instructions to the controllers about abort procedures: To abort the launch, a controller will say 'abort, abort, abort'.... controllers ...
58
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4answers
29k views

What are the towers around the SpaceX launch pad used for?

I noticed four(?) towers around the SpaceX launch pad during yesterday's aborted launch Image credit NBC News What are the towers used for? Tracking? Radio communications?
12
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2answers
1k views

What caused SES-8's Falcon 9 launch computer to abort at T+2 seconds?

SES-8 had its launch aborted at T+2 seconds. What, exactly, caused the flight computer to decide the engines weren't ready?
16
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1answer
3k views

What is involved in clearing air space for an orbital launch?

When the Nov 25th, 2013 SpaceX Falcon 9 v1.1 launch was scrubbed on a Monday, next launch opportunity was reported as Thursday (Thanksgiving) since the Tues/Wed days are the busiest day in the year ...
5
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1answer
388 views

How does a spaceport differ from a launch pad?

How does a space port differ from a launch pad in construction and what makes them different?
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3answers
1k views

Why aren't sea launches used more often?

I was reading yet another awesome Tildal answer, and this picture caught my eye:        Zenit-3SL carrying Atlantic Bird 7 lifts off from Odyssey platform (Source: The ...
6
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3answers
4k views

What is the highest inclination orbit ever attained from a Cape Canaveral launch?

The launch facilities at Cape Canaveral, FL are located at a latitude of about 28.5° N, so that puts a hard lower bound on inclinations from that site. I assume there are well-defined azimuth limits ...
9
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2answers
958 views

Why did the US lose almost all commercial launch opportunities?

With the launch of the SpaceX Falcon 9 V1.1 Nov 25th (Assuming it succeeds), it will apparently be the first US Commercial launch (I assume to GEO, since Orbital, with all the commercial small sats ...
18
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4answers
10k views

What is the base of a launchpad made of?

I'm curious as to what launchpad bases are made of - it seems to always be made of concrete, but wouldn't the concrete disintegrate rather quickly with jets of fire pounding on it?
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1answer
2k views

What is a typical energy demand and carbon footprint of a space launch?

How much greenhouse gases are released per kg launched into space, what other energy is needed? For the scope of this question, let's ignore the embedded energy in all the machinery and just look at ...
8
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3answers
2k views

How does a launch vehicle control its trajectory during the first stage?

It appears during most launches that the only engines working are the main first stage engines. It was my understanding that these engines are fixed in place and cannot turn the rocket, but I must be ...
19
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1answer
1k views

Why have a 10 minute pause at T-4 minutes?

I was watching the United Launch Alliance (ULA) Atlas 5 rocket launching NASA's MAVEN (Mars Atmosphere and Volatile EvolutioN) to Mars today, and the countdown contained a planned 10 minute pause at T-...
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6answers
18k views

Could a Human reach escape velocity by jumping from the surface of Ceres (a dwarf planet)?

According to this answer the surface gravity of Ceres is estimated to be only $0.27 m/s^2$. With a rotation period of 9 hours. The gravity seems light enough to overcome by leg muscle alone, and if ...
6
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1answer
3k views

Is it possible to literally shoot something into space? [duplicate]

Regular spaceship missions are effective but also incredibly expensive. The most discussed alternative of them would be the space elevator, but with our current technology, it isn't possible to ...
14
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4answers
2k views

What is a “space elevator”?

I've seen an hypothetical "Space elevator" referenced in various media the last couple of years. Is this something thats really planned in the making, or just a hypothetical scenario? How will a space ...
7
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2answers
791 views

Is there any plan for ISRO to reach Venus?

After successfully completing the placement of the Mangalyaan into orbit, is there any plan for ISRO to launch a spacecraft to Venus ?
17
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1answer
3k views

Why did the recent Sirius FM6 launch use such a high inclination?

Earlier today a Proton-M rocket took off, carrying a Sirius FM6 satellite radio payload destined for geosynchronous orbit. Nothing super exciting, Briz-M upper stage for transfer burns and then the ...
21
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1answer
2k views

Ariane 4: shroud around stage?

In this image of the Ariane 4, you can see a blue shroud around the second stage. At least I think it's a shroud. It is present in many photos of Ariane 4 launches, but the drawings I've seen omit ...
15
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1answer
379 views

The heaviest martian spacecraft

What was the heaviest artificial object to reach orbit of Mars? Delivering the heaviest object of all times should have been quite an achievement in itself. So I'd like to understand the details of ...
19
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1answer
59k views

How much fuel was used for a Space Shuttle launch?

Many of us have watched the launch of a Space Shuttle space ship, I think: a giant red rocket, some smaller, and the way smaller space ship on the red one. It reaches Mach 23 to be able to leave ...
28
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3answers
103k views

What is meaning of T in rocket launch countdown?

In Rocket Launch countdowns I noticed That they count with respect to some parameter T as: T-10 seconds T-9 seconds . . . T-0 seconds Why not simply count as 10 9 8 . . 0 ? http://www.nasa.gov/...
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5answers
20k views

Why does a rocket engine provide more thrust in a vacuum than in atmosphere?

According to NASA Each Space Shuttle Main Engine operates at a liquid oxygen/liquid hydrogen mixture ratio of 6 to 1 to produce a sea level thrust of 179,097 kilograms (375,000 pounds) and ...
31
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1answer
3k views

Why do the Shuttle's external tanks appear to be rusted?

Wikipedia article states as STS-1 at liftoff. The External Tank was painted white for the first two Space Shuttle launches. From STS-3 on, it was left unpainted. I wonder why the ...
13
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2answers
2k views

What are the mystery Falcon 9 v 1.1 objects?

There are 20 objects in orbit associated with the Falcon 9 v 1.1 launch. So far only 1 has been identified. 5 were payloads of the launch, plus the booster and some debris. Bottom line, 11 objects ...
28
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6answers
3k views

What technological hurdles prevent the development of a space gun?

Ever since Jules Verne wrote "From the Earth to the Moon" space guns have long been proposed as a method of launching objects into space. And for non-human, non-fragile payloads they make sense as the ...
14
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1answer
227 views

Does Redstone start sequence involve a key?

After discussing the Key to start (Ключ на старт) command during Soyuz launch sequence, I decided to look at the historic lineage of the key and the command. Gradually moving backward through R7 ...
11
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1answer
5k views

How many successful Soyuz launches have there been?

From the first Soyuz to the launch vehicles used today, how many launches have been deemed successful?
6
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2answers
839 views

Are there any space vehicles in which it would be possible to launch yourself into space on your own?

I'm thinking about something like this: Suppose you really wanted to get into orbit and didn't care about getting back down / staying alive up there. You sneak into a launch facility at night, push ...
14
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1answer
2k views

Do any spacecraft use carkeys?

The basic idea behind a key for a vehicle is to keep an unauthorized person from using your car to go somewhere else - probably further away from you than you would like your transportation to be. I ...
16
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5answers
1k views

How are multiple launches handled?

A spacecraft may launch with multiple payload, as is evidenced by How does a single rocket place multiple satellites into orbit? This question however is not about multiple payload carried in a ...
30
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1answer
58k views

What is the current cost-per-pound to send something into LEO?

As a student of economics and finance I would love to learn more about the cost structures of sending a payload into orbit. More specifically - What is the cost-per-pound to send something into LEO ...
11
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2answers
595 views

Payload mass scale economy

What is the "payload mass" curve in relation to "cost to orbit?" I mean: preparing a whole launch system for delivering a single cubesat to LEO would be an overkill, the cost to bring such a small ...
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0answers
1k views

What is the average cost of satellite construction over the last 10 years? [closed]

In the last 10 years what was the Highest and lowest, construction cost of satellites launched? What are the mean and average costs of satellite construction over the same period? Where "a" ...
8
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1answer
441 views

Does cost to orbit make the sale for a satellite launch service?

Wikipedia writes to say ...The Space Race sparked unprecedented increases in spending on education and pure research, which accelerated scientific advancements and led to beneficial spin-off ...
9
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1answer
1k views

Do rocket exhaust plumes really provide a pathway for lightning?

This Wikipedia article states that Rocket exhaust plumes provided a pathway for lightning when it was witnessed striking the Apollo 12 rocket shortly after takeoff. My question is whether this ...