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.

Filter by
Sorted by
Tagged with
4
votes
1answer
67 views

Are Powered Explicit Guidance calculations done before or during launch?

Space shuttle orbital insertion was done using a powered explicit guidance algorithm. At the surface, the algorithm is simple, as it gives the instantaneous pitch as a linear function of time: $\phi = ...
1
vote
0answers
34 views

Falcon 9 Angle of attack on return flight?

Do they control for angle of attack on the return flight of stage 1 of Falcon 9? Once it reenters thick atmosphere, aerodynamic stresses would be a concern as during launch, maybe more so because you ...
0
votes
3answers
95 views

Orbital launches

In the 1950s, many US rockets were capable of reaching the lower limit of LEO altitude. Despite this, no one thought of making the launch vehicle / its payload orbit around earth, even for one ...
18
votes
1answer
3k views

What would have happened if only one Space Shuttle SRB ignited?

The ignite command for the Solid Rocket Boosters (SRB) would not be issued unless all three Space Shuttle Main Engines (SSME) were at least 90% of thrust. The launch would have been aborted if one or ...
10
votes
3answers
2k views

How much throttleback to keep acceleration under 3g?

Most rockets generally throttle back when they reach max-q to prevent structural failure. This could be the only throttleback event of the launch. But crewed rockets normally do a second throttleback ...
4
votes
0answers
81 views

Does space weather affect spacecraft launch schedules?

Does space weather affect spacecraft launches and do scientists check it before spacecraft go to space? I know there is space turbulence and it can influence a spacecraft, but can space weather?
3
votes
1answer
66 views

What happens with the upper stage of Deep space launches?

When a rocket is sending a spacecraft to another planet, in general, where does it separate from the upper (last) stage of the rocket? What happens to most of those upper stages? They remain in Earth ...
2
votes
0answers
27 views

Falcon 9 Stage-1 Reentry Burn: Throttle Setting, Duration?

How long does stage 1 of Falcon 9 fire its engines during its reentry burn, and what throttle setting do they use? Also, is it known how much fuel is left at MECO? Thanks if you know and can share!
1
vote
0answers
16 views

Falcon 9 Stage 1 Guidance After Separation?

Does anyone know how stage 1 of Falcon 9 is guided immediately after stage separation? I'm not interested at this point in getting it to a precise landing spot, nor am I interested in the landing ...
31
votes
3answers
6k views

Do rockets leave launch pad at full thrust?

Rockets always seem to launch slower than I expect them for the thrust they can produce. Do they really launch off the pad at maximum thrust? Or do they launch at lower thrust until they clear the ...
11
votes
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?
1
vote
0answers
21 views

Falcon 9 CGT Force?

Curious how much force the Falcon 9 cold gas thrusters produce for steering? I've seen numbers in the range of 25--100 lbf, but not sure where in this range (or outside it) the Falcon 9 falls. If you ...
2
votes
0answers
30 views

Antares yaw maneuver: how many degrees?

The Antares rocket begins launch with a very noticeable yaw maneuver that seems to rotate it more than the 1.25 degrees documented for the Saturn V. Am I being misled by perspective? Does anyone know ...
3
votes
1answer
41 views

Initial Yaw Maneuver: Lean into or away from tower?

Some rockets do an initial yaw maneuver to help avoid contact with the tower. I know the yaw is in the plane of the tower: the rocket either leans into or away from the tower... But which of these is ...
0
votes
1answer
68 views

First satellite dispenser?

A rocket upper stage, sometimes called kick stage, is the last stage of a rocket and it is used to deploy satellites in orbit. A space tug is a spacecraft released from the upper stage and it is used ...
12
votes
2answers
705 views

How do they determine dynamic pressure has hit a max?

Max-Q is a key event during launch, and dynamic pressure is closely monitored so they know when a max is hit. But how exactly do they know when Q hits a max? If you track the rate at which Q is ...
1
vote
1answer
60 views

Do rockets headed to ISS get delta V benefit from Earth's rotation

A rocket on the launchpad moves Eastward with the rest of the earth as it rotates about its polar axis. This means that on launch, the rocket already has a sizable eastward velocity component: ~460 m/...
1
vote
0answers
36 views

Coordinate axes of Falcon 9 on launchpad 39A

Can someone please correct me on the orientation of the Falcon 9 rocket as it sits on launchpad 39A at Kennedy? Looking at the image below, which way should X (red), Y (green), and Z (blue) face? I ...
4
votes
1answer
79 views

Purpose of Initial yaw Maneuver?

I've read the Saturn V began launch with a short yaw maneuver which lasted from t+1 through t+8.25. The purpose mentioned for the maneuver is to avoid contact with the launch tower. But now that I ...
6
votes
4answers
559 views

Delta-V required for lift-off from a planet/ asteroid

How can I find a estimation of the delta-V needed to lift-off from a planet and go into a low orbit around it?
1
vote
0answers
31 views

Orbital Insertion Altitude for Rendevous with ISS

When SpaceX launches a CRS mission to the ISS, what altitude do they target at orbital insertion? If the ISS is 400 km above ground, do they target 400 km at SECO? Or do they target a lower number---...
2
votes
1answer
133 views

Gimbal Check: Before or After Engine Ignition?

Is the engine gimbal check done before or after ignition? Also curious: How many seconds does the check take? What does it consist of? Do they gimbal each engine separately, or do they gimbal all ...
1
vote
0answers
23 views

Falcon 9: SECO target altitude/speed?

Is there a typical target altitude and speed for SECO on a Falcon 9 CRS launch? SECO precedes orbital insertion but there are multiple orbital adjustments afterward, so I also wonder: does Dragon have ...
3
votes
9answers
197 views

Number of launches by year, by country

This is a question about how many orbital launches made each year China, then the same question for India and so on for every country that made orbital launches Additionaly, is there any country that ...
1
vote
3answers
160 views

What is the number of launches by year?

How many orbital and beyond-Earth launches have been done every year? There is a Wikipedia article: https://en.wikipedia.org/wiki/Timeline_of_spaceflight But it doesn't contain enough data. There is a ...
9
votes
2answers
560 views

Falcon 9 TVC: Which engines participate in roll control?

Stage 1 of Falcon 9 uses its gimballed engines during launch to control roll, pitch, and yaw. Only the eight peripheral engines can be used for roll control since the center engine couldn't possibly ...
8
votes
2answers
746 views

US states with most space launches?

Some space launches are made from Florida, some from Texas, some from California and so on. Which US states and territories had the most orbital space launches in all space history? I mean launches ...
3
votes
0answers
146 views

First time in orbit by USA state launched from? [closed]

Only five states and territories had launches that got into orbit: Florida, California, Virginia, Alaska and Marshall Islands But when is the first time a rocket launched from each of those that ...
2
votes
0answers
57 views

Where can I book a flight for scientific experiment to 100 km high? [closed]

I have just been wondering if is there any company in Europe which launch scientific experiments into an altitude of about 100 km?
3
votes
1answer
146 views

Number of satellites launched by decade?

How many satellites were launched each decade? Including satellites of Mars Moon Venus Sun etc Similar question Number of satellites launched per year? Most busy times in space launches by decade?
2
votes
2answers
193 views

Most busy times in space launches by decade?

If anyone has the curiosity and time and possibility to run the scripts, I think it's interesting to see the most busy day, week, month and year, by decade. Most busy week of 1960s then most busy week ...
27
votes
4answers
10k views

If the ISS had an emergency, how long would it take to get a rocket to it?

If there was an urgent need to launch a rocket to the ISS, how long would it take to have a rocket ready to launch? I am trying to understand what factors take up the time to prepare for a rocket ...
4
votes
1answer
165 views

What is the longest period of consecutive daily space launches?

What is the largest number of days with at least one space launch every day? Also what is the largest number of days with at least a launch per day on average? For example two launches yesterday and ...
18
votes
2answers
2k views

What was the most busy week in space launches?

In the history of space launches, which week has had the most space launches? It would be also nice to know the second and third place. I think its also interesting to ask about most busy month and ...
20
votes
8answers
2k views

Where to look for next rocket launches?

Is there any place on the internet showing the upcoming rocket launches? Like the launches next week or next month
7
votes
4answers
274 views

Can Oberth bike? Is biking up and down a series of hills a good real-world analogy for understanding either the Oberth effect and/or gravity drag?

When faced with a series of ups and downs while riding a bicycle, I try to pedal like mad near the bottoms to gain as much speed as possible. I do this due to some vague, ill-formed notion that either ...
2
votes
2answers
114 views

Number of China orbital launches by year [duplicate]

I've also posted the numbers below as a temporary answer here but I don't know if they are right so I'll also ask this as a question. How many orbital launches did China make every year? I got some ...
11
votes
1answer
124 views

Why did GRACE mission have launch window?

GRACE mission which was launched on March 17th, 2002 had a 10 minutes launch window. The mission was to launch a couple of earth observation satellites. And interestingly, NASA's GRACE Launch Press ...
29
votes
4answers
2k views

Has Max-Q historically been a common failure point in rocket launches?

I believe that it's common knowledge that Max-Q is the point in which a rocket is undergoing the maximum dynamic stress during a launch and ascent. But, how often have rockets actually been destroyed ...
4
votes
0answers
61 views

How soon after launch is pitchover done?

I'm reading conflicting things on the timing of the pitchover. When exactly does it start? Many people write that it's almost immediately after launch, as soon as it's practical. Once the rocket ...
5
votes
0answers
55 views

Falcon 9 plot of pitch angle vs time during launch?

I found this super helpful plot of the Saturn V pitch angle vs time during launch: Is there an equivalent plot for a typical (or atypical if must be) Falcon 9 launch?
2
votes
1answer
313 views

Number of satellites launched per year?

How many satellites were launched every year? Similar question Number of satellites launched by decade? Resources for number of orbiting and active satellites by year?
9
votes
4answers
4k views

What are the biggest challenges for high altitude rail-gun launch systems?

Use a maglev railgun for initial acceleration - in a new, hyperbolic tunnel facing eastward - this exits from the burrowed -undergrade- track to Equadors' Mt. Chimborazo peak - (a mountaintop both 6 ...
1
vote
0answers
91 views

Could the Sea Dragon light it's main engines once it is airborne, or is it too big?

Could the Sea Dragon light it's main engines once it is airborne, or is it too big? Modern submarine launched missiles use compressed gas and the buoyancy of the missile to propel the missile out of ...
3
votes
0answers
80 views

Saturn V launch footage from in/on first S-IC stages

There first launches of each Saturn-class rocket were instrumented with, among other sensors, video cameras to learn about the vehicles’ behavior. The cameras were jettisoned at some point and then ...
4
votes
1answer
209 views

Could a tank of water under the launch pad be used instead of a flame trench?

A flame trench is a massive expensive thing that needs constant repair. After each launch, concrete and steel suffer cracks, chips, melting etc., and require expensive, time consuming repair. Would it ...
9
votes
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 ...
14
votes
1answer
1k views

Are there international regulations for launching objects into space?

In the United States access to space is restricted by the FCC / FAA, which licenses private, commercial, and government entities for potential launches into space. Is there any international ...
7
votes
2answers
2k views

How might SpinLaunch actually spin something fast enough to launch it into orbit?

update: TechCrunch's SpinLaunch spins up a $35M round to continue building its space catapult is worth a read and contains this cool photo. Click for full size Ars Technica's Edition 1.34 of the ...
0
votes
1answer
102 views

Out of 47,108 lines in the Satcat why are there exactly two lines with launch of the year of 000?

This looks like this answer because that's where I found this. Celestrak offers a copy of a Satcat from which a tabulation of space objects can be gleaned: https://celestrak.com/satcat/search.php ...

1
2
3 4 5
20