All Questions
Tagged with launchlaunch-sequence
36 questions
2votes
2answers
323views
Which orbital elements are normally targeted at launch?
Say you launch a rocket for rendezvous with the ISS. You'll want to set the target orbital inclination and longitude of ascending node. These will ensure the rocket is in the plane of the ISS. You'll ...
user39728
4votes
1answer
441views
Are westward launches more expensive than eastward launches?
Basic question for those who breathe rockets: The earth's rotation imparts to the rocket a free delta V of roughly 450 m/s if you launch straight eastward. If you launch westward instead, for a ...
user36480
0votes
1answer
2kviews
Falcon 9 altitude and speed during reentry burn?
After MECO, stage 1 of Falcon 9 does up to three engine burns: a boostback burn followed by a reentry burn followed by a final landing burn. I'm interested here in the reentry burn. How high and how ...
user36480
1vote
0answers
196views
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 ...
user36480
0votes
1answer
94views
Estimating time to engine cutoff?
I'd like to calculate the approximate time left to my stage-1 velocity target. A simple way to do this would be to divide my Delta V by my acceleration. Trouble is... my acceleration changes ...
user36480
2votes
0answers
48views
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!
user36480
5votes
1answer
645views
Simple alternative to Powered Explicit Guidance for orbital insertion?
Say you're playing space ops engineer and want to simulate an orbital insertion---but you're petrified by the calculations needed to get the coefficients of the linear tangent law behind Powered ...
user36480
5votes
1answer
377views
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 = ...
user36480
9votes
3answers
2kviews
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 ...
user36480
2votes
0answers
37views
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 ...
user36480
4votes
1answer
580views
Are rocket tanks being filled up until the last seconds before liftoff?
In rocket launch videos, we often observe liquid propellant rocket engines running at full thrust for several seconds before actual liftoff. We understand that liquid propellant rockets consume a ...
48votes
2answers
7kviews
Was the payload bay of the Space Shuttle depressurized before launch?
We know that the payload bay of the Space Shuttle Orbiter carried satellites, pieces of equipment for repairing satellites and components of the International Space Station. Was the payload bay of ...
- 3,356
4votes
1answer
1kviews
Why doesn't Ariane-5 lift off at T=0 seconds?
I have seen Ariane-5 lift off at T+07 seconds and not at (or close to) T=00 seconds. The following statement is from the Ariane-5 User's Manual (Page 35, Section 2.3 - Typical Mission Profile): The ...
- 3,356
4votes
1answer
731views
Why should the roll program position the shuttle's nose to the east?
The roll program occurred during a shuttle launch for the following reasons: (...) Orienting the shuttle more parallel toward the ground with the nose to the east. ...
2votes
0answers
266views
Launch corridors
I was wondering where I could find a list of the launch azimuth ranges - i.e. the corridors - for the main launchpads worldwide (Baikonur, Kourou, KSC, ... as many as possible). Thank you in advance!
