Questions tagged [launch-sequence]
Questions regarding the steps and procedures taken prior and during the launch of a space vehicle.
75 questions
0votes
1answer
239views
Why hasn't SpaceX performed a Wet Dress Rehearsal of Starship if they are ready to fly?
SpaceX claims that "The Starship and Super Heavy vehicles for Flight 5 have been ready to launch since the first week of August." SpaceX usually performs Wet Dress Rehearsals (WDRs) before ...
23votes
3answers
4kviews
Was Starship’s “launch window” administrative, rather than due to orbital mechanics?
According to Wikipedia, a launch window is the time period on a given day during which a particular rocket must be launched in order to reach its intended target. SpaceX’s internet launch coverage ...
- 33k
2votes
0answers
125views
How do Sea Dragon style launches affect the Nozzle?
The Sea Dragon was a concept rocket to be towed empty to its marine launch-site, where it would be filled and turned upright through the weight of its propellant and some ballast. "Then it ...
- 235
5votes
2answers
1kviews
Weaponizing the Starlink constellation
Starlink aims at having tens of thousands of satellites in orbit in a few years. At any given point in time there will be a large number of satellites close by any inhabited places, including the ...
47votes
2answers
3kviews
Why did the JWST solar array deploy early?
According to NASA's Deployment Explorer tool, the solar array was expected to deploy at T+33 minutes. In the NASA livestream, the solar array deploys at T+29:08 (the clock isn't on stream at that ...
- 1,828
5votes
1answer
404views
Space shuttle MECO condition: velocity threshold or fuel level?
I've read in a place I can no longer remember that MECO would happen when fuel is depleted or, if the separating stage is returning, when fuel reaches some preset threshold---15%, say. But now... ...
user39728
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
1vote
0answers
107views
What happens at T-0 for the SpaceX Starship?
Every launch system defines a different event for T-0. The SpaceX Starship prototypes seem to ignite the engines at T-1.0 and accent seems to begin between T+1.0 and T+1.5. An overthrust abort for SN-...
- 6,863
2votes
0answers
69views
What do the double- or triple-checkers do when a launch is not scheduled?
Leading up to every manned launch, there is personnel dedicated to making sure their colleagues do everything correctly in accordance to checklists they usually have on hand. See for example the ...
- 5,545
4votes
2answers
909views
Who uses a countdown, and who doesn't?
I just learned that the Russians don't use a countdown when launching a rocket. I saw that in a YouTube video and found a Reddit discussion that confirms it. That makes me wonder who does and who ...
- 4,287
2votes
1answer
246views
Would the space shuttle do a yaw maneuver to avoid the tower?
I read some rockets do a small yaw maneuver of about a degree immediately after T0 to avoid the tower in case of wind gusts. Would the space shuttle ever do such a maneuver? Did it? I read also that ...
user36480
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
