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by pikchurn 3061 days ago
Actually, no, once the 2nd stage cuts off the trajectory is mostly fixed and we know what orbit it is in. There are, I believe, two more small burns that will be done to adjust the trajectory, but these are more of an adjustment to what kind of Martian transfer orbit it is in. It already has the hyperbolic velocity to leave Earth's orbit, and enter solar orbit with an apogee at the same distance as Mars.

In 6.5 hours SpaceX will have finished everything they wanted to test with this flight I believe, including a number of post-launch checks of various systems and sensors on the payload, and those re-ignition tests of the 2nd stage.

2 comments

Unless I'm mistaken, it's not on a trajectory out of Earth orbit currently.

It is in a parking orbit, where it will sit for a few hours and then will reignite and will be set on a trajectory toward "martian orbit".

IIRC currently they are testing (or proving depending on how confident they are) that they can have the second stage sit for several hours in space before reignighting.

I think you're correct. At stage 2 cutoff, they were showing a speed of ~26,000 km/h, which is approximately orbital velocity, not escape velocity.
Although I'm not fully correct. Mr. Musk just tweeted this:

>Upper stage restart nominal, apogee raised to 7000 km. Will spend 5 hours getting zapped in Van Allen belts & then attempt final burn for Mars.

https://twitter.com/elonmusk/status/960988527159795712

I hope we see more images of Starman, driving his car with the Earth shrinking behind him.