Hacker News new | past | comments | ask | show | jobs | submit login
Falcon Heavy Demonstration Mission [pdf] (spacex.com)
55 points by garciagomezluis on Feb 6, 2018 | hide | past | web | favorite | 30 comments

I saw the video animation of the Tesla separating from the second stage. At that point, the car no longer has thrust, so I'm assuming they've calculated the thrust to be just enough to reach Mars and to be able to fall into orbit. To quote the movie Apollo 13, "we've just put Isaac Newton in the driver's seat". I dearly hope that Musk and team have been referring to the "dummy" in the driver's seat of the Tesla as Isaac.

They aren't aiming for Mars orbit. As far as I can tell, they aren't even aiming to come close to Mars. Instead (as far as I can tell) they are aiming to come close to the orbit of Mars, i.e. where Mars will be in 4 or 5 months.

Wait, wait wait. If they aren't putting the Tesla into actual orbit, then what about--50 years from now--when they run into a situation on Mars Base Alpha where the only possible solution to an imminent cascading system failure is to dock with the orbiting Roadster and harvest a crucial part from the drivetrain in order to repair their reactor and save the base?!

> Following launch, Falcon Heavy’s second stage will attempt to place the Roadster into a precessing Earth-Mars elliptical orbit around the sun.

That's not Mars orbit. It's an orbit around the sun with perihelion ~1AU (distance the Earth orbits) and aphelion ~1.5AU (distance Mars orbits [avg]).

So basically they're just throwing a car into space.

Into deep space. This will be SpaceX's first flight beyond Earth orbit.

It will be the first commercial space flight beyond Earth orbit

iirc, they are aiming for Mar's orbit... the general public just thinks that means orbiting Mars.


Reading the OPs link it looks like that animation may have had some dramatic license. They are going to do two more mid coarse corrections on the way to “Mars” if I am reading it right. Of course the red planet won’t actually be there on the other side when they get there.

Also note that you can’t “fall into orbit” around Mars, at least not with this sort of trajectory and without an aero rake heat shield. A real mars mission would require a third stage reignition for Mars orbital insertion.

When / if the Tesla nears Mars, it'll be going at escape velocity, and so won't enter orbit. So unless lithobraking is employed, it'll fly straight by, and remain in an orbit around the sun.

Continuing the homage to David Bowie, the dummy driver is called Starman.

From what I understand it won't reach or orbit Mars (not in a current transfer window). It will attempt an approximate Mars-like Hohmann transfer orbit and continue orbiting around the Sun indefinitely.

Here’s a to-scale graph of the path each core/stage takes:


Did it get delayed? YouTube channel now says going live in another 2 hours

"The first test flight of Falcon Heavy is now targeted for Tuesday, Feb. 6th at 3:05 PM ET from Launch Complex 39A at Kennedy Space Center in Florida. Teams are watching upper level wind shear and will continue to update as information becomes available."

Yes, it is delayed due to upper level winds.



seems to have more up to date status

It's currently delayed until about an hour before the launch window closes, and they are hoping for the winds to die down. looks unlikely that they will launch today.

EDIT: nevermind fuel is being loaded and the "holy mouse click" has happened.

They're filling it with rocket fuel, so I think there's a pretty good chance of a launch.


When is the next window?

Tomorrow, same times (13:30-16:00 EST, I believe, I'm in the UK, so it's 18:30-21:00, that I do know!)

This will be a historic flight. It will be interesting regardless the outcome XD

27 engines!

"When Falcon Heavy lifts off in 2018, it will be the most powerful operational rocket in the world by a factor of two"

the most powerful operational rocket, but not the most powerful ever. I believe the Saturn V was more powerful.

Yes, they say in the same PDF:

> Only the Saturn V moon rocket, last flown in 1973, delivered more payload to orbit.

Yep, in the "current" world though is what the quote was alluding to.

Just got word from a friend that all SpaceX employee names are etched on the Tesla roadster. So either they will orbit indefinitely around the sun or blow up spectacularly.

They have just started fueling the rocket. It seems the launch may happen today...


What a time to be alive

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact