SpaceX First Deep-space Launch - DSCOVR - A Success!

[mbender]

The drone ship was having trouble station-keeping on its own Lagrange point! ;-)

 

[AndyH]

Hopefully SpaceX can get the couple of controlled landings they need so that NASA will allow them to return boosters to the Cape. Eventually, they'll be able to return them to their own spaceport.

http://www.space.com/27234-spacex-texas-spaceport-groundbreaking.html

The facility should be operational by 2016, SpaceX representatives said.

Somewhere around here...not sure exactly yet...
https://www.google.com/maps/place/B...2!3m1!1s0x866fb3baee5a1a13:0xe6c3a89c928dfab5

I'm looking forward to the first Falcon Heavy launch, as well. Too much fun!

Google to the rescue:

 

[mbender]

FYI: LOTS of great detail on DSCOVR, its mission, and even today's launch (already):

SpaceFlight101 DSCOVR

• . . . . " . . . . Mission Updates

 

[GRA]

Yeah, I just saw this tweet:

Mega storm preventing droneship from remaining on station, so rocket will try to land on water. Survival probability <1%.

I'm sure they have their reasons, but wouldn't the Pacific have made for a better place for the drone than the Atlantic in winter? I seem to remember a movie... what was it called again? Oh well, at least DSCOVR is en route.

(Yes, awesome launch.)

Edit: I guess they always launch eastward, which would effectively rule out the Pacific for Cape Canaveral launches. I guess I'm so "jazzed" up that I'm posting without thinking right now. ;-)

Missed it, but ISTR that the Pacific (i.e. Vandenberg) is used for high inclination (polar) orbits, as they can launch to the south and not worry about hitting anything with a large population if there's a malfunction shortly after launch - Cuba/Bahamas/Haiti/Puerto Rico sort of precludes that from Canaveral, even if they were willing to launch spy sats whose pieces might come down in Cuba. I'd think it would take a large amount of fuel to change the orbital inclination from roughly east-west to polar.

 

[AndyH]

Yeah, I just saw this tweet:

Mega storm preventing droneship from remaining on station, so rocket will try to land on water. Survival probability <1%.

I'm sure they have their reasons, but wouldn't the Pacific have made for a better place for the drone than the Atlantic in winter? I seem to remember a movie... what was it called again? Oh well, at least DSCOVR is en route.

(Yes, awesome launch.)

Edit: I guess they always launch eastward, which would effectively rule out the Pacific for Cape Canaveral launches. I guess I'm so "jazzed" up that I'm posting without thinking right now. ;-)

Missed it, but ISTR that the Pacific (i.e. Vandenberg) is used for high inclination (polar) orbits, as they can launch to the south and not worry about hitting anything with a large population if there's a malfunction shortly after launch - Cuba/Bahamas/Haiti/Puerto Rico sort of precludes that from Canaveral, even if they were willing to launch spy sats whose pieces might come down in Cuba. I'd think it would take a large amount of fuel to change the orbital inclination from roughly east-west to polar.

That seems right. I suspect that sort of reasoning is in play for payloads that launch from Wallops Island, VA.

The S Texas spaceport should be the preferred launch site for geostationary packages once it's in operation. And for MCT. That's gonna be a big'un! :shock:

http://en.wikipedia.org/wiki/Mars_Colonial_Transporter#Super-heavy_lift_launch_vehicle

 

[mbender]

Semi-rhetorical question that others may want to contemplate. If you want to do some back-of-the-envelope estimates and calculations, and provide an educated guess, all the better!

So here goes: let's say there's one Falcon 9 launch per month. In one year (say this one), what is greater: the amount of CO2 produced by SpaceX's launches, or the amount of CO2 reduced by the use of Tesla's (worldwide) fleet of Model S's?

I know, crazy question*, but it's still a good exercise, no?

* Understood:

• 1. Coming up with any numbers will probably require a lot of assumptions and guesses.
  2. I'm sure they're both minute compared to the fleet of ICEs out there
  3. Even if the launches are greater, I feel that they'd be worth it.
  4. Eventually, the CO2 reduced by Teslas will hopefully dwarf SpaceX's necessary contribution!

 

[AndyH]

FYI: LOTS of great detail on DSCOVR, its mission, and even today's launch (already):

SpaceFlight101 DSCOVR

• . . . . " . . . . Mission Updates

Thanks very much for this! Excellent info - and a long-range launch schedule, too. \o/

 

[WetEV]

Delta IV uses liquid hydrogen rather than kerosene used by Falcon 9. Here is one place that I think hydrogen is the correct fuel/energy store for long term development.

 

[AndyH]

Delta IV uses liquid hydrogen rather than kerosene used by Falcon 9. Here is one place that I think hydrogen is the correct fuel/energy store for long term development.

You're right - it does. Any idea why?

Falcon Heavy is projected to lift more than twice the payload that the Delta IV Heavy can lift to low Earth orbit. I wonder how much of that is related to fuel choice?

edit...
Google to the rescue, maybe. RP-1 is considerably more powerful than hydrogen by volume. It's more stable and less expensive today. Is the decision all about power to weight/power to volume? Or is there more to it?

 

[AndyH]

http://www.spacex.com/news/2015/02/11/spacex-launches-dscovr-satellite-deep-space-orbit

 

[braebyrn]

Thanks for the update on the first stage landing in the ocean within 10 meters of its destination.

 

[Nubo]

So what happens during the 110 days? Does it just keep nudging its orbit wider until it intersects with L1? I assume there would be some interaction with the Moon, etc...?

 

[AndyH]

So what happens during the 110 days? Does it just keep nudging its orbit wider until it intersects with L1? I assume there would be some interaction with the Moon, etc...?

The impression I get from the way Hohmann low-energy transfers work, is that there are sort-of three 'orbits' from launch to being on station at L1. Only the last one is intended to be a 'full orbit' - the rest are partial (half?) by design.

Launch to an initial orbit of Earth, then a burn to expand the Earth orbit so that it reaches L1 or a bit more, then a final burn to inject into an L1 orbit as if there was a rock there to orbit.

Kind of like this chart, except 'orbit 3' is around L1, not around Earth.

Right now, we're in the ~110 day unpowered/coast phase for 'orbit 2.'

 

[AndyH]

Not sure how accurate this is, but kinda fun anyway. It's supposed to be the location of the SpaceX landing barge.

This is from the comments of this video:
[youtube]http://www.youtube.com/watch?v=OvHJSIKP0Hg[/youtube]

 

[mbender]

^^^ First, gotta just say again how awesome and perfect that launch was. "Even" a week after the fact.

Second, a few points stemming from Nubo's question that I gleaned from rewatching parts of the launch from NASA TV's coverage (and using a calculator ).

So what happens during the 110 days? Does it just keep nudging its orbit wider until it intersects with L1? I assume there would be some interaction with the Moon, etc...?

1. First, the announcer said that if last Wednesday (Feb 11) 's launch were scrubbed for any reason, they would have had to wait eight days because the moon would have interfered. Specifically, he said the craft would have had to use some of its precious fuel to stay on course -- i.e., the 110-day part of the elliptical Hohmann transfer orbit that gets DSCOVER to Sun-Earth L1. Anyway, he referred to this 8-day period as a "Lunar Blackout".
2. Second, 931,000 miles or 1,500,000 km in 110 days comes to an average of 158 meters/second (0.1576 km/s). The last speed declared by the "Altitude - Downrange Distance - Speed" announcer that I heard was 5,615 meters per second (at roughly T+ 7:20 into the flight). Thus, what I suspect happens is that the 1200 lb satellite is just given a big push in the right direction and makes it there in spite of being slowed down by the earth's gravitational field. It's slowing down on the 'outbound' path of its ellipse -- from >5600 m/s to what must be quite slow if the average comes to 158 m/s.
3. Finally, once it gets to L1, it does not go into a simple circular orbit around the 'fictitious' L1 point. Rather, it goes into that strange Lissajous orbit that I mentioned before. Both to get into and to stay in it requires occasional propulsive "station keeping" bursts. The lifespan of the satellite depends on how long the fuel lasts in doing so (I forget what they're hoping/planning for, 15 years maybe*?)

Last note, I heard the DSCOVR Launch Control narrator say before the launch that once it gets there, DSCOVR "will be orbiting this point in a six month orbit, with the spacecraft-Earth-Sun angle varying between 4 and 15 degrees." If that means what I think it means, that would mean that the orbit will be quite oblique. Not sure why they would have or want to do that, rather than having it orbit as close to the ecliptic as possible.


* (Edit) From the press conference, the "nominal" life-span of the satellite is only two years(!!), and it has a five-year "operational" life-span. They are hopeful that with a good insertion, little course adjustment en route and minimal station-keeping that the on-board fuel will last many years beyond five, but had no estimates or expectations. They also gave almost no detail on how much fuel is on board or how much is expected for station-keeping. (I've noticed that even though the panel members are all experts and speak very authoritatively, they often "circumlocute" the question asked and/or omit important, relevant details. :shock: )

 

[gbarry42]

Apparently, if it could sit perfectly still at the L1 point, it would be in a position to cast a shadow on the Earth at all times--except that it's way too small to do anything remotely like that. I really said that to fix in mind where this L1 point (and thus the satellite) is. Now, with that in place, imagine that to see it from the Earth, you would have to look directly into the Sun. The Sun it quite noisy in the radio sense, so it's a whole lot easier on ground-based antenna systems to have the orbit offset a bit and just track it as it goes. I'd imagine having these offsets would also help keep other L1 dwellers out of each others' way, but that one's a guess on my part.