Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

SpaceX Falcon 9 v1.1 launch - DSCOVR satellite

This site may earn commission on affiliate links.

Grendal

SpaceX Moderator
Moderator
Jan 31, 2012
7,809
12,018
Santa Fe, New Mexico
Starting the thread for the upcoming launch. There will be another attempt at landing the first stage. It's been mentioned in other threads that this one, because of the angle will be more difficult than the last attempt.

The launch of DSCVR on Feb. 8, has a scheduled liftoff time of 6:10 p.m. EST (2310 GMT), with a backup launch date of Feb. 9 at 6:07 p.m. EST (2307 GMT). This flight will mark the second launch for SpaceX in 2015.

The static test was completed successfully:

SpaceX successfully conducts static fire test in preparation for DSCOVR launch - SpaceFlight Insider
 
Last edited:
As of the moment of this post, the launch schedule is:

The Deep Space Climate Observatory (DSCOVR) is scheduled to launch at 6:10 p.m. EST Sunday, Feb. 8 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on a SpaceX Falcon 9 rocket. A backup launch opportunity is available at 6:07 p.m. on Feb. 9, if needed.

NASA Television coverage of the launch will begin at 3:30 p.m. In addition to launch coverage, NASA TV also will air a prelaunch news conference at 1 p.m. Saturday, Feb. 7.
 
Aaah can't wait

Started as a dream and a myth
IcarusFlying.jpg


Now reality
Falcon9.jpg
 
Does anybody know what they use guide the returned stage? If I recall correctly, GPS is only accurate to a few meters and even then, it's not terribly trustworthy when it comes to elevation.

Are they using some combination of GPS/Proximity sensors and instrument guidance? I'd put this on par with landing the X-47B landing on an aircraft carrier, but I read that it actually aborted an attempt once when one of the navigational computers produced an error. That isn't exactly an option for SpaceX, so they must be using some sort of system that is a whole lot less susceptible to failure.
 
Does anybody know what they use guide the returned stage? If I recall correctly, GPS is only accurate to a few meters and even then, it's not terribly trustworthy when it comes to elevation.

Are they using some combination of GPS/Proximity sensors and instrument guidance? I'd put this on par with landing the X-47B landing on an aircraft carrier, but I read that it actually aborted an attempt once when one of the navigational computers produced an error. That isn't exactly an option for SpaceX, so they must be using some sort of system that is a whole lot less susceptible to failure.

Could be wrong but I think I read that they use some sort of radar system.
 
Does anybody know what they use guide the returned stage? If I recall correctly, GPS is only accurate to a few meters and even then, it's not terribly trustworthy when it comes to elevation.

Are they using some combination of GPS/Proximity sensors and instrument guidance? I'd put this on par with landing the X-47B landing on an aircraft carrier, but I read that it actually aborted an attempt once when one of the navigational computers produced an error. That isn't exactly an option for SpaceX, so they must be using some sort of system that is a whole lot less susceptible to failure.

As owner/operator of a Phantom II drone, which uses GPS, I would say that a meter is pretty good for such a large object as the returned stage. My drone can and does return by GPS if it loses signal from me, and lands gently at the same spot it left (+/- a foot or so). It will sit in space where ever I put it, move to where ever I want it, within a foot or so, and stay there. It's pretty amazing software, with gyros, etc., on a tiny chip. I bet they have better software than I do. I also know that military GPS is MUCH more accurate than that used by the public. Perhaps they are allowed to use it.

The newer drones which can be used indoors without GPS, rely on bi-optical cameras that "see" the floor and land gently. I believe that the rocket stages have cameras on them already.

Doesn't sound like a problem.
 
Does anybody know what they use guide the returned stage? If I recall correctly, GPS is only accurate to a few meters and even then, it's not terribly trustworthy when it comes to elevation.

Are they using some combination of GPS/Proximity sensors and instrument guidance? I'd put this on par with landing the X-47B landing on an aircraft carrier, but I read that it actually aborted an attempt once when one of the navigational computers produced an error. That isn't exactly an option for SpaceX, so they must be using some sort of system that is a whole lot less susceptible to failure.

There is an enhancement to GPS called "WAAS" (Wide Area Augmentation System), in which a ground-based system (in a very well surveyed place) transmits corrections to the GPS signals to compensate for the inaccuracies that are mostly atmospheric and ionic in origin. This is used by receivers in aircraft, for precision landings, for example.

The biggest problem with GPS (even with WAAS) is that it is quite inaccurate in the vertical direction. I believe the Falcon 9 uses a radar altimeter both for accurate altitude information and also partly to locate the barge (which is hopefully higher than the sea around it).
 
SpaceX is probably using avionics systems similar to autolanding aircraft + airports: differential GPS from the barge aka ASDS + radio altimeter (radar) + triple redundant fail operative flight control computers. That capability has been around for over 2 decades.
And BTW the accuracy can be 10 to 20 cm ! in best case which is about 10x better than they need.
 
Last edited: