4 ms·
> "Scientists say that the vessel will splashdown in the Pacific Ocean several hours later in what they are describing as “a very challenging phase of the fligh
by sparknlaunch 14y ago
> "Scientists say that the vessel will splashdown in the Pacific Ocean several hours later in what they are describing as “a very challenging phase of the flight”."
Impressed how space junk etc fall to Earth and almost always land in the ocean. Not hard when 70% of the Earth surface is covered by water. However what is the level of accuracy? I assume that it is planned to aim for a large body of water and get within an x% threshold?
- InclinedPlane 14y agoI don't know how big the landing zone is but the last Dragon reentered within a mile of it's targeted location.
- someperson 14y ago...and hit the water within something like 50 seconds of it's projected landing time IIRC O_O
- bfe 14y agoAnd it looks like they are planning for a future Dragon to do precision landings on a landing pad: http://www.youtube.com/watch?feature=player_embedded&v=mQC72UZxZlQ#t=197s http://www.youtube.com/watch?feature=player_embedded&v=m...
- InclinedPlane 14y agoThat is the manned Dragon, which will have an integral escape system allowing the capsule to be boosted away from the launcher during any part of flight. But that same system can be used to provide powered landings.
- bfe 14y agoYep - Elon talked about this about an hour ago in the post-splashdown press conference and said the future dragon will be able to do precision soft landings where there is little atmosphere or no atmosphere, so we can deliver payloads to other bodies in the Solar System. I love how he also said it's how spaceships simply should do a landing. (He didn't quite say that's how God and Heinlein would have wanted it, but same idea.)
- Maakuth 14y agoI don't believe the implication here is that it's hard to aim to the ocean, but to actually survive the re-entry. You know, high speed, high temperature and all that.
- bigiain 14y agoAccording to this page: http://www.spacex.com/press.php?page=20120530 http://www.spacex.com/press.php?page=20120530 It parachutes down from 10,000 feet, at 16 to 16 feet per second - which means it spends almost 10 minutes at the mercy of the wind (I'm guessing the re-entry thrusters probably don't get used while it's parachuting down?) That means that even if they can drop it onto the atmosphere accurately, the actual splash-down point can't be determined any more accuracy than they can predict the wind velocity along the parachute path.
- Retric 14y agoA back of the envelope worst case would be assume they are off by 50 MPH and it takes 10 minutes to fall 10,000 feet at 17feet per second. That seems like 5 miles in the worst case. But, the parachutes don't instantly slow the thing to 15-18 MPH and the wind does not instantly get it to match wind speed and normally it's not dropping into a steady 50 MPH wind from 10,000 feet to sea level.
- TeMPOraL 14y agoIt can be much, much more accurate than that if needed. In 1960s America had spy satellites that dropped canisters with photo film, that were captured mid-air by planes. See: http://en.wikipedia.org/wiki/Corona_(satellite)#Discoverer http://en.wikipedia.org/wiki/Corona_(satellite)#Discoverer
- sparknlaunch 14y agoWow! Wonder if the weight of a canister and mobility of a plane may help in connecting the two together? Or make it harder? Awesome story.
- planetguy 14y agoThe canisters had little parachutes, so it's not quite as amazing as it sounds.
- omegant 14y agohttp://youtu.be/9jOGicfF_vQ http://youtu.be/9jOGicfF_vQ
- JoeAltmaier 14y agoJust barely less amazing. Still like finding one particular mosquito in Pittsburgh?
- planetguy 14y agoIf the mosquito were two feet across and equipped with a radio transmitter, yeah.
- drbawb 14y agoAnd I assume this was all necessary because: (a) They wanted to see if it could be done. or (b) They couldn't yet build a digital camera and/or digital cameras didn't work in space because of some obscure issues with radiation?
- bane 14y agoThe Russians typically landed their recoverable craft in Kazakhstan if I'm not mistaken.
- cema 14y agoOften in Russia. You are right that it was (and is) intended for the on-land, not on-water, landing, although there are provisions for the on-water landings as well. See Wikipedia entries for Soyuz 23 and, more generally, splashdown.
- sp332 14y agoIt has to splash down near the recovery vessels to be recovered. It's a much smaller target than "the Pacific Ocean".
- andyjohnson0 14y agoDuring the Apollo program the accuracy with which reentry could be predicted got to be very good. Initially, the practice was to sail an aircraft carrier to the projected splashdown point and wait for the command module to hit the water some miles away. This had to be changed due to the growing risk of the spacecraft hitting the carrier. Instead, the carrier parked a few miles away. I don't know if the increase in accuracy was due to improvements in trajectory control during reentry, better aerodynamic modelling based on experience of real flights, or other factors. I assume that SpaceX would be pretty confident about their accuracy, but this is only the second flight of a Dragon.