Editing Splashdown (section)

==Disadvantages==
Perhaps the most dangerous aspect is the possibility of the spacecraft flooding and sinking. For example, when the hatch of [[Gus Grissom]]'s ''[[Mercury-Redstone 4|Liberty Bell 7]]'' capsule blew prematurely, the capsule sank and Grissom almost drowned. Since the spacecraft's flooding will occur from a location in its hull where it ruptures first, it is important to determine the location on the hull that experiences the highest loading.<ref>{{cite journal|last=Jain|first=U.|display-authors=et al.|journal=Journal of Fluid Mechanics|date=2021|volume=938|issue=4|title=Air entrapment and its effect on pressure impulses in the slamming of a flat disc on water |page= A31 |doi=10.1017/jfm.2021.846| arxiv=2012.10137|bibcode=2021JFM...928A..31J }}</ref> This location along the impacting side is determined by the surrounding `air cushion' layer, which deforms the water surface before the moment of impact, and results in a non-trivial geometry of the liquid surface during first touch-down.<ref>{{cite journal|last=Jain|first=U.|display-authors=et al.|journal=Physical Review Fluids|date=2021|volume=6|issue=4|title=Air-cushioning effect and Kelvin-Helmholtz instability before the slamming of a disk on water |page= L042001 |doi=10.1103/PhysRevFluids.6.L042001|arxiv= 2106.09551|bibcode=2021PhRvF...6d2001J }}</ref><ref>{{cite journal|last=Verhagen|first=J.H.G|journal= Journal of Ship Research|year=1967|title=The Impact of a Flat Plate on a Water Surface|volume=11 |issue=4 |pages=211–223 |doi=10.5957/jsr.1967.11.4.211 |url=https://archive.org/details/Verhagen1967}}</ref><ref>{{cite journal|last= Asryan |first=N.G.|journal= Izv. Akad. Nauk Arm. SSR Mekh|date=1972|title=Solid plate impact on surface of incompressible fluid in the presence of a gas layer between them|url=https://archive.org/details/Asrian1972_201803}}</ref> [[Soyuz 23]] was dragged under a frozen lake by its parachutes. The crew became incapacitated by [[carbon dioxide]] and were rescued after a nine-hour recovery operation.<ref name="NASA CO2">{{cite web |title=Carbon Dioxide (CO2) OCHMO-TB-004 Rev C |url=https://www.nasa.gov/wp-content/uploads/2023/12/ochmo-tb-004-carbon-dioxide.pdf |website=NASA |access-date=27 November 2024}}</ref>

If the capsule comes down far from any recovery forces, the crew may be stranded at sea for an extended period of time.  As an example, Scott Carpenter in ''[[Mercury-Atlas 7|Aurora 7]]'' overshot the assigned landing zone by {{convert|400|km|sp=us}}.  These recovery operation mishaps can be mitigated by placing several vessels on standby in different locations, but this can be an expensive option.

Exposure to salt water can have adverse effects on vehicles intended for reuse, such as [[SpaceX Dragon|Dragon]].<ref name="NASA Reusable Rocket">{{cite web |work = NASA|page=4-5|title=A FRAMEWORK FOR ASSESSING THE REUSABILITY OF HARDWARE (REUSABLE ROCKET ENGINES |url=https://ntrs.nasa.gov/api/citations/20170000606/downloads/20170000606.pdf |access-date=11 November 2024}}</ref>