Little Joe 5B

{{Infobox spaceflight

| name = Little Joe 5B

| image = Little Joe 5B liftoff.jpg

| image_caption = Launch of Little Joe 5B from Wallops Island

| insignia = Mercury insignia.png

| mission_type = Abort test

| operator = NASA

| mission_duration = 5 minutes, 25 seconds

| distance_travelled = {{convert|9|mi|km|disp=flip}}

| suborbital_apogee = {{convert|2.8|mi|km|disp=flip}}

| spacecraft = Mercury No.14

| manufacturer = McDonnell Aircraft

| launch_mass = {{convert|1141|kg|lb}}

| landing_mass =

| launch_date = {{start-date|April 28, 1961, 14:03|timezone=yes}} UTC

| launch_rocket = Little Joe

| launch_site = Wallops LA-4

| landing_date = {{end-date|April 28, 1961, 14:08|timezone=yes}} UTC

| landing_site =

| previous_mission = Little Joe 5A

| programme = Project Mercury
Abort Tests

File:Little Joe 5B High-Q-Abort Test - GPN-2002-000041.jpg

}}

Little Joe 5B was an uncrewed launch escape system test of the Mercury spacecraft, conducted as part of the US Mercury program. The mission used production Mercury spacecraft # 14A. The mission was launched April 28, 1961, from Wallops Island, Virginia. The Little Joe 5B flew to an apogee of 2.8 miles (4.5 km) and a range of 9 miles (14 km). The mission lasted 5 minutes 25 seconds. Maximum speed was 1,780 mph (2865 km/h) and acceleration was 10 g (98 m/s²). The mission was a success and Mercury spacecraft # 14A was recovered.{{cite book |chapter-url=https://history.nasa.gov/SP-4201/ch10-9.htm |title=This New Ocean: A History of Project Mercury - NASA SP-4201 |author1=Loyd S. Swenson Jr.|author2=James M. Grimwood|author3=Charles C. Alexander |chapter=10 |page=9 |publisher=NASA Special Publication-4201 in the NASA History Series |year=1966 |accessdate=26 June 2013 |archiveurl=https://web.archive.org/web/20090407044921/https://history.nasa.gov/SP-4201/ch10-9.htm|archivedate=2009-04-07}}

Mercury spacecraft #14A used in the Little Joe 5B mission, is on display at the Virginia Air and Space Center in Hampton, Virginia.{{cite web|title=Spacecraft|url=https://vasc.org/exhibits/spacecraft/|publisher=Virginia Air & Space Science Center|access-date=March 20, 2023}}