Everything you never knew you wanted to know about the Mercury Project

MR-4

From RixWiki

Project Mercury Missions

Flight Order

LJ-1		12 Aug 1959
BJ-1		9 Sep 1959
LJ-1A		4 Nov 1959
LJ-2		4 Dec 1959
LJ-1B		21 Jan 1960
Beach Abort		9 May 1960
MA-1		29 Jul 1960
LJ-5		8 Nov 1960
MR-1		21 Nov 1960
MR-1A		19 Dec 1960
MR-2		31 Jan 1961
MA-2		21 Feb 1961
LJ-5A		18 Mar 1961
MR-BD		24 Mar 1961
MA-3		25 Apr 1961
LJ-5B		28 Apr 1961
MR-3		5 May 1961
MR-4		21 Jul 1961
MA-4		12 Sep 1961
MA-5		29 Nov 1961
MA-6		20 Feb 1962
MA-7		24 May 1962
MA-8		3 Oct 1962
MA-9		15-16 May 1962

[edit]

Description of Mission

From SP-45 Mercury project summary

The Mercury-Redstone 4 (MR-4) flight was successfully made on July 21,1961, from the Cape Canaveral launch site. Astronaut Virgil I. Grissom was the pilot. The space vehicle was made up of the 11th production spacecraft and a Mercury-Redstone launch vehicle essentially identical to the one used for MR-3 mission. The spacecraft on this mission was somewhat different from spacecraft 7, in that, for the first time, a manned spacecraft had a large top window, a side hatch to be opened by an explosive charge, and a modified instrument panel. The spacecraft achieved a maximum altitude of about 103 nautical miles, with a period of weightlessness of about 5 minutes. The flight was successful. After landing, premature and unexplained actuation of the spacecraft explosive side hatch resulted in an emergency situation in which the space craft was lost but the pilot was rescued from the surface of the water. Analyses of the data from the flight and debriefing by the astronaut indicated that, in general, the spacecraft systems performed as planned, except for the action of the spacecraft hatch. An intensive investigation of the hatch actuation resulted in a change in operational procedures. No fault was found in the explosive device. ---

[edit]