NSSDCA ID: MERCA2
Mercury Atlas 2 (MA-2) was a sub-orbital test vehicle launch to check maximum heating and its effects during the worst reentry design conditions. Its goals were to: (1) determine the integrity of the spacecraft structure, ablation shield, and afterbody shingles for a reentry from a critical abort; (2) evaluate the performance of the operating spacecraft systems during the entire flight; (3) determine the spacecraft full-scale motions and afterbody heating rates during reentry from a critical abort; (4) evaluate the compatibility of the spacecraft escape systems with the Mercury-Atlas system; (5) establish the adequacy of the location and recovery procedures; (6) determine the closed-loop performance of the Abort Sensing and Implementation System (ASIS); (7) determine the ability of the Atlas booster to release the Mercury spacecraft at the position, altitude, and velocity defined by the guidance equations; and, (8) evaluate the aerodynamic loading vibrational characteristics and structural integrity of the liquid oxygen boiloff valve, tank dome, spacecraft adapter, and associated structures.
The trajectory was designed to provide the most severe reentry heating conditions which could be encountered during an emergency abort during an orbital flight attempt. Prior to launch, the reentry heating rate of the trajectory was estimated to be 30% higher than a normal reentry and temperatures were predicted to be about 25% higher at certain locations on the afterbody of the spacecraft. In addition, the deceleration g-load was calculated to be about twice that expected for a normal reentry from orbit. The flight closely matched the desired trajectory, attaining a maximum velocity of just over 21,000 km/hour and an altitude of about 185 km. The spacecraft came down in the Atlantic Ocean some 2,300 km down range. Total flight time was 17 minutes 56 seconds.
Inspection of the spacecraft aboard the recovery ship indicated that the test objectives had been met and the structure and heat protection elements were in excellent condition. Further evaluation found that the spacecraft afterbody temperatures were somewhat lower than originally anticipated.
Launch Date: 1961-02-21
Launch Vehicle: Atlas
Launch Site: Cape Canaveral, United States
Questions and comments about this spacecraft can be directed to: Dr. Edwin V. Bell, II
Name | Role | Original Affiliation |
---|
MA-2 information (NASA KSC)
MR-1 Press Release images (NASA JSC)
Project Mercury Drawings and Technical Diagrams (NASA History Office)
On-line version of Project Mercury: A Chronology (NASA History Office)