3.5 Entering the Age of Space Flight
155
(MR), the unmanned vehicles BA-1 (Beach Abort with the Redstone), MR-1, MR1A, MR-2 and MR-BD were launched sequentially, of which the flight tests of
the BA-1, MR-1A and MR-BD were fully successful, verifying the suborbital flight
performance of the Redstone rocket, the technology of spacecraft heat protection, and
the technology of splash-down and recovery on the sea. By combining the Mercury
crafts with the Atlas rockets (MA), three unmanned crafts MA-1, MA-2 and MA-3
were launched sequentially, of which only the MA-2 test was successful, verifying the
entire technical flow and operational process: rocket-firing launch, engine shutdown,
escape tower separation, craft separation, retro-thrust engine firing, craft reentry,
parachute opening, and finally splash-down on the sea. Until the first space flight of
Gagarin in April 1961, for the Project Mercury, there were still many technologies
and designs that need to be verified by the flight tests.
The second stage was to test the manned suborbital flights from May to August
1961. On May 5, 1961, the first American astronaut Alan B. Shepard by the MR-3
spacecraft Freedom-7 was launched from the Cape Canaveral launch site, Florida, by
using the Redstone rocket. The spacecraft was normally separated from the rocket,
and its maximum altitude only reached 186 km. And finally, the spacecraft reentered into the atmosphere along its trajectory and recovered safely. The duration
of the entire flight was 15 min and 28 s. This is a typical suborbital manned flight
test. On July 21, the MR-4 spacecraft carrying an astronaut Virgil I. Grissom was
launched successfully, whose flight process was basically as same as the MR-3. For
the United States with a backward position in the Space Race, although the publics
with dissatisfaction were slightly calmed down by the two suborbital manned flights,
the Redstone rocket did not have the capability of launching manned spacecraft into
orbit yet.
The third stage was to carry out the manned orbit flight from September 1961 to
June 1963. In order to fully test the rocket’s performance, NASA decided to conduct
again three unmanned flight missions. On September 13, 1961, the MA-4 craft was
launched by using the Atlas rocket, which although was partially successful, the
rocket performance, orbital flight capability and control system had been verified
fully. Subsequently, the MS-1 craft combining the Mercury spacecraft and the Scout
rocket (a series of solid-fueled rocket designed at the Langley Research Center) was
launched on 1 November 1961, but immediately after lift-off, the rocket developed
erratic motions, after 28 s the booster began tearing apart, at 43 s after launch the
safety officer of the launch site sent a self-destruct order, and thus the mission was
ended in failure. Finally, on November 29, the MA-5 craft carrying a chimpanzee was
launched by using once again the Atlas rocket, and at 3 h and 22 min after launch, the
capsule was spotted by a P5M search airplane at an altitude of 15 km. At this time,
the ships Stormes and Compton were contacted and they moved into position from a
distance of 48 km away. The “Stormes” arrived in the area 1 h and 15 min after landing
and hauled the capsule aboard via its lanyard, cracking the onboard window. The
chimpanzee fared well in the orbit, who withstood a peak of gravitation acceleration
of 6.8 G during booster-engine acceleration and 7.6 G with the rush of the sustainer
engine. Consequently, the flight test of the MA-5 was successful. The two perfect
demonstrations of the Atlas rockets strengthened NASA’s confidence in launching
155
(MR), the unmanned vehicles BA-1 (Beach Abort with the Redstone), MR-1, MR1A, MR-2 and MR-BD were launched sequentially, of which the flight tests of
the BA-1, MR-1A and MR-BD were fully successful, verifying the suborbital flight
performance of the Redstone rocket, the technology of spacecraft heat protection, and
the technology of splash-down and recovery on the sea. By combining the Mercury
crafts with the Atlas rockets (MA), three unmanned crafts MA-1, MA-2 and MA-3
were launched sequentially, of which only the MA-2 test was successful, verifying the
entire technical flow and operational process: rocket-firing launch, engine shutdown,
escape tower separation, craft separation, retro-thrust engine firing, craft reentry,
parachute opening, and finally splash-down on the sea. Until the first space flight of
Gagarin in April 1961, for the Project Mercury, there were still many technologies
and designs that need to be verified by the flight tests.
The second stage was to test the manned suborbital flights from May to August
1961. On May 5, 1961, the first American astronaut Alan B. Shepard by the MR-3
spacecraft Freedom-7 was launched from the Cape Canaveral launch site, Florida, by
using the Redstone rocket. The spacecraft was normally separated from the rocket,
and its maximum altitude only reached 186 km. And finally, the spacecraft reentered into the atmosphere along its trajectory and recovered safely. The duration
of the entire flight was 15 min and 28 s. This is a typical suborbital manned flight
test. On July 21, the MR-4 spacecraft carrying an astronaut Virgil I. Grissom was
launched successfully, whose flight process was basically as same as the MR-3. For
the United States with a backward position in the Space Race, although the publics
with dissatisfaction were slightly calmed down by the two suborbital manned flights,
the Redstone rocket did not have the capability of launching manned spacecraft into
orbit yet.
The third stage was to carry out the manned orbit flight from September 1961 to
June 1963. In order to fully test the rocket’s performance, NASA decided to conduct
again three unmanned flight missions. On September 13, 1961, the MA-4 craft was
launched by using the Atlas rocket, which although was partially successful, the
rocket performance, orbital flight capability and control system had been verified
fully. Subsequently, the MS-1 craft combining the Mercury spacecraft and the Scout
rocket (a series of solid-fueled rocket designed at the Langley Research Center) was
launched on 1 November 1961, but immediately after lift-off, the rocket developed
erratic motions, after 28 s the booster began tearing apart, at 43 s after launch the
safety officer of the launch site sent a self-destruct order, and thus the mission was
ended in failure. Finally, on November 29, the MA-5 craft carrying a chimpanzee was
launched by using once again the Atlas rocket, and at 3 h and 22 min after launch, the
capsule was spotted by a P5M search airplane at an altitude of 15 km. At this time,
the ships Stormes and Compton were contacted and they moved into position from a
distance of 48 km away. The “Stormes” arrived in the area 1 h and 15 min after landing
and hauled the capsule aboard via its lanyard, cracking the onboard window. The
chimpanzee fared well in the orbit, who withstood a peak of gravitation acceleration
of 6.8 G during booster-engine acceleration and 7.6 G with the rush of the sustainer
engine. Consequently, the flight test of the MA-5 was successful. The two perfect
demonstrations of the Atlas rockets strengthened NASA’s confidence in launching