Space Briefs
Masten’s Xombie rocket tests
new precision landing software
A year after NASA’s Mars
rover Curiosity’s landed on
Mars, engineers at NASA’s
Jet Propulsion Laboratory in
Pasadena, Calif., are testing
a sophisticated flight-control
algorithm that could allow for
even more precise, pinpoint
landings of future Martian
spacecraft.
Flight testing of the new
Fuel Optimal Large Divert
Guidance (G-FOLD) algorithm
for planetary pinpoint landing
is being conducted jointly by
JPL engineers in cooperation
with Masten Space Systems
in Mojave, Calif., using
Masten’s XA-0.1B “Xombie”
vertical launch and landing
experimental rocket.
“The collaboration between
JPL and Masten to test
G-FOLD is a great example
of how we hope to further
the exploration of the solar
system while building up
the industrial base needed
to advance future space
endeavors,” said Christopher
Baker, a campaign manager
for the program.
Current powered-descent
guidance algorithms used
for spacecraft landings are
inherited from the Apollo
era. These algorithms do
not optimize fuel usage and
significantly limit how far the
landing craft can be diverted
during descent. The new
G-FOLD algorithm invented
38
38
by JPL autonomously generates fuel-optimal landing
trajectories in real time
and provides a key new
technology
required
for
planetary pinpoint landing.
Pinpoint landing capability
will allow robotic missions to
access currently inaccessible
science
targets.
For
crewed missions, it will allow
increased
precision
with
minimal fuel requirements
to enable landing larger
payloads in close proximity to
predetermined targets.
Masten Space Systems
launched the Xombie July
30 from the company’s test
pad at the Mojave Air and
Space Port. JPL and Masten
are planning to conduct a
second flight test with a more
complicated divert profile,
pending data analysis.
To simulate a course
correction during a Martian
entry in the July test, Masten’s
Xombie was given a vertical
descent profile to an incorrect
landing point. About 90 feet
into the profile, the G-FOLD
flight control software was
automatically triggered to
calculate a new flight profile
in real-time, and the rocket
was successfully diverted to
the “correct” landing point
some 2,460 feet away.
“This
flight
was
an
unprecedented
free-flying
demonstration of the on-
board calculation of a fueloptimal trajectory in real
time,” said Martin Regehr,
acting task lead for the
Autonomous Descent Ascent
Powered-Flight Testbed at
JPL.
Masten Space Systems
is one of seven suborbital
reusable launch companies
contracted by NASA’s Flight
Opportunities
Program
to fly experiments in suborbital
space
to
verify
new
technologies
work
as expected in this harsh
environment.
NASA Dryden also aided
development of Curiosity’s
“sky crane” landing system
by conducting two series of
pre-launch flight tests of its
landing radar, the first under
a helicopter in 2010 and
a follow-on series with the
radar housed in a Quick Test
Experimental Pod mounted
under the wing of a Dryden
F/A-18 in June 2011. The 2011
tests focused on the on-chute
acquisition portion of the Mars
Science Laboratory’s entry
into the Martian atmosphere,
when the spacecraft was
suspended from its parachute.
Data collected from the
flights were used to finesse
the mission’s landing radar
software to ensure that it was
calibrated as accurately as
possible prior to Curiosity’s
landing.
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