Edited by Peter Lawson
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DS1 kicks off New Millenium
By John G. Watson
Reprinted with Permission from JPL Universe Vol.29, No. 1, January 8, 1999.
With one mission launched in 1998, another having launched on Jan. 3 and
four others in the hopper, the New Millennium Program has been busy indeed
over the last 12 months.
The program's goal is to identify and test advanced technologies that will
provide future spacecraft with capabilities needed to achieve important
science goals. Through a series of deep space and Earth-orbiting flights,
the New Millennium Program will validate these technologies in space: that
is, either prove that they work or determine what problems may crop up. The
testing of advanced technologies is the basic requirement for New
Millennium Program missions; as a bonus, missions can also collect science
data as new instrument technologies are put through their paces.
The first New Millennium mission to launch was Deep Space 1, whose
picture-perfect liftoff on Oct. 24 culminated many months of test and
assembly. Unlike the typical mission that enters a cruise phase after
launch, this mission began testing its new technologies immediately. In
fact, two of them - large solar arrays and a new radio
transmitter/receiver - were functionally validated within just two hours
of launch.
A much-watched technology on Deep Space 1 is its ion propulsion system,
which combines the gas xenon with some of the technologies that make
television picture tubes work. Despite an almost imperceptible level of
thrust, over the long haul Deep Space 1's ion engine can deliver up to 10
times more thrust than a conventional liquid or solid fuel rocket for a
given amount of fuel. It has since been turned on and off repeatedly,
performing beyond expectations throughout.
Deep Space 1's other new technologies, many of which have already been
validated, include autonomous optical navigation, several microelectronics
experiments, and software to plan and execute many onboard activities with
only general direction from the ground. Two science instruments - one
combining a camera, ultraviolet imaging spectrometer and infrared imaging
spectrometer, the second combining several instruments that study space
plasma - will be further tested during a planned flyby of asteroid 1992 KD
this July. By Dec. 1, Deep Space 1 had accomplished enough testing to
satisfy the technology validation aspects of the minimum mission success
criteria and is now well on its way toward meeting maximum criteria as well.
Following its Jan. 3 launch, Deep Space 2's two small probes will reach
Mars this December and will crash into the Martian soil to test new
technologies and conduct science experiments. Each probe, approximately the
size of a large grapefruit inside a basketball-sized aeroshell, contains a
suite of miniature electrical and mechanical systems that must withstand
extreme environments, including crashing into the planet's surface at
speeds of up to 500 mph and surviving extremely low temperatures. Upon
impact, they will begin collecting data to verify the survival of the
penetrator system, which contains 10 new technologies.
Within the first six hours, they will also attempt to detect the presence
of water ice. If successful, this mission will pave the way for future
science projects involving scores of microinstruments sent to all regions
of a solar system planet or moon.
The probes's three parts - a forebody that pierces up to nine-tenths of a
meter (three feet) into the ground, an aftbody that remains above the
ground (tethered to the forebody for telecommunications) and the aeroshell
in which they are traveling to Mars - were delivered to the Kennedy Space
Center this fall and attached to the Mars Polar Lander cruise ring, on
which they are piggybacking to the red planet. Launch was the crowning
touch to an intensive year of test and assembly for the mission team.
Deep Space 3, a proposed optical interferometry mission involving
spacecraft orbiting the Sun in formation, made significant progress in
1998, as the mission was reconfigured from three spacecraft to two.
Engineering design experiments determined that separated spacecraft
interferometry could be accomplished using two spacecraft separated by up
to one full kilometer. This change has yielded both cost and mass savings.
An industry partner is scheduled to be selected and on contract by this
March. Deep Space 3, which is scheduled to launch in December 2001, will
undergo system requirements and architecture review in August.
Deep Space 4/Champollion, a proposed mission that will send a lander to the
nucleus of comet Tempel 1 in 2005 following a scheduled launch in 2003,
achieved many milestones in 1998. The team continued working on the
detailed design of the lander and mother ship, including the construction
of a striking, full-scale mockup of the diminutive lander. An observational
program on Tempel 1 has revealed the size of the nucleus to be 3.9 by 2.8
kilometers; the team is now trying to determine additional information on
the nucleus's shape and its rotation period. A NASA review is scheduled for
April.
Earth Orbiter 1, New Millennium's first Earth orbiter flight, will validate
technologies for future land-imaging missions. Over the course of this
mission, launching in December 1999, three new land-imaging instruments
will collect multispectral and hyperspectral scenes in coordination with
the Enhanced Thematic Mapper (ETM+) on Landsat-7. Managed by NASA's Goddard
Space Flight Center, EO-1 will demonstrate breakthrough technologies in
lightweight materials, high-performance integrated detector arrays and
precision spectrometers. Detailed comparisons of the EO-1 and ETM+ images
will be carried out to validate these instruments for future missions.
In 1998, EO-1's advanced land imager completed environmental testing and is
now in final calibration. Its Hyperion instrument was added in May and is
now being fabricated; this unique instrument^Òs capabilities provide
resolution of surface properties into hundreds of spectral bands, versus
the 10 multispectral bands flown on traditional Landsat imaging missions.
Other instruments delivered for integration and test included EO-1^Òs pulsed
plasma thruster, carbon-carbon radiator, X-band phased array antenna,
lightweight flexible solar array and enhanced formation flying software.
With Earth Orbiter 2, New Millennium will fly an infrared laser in the
cargo bay of the space shuttle to see if a space-based sensor can
accurately measure global winds within Earth's atmosphere from just above
the surface to a height of about 16 kilometers (10 miles). Successful
measurements in this key region of the atmosphere could lead to improved
weather forecasting and better understanding of such climate-related events
as El Niño.
Based on technology tested aboard research aircraft, the Space-Readiness
Coherent Lidar Experiment (Sparcle) will detect the frequency shift of an
eye-safe laser pulse as it reflects off dust and aerosol particles as they
move with the winds. The resulting measurements should give researchers
precise information about the speed, direction and vertical profile of
tropospheric winds. Due to launch in 2001, Sparcle is managed by NASA's
Marshall Space Flight Center. This year's milestones included a preliminary
system design review in October, to be followed by a critical design review
this April.
Maintained by Peter Lawson
MS 306-388
Jet Propulsion Laboratory
4800 Oak Grove Drive
Pasadena, CA 91109
USA
Last Updated 13 January 1999
