Tuesday, June 28, 2011

ORS -1 Operationally Responsive Space Satellite.

ORS-1



ORS-1 is the first satellite in the DOD’s Operationally Responsive Space Office (ORS) program designed to support Combatant Command operations as an operational prototype. The payload leverages a SYERS-2 sensor, the primary imaging sensor on the U-2 reconnaissance plane. The ORS-1 payload was built by the Goodrich Corporation, who also served as prime contractor, while the spacecraft bus was built by ATK Spacecraft Systems & Services, Beltsville, Md. It includes an integrated propulsion system as well as other critical subsystems for communications, attitude control, thermal control and command and data handling. ORS-1 will provide crucial battlespace awareness supporting U.S. Central Command.
Col. Carol P. Welsch, Acting Director of the Space Development and Test Directorate, and the mission director for ORS-1 shared some background and thoughts on the mission.
“In 2008, the Operationally Responsive Space Office approached the Space Development and Test Directorate and suggested a partnership to meet an urgent warfighter need. We knew this would be a tough challenge, but we were eager to do whatever we could to assist US Central Command. I want to thank Dr. Wegner for his confidence in the Space Development and Test Directorate. As a result of this partnership, the Space Development and Test Directorate was tasked to provide the satellite, command and control system, test capabilities, and the launch vehicle. We are immensely proud to field space capabilities supporting U.S. Central Command and our forces engaged in the fight.
“In order to meet the timelines requested by US Central Command, we tailored the Space and Missiles Systems Center’s standard approach to space acquisition to accept a higher risk posture than other than other space system acquisition programs. For example, ORS-1 uses some components which have not been qualified to standards for space flight. To mitigate some of the risk, the team introduced measures such as memory error detection and correction algorithms to help detect and repair any upsets to the on-board memory. Along the way we’ve learned many lessons in the art of rapid space acquisitions, and once ORS-1 is on-orbit, we will continue to learn how to more rapidly provide space capabilities. This combined government and contractor team has demonstrated great dedication and persistence to meet the challenge of developing a new satellite and supporting ground system in record time.
“On the launch vehicle side, this mission represents another milestone for the Minotaur program. This will be the 10th launch of the Minotaur I and the 4th launch for the Minotaur program from the Wallops Flight Facility.”
The Space Development and Test Directorate’s mission is to deliver small, responsive space capabilities to users across the National Security Space community. The Directorate consists of a combined team of 1,000+ military, government civilians and contractors responsible for the development, acquisition, launch, demonstration, test and operations of Department of Defense and civil space systems. As the Director of the DOD Space Test Program, Col. Welsch is responsible for executing the DOD Space Test Program, providing access to space for over 73 space experiments from across the DOD Services and Agencies.

Friday, June 10, 2011

Aquarius Satellite.



Seeking a missing ingredient to understanding Earth's environmental changes, a new satellite conceived through unique international collaborations was launched today to map the planet's salty seas from space.


The Satelite de Aplicaciones Cientificas-D spacecraft blasted off aboard a United Launch Alliance Delta 2 rocket at 7:20 a.m. local (10:20 a.m. EDT; 1420 GMT) from Vandenberg Air Force Base, California on 8 june 2011.
The 12-story rocket escaped the ground-hugging marine layer blanketing the Central Coast, thundering southward to eventually reach a 408-mile-high sun-synchronous orbit and successfully living up to its reputation of dependability.
Built by Argentina, the SAC-D satellite is equipped with multiple scientific instruments from several countries including NASA's Aquarius sensor package designed to make exceptionally precise global measurements of salt content at the ocean surface.
"Measuring ocean surface salinity from space is NASA's latest technology achievement and it's really going to be a great leap forward for the science of oceanography," said Eric Lindstrom, Aquarius program scientist at NASA Headquarters.
"For many of you, salinity is a rather obscure quantity, but I must tell you it's of critical importance in the ocean circulation, in the climate system and in diagnosing the flow of fresh water through our Earth system."
Standing 16.4 feet tall and 9 feet wide within the Delta rocket's protective nose cone, the SAC-D spacecraft weighed 2,977 pounds at launch. The two-stage launcher reached a preliminary parking orbit about 11 minutes after liftoff, then coasted around the South Pole and soared towards Africa when the booster performed a final maneuver to inject the satellite into the desired orbit. Deployment of the payload occurred as expected 56-and-a-half minutes into flight.
NASA has spent $287 million on the Aquarius project, which includes paying for the satellite's launch. A Delta 2 rocket has never faltered in its 48 missions for the space agency over the past two decades.
The large oval antenna reflector and three microwave radiometers at the heart of Aquarius will work like highly sensitive radio receivers to detect variations in the electrical conductivity of seawater, enabling scientists to deduce the ocean salinity levels.
"Salinity is the glue that bonds two major components of Earth's complex climate system: ocean circulation and the global water cycle," said Aquarius principal investigator Gary Lagerloef of Earth & Space Research in Seattle. "Aquarius will map global variations in salinity in unprecedented detail, leading to new discoveries that will improve our ability to predict future climate."
The satellite will orbit the planet every 98 minutes, covering a swath 242 miles wide for Aquarius to accumulate entire global maps of the planet each week.
"Salinity is the amount of salt dissolved in seawater and you might be surprised to know it varies through the ocean," Lindstrom said. "It's measured in grams of salt in kilograms of seawater. It's typical range is from 32 parts per thousand to 38 parts per thousand. These are small numbers, small differences, but they make enormous difference in the circulation and climate."
Scientists have collected a few million measurements of ocean salinity over the last hundred years, but vast stretches of the planet have never been sampled. Gaining a complete picture every seven days should revolutionize scientists' knowledge of the oceans by unveiling for the first time how salinity changes across the entire globe month-to-month, season-to-season and year-to-year.
"We stand to discover a lot from the Aquarius measurements by having year-round measurements of salinity," said Lindstrom.
"The temperature in the winter in the Southern Ocean or in the Greenland Sea is horrible, you don't want to go do that, you'd be much better to get that from space. So I'm all in favor of this. I don't want to spend any more days out in 50-foot waves!"
What's more, the accuracy promised by Aquarius is two parts in 10,000, the equivalent of a 1/8th teaspoon of salt into a gallon of water. Aquarius will be able to detect that tiny amount of salinity change.
Aquarius and SAC-D join a constellation of other environmental research satellites and ocean observers that study sea temperatures, levels, colors and surface winds.
"The addition of Aquarius to this suite of instruments helps create a more complete picture of our oceans and the impact on Earth's climate," said Eric Ianson, Aquarius program executive from NASA Headquarters.
"This important Earth science mission is NASA's first attempt to measure ocean surface salinity from space. Obtaining global measures of salinity is key to our better understanding of ocean circulation, climate and the Earth's water cycle."
"A key missing piece that is really in demand by the ocean science community is salinity. Together with surface temperature, salinity determines the density of the surface water of the ocean. Density variations and wind drive the ocean circulation. So this is why we want to get this missing piece. Particularly, the deep waters of the ocean get their properties at the sea surface in winter, so their temperature and salinity are set for their lifetime, they get dense and sink to the bottom of the ocean and fill up the ocean basins," Lindstrom explained.
Never before has the U.S. entrusted such a key instrument to fly aboard an Argentinian satellite. But the cooperation between the nations' space agencies -- NASA and CONAE -- has seen American rockets launch the earlier SAC-A on the shuttle Endeavour in 1998, SAC-B on a Pegasus in 1996 and SAC-C on a Delta 2 in 2000.
The SAC-D spacecraft, which also carries instruments contributed by Canada, France and Italy, was assembled in Argentina, then shipped to Brazil for pre-flight testing before finally traveling to Vandenberg Air Force Base for launch. The mission is expected to run at least several years to answer fundamental questions about the climate.
"Another grand problem in Earth science is to understand the water cycle -- evaporation from the ocean, clouds, rain, formation of ice, runoff from the land back into the sea -- and the ocean salinity really turns out to be a pretty useful diagnostic of the big-picture in the water cycle," said Lindstrom.
A 50-year trend of the limited sampling shows that salty places are getting saltier and the freshwater places are getting fresher.
"Is this an indication we're having an acceleration of the planet's water cycle? The salty places in the subtropical (areas) are having more evaporation, the rain belts are having more precipitation and the ocean is giving us this signal," said Lindstrom.
"This is an indicator but there could be other explanations for this. It could be the ocean circulation is changing, it could be ocean mixing is changing. What we really need to do as oceanographers is dig into this more deeply and Aquarius will help us illuminiate these processes. It's a diagnostic for the water cycle but it can also help us tell about ocean circulation and mixing."
Once Aquarius is commissioned and ready for service in about three months, scientists plan a field campaign with ships, buoys, floats and gliders to compare data with the satellite instrument as the mission commences in earnest. 

Wednesday, June 8, 2011

Deep Space Network

The Origin and Evolution of the Deep Space Network 

NA SA’s system for communication with solar-system exploration 
spacecraft began as a Cold War crash program, but iis evolution was 
carefully planned from the starl 
Thirty-four years ago, a single principal antenna, installed the 
previous year (1958) on a crash basis in an isolated location of the 
Mojave Desert of California, supported Pioneer 4, the first United 
States spacecraft to escape the Earth’s gravitational pull and travel 
toward another solar-system body, namely the Moon, the nearest 
such body to Earth. 1 hat lone antenna, situated near the Goldstone 
Dry Lake Bed within the Department of the Army’s Fort Irwin, would 
become the cornerstone clf NASA’s Deep Space Network, a system 
currently composed of 13 antennas of various designs and sizes that 
collectively have the capability of continuously communicating with 
spacecraft at distances ranging from high altitudes above the Earth 
to the outer edge of the solar system. 
When the Goldstone antenna was procured, however, NASA had 
not yet come into being. It was instead the Department of Defense 
that provided the funding for the procurement, fabrication, erection, 
and testing of this antenna during a relatively short eight-month 
period in 1958.  The antenna, as well as the series of early lunar- 
probe attempts of which Pioneer 4 was a part, was, as we shall  
show, approved on a crash-program basis as one aspect of the Cold 
War then raging between the United States and the Soviet Union. It 
would not have been surprising if an antenna so hurriedly
manufactured and installed for a short-term goal would 
subsequently abandoned when NASA began setting up a 
have been 
permanent 
system for later lunar and planetary probes. The fact that it was 
not was a reflection of careful planning by the procurer of the 
Goldstone antenna, a group of engineers at the Jet Propulsion 
laboratory (J Pi.), an Army facility in Pasadena, California, that 
became a part of NASA in late 1958. The early evolution of the Deep 
Space Network illustrates how a major communication system can 
be firmly established through a combination of carefully chosen 
initial elements, put in place during a period of limited time and 
funding, arid later additions, installed as requirements become more 
ciemanding and further resources (such as funding and cooperating 
agencies) become available. 
The Cold War origin of solar-system exploration 
An official requirement for a system to communicate with 
space probes developed for the first time on 7 March 1958, when 
the Eisenhower Administration, through the Department of Defense’s 
new Advanced Research Projects Agency, authorized a program of 
five lunar-probe attempts, three by the Air Force and two by the 
Army, all to be conducted within a year.  The Administration publicly 
characterized the program (shortly to be named Pioneer) as a 
scientific project an effort “to determine our capability of 
exploring space in the vicinity of the moon, to obtain useful data 
concerning the moon, and provide a close Iook at the moon. ” Archival 
records show, however that the major impetus for the program disapproval was a desire by many inside and outside of government to 
find some quick means of restoring international prestige to the 
United States, after the Soviet Union’s successful orbiting the 
previous October of WJIDK  the world’s first artificial satellite, 
had shattered a widely-held percepticln of American technological 
superiority. 
In the six months between this event and Pioneer program 
announcement, in fact, numerous proposals for immediate “Moon 
shots” had been submitted to the Pentagon, and many cited the 
perceived Soviet threat. one of the first institutions to do so was 
JP1 . In a proposal entitled “Project Fled Socks” issued on 21 October 
1957, the lab observed that the launching of Sputnik 1 ICNS than 
three wcmks earlier “has had a tremendous impact on people 
everywhere” and that it “has significance which is both technical 
and political. ” The proposal stated that it was “immediately 
imperative that the United States regain its stature in the eyes of 
the world by producing a significant technological advance over the 
Soviet Union.” Pointing out that all had “some fairly sophisticated 
instrumentation and communication” capability that would allow it 
to achieve a successful lunar flyby mission, the lab advocated that 
the country “go to the moon instead of just going into orbit.” 

JPL was not alone in perceiving a potential political benefit 
deriving from a successful lunar mission. F{amo Wooldrige’s newly 
formed Space Technology Laboratories (S1 L ), located in I os Angeles, 
California, argued, in a proposal entitled “Project 13aker” issued on 
27 January 1958, that an early lunar flight with a moderate payload 
of scientific instruments could make a determination of conditions 

on the Moon that would be valuable for planning later flights with 
much heavier payloads that were certain to come within a few years. 
The firm also suggested, however, that “Of greater national 
importance may be the prestige of sencfing the first rocket to the 
moon, with clear proof that it reached its objective. ” 
Scientists and politicians, however,  were initially not 
enthusiastic about these and other lunar-probe proposals. The 
director William  Flickering recalled that members of the Office of 
Defense Mobilization’s Scientific Advisory Committee (ODMSAC) 
“were not sure that [the Red Socks proposal] was more of a stunt, as 
it were, and were not really that enthusiastic about it from a 
scientific point of view. ” Deputy Secretary of Defense Donald A. 
Quarles testified before Congress in late November 1957 that he 
found “no cause for national alarm” in the existence of the USSF1’s 
Sputnik satellites and argued that the United States “must not be 
talked into ‘hitting the moon with a rocket’ just to be first, unless 
by doing so we stand to gain something of real scientific or military 
significance. ” Eisenhower himself tolci colleagues that he would not 
be drawn into a “pathetic race” with the Soviet Union, and he 
characterized a lunar probe as “useless. ” 
The views of the scientists and politicians regarding “Moon 
shots” gradually changed, however, especially after the United 
States’ first attempt to launch a satellite (Vanguard) on 
1957 ended in spectacular failure--the explosion of the first stage 
of the launch vehicle within seconds of liftoff was recorded on live 
television. On 17 February 1958 the Space Science Panel of the new 
President’s Scientific Advisory Committee (reorganized from the old.J- 
OLMSAC) held a meeting in the Executive Office Eluilding (next to the 
White House) at which panel member Herbert York announced, to 
attending representatives from JPL and S-IL, that “it had been 
decided to attempt a lunar mission with the objectives of: a. Making 
contact with the moon as soon as possible, but with the limitation, 
 that the contact be of a type that has significance such that the 
public can admire it. ” York further stated that the panel had 
concluded, given the second objective, that “some kind of visual 
reconnaissance” (e.g., a camera to take a picture of the back side of 
the Moon) was the most significant experiment that a lunar vehicle 
could carry. PSAC’S endorsement c)f an early lunar mission would 
lead to the aforementioned Pioneer program authorization in late 
March. 
Supporting the Pioneer probes: S71 ‘s short-term approach 
The 
of launch 
would trai 
positions, 
for withou 
Pioneer program would require simultaneous development 
vehicles, spacecraft, and ground-support stations that 
lsrnit commands to the spacecraft, determine their 
and receive data from thcm. The stations were important, 
them no close-up photograph of the Moon could be 
c] btaincd and, more fundamentally, no confirmation that tho 
spacecraft were anywhere near the Moon was possible. 
[Iut what kind of network of stations should be set. Should 
it be cicsigneci solely to support the Pioneer program and its limited 
objective of photographing the Moon? Or shou Id a more elaborato 
system be constructed that would meet not only the requirements of

the pioneer program but also the anticipated needs of future 
programs not yet authorized? 
STL, initially under the leadership of Frank Lehan, had little 
choice but to undertake the short-term approach. Because of the 
more ready availability of their iaunch vehicles (1 hor IRF3M and 
Vanguard upper stages, the. three Air Force probes would be launched 
first, beginning in nlid-August 1958. l-his situation wouid allow the 
Air Force and STL the initial opportunity to reap the glory of a 
successful first lunar mission, but it allowed the latter less than 
five months to set up a network of ground-support stations. 
By necessity, the antennas used at the two principal stations 
had to be already erected or at least manufactured, and their 
locations were governed by the roles they would play in 
communicating with the lunar probes while they were in the vicinity 
of the Moon. For example, a 60-ft-diameter parabolic antenna with a 
transmitter a modification of the l“LM-18 antenna that Foundation, 
Inc., was currently manufacturing for we in the forthcoming Air 
Force Discoverer reconnaissance-satellite program--was installed 
at South Point on the island of t Iawaii because there it would have a 
favorable look-angle at the probes at the time of their fourth-stage 
retrorocket firings. 
S-l L planned for the picture taking to occur as soon as the 
probes entered orbit, before anything might go wrong with the 
spacecraft, and this milestone was expected to occur over about the 
0° longitude, which crossed parts of Europe and Africa. Lehan and 
his colleagues knew that the quality c]f the picture taking would 
improve as the diameter of the receiving ground-based antennaincreased, but the time constraint, as well as diplomatic and funding 
considerations, did not permit the installation overseas of a new 
large antenna, possibly one 200 ft or more in diameter. l-he 
University of 
Jodrell Bank, 
an Air Force 
Bank facility, 
Manchester’s 250-f t-diameter  radio telescope at 
however, already existed. A secret meeting between 
officer and Bernard Lovell, the director of the Jodrell 
enabled STL to install temporarily an appropriate feed 
and other specialized equipment on the antenna in support of the 
picture-taking activity. 
S1 
- 
The engineers appear to have given little thought initially as 
to what might constitute a permanent system of stations for 
supporting an ongoing program of unmanned solar-system spacecraft 
exploration, and whether any of the antennas installed or modified in 
1956 could become part of such a permanent system. JP1. engineers, 
by contrast, began planning for a permanent system even before the 
Pioneer lunar-probes authorization was issued. 
JP1. looks to the future 
Probably the strongest advocate for s ch a permanent system 
/ Y,< /,, J) 
was Lberhardt Flechtin, chief of JPL’s CEO Research S@ion. 
More aware than his colleagues in the propulsion field of the likely 
advances in electronics and the potential distances that could be 
reached in space communications (l-able xx), he strongly urged, in 
the spring of 1958, the development of a launch vehicle (Juno IV) 
capable of delivering a 550-pound payload to the Moon and a 300- 
pound payload to the planet Mars. Such a vehicle, he argued, was 
needed “to accomplish significant missions competitive with the 
USSR; lesser vehicles will only keep us to the rear in 
accomplishment of missions. ” Juncl IV’S capability of soft landing on 
the Moon, Rechtin pointed out, could eventually permit the 
establishment of “quite stable” radio and optical telescopes on the 
lunar surface. 
As for Mars, Rechtin argued that the often discussed similarity 
of this planet to the Earth would rnakc photographic exploration of it 
“one of the major goals of prestige between the United States and 
the USSR. ” Looking further into the future, he noted that 
meteorological and surface-condition instrumentation could 
determine “the practicality of putting people on Mars.” Rechtin 
predicted that “if conditions on Mars are even slightly more suitable 
than anticipated, the past success of the human race in new 
exploration will unquestionably start the drive to Mars. Based on 
human history, it will then be first come-first served on Mars. ” l-eft 
unsaid, but most likely implied, was the desire that the United 
States get there before the USSR. 
Rechtin was not alone at JP1 in perceiving Mars and other 
planets of the solar system as the ultimate goals of space 
exploration. Albert Hibbs, who became the first chief of JF)l’s new 
Space Science Division, recalled in an interview that “[W]e wanted a 
good challenge, and that was & technical challenge, getting a 
useful payload to a planet. It was really tops in engineering 
challenge--propulsion, guidance, communications, you name it. ” 
It was for this envisioned amt]itious program of lunar anc~ 
planetary missions that JP1 , and particularly F{echtin and his fellowcommunications engineers, desired in early 1958 to build a 
permanent network of stations that could transmit commands 
spacecraft, determine their positions relative to the Earth or 
to 
other 
objects, and receive scientific and cngirrcering telemetry data from 
them. Rechtin’s conception of a permanent network was based on a 
consideration of the apparent motions of space probes and a 
requirement, sure to be iniposed by any funding agency, to keep costs 
to a minimum.  
He knew that after a space probe launched from Cap& Canaveral 
completed its injection phase, during which it would move rapidly to 
the east, it would (due to a decreasing angular velocity as it gained 
altitude) have an apparent motion from east to west that closely 
approximated that of a fixed radio source. During this post- 
injection phase the greatest components 
motion will be due to the rotation of the 
 Obviously results in the probe apparently 
the eastern to the western horizon of a 
of the probe’s apparent 
Earth, and such rotation 
moving across the sky from 
particular antenna station 
once each day. Simple geometry dictates that the minimum number 
of principal antenna stations that permits continuous, overlapping 
monitoring (necessary as missions became more complex and longer 
in duration) after the injection phase is three . Because 
the world is divided into 360° of longitude, the three stations should 
ideally be located 120° apart in longitude. 
d Confid&rt that solar-system exploration would “continue in the 
coming years, ” Rechtin and his colleagues--particularly Walter K. 
Victor, head of the Electronics Research Section, and Robertson 
Stevens, head of the Guidance 1 echniques Research Section--sought 
a communication system design that would “be commensurate with 
the projected state of the art, specifically with respect to 
parametric and maser amplifiers, increased power and efficiency in 
space vehicle transmitters, and future attitude-stabilized 
spacecraft .“ Because of the later availability of the Army lunar- 
probe launch vehicles (Jupiter IF{BM and a cluster of upper stages 
employing Baby Sergeant rocket motors), they had just enough extra 
time to design and install a communication system that could not 
only support the Pioneer lunar probes, but also evolve into a 
permanent system for supporting future solar-system exploration 
spacecraft. 


Choosing an antenna design

With regard to antenna design, Rechtin, Victor, and Stevens 
ciesired an instrument with an accuracy of 2 minutes of arc or 
better, Operation on a 24-hour basis dictated that this accuracy 
would have’ to be maintained regardless of solar exposure and rapid 
ambient temperature changes. Furthermore, “since missile [la 
vehicle] firings cannot bc held up because the wind is blowing 
somewhere around the earth nor can the bird [spacecraft] be 
Inch 
whistled back from a space mission when the wind comes up,  the 
antenna would have to be usable in winds of 60 mph and be capable 
of withstanding (in a stowed position) winds of 120 mph. 
Rechtin assigned William Mcrrick (head of the Antenna 
Structures and Optics Group) to icientify an antenna design that could 
satisfy these demanding requirements. Confident that JPL wouldreceive an lunar-mission assignment but aware that the “ 
procurement, fabrication, and erection of the antennas would be the 
“longest lead time item” for carrying out such an assignment, 
Rechtin made this assignment on 7 February 1958, nearly seven 
weeks before the Pioneer authorization. Merrick concluded that the 
desired antenna would have to combine the best features of a 
precision radio-astronomy antenna and a precision guidance or 
tracking radar. Merrick recalled later’ that the radio astronomers 
and suppliers he consulted “questioned our sanity, competence in the 
field ar)d/or our ability to accomplish the scheduled date [initially 
November 1958] even on an ‘around the clock’ basis.” 
Merrick and his colleagues rejected many existing antenna 
designs because of foreign manufacture, high cost, inadequate 
aperture, and/or acknowledged design flaws. Others, such as the 
CSIRO’S 21 O-ft diameter antenna at F’arkes, Australia, and NRAO’S 
140-f t-diameter antenna at Green Bank, West Virginia, were 
eliminated from consideration because these prototypes would not 
be completed until 1960 or later. 1 he Jodrell Elank type c)f antenna 
was rejected because it was “too big and expensive” and its design 
and assembly had required seven years. 
Merrick and his colleagues ultimately chose a design that had 
been initiated at the Naval Research laboratory in 1953, developed 
further by t-toward W. 1 atel at the Carnegie Institution of 
Washington, and refined by the Associated Universities, Inc. (AUI), 
and that had just been completed by the E31aw Knox manufacturing 
company in Pittsburgh. the 26-m-diameter (85-ft) antenna had a 
cantilevered-equatorial mounting and very large hour-angle and
dcclination drive gears that gave high driving accuracy for relatively 
low tooth accuracy and a low tooth loading during high winds. EIlaw 
Knox, which priced the antenna at about $250,000, had already 
received orders from the University of Michigan and AU I (for 
erection at Ann Arbor and Green Bank, respectively), but neither had 
been completed when JPL placed an order, with ARPA’s approval, for 
Eventually, citing national priority, the 
three antennas in April. . 
Army was able to move one of these probe-supporting antennas to 
the front of the manufacturing line, 

Choosing a station site

That first antenna was slated for a site in the United States. 
Rechtin later recalled the planned overseas stations “so rapidly 
became bogged down in approval red tape” that their earliest 
possible activation date gradually moved beyond the second Army 
lunar-probe attempt. Three stations would be essential for possible 
future long-duration flights to the planets, but the limited objective 
of the Army lunar probes allowed JPL engineers to make do 
temporarily with one antenna. Continuous around-the-clock 
monitoring of the probes was of course impossible, but JPL 
engineers could deliberately select a trajectory that would cause 
them to arrive at the vicinity of the Moon when they were in the line 
of sight of the single principle antenna. Also, they, unlike their 
counterparts at S3 L., had no need for a separately located 
transmitter station.the probes were slated to fly by the Moon (thus 
requiring no retrorocket firing commands), and the desired pictureswould be taken automatically when a photocell mechanism indicated 
that the probes were within a certain distance of the Moon. 
With the expectation that probes would eventually be sent to 
the planets and thus their received signals would be extremely 
weak, JPL communication engineers desired a site for their single 
initial principal antenna that would minimize outside radio 
interference as much as possible. In addition to avoiding areas with 
power lines, radio stations, radar transmitters, and/or considerable 
numbers of aircraft passing overhead, they sought in particular a 
natural bowl, so that the surrounding terrain could shield the 
antenna from nearby towns and passing vehicles. The underlying soil 
had to be suitable for accurate and stable support of the antenna, 
and an access road, for transport of the sizable steel components of 
the antenna, would have to be built for what was likely to be a 
remote site. Finally, the more immediate funding and time 
constraints of the Pioneer program mandated use of Govern merit- 
owneci land. 
Thanks to a search two years earlier for an off-lab site to test 
rocket engines, JPL engineers were aware that an area near 
Goldstone Dry [Lake at the Army’s Fort Irwin, located in the Mojave 
Desert about 150 mi northeast of Pasadena, would meet these 
criteria. After General John B. Medaris, the head of the Army 
Ballistic Missile Agency, in mid-May 1958 overruled another general 
who wanted to use the Goldstonc area for a proposed missile firing 
range, the work needed to convert the site into the desired antenna 
station swung into high gear. Carefully avoiding unexploded 
ordinance lying in the area, workers constructed access roads, laid
the antenna foundation, and constructed support buildings during the 
late spring and early summer. Soon after he steel components 

arrived in mid-August, a crew from the Ratio Construction Company 
began erecting the antenna. After the crew completed its work two 
months later, the feed was installed and various optical and radio- 
frequency tests were conducted to establish the system tracking 
accuracy. 


Choosing an operating frequency 

Unlike their counterparts at S1-L, JPL engineers, led by Victor, 
chose not to operate at the 108 Mtlz frequency being used for the 
Vanguard and Explorer satellites. With future missions clearly in 
mind, they noted in an early report that the presence of interference 
at frequencies below 500 MHz would “seriously limit the growth 
potential of any space communication technique” using a frequency 
in this region. Victor at first favored a frequency in the region 
between 1365 and 1535 MH7, where he anticipated significant 
hardware developments for improving receiver sensitivities because 
the region bracketed the astronomically important 21 -cm hydrogen 
line. Colleagues soon convinced him that a stable, efficient 
spacecraft transmitter operating in that region could not be built in 
time for the Pioneer probe missions, however, and he instead opted 
for a 960 MHz (L-band) operating frequency. 
l-he hard work that ST1.. and JPL communications engineers 
expended in setting LJp their respective systems of antenna stations 
(which included several with smaller antennas at launch-point anddownrange locations) in relatively short time periods paid off in 
very satisfactory operation during the actual missions. Various 
rocket failures, however, prevented all but the second Army probe 
(launched on 3 March 1959) from reaching escape velocity, and this 
probe (Pioneer 4) passed too far away (37,000 mi) from the Moon to 
activate the camera system. By then, the USSR’s .luna 1, launched on 
2 January, had already passed within 6,000 mi of the lunar surface, 
l.una 3, launched on 4 October 1959, took the first photographs of 
the far side of the Moon. 

Gaining approval for a permanent system 

The expansion of JPL’s ground-support system for the Pioneer 
lunar probes into a complete worldwide three-station network was 
not inevitable. The first challenge to JPL’s plans came from STL, 
which in late June 1958 iSSLJed a proposal that called for the 
construction of three 250-f t-diameter antennas to be located in 
t{awaii, Singapore or Ceylon, and near the eastern coast of Brazil. 
The firm claimed that diSCLJSSiOnS with JPL and “a thorough analysis 
of foreseeable space programs” (including a series of new probes 
aimed at the planets Venus and Mars that STL was simultaneously 
proposing) indicated that “the long-range interests of the United 
States in high-altitude communications relay satellites and in 
interplanetary space programs could best be served” by the 
establishing of two networks of three stations each, placed at 
intervals of about 60° around the equator of the earth.
- 16 
Rechtin thought otherwise; he considered the proposal “a ploy 
to block JPL’s [network plans] by forcing a study and reconsideration 
of JP1.’s ARPA order [for three 26-m-ciiameter antennas]. ” He may 
have been right. The estimated overall cost of STL’S proposed new 
sy$tem was $34 million. How STL expected the government to 
(
approve such a large sum in so short a time (the company claimed 
that it could “realistically” complete construction of the first 
antenna in Hawaii by 15 October 1959) is unclear. The proposal, in 
any case, was not funded. 
A greater threat came in early July 1958, when Deputy 
Secretary of Defense Donald @larlOs questioned why S1’L and JPL 
were developing two separate systems for supporting the Pioneer 
lunar probes. In response, Rechtin traveled immediately to 
Washington, and in a 8 July meeting at the Pentagon with Richard 
Cesaro, chairman of an AFIPA advisory panel on tracking, he 
acknowledged that JPL was using the extra time afforded by the 
later launch dates of the Army lunar probes “to begin a longer range 
space tracking program using the proper parameters. ” These 
parameters included the 960 Mtlz operating frequency and the 26-m- 
ciiameter antennas that would be “capable of tracking all vehicles 
from a 330-mile altitude satellite to space probes to Mars. ” 
Cesaro was impressed with Flechtin’s presentation, but asked 
that JPL prepare a formal proposal for a “World Net” that would 
consider as well the communications requirements of other intended 
ARPA space programs. J P L ‘s Aetianeta . 
rv T-racking 
Network, issued on 25 July, considered (despite its title) such 
requirements for six different space programs that the UnitedStates planned to undertake--manned space flight, meteorological 
satellites, reconnaissance satellites, communications satellites 
(both geosynchronous and low-Earth-orbiting), scientific satellites, 
and space probes--as well as the detection of “noncooperative” (i.e., 
foreign) satellites. Comparing all the requirements ), 
Rechtin and several colleagues suggested that two principal 
overseas antennas could be most advantageously placed, for 
supporting space probes and certain other space programs, at 
Woomera, Australia, and somewhere in Spain. 
Cesaro was once again impressed with JPL’s work, and 
indicated to Rechtin his intention to recommend that “all the 
tracking and computational facilities should be handled under 
administration with JPL as the technical arm. ” Rechtin was 
delighted with this recommendation, but nevertheless cautious. 
believed  that Cesaro “may be way over optimistic” in thinking 
Army 
He 
that 
“ARPA certainly has the power to do this and would put down any 
rebel lion.” In particular, Rechtin warned a JP1 colleague that “we 
should expect considerable uproar from the Naval Research 
Laboratory who probably figures it knows more about tracking than 
anybody else. ” The NRL’s Radio lracking Branch, under the leadership 
of John 1. Mengel, had developed the Minitrack tracking system for 
the Vanguard satellite program. 
1 he basis for Rechtin’s caution was his knowledge that 
Congress in the summer had approved President Eisenhower’s 
request 
Nation 
into being 
for establishing a civilian space agency, and as a result the 
Aeronautics and Space Administration was slated to come 
 on 1 October 1958. NASA’s impending formation meant
that ARPA was gradually losing its status as the interim United 
States space agency. 
Furthermore, by early January it became clear that not only did 
the Defense Department want a station network separate from any 
set up by NASA (because their need for secrecy conflicted with the 
new space agency’s professed openness), but also those involved in 
setting up NASA’s manned-space-flight, satellite, and space-probe 
programs desired separate station networks. As Rechtin feared, 
JPL’s plans were also strongly opposed by Mengel, whose group had 
already been transferred into NASA. Mengel claimed that the 
installation of more Minitrack stations was more essential than 
than overseas space-probe-supporting stations, because “the 
satellite experiments and their associated tracking was more 
important [than space probes] as far as NASA plans were concerned.” 
Despite Mengel’s views, on 10 January 1959 NASA, which had 
supported since early November JPL.’s development of a recommended 
set of future lunar and planetary probes and had also acquired JP1. 
from the Army, signed an agreement with the Department of Defense 
that called for, among other things, installation of stations for 
deep-space probes at Woomera and in South Africa. The preference 
by NASA and JPL for South Africa as the host country for a dedicated 
probe-supporting station derived from the fact that most space 
probes would pass over southern Africa during the injection phase of 
their flights, when it was vitally important to establish their actual 
trajectories for later accurate pointing of the other probe- 
supporting antennas.Overseas expansion 
In establishing the overseas stations, Rechtin insisted that 
they be operated by local nationals rather than “displaced 
Americans. ” Desiring the best possible performance from each of 
the stations, he reasoned (and was supported by later experience) 
that this could be obtained from professionals “proud of their work, 
held responsible, and cooperatively cc)mpetitive in spirit. ” NASA and 
JP1. fortunately identified in Australia and South Africa 
organizations--the Department of Supply’s Weapons Research 
Establishment (WRE) and the Council for Scientific and Industrial 
Research’s National Institute for Telecommunication Research 
(NITR), respectively--that were eager to cooperate in the 
establishment of the network for supporting space probes. 
l-he WRE was managing the Woomera rocket range at which the 
United Kingdom and Australian governments had been conducting 
high-altitude missile firings over the past decade, and WF3E; 
superintendent Bill Boswell anticipatecj that the addition of an 26- 
m-diameter antenna could not only expand support of these firings 
but also ensure Woomera “a leading place in satellite and space 
research, ” NITR director Frank Hewitt anticipated that the antenna 
would be a “most valuable scientific tclol” that could be used 
between missions to conduct radio-astronomy research. He also 
believed that the techniques involved with the antenna would be 
fundamental to future intercontinental communications an activity 
of great performance to a country quite distant from Europe and the
United States--and that therefore the NITR should become familiar 
with them. 
NASA sent site-survey teams to Australia and South Africa in 
February and September-October 1959. With extensive assistance 
from WRE, NITR, and other local officials, NASA and JPL eventually 

identified and selected two appropriate sites: a semi circular bowl 
open to the south at the edge of a dry lake bed known as Island 
lagoon about 18 mi from the village of Woomera and about 30 mi 
south of the range head, and a Y-shaped valley near the town of 
Hartebeesthoek about 30 mi northwest of Johannesburg and 18 mi 
west of Pretoria. 
NASA funded the construction of the overseas stations and 
sent field crews to erect the antennas and install the electronics, 
but it was WRE and NITR that bore the responsibility for acquiring 
the land, constructing access roads and support buildings, and hiring 
staff to operate the station. With a new program of Ranger lunar- 
impact probes scheduled to be launched beginning in mid-1961, both 
agencies worked hard with NASA and JPL to ensure that the stations 
would be ready in time. NITR’s success in doing so was made more 
difficult by delays (occasioned by the Sharpeville township 
disturbance and the Soviet Union’s downing of a United States U-2 
spyplane in March and May 1960) in the signing of a diplomatic 
agreement governing the station and other NASA facilities in South 
Africa, By the time Ranner 1 was launched on 23 August 1961, 
however, both stations were ready and the Deep Space 
Instrumentation Facility (renamed the Deep Space Network in 1963) 
at long last had become operational.Subsequent evolution 
Anticipating that space probes would become more 
sophisticated in future years and would eventually travel beyond the 
orbits of Venus and Mars (in contrast to the fixed range of Earth- 
orbiting satellites), Rechtin sought and received from NASA a 
continuing commitment that a relatively fixed portion (generally 
about 10 percent) of the Deep Space Network budget would be 
devoted to research and development. This commitment allowed the 
Network to evolve in a timely way in subsequent years, as new 
requirements were anticipated and means to meet them were 
conceived, tested, and installed. 
In early 1961, for example, Flechtin recognized that NASA’s 
deep-space program would soon be expanding very rapidly (further 
Rangers, Mariner flybys of Venus and Mars, Lunar Orbiters, Surveyor 
lunar soft-landings, and Apollo manned lunar landings). He could 
foresee occasions when “so many flights [would be] operating at any 
one time . . . that a single antenna at each DSIF station could not 
conceivably carry the load. ” Rechtin envisioned a future situation 
when project managers could be “confronted with impossible choices 
between probes measuring dangerous solar flares, observing violent 
effects c]n Mars, roving among the crevasses on tho Moon, and 
carrying men into deep space. ” 
New 26-m-diameter antennas were thus needed (to be 
accompanied by a change in operating frequency to S-band (2388 
MHz)), and the first of these antennas was installed at Goldstone in
early 1962. Although the Woomera and Hartebeesthoek stations 
would continue to operate through the early 1970s, neither was the 
site of the new overseas antennas. WRE; had difficulties fully 
staffing the Woomera station, due to its isolated location (in the 
outback about 200 mi north of Adelaide) and insufficient housing 
staff members and their families. Although the WRE gradually 
for 
resolved the staffing and housing problems at Woomera, the long- 
term solution was to find a new adequately shielded site nearer a 
center of population. Officials from JPL. and the Australian 
Departments of Supply and Interior eventually identified such a site 
in the Tidbinbilla Valley, located 11 rni sC)lJt west of Canberra 
(Australia’s capital) along the northeastern edge of the Australian 
Alps. The station constructed at this site became operational in 
March 1965. 
NASA and JPL were quite satisfied with 
the station at Hartebeesthoek, but Rechtin in 
that relations between the governments of the 
South Africa might eventually deteriorate, due 
NITR’s operation of 
particular was fearful 
United States and 
to condemnation in 
the United States and abroad of the latter’s apartheid policies, to a 
point where operations at this station would have to be sharply 
limited and curtailed. He argued that any expansion of the station 
would make it more costly for NASA to duplicate the station 
elsewhere at a later date. 
An initial survey of sites in Italy proved unsuccessful, A 
survey team found natural bowls on the island of Sard~nia, but such 
,., 
a location would be difficult to support logistically. Potential sites 
near Rome would not have this difficulty, but they were less wellshielded and would create coverage gaps between a station here and 
the one at Goldstone. 
NASA and JPL ultimately chose a site in a valley near the 
village of Robledo de Chevala, 31 mi west of Madrid, Spain, for the 
location of a 26-m-diameter antenna. A second such antenna was 
subsequently installed near the town of Cebreros, 8 mi southwest of 
Robledo de Chevala, These stations became operational in July 1965 
and January 1967. Despite some misgivings about dealing with the 
Franco authoritarian government, NASA had been quite pleased with 
assistance rendered by the Spanish government’s Instituto National 
de T6cnica Aeronautic (INTA) in the operation of a Project Mercury 
station in the Canary Islands, and this organization became NASA’s 
cooperating agency for the new Deep Space Network stations in 
Spain as well. 
A major evolutionary step was the design and installation of 
new 21 O-ft-diameter antennas at Goldstone, Tidbinbilla, and 
Robledc) de Chevala. These were built in response to the expected 
advent of more sophisticated spacecraft (as launch vehicles became 
more powerful), which would create a requirement for an increasing 
rate in the communication of data from the spacecraft back to Earth. 
JPL considered a number of alternatives for meeting this 
requirement increasing the power of the spacecraft transmitter, 
electronic arraying of two or more 26-m-diameter antennas, and use 
of existing large radio-telescope antennas--but economics and 
availability considerations ultimately dictated the construction of 
new large antennas up to 250 ft in diameter. After two years of 
design studies and nearly four years of contract negotiation, ground
preparation, support-building construction, and antenna erection, the 
first of the Deep Space Network’s large antennas became operational 
in May 1966. Two other such antennas became operational at 
Tidbinbilla and Robledo de Chevalla in April and September 1973. 
The Deep Space Network expanded the newer of the 26-m- 
diameter antennas at Goldstone in 1978 in order to add X-band (8.4 
GHz) capability and increase the antenna gain (received signal 
strength) for the two Voyager outer-planet missions. Antennas at 
Tidbinbilla and Robledo de Chevala were similarly expanded in 1980, 
This improvement was sufficient for the Jupiter and Saturn 
encounters (1979-81) of the two spacecraft. The extension of the 
VQ2U mission to include encounters with the more distant 
planets Uranus in 1986 and Neptune in 1989, however, forced 
Voyager and Network engineers to find new means to compensate for 
a still more severe decrease in signal strength and thus avoid an 
undesirable great limitation on the science data return. 
One means was the installation of new 34-m diameter high- 
efficiency antennas (so-called because their reflector surfaces’ are 
precision-shaped for maximum signal-gathering capability) at 
Goldstone in 1984, Tidbinbilla in 1985, and Robledo de Chevala in 
1987. The 64-m diameter antenna and the two 34-m-diameter 
antennas could now form a three-element array. This combination 
(together with a reprogramming of two of the Voyager computers to 
accommodate an image data compression technique) permitted a 
higher data rate (19 kilobits/see). 
Because a still higher data rate would be needed to meet the 
imaging science requirements at Uranus and Neptune, Deep SpaceNetwork engineers sought and received permission from Australia’s 
Commonwealth Scientific and Research Organization to add 
temporarily (in 1986 and 1989) their 64-m-diameter radio 
telescope at Parkes to t 
link. The Network made 
when the twenty-seven 
 Tidbinbilla array via a ground microwave 
use of a second interagency array in 1989, 
25-m-diameter radio-telescope antennas of 
the National Radio Astronomy Observatory’s Very Large Array in New 
Mexico were linked with the Goldstone’s antennas. 
One further step taken for the Neptune encounter was the 
extension of the 64-m diameter antennas at each station to a 
diameter of 70 m and the the reshaping of their reflector surfaces 
to improve their efficiency. These improvements, which increased 
the effective signal capture of these antennas by 5:lp~r ce t where 

completed at Tidbi#Ma.and Robledo de Chevala in+) and 

Goldstone in 1988. 
The Deep Space Network continues to evolve even today. The 
original 26-m diameter antennas installed in the 1958-61 period 
are no longer in service the one at Goldstone is now a national 
monument, the one at Woomera has been scrapped, and th& one at 
Hartebeesthoek is now used by South Africans for radio-astronomy 
research. The second set of such antennas (those extended to 34 m 
in the late 1970s) are nearing the end of their usefulness. The onset 
of metal fatigue and the mechanical limitations of their late 1950s 
design do not permit further upgrades to improve performance. l-he 
Deep Space Network will therefore soon be replacing these antennas 
with 34-m-diameter multifrequency bearn-waveguide antennas. 
These new antennas will allow critical weather-sensitive

microwave components to be located in an equipment room in the 
antenna pedestal rather than on the rotating and tipping main 
reflector. The first of these new antennas was recently installed at 
Goldstone and will shortly become operational after completion of 
performance testing. 
To probe further 
The author is nearing completion of a book-length history of 
the Deep Space Network that will be based on published sources, oral 
history interviews, and unpublished dc]cuments in archives in the 
United States, Australia, South Africa, and Spain. Photocopies of 
the documentation supporting the book (and the article above) will 
be deposited in the JPL Archives. His article “Designing the United 
States’ Initial ‘Deep Space Networks . ...” jEEE Antennas and 
+Qtion ‘aaazine’ vol. 35, no. 1, February 1993, provides 
additional detail concerning the choices of antenna design, operating 
frequency, and antenna location made by STL. and JPL for supporting 
the Pioneer lunar-probe attempts of 1958-59. 
William R. Corliss’s A History gf the Deep Space Netw@